THE JOURNAL

OF THE

(Duehijtt

Microscopical Club.

EDITED BY

HENRY F. HAILES

SECOND $ERIJS.>J

^J?VOLUMElflT^

Uontion :

[Published for the Club.]
WILLIAMS and NORGATE,

14, Henrietta Street, Covent Garden, London,
and 20, South Frederick Street, Edinburgh.

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THE JOURNAL

WOOD
HOLE,

MASS.

OF THE

(Qnxtlxtti ||Urr0Sf0pUctl Clair.

On the Kola Bean (Cola Acuminata).
By Hahnemann Errs, Associate of King's College, London.

Bead Sept. 24, 1SS6.

This equivalent, throughout tropical and equatorial Africa, of
tea, coffee, mate, cocoa, &c, has probably been used from time
immemorial.

The Kola is a tree 30 to 60 feet high, belonging to the
SterculiacecBj of which the Tkeobroma Cacao is a well-known
member (Hooker). It yields about a cwt. of seeds annually, in
two crops, the seeds or beans being enclosed in pods containing not
more than 15. Specimens of these beans, both fresh and dry, are
here to-night, also a small growing tree. In this paper it is hardly
necessary to describe the form of the beans, but it will be as well
to give the principal features of their latest analysis, so that the
extraordinary properties claimed for them from time to time, during
the 50 years and more that scientific attention has been directed to
them, may be the better appreciated.

Analysis. — (Lascelles-Scott, 1886).

Alkaloids (principally

Caffeine) .

• • ■

2-812

Fatty Matters

• •

• • •

•815

Iiesinoid Matter ...

, ,

► • •

1-012

Sugar

• •

• •

3-914

Starch

1 1 •

• •

... 31-120

Gum

• •

O • «

4-876

Albuminoid Matters

• •

• • 1

8-642

Colouring Matters . . .

1 * •

► • •

... 3-670

Kolatannic Acids ...

• •

• •

1-204

Mineral Matter

• •

• • «

4-818

Moisture ..

» • •

» • •

9-722

Ligneous Matter and .

Joss

• •

• •

.. 27-395

100-000

in. Q. M. C, Series

II.,

No.

17.

1

2 H. EPPS ON THE KOLA BEAN.

The earliest reference to scientific inquiry I have met with is a
record in Dr. Attfield's article (which will be referred to later on)
of several papers in the " Journal de Pharmacie " for 1832, p. 702,
which matter, however, I have not seen. In 1865 Mr. W. F.
Daniell, M.D., F.L.S., read a lengthy communication before the
Pharmaceutical Society on Kola (" Pharni. Journ." [2], vi, 450),
and Mr. John Attfield, Ph.D., F.C.S., followed with a paper on its
analysis and food-value {Tdetn, p. 457). Mr. Thomas Christy,
F.L.S., has also since 1878 given his attention to Kola, and been
instrumental in making its properties widely known in this
country, having dealt with the subject at considerable length
(" New Commercial Plants and Drugs," Nos. 8 and 9).

In France Messrs. E. Heckel and F. Schlagdenkauffen have
examined the Kola bean systematically, dealing principally with
its natural history, social and political relations, chemical composi-
tion, and physiological properties. The result was a lengthy
memoir read before the Union Scientifique des Pharmaciens de
France, a long and interesting abstract of which appeared in the
tl Pharmaceutical Journal," January 26th, 1884. There have also
been a few later notices on the action of the Kola bean, including
one by Mr. Watson Smith, F.C.S., on its effects in excess of
drinking (" Pharm. Journ.," June, 1886).

Just to give some idea of the marvellous properties claimed for
Kola, it may be here recorded that the beans are said to be a
powerful disinfectant, a sure preventive against dysentery and
liver complaint, also enabling those eating them to support
lengthened strain and labour without other sustenance. Kola
bean has been recommended in cases of nervous depression,
sleeplessness, melancholia, and suicidal mania, also in heart and
kidney disease. But it is as a reputed remedy for dipsomania that
the Kola bean is now attracting the most attention. At the
Linnean Society, in 1884, one of the members gave an interesting
account of the properties of the Kola bean from actual experience.
He stated that the foreman of his estate in Jamaica (where the
Kola was introduced about 1635) was in the habit of getting
drunk every Saturday, and shortly before he had to go on duty
every Monday morning, his wife used to reduce a Kola bean into a
paste, which the man was made to swallow, and in thirty minutes
he was quite clear in his head again. Further, he maintained that
after the use of the Kola cure, a drunkard cannot return to stimu-

H. EPPS ON THE KOLA BEAN. . 6

lants for some days without feeling nausea. There seems here an
ample field for the physiological investigator, and if only a few
intelligent (!) inebriates could be provided, for sobering experiments
to be made upon them, the startling claim (among others) made for
the Kola bean, of being a remedy for dipsomania, might be verified.
This, however, is not the function of a microscopical society such
as ours.

The microscopic examination of the Kola bean has not yet pro-
ceeded very far, and there must still be much to illustrate. I have
on view to-night several sections of the dry bean, which show very
clearly the brownish-yellow cell-walls of the tissue, packed closely
with granules of starch. The Kola bean of commerce, dry, brown,
roundish, about 1-^ inches in size, is of a hard, tough, almost
flinty character, but in its fresh state, in which state I have obtained
samples, it is soft and succulent, lending itself readily to the pro-
cess of cutting up into sections.

I will .now proceed to mention the various points of micro-
scopical interest that I have as yet met with, in both the fresh and
dry bean.

The mass of the cotyledonary tissue is composed regularly of
cells, generally sexagonal, packed full of starch granules, these
becoming more and more numerous with increased distance from
the surface. The cellular tissue presents no particular feature of
interest. The cells themselves vary in diameter from '0012 to
•0020 of an inch, and each cell contains (when observed in
section) from 8 to 15 starch granules. The latter vary in size
from "00025 to *0005 of an inch ; are oval but rather irregular in
shape, somewhat like Natal arrowroot, but smaller. There is
generally a deeply marked hilum visible in the centre of each
granule, which under the polariscope appears traversed by a very
regular cross, and with the addition of a plate of selenite the
granule is very clearly divided into pure red and green sections. It is
in the tissue walls that the alkaloids caffeine and theobromine are
to be found in an uncombined form, and remembering the large per-
centage (2*8) present, it should be comparatively easy to obtain
them for microscopical examination.

The epidermis, which in the fresh bean is the principal seat of
the colouring matter, is composed of a layer of oblong-shaped
cells measuring about -001 of an inch, and there are other layers of
cells lying beneath, varying in size from '001 to '0003 of an inch.

4 H. EPPS ON THE KOLA BEAN.

Till colls in these layers contain little if any starch. In the
epidermis are found numerous stomata, which measure from "0006
to *001 of an inch, which are placed at irregular intervals, are
oval-diamond shaped, and are generally situated in the centre of
dome-like elevations. There is often considerable fungoid growth
present, which has sometimes seated itself in the stomata, the
walls of which have in such cases been consumed, and large
irregularly shaped cavities formed in the epidermis.

It has been stated by Van Tieghem, that gum-canals are present
in the pith and bark, but are absent from the cotyledons (" Bulletin
Socirte Botanique de France," p. 11; quoted in " Pharm. Journ.,"
May 2nd, 1875, p. 803). This is not, however, altogether what
I should have expected, as by analysis the cotyledons have been
shown to contain nearly 5 per cent, of gum, besides 1 per cent, of
resin. After repeated examinations of sections of the dry Kola
beans, I have observed what I believe must be masses, and in some
cases " canals " of gum. What I refer to may often be found near
the exterior of the dry bean, in irregular masses, and in radial
streaks from -02 to -03 of an inch long, and from '005 to *01 of an
inch wide. There are also to be seen separate nodules, away from
the masses and streaks. These masses under a \ inch objective
have all the character of gum or resin. The correctness of my
supposition I have not yet verified by dissolving out and examining
the tissues afresh. I have not observed the same feature in the
fresh bean, and the masses referred to may consist partly of sugar,
of which the analysis shows nearly 4 per cent.

Repeated microscopical examination has not afforded any other
results. What must remain the most noteworthy features of the
Kola bean are, the immense percentage (31-120) of starch present,
also of alkaloids (2-812), and the all but complete absence (*815) of
fatty matters. It is this last feature that most distinguishes Kola
from the other members of the Sterculiacece.

Notes on Zoothamnium Arbuscula.

By James Spencer, F.R.M.S.

(Read October 22, 18S6.J

Plate I.

All the members of the Club are no doubt more or less familiar
with the appearance of this organism, which bears a general
resemblance to a minute apple tree, with trunk, boughs, branches,
twigs, leaves, and fruit. Mr. Saville Kent, in his " Manual of the
Infusoria," says : — " Examined separately, each colony-stock may
be compared to a minute crystalline standard fruit tree, of which
the ordinary campanulate zooids may be likened to the leaves, and
the spheroidal or reproductive units to the fruit." The muscular
fibres all contract at the same time, and from time to time change
the appearance of the organism, from that of a tree into that of a
fluffy ball. I do not propose, however, to attempt to give any
complete description of the species, but merely to note some
observations of my own.

The specimen which I observed was obtained by me at Walton-
on-Thames, on Saturday, the 11th of September, 1886, and was
attached to a rootlet of willow, on which there were besides some
sponges and other living organisms. It was placed in an observing
trough, holding half-a-pint of water brought from Walton. Its
natural size is shown in Plate 1, Fig. 1. In. Figures 2 and 3 are
sketches of it, x 10 diam., fully expanded and contracted, and
Fig. 4 is a drawing of a branch x 50 diam. I placed a microscope
in front of the tank, and gave the object an occasional look. I
noticed nothing particular till the following Tuesday morning,
when I saw upon the colony one fully-grown spheroidal zooid, and
eight others of various sizes, which afterwards became as large as
the first one. They were distributed pretty evenly about the
colony, and were in shape slightly prolate spheroids. I continued
my observations of these bodies from time to time as opportunities
offered themselves, and on the following Thursday morning found
that only eight remained, and that changes were taking place in
some of them. One had become shaped somewhat like a peg top

6 J. SPENCER ON ZOOTHAMNIUM ARBUSCULA.

•without the peg, and was furnished round the widest part with an
undulating ribhon or membrane of sarcode broken at the edges,
but not quite developed into cilia, parts of which moved slowly
like little tongues of flame, some waving in one direction, some in
another. In the course of five minutes this membrane became
completely divided into cilia, which commenced the characteristic
movements of the cilia of the vorticella, and in a few seconds
acquired rapid movement, when the creature became disconnected
from the parent stem and swam out of the field of view. When I
first observed it on the Thursday morning it had already acquired
the shape shown in Fig. 7, and when it was detached it was shaped
as in Fig. 9. I continued watching the colony, and saw that near
the point of junction of another spheroid with the stem a slight
movement of a mere thread of sarcode projecting from the
periphery. This became gradually broader, forming a thin un-
dulating ribbon, attached by its edge to the ball, and insensibly
rising until it occupied the position shown in Fig. 6 ; then the ball
very gradually altered in shape until it resembled two conoidal
bodies united at their bases, as shown in side and front view at
this stage in Figs. 7 and 8. In a few seconds it assumed the
shape indicated in Fig. 9, with swiftly vibrating cilia, and detached
itself and swam away. I saw another spheroid pass through all
these changes on the Thursday evening, and saw the last of the
nine do so the next day.

While the alterations in the reproductive zooids were progress-
ing, the ordinary campanulate zooids gradually disappeared, and
when the last reproductive zooid swam away there were but a few
of the ordinary zooids left at the ends of the twigs, but the
muscular system was contracting as vigorously as ever. I saw the
objects I have described in all positions, and the nature of the
changes was very distinctly visible. From the time I began to
observe each of the zooids, in which I saw the whole of the
changes from a spheroid attached to the colony to a freely
swimming bell, I did not take my eye from the microscope, the
time occupied in each case being from 30 to 35 minutes.

Joiim. C

Ser

Fig. I

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Fiq.5

Fiq. 6

Fiq.7

Fiq.8.

Fiq.9.

Wes%NewmsiTi & Co.htK

On a Fossil Marine Diatomaceous Deposit from Oamaru,

Otago, New Zealand.

By E. Grove and G. Sturt, F.F.R.M.S.

PART II.

Plates II., III.

(Taken as Read, November 26th, 1886.)

Tricemtium intermedium, n. sp., Gr. & St. — Valve small, "with
four rounded angles, and distinct nodules. Sides slightly convex,
Centre clear. Rest of surface sparsely dotted except at the margin,
which is edged with two rows of closely-set granules. Length of
side -0022". Rare. (PI. II, Fig. 1.)

T. lineatum, Grev. (« T. M. S.,"Vol. xi, p. 75, PI. 5, Fig. 24).—
Agrees with Greville's figure, except in having four instead of three
clear linear spaces within each angle. Length of side "007 5". Rare.

A form of this species occurs with two processes only, which we
figure as an additional proof of the connection between the genera
Trieeratium and Biddulphia. (PI. II, Fig. 2.)

T. obeswn, Grev. (" T. M. S.," Vol. xii, p. 90, PL 13, Fig. 11.)
— Scarce.

T. crenulatum, n. sp., Gr. & St. — Avery distinct species, frequent
in this deposit. Valve with four indentations or " scallops " in
each side. Centre and angles elevated, the latter produced into
distinct nodules. Umbilicus clear, surrounded by a ring of small
granules, from which lines of larger granules, about 8 in *001",
extend to the margin. This species varies in outline some speci-
mens having concave, and others gibbous margins, with very
shallow indentations. A curved line may be seen at the base of
the raised angles, particularly in the gibbous forms. Length of
side '005". (PI. II, Fig. 3, typical. Fig. 4, forma gibbosa.)

T. neglectum, Grev. (« T. M. S.," Vol. xiii, p. 7, PI. 2, F. 20).
— Rare, but corresponding with Greville's form.

T. Morlandii, n. sp., Gr. & St. — Valve with slightly concave
sides and large prominent ovate nodules, covered with delicate
granules. In the centre is a blank space, surrounded by two or

8 E. GROVE AND G. STURT ON

three circles of granules, increasing in size outwards ; from this to
the margin ran radiating costse, enclosing large oblong cells, extend-
ing at the sides to the margin, but shorter opposite the angles. At
the foot of each nodule is a blank space, covered with large granules,
resembling those at the centre. Between the radiating costas are
double lines of granules. A very beautiful form, which we have
much pleasure in naming after the introducer of this deposit. Dis-
tance between angles of specimen figured, -0044". A smaller form
also occurs, -003" length of sides. (PI. II, Fig, 5.)

Entogonia Davy ana, Grev. (T? iceratium Davyanum, Grev., " Q.
J. M. S.," Vol. ii, n.s., p. 232, PI. 10, Fig. 4).— A variety of this
form occurs, in which the transverse lines in the central compart-
ment, and the clear spaces at the base of each process shown in
Greville's figure are wanting.

Eunotogramma Weissii, Ehr., var. producta, n. var. Gr. & St.
(E. Weissii, Gran., in " Franz. Jos. Land," p. 7, PI. B., Fig. 21-22),
— Valve with very prominent, sharply-defined, central projection ;
considerably produced towards the ends, and terminating with elon-
gated angles. The surface of the valve is covered with scattered
granules. Length up to -0088". Breadth at centre -003". (PI.
II, Fig. 6. Frustule, Fig. 7.) We have classed this as Eunoto-
gramma, following Grunow, but it is totally distinct from E. varia-
bile, Gran., which may be taken as the type of the genus. E. Weis-
sii has great affinity to the Biddulphiw.

Aulacodiscus Crux, Ehr. (" Grun. Franz. Jos. Land," p. 17
vars. " Schm. Atl.," PI. 33, Fig. 1-3). — Small forms are not unfre-
quent up to -0052" in diameter. The smaller forms suggest the
var. tcnera, Witt. (" Simbirsk," p. 19, PI. 6, Fig. 10).

A. Comberii, Arnott (" Pritch.," p. 844). Scarce but typical.

A.decorus, Grev. ("T. M. S.," Vol. xii, p. 82, PI. 10, Fig. 2).
— Rare. Processes six in number. Diameter, -01 2".

A. Stoschii, Janisch (" Schm. Atl.," PI. 34, Fig. 11 ; Walker
and Chase, " New and Rare Diatoms," p. 3, PI. 1, Fig. 2). — Scarce.
Corresponding to Walker and Chase's form. Processes seven in
number. Diameter up to -02". This form is closely allied to A.
inflatus, Grev., or the better known A. formosus.

A. cellulosus, n. sp., Gr. & St. — Valve covered by radiating,
distinctly punctate, irregular hexagonal cellules, with a central
rosette of small oblong cellules. Furrows distinct, formed by two
parallel rows of cellules running from the central rosette to the

A F0881L MARINE DIATOMACEOUS DEPOSIT. V

processes, which are small, submarginal, and 4-9 in number.
Extreme margin striated. Diameter up to '0066" ; cellules seven
to eight in '001". Not very rare. — PL II, Figs. 8 and 9.

A. Beeverice, Johnson (" Prich.," p. 844, PI. 6, Fig. 5). — Forms
with three or four processes are not unfrequent. Diameter "005".
A form with only two processes also occurs.

A. ajigulatus, Grev. (" T. M. S.," Vol. xi, p. 71, PI. 5, Fig. 15;
u Schm. Atl.," PI. 34, Fig. 8). — Not unfrequent. Processes 8 or
9 ; the size varies considerably from *005" to •Oil" in diameter.

A. margaritaceus, Ralfs. ("Prich.," p. 844; "Schm. Atl.," PI.
37). — A form with four processes, , 007 // in diameter, occurs ; a
very large variety (with processes up to 11), attaining a diameter of
•028", is not very rare in the heaviest density.

A. amcenus, Grev., var. sparso-radiata, n. var. Gr. & St. (Grev.
in « T. M. S.," Vol. xii,p. 10, PI. 1, Fig. 3).— Differs from the type
by its larger size, and the greater distance between the radiating
lines of granules. Diameter up to *009". Lines of granules six in
•001". Smaller forms more closely resemble the type, while the
largest ones suggest A. oreganus. The processes vary up to 10 in
number ; and the disc is not convex. Not unfrequent.

A. Sollittianus, Norm. var. nova Zealandica, n. var. Gr. & St.
(Norm, in " T. M. S.," Vol. ix, p. 7, PI. 2, Fig. 5).— In general
aspect resembles the type ; but is smaller, with only three processes,
and a well-defined, striated margin. The umbilicus is sometimes
wanting. The cellules are about 11 in "001", and the diameter
varies up to -0075". Not rare. (PL III, Fig. 10.)

A. ?iotatus, n. sp., Gr. & St. — Valve small with indistinct
umbilical space, and four large opposite, almost circular, hyaline,
submarginal spaces about •001" diam. ; from the centre of each of
which projects a very short urn-shaped process. The valve is
slightly inflated towards the processes, leaving between the hyaline
spaces a slight depression ; the surface is covered with fine radia-
ting granules, which at the centre are irregularly arranged. The
furrows are narrow, but quite distinct ; the margin is well defined
by a clear zone. Diameter, *004". Rare. A very delicate form,
distinguished from other species in the genus by the large hyaline
spaces. (PL III, Fig. 11.)

Glyphodiscus stellatus, Grev. (" T. M. S." Vol. x, p. 91, PL 9,
Fig. 5.) — Scarce. Similar to that occurring in the Californian
deposits ; up to -0035" in diameter.

10 E. GROVE AND G. STURT ON

G. scintillans, A. Schm. (" Atl.," PI. 80, Fig. 7).— A variety
rarely occurs; one observed with 14 processes.

Auliscus mcemosus, Ralfs. (Grev. in "T. M. S." Vol. xi, p. 46,
PI. 2, Fig. 9 ; Schm., " Atl.," PI. 30, Fig. 12, 13). Small and
scarce.

A. pruinosus, Bail. (Grev., loc. cit., p. 48, PI. 3, Fig. 13). — In
addition to the radiating lines, the surface is slightly punctate,
corresponding with the figures of A. punctatus, Bail., in " Atl.,"
PI. 31, Fig. 8, 9. Scarce.

A. notatus, Grev. ("T. M. S.," Vol. xiii, p. 5, PI. 1, Fig. 2).— A
form occurs rarely, which we consider a variety of Greville's
species. The valve is larger, and the surface is covered with close-
set, fine granular dots, in addition to the numerous large, well-de-
fined puncta ; there is no umbilical space. Diameter, -004". It is
very probable that this form is merely a variety of A. punctatus,
Grev. (nee. Bail.), " T. M. S.," Vol. xi, p. 49, PI. 3, Fig. 15, 16.

A. punctatus, Bail. var. (A. Schm. "Atl.," PI. 67, Fig. 7). —Differs
from the typical form in the presence of a crescent-shaped clear
space enclosing the inner half of each process. This space is
more clearly defined in our form than in the figure in the Atlas.
Diameter -004".

A. Barbadensis, Grev. ("I. M. S.," Vol. xiii, p. 5, PI. 1, Fig.
1). — This is more oval than Greville's form, but in other respects
closely resembles it; the radiating characteristic lines being es-
pecially distinct.

A.fenestratas,n. sp., Gr. & St. — Valve small, oval; processes
two, small, situated at a little distance from the margin ; umbilicus
subdistinct. On the inside of each process, and partly encircling
it, is a crescent-shajDed clear space ; then, for a little distance
inwards, the valve is flat, but gradually becomes slightly depressed
as it approaches the centre ; the point where the depression com-
mences being marked on each side by a narrow clear space,
extending nearly across the valve. Surface covered with mark-
ings resembling those of A. pruinosus. Not scarce. Diameter
generally up to -003". One specimen observed with diameter of
•0045% (PI. Ill, Fig. 12.)

A. ccelatus, Bail. (Grev. " T. M. S.," Vol. xi, p. 44, PI. 2, Fig.
4-7). — A variety of this is rare.

A. Oama?uensis,n. sp., Gr. & St. — Valve nearly circular, large ;
processes two, very prominent ; umbilicus similar to that in A.

A FOSSIL MARINE DIATOMACEOUS DETOSIT- 11

Hardmannianus, Grev., (" T. M. B.," Vol. xiv, p. 6, PI. 2, Fig. 17).
The markings are formed of large rough Costa?, arranged in four
sets, two of which converge to the processes, whilst the others
radiate along the lateral depressions continuously to the margin.
Longest diameter of largest observed -009" (PI. Ill, Fig. 13.)

EuODIEiE.

Euodia Janischii, Gran. (" V. H. Synop.," PL 127, Fig. 1-4).
— Scarce.

E. striata, n. sp., Gr. & St. — Valve small, similar in shape to
Eunotia faba, Ehr., with small terminal nodules. Dorsal margin
moderately curved, ventral nearly straight. Stria? radial, about
nine in -001", composed of very short transverse lines about 45
iu -001". Length to -003". Breadth -00056". (PL III, Fig. 14).

Hemiaulid^e.

H. includeus (Ehr.), Grun. (" Franz. Jos. Land," p. 12, PL B.,
Fig. 36, 38). Not unfrequent. H. capitatus, Grev. (" T. M. S.,"
Vol. xiii, p. 54, PL 6, Fig. 24). seems a similar form, and perhaps
identical.

H. ornithocephalus, Grev. (" T. M. S.," Vol. xiii, p. 32, PL 3,
Fig. 16). — A form which we identify with this species is not very
rare ; it is, however, slenderer than Greville's figure ; and the
horns more elongated, but in other respects similar.

//. tenuiformis, Grev. («T. M. S.," Vol. xiii, p. 29, PL 3, Fig.
10). — Frequent.

H. hjriformis, Grev. (loc. cit., p. 30, PL 3, Fig. 11).— Not
frequent.

H. Barbadensis, Grun. (''Franz. Jos. Land," p. 11).— Frequent.

H. polymorphic Grun. (loc. cit., p. 14). — Forms of this, vary-
ing considerably in appearance, are numerous.

While this part of our paper was going through the press we
were shown a copy of a letter received by Professor Rupert Jones
from Captain F. W. Hutton, Professor at Canterbury College,
Christchurch, New Zealand, dated in January of this year, en-
closing a sample of this deposit for examination, and giving par-
ticulars of its geological age and position. It appears from this
that Captain Hutton is the original discoverer of this deposit ;
and we accordingly hasten to acknowledge our indebtedness to him
and tender him our thanks.

12 ON A FOSSIL MARINE DIATOMACEOUS DEPOSIT.

DESCRIPTION OF PLATES.

Plate II.
Fig. 1. Triceratium intermedium, Gr. and St., n. sp., 5 y°.
„ 2. „ lineatum, Grev., var., 4 ^°.

„ 3. „ crenulatum, Gr. and St., n. sp., 4 T \°.

4. „ „ forma gibbosa, 4 £°.

5. „ Morlandii, Gr. and St., n. sp., 5 ^°.
6. MunotogrammaWeissii, Ehr., v&r.producta, Gr. and St., valve, 3 f°.

7. „ 3 , „ frustnle, »|<>.

8. Aulacodiscus cellulosus, Gr. and St., n. sp., 4 y°.

9. „ „ Portion highly magnified, 1Q f°.

Plate III.

10. Aulacodiscus Sollittianus var . i^om Zealandica, Gr. and St., 4 °°.

11. „ notatus, n. sp., Gr. and St., 6 T °.

12. Auliscus fenestratus, n. sp., Gr. and St., 4 ^°.

13. ,, Oamaruensis, n. sp., Gr. and St., 4 T "°.

14. Euodia striata, n. sp., Gr. and St. 3 5 £°.

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13

On a Method of Finding the General Character of the
Components of a Cemented Combination Lens.

By E. M. Nelson.

(Read November 26th, 1S86.J

Some microscopists take no special interest in their lenses,
beyond occasionally wiping the front, and brushing the dust,
when it gets too thick, with a camel's-hair pencil from the
back.

Others unscrew the combinations to clean them, and like to
know whether they are composed of two, three, or four sets of
lenses.

Some, again, know all about the components of each com-
bination, and some wish they did. It is to this last class of
inquirers that this paper is directed.

Let me first say that there is only one way of finding out the
exact composition of a lens, and that is by taking down every
combination, uncementing every lens, measuring the exact cur-
vature, and the refractive and dispersive power of the glass of
which it is made.

It will be admitted, however, that it is very useful to know
whether a combination consists of two, or three lenses, and if
those are biconvex, biconcave, plano-convex, meniscus, &c. To
find such information without uncementing a combination is the
scope of this paper.

The method I employ, is simply the consideration of the
reflected images from the surfaces of the glass. Take the plain
mirror of your microscope in your hand, and examine the reflec-
tion of a window, notice that it is an erect image, and that
when you move the mirror in a certain way the image appears
to come towards you.

Now look at the concave side, the image is inverted, and when
the mirror is moved in the same direction as before the image
goes away from you.

A convex mirror behaves as a plain mirror, there being only
this difference, that the greater the convexity the smaller is the

14 E. M. NELSON ON THE GENERAL CHARACTER OF

image ; which difference is also true of a concave mirror, viz.,
the greater the concavity the smaller the image.

If you now examine a single biconvex lens, you will see a
large erect image from the surface next the window, and a
small inverted image from the surface on the other side. It
acts precisely as if it were a convex and a concave mirror. In
a single biconcave lens you have a large inverted, and a small
erect image. In a plano-convex, with the convex side towards
the window, you will find a small erect image from the convex
side, and a large inverted image from the plane side. With the
plane side towards the window, you will have a large erect
image from the plane side, and a small inverted one from the
other side.

With the concave side of a plano-concave towards the window,
the concave side will give an inverted image, and the plane side
an erect image ; but with the plane side to the window, you
will get two erect images. Converging and diverging menisci
have for their convex sides two erect images, and for their
concave sides two inverted. I find, however, that in a converg-
ing meniscus, if the concave surface is of very large radius, the
reflection from it, when viewed from the convex side, will be
inverted instead of erect; in other words, it will take the form,
of a plano-convex. I imagine that in a diverging meniscus,
which closely approximates the form of a plano-concave, the
same result would be found, viz., that the image from the flat
side, seen through the more concave side, would be erect
instead of inverted, as one would expect ; but of this I have no
practical experience, as I have not got a lens of that form to
experiment on.

Now, if we take a cemented doublet, consisting of a biconvex
and a plano-concave, we shall very easily see the two bright
reflections from the two exterior surfaces, viz., the plane and
the convex. The image from the cemented surfaces, however,
will not be so readily apparent. With a little attention it will
be discovered as a faint image, with most probably a bluish
tinge, though occasionally it may have a reddish tinge. When
once seen it will be easily recognized again. A triple combina-
tion will have two faint images, as well as two bright ones. I
find the following the best method of procedure : —

First, lind out by the number of faint reflections if the lens

THE COMPONENTS OF A CEMENTED COMBINATION LENS. 15

is a doublet or a triplet. Next find out the nature of the
exterior surfaces, and write them down, e.g., plano-convex
doublet. This means that the combination is composed of two
lenses, and that one of the exterior surfaces is convex and the
other plane. Now write down the reflections as they come,
beginning at the side next the window, underlining the reflec-
tion from the first surface, and putting the reflection from the
cemented surface in parenthesis. In writing these down I use
the following abbreviations : — e for erect, i for inverted, s for
small, I for large, and L for very large. It is a good plan to
draw the lens by representing, first the exterior surfaces only,
and then filling in the cemented surfaces, according to the
reflections you obtain. It is absolutely necessary that the
character of the reflections from both sides of the combination
should be ascertained, as it is impossible to discover the con-
struction of the combination from one set of reflections.

When the images are large, it is as well to look at the reflec-
tion of the bar across a window ; the knob of the hasp showing
if the image is erect or inverted.

The images from small lenses require to be examined by a
magnifying glass.

One word of caution, and that is, until one is practised in
picking up these faint images the very large faint ones are apt
to be overlooked. Until one is familiar with the manner of
holding a lens only a faint blue tinge will be seen over the
glass, but after a little practice a distinct image of the window
bar will be obtained.

The following are a few examples : —

A plano-convex doublet : —

Convex side, se (si) li.

Plane side, le (se) si.

It therefore consists of a biconvex and a plano-concave.

The next two form an interesting pair.

A converging meniscus doublet : —

Convex side, se (si) li.

Concave side, li (se) si.

This, therefore, consists of a biconvex, and a biconcave.

Another lens of the same exterior form : —

Convex side, se (se) li.

Concave side, li (si) si.

16 E. M. NELSON ON THE GENERAL CHARACTER OF

This consists of a converging and diverging meniscns. The
difference between these two last combinations is at once shown
by the different characters of the reflections from their
cemented surfaces. The intelligent observer will note that the
concave exterior surface when seen through the convex surface
has its sign changed from e to i ; of this I spoke above.

An unequal biconcave doublet : —

Most concave side, li (se) si.

Least concave side, Li (si) se.

It consists therefore of a biconcave and a converging
meniscus. The si in the most concave side is not what one
would have expected. The interior curve of the meniscus
must have a short radius, so that it overpowers the exterior
concave surface of the biconcave. The least concave side is
very flat, as shown by L.

A biconvex triple, equiconvex : —

e (i) (e) i both sides alike.

It consists of a biconvex, binconcave, biconvex. A plano-
convex triple consisting of a biconvex, a biconcave, and a plano-
convex, will have the same form, only the plane side will be
Le instead of se and li instead of si.

An unequal biconvex triple as in a properly constructed opera
glass objective : —

Most convex side, le (si) (Li) li.

Least convex side, le (Le) (se) si.

The lenses are therefore biconvex, diverging, and converging
menisci.

A biconcave triple as in a properly constructed opera glass
eye-piece : —

From side of thickest lens, li (se) (le) se.

From side of thinnest lens, li (Le) (li) se.

Its form is biconcave, converging meniscus, and diverging
meniscus.

If the middle were a piece of plain glass, which is sometimes
fraudulently put, its form would be : —

i (e) (e) e,
which would read the same from both sides. But if it had a
thin converging meniscus in the middle, it would read : —

li (le) (le) se from one side.

li (Le) (Le) se from the other.

THE COMPONENTS OF A CEMENTED COMBINATION LENS. 17

You will notice that the diverging meniscus turns the (i)
into an (e), following a plano-concave as I hinted above, only
making the s into an L.

These examples will be sufficient to make anyone acquainted
with the method I employ.

I have for long thought it was possible to find out the char-
acter of a combination by means of the reflections, but having
only received negative replies to my repeated inquiries from
those who ought to know, I have been deterred from investigat-
ing the matter for myself until this summer.

Journ. Q. M. C.j Series II., No. 17.

18

PROCEEDINGS.

August 13th, 188G. — Conversational Meeting.

There were no objects exhibited, and the meeting separated at an early
honr.

Attendance — Members, 1G ; Visitors, 1.

August 27th, 1886.— Ordinary Meeting.

J. G. Waller, Esq., F.S.A., in the Chair.

In the absence of the President, Vice-Presidents, and Secretary, Mr. H.
F. Hailes called upon the members present, in accordance with Rule 4, to
appoint a chairman for the evening. Mr. J. G. Waller was accordingly
elected.

Mr. Hailes read the minutes of the preceding meeting, which were duly
confirmed.

Mr. W. S. Daddo was balloted for and elected a member of the Club.

The following donations to the Club were announced : —

An old work on Natural Philosophy ... x

A copy of " Quekett " on the Microscope, in

German
" Papers on the Microscope," in German
" The American Naturalist" ... ... ... In exchange.

" The Botanical Gazette "...

" Proceedings of the Belgian Microscopical )

Society" ... ... ... ... j

" Proceedings of the New York Microscopical ")

Society" ... ... ... ... )

K The American Monthly Microscopical *)

Journal" ) "

" Annual Report of the Brighton and Sussex ")

Natural History Society " )

"Journal of the Royal Microscopical Society".,.

" British Desmids/' No. 2 ... Purchased.

The thanks of the Club were voted to the donors.

From Mr. Crisp.

J o x

>>

>>

>> V

19

The Chairman having remarked that they had no paper to bring before
the meeting, expressed a hope that some member present would be able to
communicate something of interest.

Mr. Buffham thought it would be a good thing if the Society would make
a rule that no meetings should be held in the summer, as there were so
many members absent during July and August. He hoped, however, that
someone present who had been for a holiday would be able to describe
something which he might have come across.

No response being made to the Chairman's appeal, notices of excursions,

&c, for the ensuing month were given oat, aud the meeting terminated in

the usual Conversazione, and the following objects were exhibited : —

Actinophriis Eichhornii. Ehr.

Mr. F. W. Andrew.

}

•uption ")

r Mr. H.G. Glasspoole.

= Actinospherium JEichhornii (Huxley)..
Volcanic dust ejected during the late er

of Tarawera, New Zealand ...
Pre-cambrian volcanic rocks, lavas, aud tufa -\

from the Wrekin, and tertiary lavas, &c., )■ Mr. G. Smith.

from Hungary, compared ... ... )

Attendance — Members, 31 ; Visitor, 1.

September 10th, 1886. — Conversational Meeting.
The following objects were exhibited : —

Cordylophora lacustris

Gall fly of oak, Cynips

Living podurai

Diatoms, Triceratium sculplum ..

Spirogyra nitida ...

Mr. F. W. Andrew.
Mr. F. Enock.
Mr. G. Hind.
Mr. H. Morland.
Mr. J. Spencer.

Attendance — Members, 25 ; Visitor, 1.

September 24th, 1886. — Ordinary Meeting.
A. D. Michael, Esq.. F.L.S., F.H.M.S., President, in the Chair.

Mr. H. F. Hailes (in the absence of the Secretary) read the minutes of
the preceding meeting, which were duly confirmed.

The following additions to the Library were announced: —

" The American Naturalist " ... ... ... In exchange.

"The Scientific Inquirer"

" Proceedings and Report of the Bristol

Natural History Society "
" The Botanical Gazette '',.. ... ... ... ,, ,,

( if )J

20

• "Proceedings of the New York MicroscopL.

In exchange.

)ical )

Society"

"Grcvillea" Purchased.

"British Desmids/' Part 3 „

" Annals of Natural History " ... ... ... „

Mr. H. Epps read a paper on " Kola" — a new commercial plant, said to
possess some very remarkable properties. The subject was illustrated by
the exhibition of a growing plant, also by specimens of the nuts, together
with samples of the powder prepared therefrom, and by sections of the
nut shown under the microscope. Samples of the powder, &c, were
offered for distribution amongst those members who were interested in the
subject.

The President said they were very much obliged to Mr. Epps for his
interesting communication. He perfectly well remembered the evening
when the subject was brought before the Linnean Society, and was much
struck by the evidence which was given — as it seemed quite by accidental
circumstance — in confirmation of the statements made by the reader of the
paper. Mr. Christy brought the matter before the Society as something
new, and a gentleman who was present, and said he was a West India
planter, got up and stated that he was quite well acquainted with the
plant and the effects of its preparations, and then told how he had a fore-
man who was an excellent servant, but whose one drawback was his liking
for spirituous liquors. This man used to indulge freely in drink as soon as
work was over on Saturday, and remained under its influence until the
middle of Sunday, when his wife gave him a spoonful of the prepared kola,
which had the effect of rapidly counteracting the effects of the alcohol, and
enabled him to appear at the house and take his orders intelligently.
There appeared to be several other persons in the room who were
acquainted with the power of the kola nut as an antidote to alcoholic
poisoning. The repugnance with which alcohol was regarded by persons
to whom this drug had been administered was possibly a property upon the
advantages of which everyone might not be entirely agreed, but it was
probable that the nut possessed a stimulating property which might have a
sustaining action, and this, together with its peculiar antagonism to alcohol,
made it an exceedingly interesting production, and one well worthy of the
attention of a Society such as theirs.

The thanks of the meeting were voted to Mr. Epps for his communi-
cation.

Announcements of meetings, &c, for the ensuing month were then made
and the proceedings terminated with the usual Conversazione, the follow-
ing objects being exhibited : —

Palmodicti/un virida, Pbrticellidce, &c. ... ... Mr. F. W. Andrew.

Alcyonella fungosa ... ... ... ... Mr. C. Emery.

Antenna of moth, Salumia carp in i ... ... Mr. F. Encck.

Sections, Kola bean, Cola acuminata ... ... Mr. H. Epps.

Poduridce smynthurus ... ... ... ... Mr. J. D. Hardy.

21

L.S. stem of Helianthus ...

Spider, Pholcus phcclangoides $ .

Thistle bug, Monanthia cardui .

Alcyonella fungosa

Olivin basalt

Lacinularia socialis

Wheel plates, Chirodota violacea.

Mr. A. W. Lyons.
Mr. G. E. Mainland.
Mr. R. T. G. Nevins.
Mr. C. Rousselet.
Mr. G. Smith.
Mr. J. Spencer.
Mr. W. Watson.

Attendance — Members, 51 ; Visitors, 5.

October 8th, 1886. — Conversational Meeting.

}

The following objects were exhibited : —

A new Rotifer ... ... ... ... ... Mr. F.

Wheat-flies, Cecidomyia sp. ... ... ... Mr. F.

Leaf of China grass, Conocephalus nivens ... Mr. H.
New Foraminifera from King George's Sound,

W. Australia
Spider, Dysdera Hombergii Q ... ... ... Mr. G.

Diatoms, Psendo-ru I ilaria monile ... ... Mr. H.

Head of Blow-fly Mr. K.

Pupa and imago of Dipteron sp. ... ... ... Mr. R.

Carchesium ... ... ... ... ... ... Mr. C.

Monads, Spirostomum ambiguiim, and Rotifer,

Anurea aculeata

W. Andrew.

Enock.

Epps.

Mr. H. F. Hailes.

E. Mainland.
Morland.
T. G. Nevins.
T. G. Nevins.
de Pelley.

Air. C. Rousselet.
Atteudance — Members, 39 ; Visitors, 0.

October 22nd, 1886. — Ordinary Meeting.

J. G. Waller, Esq., F.S.A., in the Chair.

The Secretary called attention to the fact that as the President and Vice-
Presidents were again absent, it devolved upon the members present, in
accordance with Rule 4, to elect a chairman to preside on the occasion.

Mr. J. G. Waller having been proposed by Mr. Parsons, and seconded by
Mr. Curteis, was elected chairman for the evening.

The minutes of the preceding meeting were read and confirmed.

Mr William Hampton was balloted for and duly elected a member of the
Club.

The following additions to the Library were announced : —

" The American Naturalist " ... ... ... In exchange.

" Proceedings of the New York Microscopical
Society"

1 •■

}

22

" The Botanical Gazette " In exchange.

"Proceedings of the Hertfordshire Natural \

History Society" ) " "

" Journal of the Royal Microscopical Society "... „ ,,
" Fifteenth Report of the South London
Natural History Society " ...

Part VI. of Dr. Hudson's " Rotifera" Purchased.

" Annals of Natural History " ... ... ... ,,

The Secretary said that he had been requested to announce that the
Annual Soiree of the Croydon Microscopical Society would take place on
November 17th, and that forms were placed upon the table for the use of
any members of the Club who were desirous of responding to the invitation
to assist on the occasion.

Mr. Spencer read a paper on Zoothamnium arbuscula, which he illustrated
by drawings on the black-board.

The Chairman thought the communication was one of great interest,
although not relating to a branch of microscopy to which he had given any
personal attention. He hoped some other members would contribute fur-
ther information upon it.

Professor Stewart said there was one point about the subject which
appeared of special interest, and that was as regarded the splitting up of
what was originally a membranous collar into individual cilia. He thought
if this was so. it would be an interesting question as regarded other infusoria
which were provided with a vibratile collar, and he should be very glad to
hear if any other observers present had noticed this process.

Mr. J. D. Hardy regretted that he had not been able to reach the meeting
in time to hear the whole of the paper, but he could quite corroborate the
fact as to this splitting process. Whenever he had observed it, he had
always noticed that the fresh bell broke off, swam away and adhered by its
ciliary processes, and that what was originally the lower portion of the
animal formed the cilia in the new one.

Mr. Spencer said that Mr. Hardy's observation probably referred to some
other species. He had never seen this himself, but might not have seen the
bodies attach themselves because his trough was too large.

The thanks of the meeting were voted to Mr. Spencer for his paper.

The Chairman said that some new objectives had been sent by Dr. Carl
Zeiss, of Jena, and called upon Mr. dirties to give some account of them.

Mr. Curties said he was glad to embrace that early opportunity of exhi-
biting to the Club the new apochrornatic objectives and their eye-pieces
recently introduced by Dr. Zeiss, knowing, as he did, the lively interest shown
by the members in all matters relating to the use of, and improvements in, the
microscope. He thought it would be unnecessary for him to occupy time in
giving a detailed account of the apochromatics, as they were termed, as in the
last number of the "Journal of the Royal Microscopical Society" would be
found, through the kindness and by the aid of our Hon. Secretary, Mr.
Karop, a full translation of the descriptive pamphlet just issued by Dr. Zeiss,

23

the pamphlet also being now in circulation. He begged permission, how-
ever, to offer a very few remarks on the subject. Prof. Abbe, to whom micro-
scopists owed so much, together with Dr. Schott and Dr. Zeiss, commenced
in 1881 a series of experiments in order to produce new kinds of glass, with
the result that objectives could now be manufactured in which the so-called
secondary spectrum was removed and the spherical aberration uniformly
corrected ; hence the application of the term apochromatic — a higher state
of achromatism than had been hitherto obtained. These objectives, when
used under the special conditions recommended, i.e., exact length of body
tube (ICO millimetres for the Continental and of 250mm. for the English),
and with their own proper 'eye-pieces, exhibit a marked improvement in
definition, and in other particulars, notably long working distance, increased
illumination, flatness of field, and a capacity for eye-piecing quite unusual in
lenses of the old construction. For the proper use of these objectives, and for
their more perfect correction, it has been found necessary to design new eye-
pieces called " Compensating Oculars." These were of two kinds — " Finder"
or " Searcher," and "Working." The first were of very low power ; in fact
No. 1 enabled an objective to be employed with its own magnifying power,
the same as if it were used as a magnifier without an eye-piece. The
working eye-pieces commenced with a power of four, anl gave good results,
even with the highest number.-. Ik' thought there was little doubt but that
the Finder or Searcher eye-pieces would supply a want long felt, as they
afforded sufficient field of view for general examination, and would be of
special service when immersion objectives were used, as the great inconve-
nience caused by having to change an objective, already adjusted, for one of
lower power, could now be avoided. They were also arranged upon a method
suggested by Professor Abbe, viz., on the increase in the total power of the
microscope obtained by means of the eye-pieces, as compared with that given
by the objective alone ; for example, on the microscope now showing A'
pellv.cida is the 3*0 mm. homo, immer. (|) objective, which of itself magnifies
83 diameters. The eye-piece employed is the No. 12, and magnifies 12 times.
Now, if 83 be multiplied by 12, the result is 996, or say 1,000 as stated by the
maker. There was another series called projection eye-pieces, which Mr.
Curties stated could not be shown on that occasion, but he hoped to bring
them to an early meeting and give a practical illustration of their value.
They were intended for purposes of demonstration on a screen or for photo-
micrography. He concluded by stating that upon the tables were arranged
microscopes of English, and of Continental form, each supplied with a full
series of the new objectives and eye-pieces, together with a number of fami-
liar objects, by which the members of the Club would be able to form an
opinion for themselves of these interesting and remarkable productions.

Mr. J. E. Ingpen said he did not know that he could add anything to the
description given by Mr. Curties in his paper except of a technical nature,
and, therefore, not likely to be of general interest. But he might mention
that there was an editorial article in the April number of the Eoyal Micro-
scopical Society's Journal which, together with what appeared in the

24

October number, would put the members of the Club in possession of the
technical nature of the glass which was employed. It was not the first time
they had been indebted to Professor Abbe for what they would otherwise
have been most unlikely to obtain. Tn 187-i Abbe published the first of his
remarkable scries of treatises upon the definition of the microscope, and
what great results had come from this they all knew. That work had
now been supplemented by the present great addition to the optical means
at their disposal. Iu the April number of the Royal Microscopical Society's
Journal there was a short account of the manner in which these glasses
were gradnated, and it was very curious to find that after Professor Abbe"
and Dr. Schott had made their elaborate series of experiments they were
disposed to leave them at that stage. Happily, however, they were induced
to go on, and in connection with Dr. Zeiss, subsidised by the Prussian
Government, the matter was carried on to its present results. He thought
that at present the new glass was more likely to be used for astronomical
purposes, seeing the very great complexity of the combinations for micro-
scope objectives. One of the series contained as many as ten lenses, arranged
in five systems, one of which was made of ordinary glass. The question
of getting rid of the secondary spectrum had taken a great deal of attention
at various times. Professor Stokes and others had worked at it, but he did
not suppose that any such systematic and exhaustive experiments had ever
before been applied to any optical theory. As regarded the new lenses, the
improved definition, the increase of power and convenience in use were
something perfectly astonishing, whilst the manner in which the objectives
were supplemented by proper eye-pieces showed how extremely carefully
the whole theory had been worked out into practice. It was Professor
Abbe s peculiarity that he always perfected his formulae in every detail
before bringing it into practice, and in the case of these new lenses the
whole scheme of every one had been entirely worked out beforehand. It
was quite a new point of departure in practical optics, and it was impos-
sible to say where it might lead to in the future.

A vote of thanks to Mr. Cur ties was unanimously carried.

Mr. Freeman said he had brought a series of sections of Spiders, cut by
Mr. H. M. J. Underhill, of Oxford, who, a few years ago, wrote some articles
on Spiders, and Diptera in " Science Gossip." Mr. Underhill had recently
been cutting sections of the Garden spider, Epeira Diadema, and from a
careful study of these sections had prepared a drawing, giving, what he
believed to be, a correct representation of the internal organs in their natural
position. Some of the results of his investigations had been given to the
world in an article which appeared in " The Welcome " for the present month,
a copy of which periodical was on the table. The principal drawing illus-
trating that article had been built up, as it were, from various sections taken
in different directions through the Spider, it being evident that a single
section would not convey a very comprehensive view of the interior economy
of the creature. He (Mr. Freeman) had also brought the original drawings,
which bad been kindly lent by the editor of " The Welcome." The article

25

was written in a free and simple style, in order to interest the general
public, and especially the young, but he thought it would be found
interesting to many of the members. Mr. Underbill's chatty, though terse,
style made the dryest details readable. In his next article he proposed
to deal with the web-making, and web-making apparatus, of the spider.
The sections were cut with an ordinary machine, and were remarkable
not only on account of their anatomical value, but, like all Mr. Under-
bill's work, for their careful and methodical preparation. He (Mr. Freeman)
remembered hearing Dr. B. T. Lowne, some years ago, suggest that a con-
secutive series of sections of the human spinal cord, from the top to the
bottom, would be most instructive and valuable, and thought it could be
done in a few hundreds of slides. Mr. Underhill had gone a good way in
that direction, for some of his slides had as many as 60 distinct sections of
a species of slug on a 3 X 1 slip. Of the Spider series some have as many as
32 sections on a slide, grouped with the greatest regularity. On seeing the
article it occurred to him that some of the members of the Quekett Club
would like to have an opportunity of examining the preparations themselves,
and he therefore communicated with Mr. Underhill, who most kindly, per-
haps somewhat rashly, sent some slides up for exhibition. He had asked Mr.
Underhill to send one that would best illustrate the drawings. He said, in
reply, " The fact is I have not one single perfect section. It is only by
diligently comparing some number of slides that you can see all that I have
put into the drawings. I think they are quite accurate."

The thanks of the meeting were voted to M r. Freeman for his communi-
cation.

Announcements of meetings for the ensuing month were then made, and
the proceedings terminated with the usual Conversazione, and the following
objects were exhibited : —

Palludicella Ehrenbergi ... ... ... ... Mr. F. W. Andrew.

Dr. C. Zeiss's apochromatic objectives and) , r ~ p ,

compensating eye-pieces ... ...j

Cimex lectularia ... ... ... ... ... Mr. F. Enock.

Sections of Garden Spider, Epiera diadema,

Mr. H. E. Freeman.

}

prepared by Mr. H. M. J. Underhill ...
Larva of Nepa cinerea ... ... ... ... Mr. R. T. G. Nevins.

Hairs of centipede, Scolopendria paradoxa ... Mr. C. Rousselet.

Attendance — Members, 56; Visitors, 3.

Journ. Q. M. C, Series II., No. 17.

26

November 12th, 1886. — Conversational Meeting.

The following objects were exhibited : —

Uroceni rum turbo Mr. F. AY. Andrew.

Diatoms from Oamaru ... ... Mr. A. Cottam,

Mr. F. Enock.

Crenulate antenna of Moth ... ... ~)

Pygera Lucephala, natural form and colour )

Human retina, normal ... ... ... ... Mr. G. C. Karop.

Pyrgodiscus simplex ... ... ... ... Mr. H. Morland.

Navicula disciformis, with \ apochromatic "^ jj- -^ ,»- w e i aon

object glass ... ... ... ... }

Fredericella sultana ... Mr. C. Le Pelley.

Zoothaninium arbuscula... ... ... ... } , ,,

Anthodiscus floreatus (G. & S.), n.s. from j -V ^ gturt

Oamaru... ... ... ... ... J

Atttendance — Members, 35 ; Visitor, 1.

November 26th, 1886. — Ordinary Meeting.
A. D. Michael, Esq., F.L.S., F.E.M.S., President, in the Chair.

The minutes of the preceding meeting were read and confirmed.
The following additions to the Library were announced : —

" Annals of Natural History " ... ... ... Purchased.

" British Desmids," Part V. ... ... ... „

" British Petrography " ... ... ... ... „

" The Rotifera," Part VI. ... ... ... ... „

" The Botanical Gazette " ... ... ... ... In exchange.

" Proceedings of the Geologists' Association "... „

The Secretary annonnced that the second part of Mr. Sturt's paper " On
Diatom Structure" had been received, and would be taken as read that
evening.

Mr. E. M. Nelson read a paper " On the New Apochromatic Lenses," in
the course of which he explained, by the aid of diagrams, what was meant
by the " secondary spectrum," which was said to be got rid of by the use
of the glass of which these combinations were constructed.

Mr. Nelson also read a further paper " On a Method of Finding the
General Character of a Cemented Combination," the subject being largely
illustrated by means of diagrams.

Mr. John Mayall, jun., inquired if Mr. Nelson had, by any chance
attempted to estimate the forms adopted by Zeiss in the new apochro-
matic objectives, so as to get an approximate idea of the combinations ?

27

Mr. Nelson said he had not yet had the opportunity of doing so, and had
not referred to the matter because his paper was written before his return
to town, and, therefore, previous to his having been able to see these lenses.

The President was sure that all present would join in thanking Mr.
Nelson for his two very interesting communications, relating as they did to
subjects upon which some people at least had rather misty ideas. He had not
only given them a very clear description of what was meant by the secondary
spectrum, but had in his second paper introduced them to what appeared to
be an interesting method of obtaining some idea as to the combinations of
an objective.

The thanks of the meeting were unanimously voted to Mr. Nelson for his
communications.

The President said he had brought down to the meeting an object which,
he thought might be interesting to some of the members. It was not
strictly microscopic, for although it was one of his " pets," it was a
creature of appreciable size — one of the Argasidas, the Persian Argas
originally introduced to the notice of zoologists in 1823 by Fischer, who
published an account of it in the Transactions of the Academy of Moscow.
Fischer had been travelling in Persia, and had collected a large amount of
information on Natural History subjects, and he gave a terrible account of
this creature, whose bite, he said, produced violent fever, madness, and
sometimes death in the course of 24 hours, and that it was particularly
fatal to strangers. These remarks got abroad, and appearing in various
works on Natural History and Entomology, became generally received as
facts, especially as they appeared to receive confirmation from time to time
by the reports of other writers. In 1858 Heller managed to obtain some
specimens, his object being to study their anatomy, and he gave the results
of his observations in the Transactions of the Vienna Academy of Sciences,
giving also some very good figures of the creature. Nothing more seemed
to transpire on the subject until 1878. A few years previous to this date
the Shah of Persia wrote to the French Government to ask for a physician
to be sent out to him at Teheran, and in response to this request Dr.
Tholozan was appointed to the post, and was asked to collect and send
home specimens of the Argasida?. This he accordingly did, collecting
them from Miana and other places. At Miana he found that at the present
day they did not bear such a terrible reputation as that given to them by
Fischer ; they were found in the neighbourhood, chiefly upon sheep, but
were not thought to be dangerous. However, at another place he found
that they were not only considered dangerous, but that they were called by
the natives Guerib-gueZyOV " Strangers beware." Dr. Tholozan sent them to
Laboulbene, and soon after they arrived he sent them on to Megnin for
examination. Megnin was busy at the time, and put them aside in a
drawer until he had time to attend to them, but forgetting what he had
done with them, and being unable to find them, he had to tell Laboulbene
that they were lost, and he in turn not liking to ask for more, the matter
for the time ended there. Three and a half years afterwards, however,

28

Megnin happening to turn out the drawer found the lost box, and on
opening it, found, to his astonishment, that the creatures were still alive,
and apparently nearly as active as usual. He then examined them care-
fully, and found that those which came from Miana were identical with
those which had been described by Fischer, those which were considered
harmless were of a different species, whilst those called " Strangers
beware " were a mixture of the two species. Megnin wrote a skilful
paper upon the subject, but he wanted very much to know if they were
really as dangerous as they had been made out to be, Dr. Tholozan having
come to the conclusion that their bites, under certain conditions, favoured
by the miasma of the place, would probably produce a state of affairs which
might prove to be serious, but were not in themselves dangerous. Megnin
himself took one of the creatures and placed it upon his arm, when it bit
at once and sucked blood until it was satisfied, and he found that the place
where it had bitten continued to irritate, more or less, for about a fortnight,
but no serious effect took place beyond. A short time ago he (the President)
received a letter from Miss Ormerod, saying that she had received from Mr.
Crawford, the State Entomologist of Adelaide, Australia, some specimens,
asking her to identify them. She did not know the species, but seeing that
one was an Argas threw them into boiling water and killed them at once,
and then forwarded them to him to see if he could name them. He examined
them as well as their condition permitted, and was entirely unable
to see any difference between these and the Persian Argas described by
Megnin. He thought, however, that he should like to see them alive if
possible, and so sent for some more, and in answer to his request Mr.
Crawford sent him some — only two — by post from South Australia. They
arrived whilst he was out of town, and so they were left for a month or six
weeks without attention, but subsequently he found that one of them was
still alive. He had mounted the other and had brought it to the meeting
that evening together with the living specimen, both of which were ex-
hibited under microscopes in the room.

Mr. H. Epps said he should like to make a few remarks on the subject of
a new cement, but rather with the object of seeking information than of
being able to give it. Perhaps some of the members might have noticed the
letters which recently appeared in the "Times" on a new use for sugar, in
which the writer pointed out that it formed an ingredient in a very hard
cement, and claimed for the process great antiquity, stating that it was in
use amongst the Romans, and in India in early ages, and then proceeded to
give various suggestions for making a cement which should be harder than
anything of the kind previously known. It struck him on reading this
account that it might perhaps be a good cement for microscopical purposes,
and therefore thought he would try how it worked. The directions were to
mix together equal quantities of sugar and lime, and it was particularly
emphasized that cane sugar should be used for the purpose. He had tried to
follow the receipt as closely as possible, but was sorry to say that the results
had proved to be very disappointing. He first took some ordinary cane
sugar and endeavoured to mix it with lime and water, but he soon found

29

that this was not the way to proceed, as the sugar seemed to maintain its
crystalline condition. He then tried dissolving some sugar in water until he
got it highly saturated, afterwards adding the lime. By this process he
seemed at first to get more satisfactory results, but the next morning he
found the cement had come'to an untimely end, with the exception of one
specimen. In this case he had united two slips of glass with cement between
them, and he tried to break them apart, but though he dropped them and
broke the glass, the two surfaces did not separate, and he thought he had
met with success ; but on looking at them again on the previous evening he
found that the cement had once more resolved itself into its original con-
stituents, and the result was that he was no wiser than before. He had
mentioned the matter to a sugar refiner, who told him that he thought the
idea was quite a mistake, and that the action of sugar upon lime was simply
a rotting action, as he frequently found in his factory when sugar happened
to be dropped upon a cement floor. He thought, however, that notwith.
standing his want of success, his experiences in the matter might be worth
noting.

Votes of thanks having been passed to the President and to Mr. Epps for
their communications,

The Secretary announced that as the date of their ordinary meeting in
December fell this year on Christmas Eve it would be omitted. The next
ordinary meeting would therefore be held on January 28, when, according to
their new rules, nominations for officers and council to be elected at the
meeting in February would have to be made. It was also announced that
the usual annual dinner of the Club would take place at the Holborn
Restaurant on the day following the Annual General Meeting of the Club.

The proceedings then terminated with the usual Conversazione, and the
following objects were exhibited : —

Eurycercus lamellatus ... ... ... ... Mr. P. W. Andrew.

Cladophora, with diatoms m situ ... ... Mr. A. L. Corbett.

Diatoms mounted in cassia oil ... ... ... Mr. C. L. Curties.

Generative organs of male Flea, dissected ~) -^ ^, (j ur +: es
entire by Mr. Tatem ... ... ... )

Myriapod, Julus pulchellus, with parasitical ") -»j ^ ™ Mainland
acari attached ... ... ... j

Argas persicus, from Adelaide, Australia, living Mr. A. D. Michael.

Arachnoidiscus omatus j Mr , E . M . Nelson<

Actinoptychus splendens ... ... )

Scale of Podura (Lepidocyrtus curvicollis) } ^
with T Vth apochromatic homo, immer.
N.A. 1.40

AmpMpleura pellucida, with the same, and
achro. imm. condenser

Rotifer, Polyarthra platyptera Mr. C. Rousselet.

Section of Quartzite from the Wrekin, Salop... Mr. G. Smith.

Spicules of Gorgonia, Holothuria, &c Mr. W. Watson.

Attendance — Members, 62 ; Visitors, 7.

Messrs. Powell and
Lealand.

30

December 10th, 1886. — Conversational Meeting.

The following objects were exhibited : —

Desmids, various ... ... ... ... Mr. F. W. Andrew.

Head of Plumed Gnat, Chironomus vlinno-*) ■** ™ -p u

stis, $ j

Spider, WalcJcendera acuminata, $ ... ... Mr. G. E. Mainland.

Diatoms, Triceratium castellatum ... ... Mr. H. Morland.

Barbed spine of Sting Ray ... ... ... Mr. S. H. Needham.

Diatoms in balsam, shown with lieberkuhn ... Mr. E. M. Nelson.

Pkilodina, sp. ... ... ... ... ... Mr. C. Le Pelley.

Rotifer, EucManis triquetra ... ... ... Mr. C. Rousselet.

Granulite, Rosswein, Saxony ... ... ... Mr. G. Smith.

Lherzolite, Haute Garonne ... ... ... „ „

Diatom, Hemiaulus amplectans, n.s. ... ... Mr. G. Sturt.

Attendance : — Members, 32 ; Visitors, 0.

31

Q.M.C. EXCURSIONS, 1886.

April 10th.

List of Objects Found on the Excursion to the Gardens
of the Royal Botanic Society of London, by Messrs.
Bousfield, Dunning, Funston, Hardy, Kern, McIntire,
A. D. Michael, Nevins, Oxley, Parsons, and Rousselet.

CRYPTOGAMIA. Alg*:.

Gonium pectorale.
Pandorina morum.
Scenedesmus caudatus.
Spirogyra calospora.

,, nitida.
Zygnema stagnate.

DeSMIDIACEjE.

Closterium didyuutocum.
„ lunula.

,, moniliferum.
Diatomace^e.

Cocconema lanceolatum.
Synedra radians.
PROTOZOA.

Acineta mystacina.

„ tuber osa.
Actinophrys brecicirrhis.
pennipes.

sol.

viridis.

Actinosph&rium Eichhornii.
Am&ba diffluens.

princeps.

radio sa.
Amphileptus anser.
Anthojjhysa vegetans.
Astasia limpida.

n

>>

Bursaria truncatella (?)
C lire ton otus larus.
Codosiga botrytis.
Coleps hirtus.
Cothurni* 1 imberbis.
Dileptus folium.
Enchelys.

Epistylis anastatica.
flavicans.
plicatilis.
Engl en a acus.

,, viridis.
Halteria volvox.
Lacinularia olor.
Litonotus fasciola.

„ Wrzesniowshi.
Loxophyllum meleagris.
Opercularia articulata.

„ nutans.

Phacus longicauda.
Phialina viridis.
Platycola longicollis.
Pleuronema coronata. '
Podophrya fixa.
Pyxicola affinis.
Spirostomum teres.
Stentor Barretti.
Midleri.

?>

Journ. Q. M. C, Series II, No. 18.

32

Stentor polymorphus.
„ Rceselii.
< Strombidinopsis gyrans.
Stylonichia fisseta.
„ mytilus.

Trachelitis ovum.
Trichodina pediculus.
Urocentum turbo.
Vaginicola crystallina.
Vorticella nebulifera.
Zoothamnium, sp.
PORIFERA.

Spongilla fluviatilis.
CCELENTERATA. Hydro-

ZOA.

Supposed polyp, stage of
Limnocodiwn Sowerbii.
VERMES. Rotifera.
Brachionus Bakeri.

pala (= Amplii-

ceros).
p)oly acanthus.
Eosphora aurita.
Euchlanis triquetra.
Floscidaria campanulata.
,, longicaudata.

Limnias ceratophylli.
Lindia torulosa.

})

5J

Monostyla bulla.
Notommata aurita.
(Ecistes crystallinus.
Philodina citrina.

„ erythrophthahna.
Polyarthra platyptera.
Pterodina patina .
Rotifer macroceros, vel mega-
ceros.
„ vulgaris.
Stephanops lamellaris.
Synchwta pectinata.
Annelida. Oligoch^eta.
JEolosoma album (sp. nov.).
quatemarium.
tenebrarium.
Cho2tog aster minutus (sp.

nov.).
Dero furcata.
limosa.
Perrieri.
Nais elinguis.
Pristina (sp. nov.).
MOLLVSCOIDE^E. Poly-

ZOA.

Fredericella sultana.
IN SECT A.

Notosp>is lacustris, nymph of.

??

j>

>>

V

Melicerta ringens.

The day was very showery, but, in spite of the bad weather, the
party numbered forty-one, of whom seven were members of other
Societies and eight were visitors.

May 1st.

Objects Found on the Excursion to Totteridge, by Messrs.
Dunning, Funston, McIntire, Mainland, Parsons, and
Kousselet.

CRYPTOGAMIA. ALGiE. Pediastrum Boryanum.

Chcetojthora elegans. Raphidivm falcatum (=An-

Goniuui pectorale. kistrodesmus falcatus).

33

Spirogyra communis.
Stigeoclonium elongatum.
Volvox globator.

DeSMIDIACEjE.

Arthrodesmus octocornis.
Closterium acerosum.
„ lunula.
„ moniliferum.
Hyalotheca dissiliens.
Micrasterias rotata.
Staurastrum gracile.
Xanihidium fasciculatum.
PROTOZOA.
Acineta, sp.

A ctinosph cerium Eiclihornii.
Amphileptus fasciola.
Anthophysa vegetans.
Arcella vulgaris.
Cho3tonotus larus.
Coleps hirtus.
Difflugia pyriformis.
Dileptus folium.
Euglena viridis.
Stentor Eiclihornii.
Stentor Mulleri.

„ polymorphic.
Trachelius lamella.

Attendance : Sixteen members
members of other Societies.

Uvella virescens.
Vorticella nebulifera.

„ sp., probably alba.

This and the Acineta were

growing on Daphnia

S chaffer i.

VERMES. Rotifera.

Brachionus pala (=B. am-

phiceros).
Colurus deflexus.
Distemma forficu la .
Floscularia cornuta.
Monura dulcis.
Rotifer macrurus.

,, vulgaris.
Stephanoceros Eiclihornii.
CRUSTACEA. Entomos-

TRACA.

Cypris reptans.

Daphnia Schcefferi.
INSECT A. Coleoptera.

Dytiscus marginalis, larva of
Diptera.

Corethraplumicornis^.nxv& of.
Neuroptera.

Agrion puella.

Ep>hemera vulgata.

of the Qnekett Club and four

May loth.

Objects Found on the Excursion to Wood Street, by
Messrs Kern, Parsons, and Rousselet.

CRYPTOGAMIA. Cyrtostomum leucas.

ALGsE. Desmidiaceje. Enchelys farcimen.

Closterium moniliferum. Ejnstylis anastatica.

Penium Brebisonii. „ flavicans.

PROTOZOA. Litonotus Wrzesniowslci.

Carchesium polypinum. Platycola longicollis.

;u

Sjni'ostomum antbigumn.
Tracheitis ovum.
Uroglena volvox.
VERMES. Rotifera.
Annrcca aculeata.
Brachionvs pala.
Conochilus volvox.
Mastigocerca rattus.

Attendance : Eleven members
members of other Societies.

Melicerta ringens.
Notops hyptopus.
CEcistes pillua.

,, umbella.
Polyarthra platyptera.
Rotifer megaceros.
Stcphanoceros Eichhornii.
Synchccta pectinata.

of the Quckett Club and five

May 29th.

Objects Found on the Excursion to Wiiitstable, by Messrs.
Dunning, Hembry, Priest, and Spencer.

PROTOZOA. FORAMINIFERA.

Miliolina seminu lum.
Polystomella crispa.

„ umbiliculata.

Rotalina beccafii.
PORIFERA.
Grantia ciliata.

„ compressa.
Halichondria panicea.
Hymeniacidon, sp.
Leucosolenia botryoides.
CCELENTERATA. Hydro-

ZOA.

Halecium hcdecinum.
Laomedia geniculates.
Plumularia setacea.
Sertuluria argentea.
pumila.

Tubularia indivisa.
E CHINODERMA TA .

Ophiocoma rosula.

Ophiura texturata.

Solaster papposa.

I/raster, sp.
CRUSTACEA.

Phoxichilidium coccineum.
Male and female.

Phoxichilidium littorale.
MOLLUSCOIDA. Polyzoa.

Bicellaria ciliata.

Bowerbanhia imbricata.

Bugida avicidaria.

Crista eburnea.

Serialaria lendigera.

Valkeria cuscuta.

>>

Attendance : Sixteen members of the Club and eight members
of other Societies.

35

June 5th.

Objects Found on the Excursion to Staines, by Messrs.
Kern, Parsons, asd Rousselet.

CRYPTOGAMIA.
ALGAL. Desmidiace^e.

Closterium didymotocum.
„ moniliferum.
CHAR ACE A.

Chara vulgaris.
PROTOZOA.

Anthophysa vegetans.

Chcetonotos larus (?).

Dendromonas virgaria.

Dinobryon serhdaria.

Epistylis anastatica.

Loxophyllum meleagris.

Ophridium versatile.

Stentor Miilleri.
„ polymorphus.

Trachelocerca olor.

Vaginicola crystallina.
Vorticella campanula.

„ chlorostigma.

,, fasciculata.
VERMES. Rotifera.
Asplanchna Brightwellii.
Dinocharis tetractis.
Euchlanis triquetra.
Floscularia campanulata.

„ ornata.

Hydatina senta.
Mastigocerca bicornis.
Melicerta ring ens.
(Ecistes crystallina.
Polyarthra platyptera.
Synchceta pectinata.
Stephanoceros Eichhornii.

Attendance : Nine members of the Club and three members of
other Societies.

June 19th.

Objects Found on the Excursion to Rye House, by Messrs.

Ransom and Parsons.

CRYPTOGAMIA.
ALGM. . Diatomace^e.
Cocconeis placentula.
Cymatopleura apiculata.
elliptica.
Solea.
Cymbella Helvetica.
Diatoma elongatum.

,, vulgare.
Gomphonema acuminatum,
constrictum.
curvalum.

r>

5)

j>

>J

Melosira rarians.
Nitschia linearis.

„ sigmoidea.
Pleurosigma attenuatum.
Surirella biseriata.
Synedra radians.

,, Ulna.

Tryblionella angustata.
PROTOZOA.

Amphileptus anser.

Astasia limpida.

Ca relies ium ep is ty lides .

36

Cercomonas longicauda.
Cluvtonotus larus (?).
Coleps hirtus.
Epistylis nutans.
Peiidinium, sp.
Stentor Mulleri.

,, polymorphus.
Vorticella chlovostigma.
longifilum.

VERMES. Kotifera.

Floscularia regalis.

QjJcist.es crystalline/,.

Polyarthra platypterd.

Pterodina patina.

Saccidus viridis.
Annelida. Oligochjlta.

sEolosoma quaternarium.

j>

Attendance : Ten members of the Clnb and four members of
other Societies.

July 3rd.

Objects Found on the Excursion to Walton, by Messrs.
Dunning, Kern, Parsons, and Western.

CRYPTOGAMIA. Algjb.

Pediastrum Boryanum.
Desmidiace^e.

Closterium moniliferum.
PROTOZOA.

Anthophysa vegetans.

Carchesium ■polypinum.

Chcetonotus larus.

Dendrosoma radians.

Dileptus folium.

Epistylis anastatica.
Jlavicans.
nutans.

Folliculina elegans (?).

Pliacus longicaudus.

Podocyathus diadema.

Stentor Mulleri.
,, polymorphus.

Stichotricha (?), sp.

Stylonichia mytilus.

Trachelitis ovum.

Vag in ico la ci -ysta 1 1 in a .
VERMES. Rotifera.

55

Brachionus Bakeri.
Ceplialo siphon limnias.
Euchlanis dilatata.
Floscularia campanulata.
,, cornuta.

„ ornata.

Lacinularia socialis.
Limnias ceratophylli.
Mastigocerca carinata.
Melicerta ring ens.
(Ecistes brachiatus.
,, crystallina.
Philodina citrina.
Pterodina patina.
Rotifer megaceros.
„ tardus.
,, vulgaris.
Stephanoceros Eichhornii.
Tardigrada.

Tardigrada, sp.
Annelida.

JEolosoma quaternarium.
Stylaria, sp.

Attendance : Thirteen members of the Club and two members
of other Societies.

37

July 17th.

Objects Found on the Excursion to Godstone, by Messrs.
Dunstall, Kern, and Parsons.

CRYPTOGAMIA.

ALGJE. Desmidiace^e.
Closterium moniliferum.
PHANEROGAMIA.

Anchusa arvensis.

Anthjllis vulneraria.

Atropa belladonna.

Campanula trachelium.

Chelidonium majus.

Chlora perfoliata.
Echium vxdgare.
Epipactis latifolia.
Euphrasia officinalis.
Hypericum hirsutum.
Lathyrus pratensis.
Malva moschata.
Ophrys apifera.
Spirea ulmaria.
Vicia cracca.

Only three members of the
Hackney Society attended, the
departure from town. The after

PROTOZOA.

Bursaria truncatella.

Carchesium polypinum.

Chloropeltis hispidula.

Difflugia proteiformis.

Epistylis anastatica.

Trachelocerca olor.
VERMES. Rotifera.

Brachionus pala.

Notommata aurita.

(Ecistes crystallina.

Philodina citrina.

Plagiognatha hyptopus
(? Notops hyptopus).

Pterodina patina.

Rotifer vulgaris.
M OLL USC0IDE2E. Poly-

ZOA.

Alcyonella fungosa.

Club and one member of the
morning being wet up to time of
noon was very fine.

September 4th.

Objects Found on the Excursion to Richmond, by Messrs.
Hardy, Kern, Parsons, and Western.

CRYPTOGAMIA.

ALG2E. Desmidiaceje.

Closterium cynihia.

didymotocum.

Kutzingii.

lineatum.

lunula.

moniliferum.

setacium.

V

Docidium baculum.
PROTOZOA.
Actinophrys sol.
Anthophysa vegetans.
Chostonotus larus.
Codosiga botrytis.
Difflugia proteiformis.
Dinobryon sertularia.
Euglena oxyurus.

38

Holophyra ovum.
Litonotus fasciola.
Stentor M tiller i.
Stichotricha secunda.
Trichodina pediculus,

hydra.
Vvella virescens.
Vaginicola crystalline
VERMES. Rotifera.
Cephalosiphon liiunias.
Dinocharis pocillum.
„ tetractis.

Floscularia campanulata.
• cornuta.
ornata.
Furcularia cequalis.
longiseta.

on

»

55

>5

))

11

Mastigocerca bicornis.
Melicerta conifera.

„ rig ens.

Microcodon clavus.
Noteus quadricornis.
(Ecistes crystallina.
,, longicornis.

Attendance : Six members of
other Societies.

Plagiognatha hyptopus
(? Notops hyptopus).

Polyarthra platyptera.

Pterodina patina.

llattulus tigris.

Rotifer megaceros.
tardus,
vulgaris.

Sacculus viridis, with two
eggs attached below.

Scaridium longicaudum.

Stephanoceros Eichhornii.

Syncho?ta tremula.

Taphrocampa selenura, swim-
ming with auricles ex-
panded.
CR VST A CEA. Entomos-

TRACA.

Sida Crystallina.
MOLL VSCOIDEM. Poly-

ZOA.

Alcyonella fungosa.
Plwnatella repens.

the Club and five members of

September 18th.

Objects Found on the Excursion to Hayes, by Messrs.
Etps, Kern, Parsons, and Spencer.

CRYPTOGAMIA. Alg2e.

Euastrum oblongum.

Batrachospermuni monili-

Micrasterias denticidata .

forme.

„ rotata.

Cha'tophora tuberculosa.

Penium digitus.

Desmidiacej:.

Tetmemorus granulatus.

Closterium acerosum.

Xanthidium armatum.

„ Diana;.

DlATOMACEJ!.

„ lunula.

Cocconema lanceolatum.

„ setaceum.

Diatoma vulgare.

39

Gomphonema acuminatum.

Hyalosira rectangulata..

Pinnularia nobilis.

Surirella bifrons.
PHANEROGAMIA.

Calluna vulgaris.

Drosera rotundifolia .

Hydrocotyle vulgaris.

Hypericum E lodes.

Hypericum quadra ngulum.
„ humifusum.

Narthecium ossifraga.

Reseda lutea.

&c, &c.
PROTOZOA.

Actinosphcerium Eichhornii.

Bursaria truncateUa.

Carchesium poly pin urn.

Attendance : Nine members of
other Societies.

Difflugia proteiformis .

Dinobryon sertularia.

Epistylis anastatica.

Litonotus fasciola.

Stylonichia mytilus.
VERMES. Rotifera.

Euchlanis iriquetra.

Floscularia ornata.

Monocerca rattus.

Noteus quadricornis.

Notommata Na'ias.

Rotifer megaceros.
,, tardus.

Salpina redunca.

Taphrocampa annulosa.

Triarthra longiseta.
Tardigrada.

Macrobiotus Iluftla ndii.

the Club and eight members of

October 2nd.

Objects Found on the Excursion to Chingford, by Messrs.
Epps, Le Pelly, Parsons, and Rousselet.

CRYPTOGAMIA. Alg,e.

Chcetophora elegans.

Scenedesmus quadricauda.
Desmidiace^.

Closterium setaceum.

Micrasterias rotata.

Penium closterioides.
PROTOZOA.

Acineto?, various forms.

Actinophrys sol.

Anthophysa vegetans.

Carchesium polypinum.

Chostonotus larus.

Coleps hirtus.

Epistylis plicatilis.

Euglena acus.

„ viridis.
Glenodinium tabulatum.
Loxophyllum meleagris.
Paramecium aurelia.
Platycola longicollis.
Podophrya fixa.

,, quadripartita.

Spirostoma ambiguum.
Stentor polymorphous.
Stichotricha (?), sp.
Stylonichia pustulata.
Trichodina pediculus.
Vaginicola crystallina.
Vorticella nebulifera.

40

ZoothamniUTtl arbuscula.
VERMES. Kotifera.

Anurcea aculeata.
Cephalosiphon limnias.
Colurus dejlexus.
Diglena lacnstris (?).
DinocJiaris tetractis.
Diplois Daviesice (?).
Distemma forficula.
Floscularia campanulata.

cornuta.

ornata.
Limnias ceratophylli.
Mastigocerca carinata.
Melicerta ringens.
Metopidia rhomboides.
Polyarthra platyptera.

?>

»>

Rotifer megaceros.
„ vulgaris.

Sacculus viridis.

Scaridium longicaudum.

Synchata pectinata.

Triarthra longiseta.
ARACHNID A.

Chelifer, sp.
MOLLTJSCOIDEJfi. Poly-

ZOA.

Fredericella sultana.

Lophopus crystallinus.
MYRIOPODA.

Polyxenes lagurus.
IN SECT A. Diptera.

Coreihra plumicornis, larva
of.

Attendance : Nineteen members of the Club and six members
of other Societies.

Fredk. A. Parsons,
Hon. Sec. Excursions Sub-Corn.

41

On the Finer Structure of Certain Diatoms.

Part II.

By E. M. Nelson and G. C Karop.

Plate IV.

(Taken as read January 28th, 1SS7.J

Since our last paper on this subject (read March 26th, 1S86) an
achromatic oil immersion condenser has been made by Mr. T. Powell,
Mr. Nelson having, in 1882, suggested to him the necessity for
achromatising the then chromatic oil condenser. This has enabled
us to illuminate objectives by solid axial cones of larger angle
than before ; the spherical aberration of a chromatic condenser
being so great that only the rays passing through the centre or
thronsrh a narrow zone of the condenser could be focussed on the
object at one time. The result has been a marked increase in
resolution. In illustration of this increased resolution we would
refer you to Fig. 6, which is a drawing of an areolation of the same
valve of Tsthmia nervosa, which we figured in our former paper
(Plate 17, Fig. 2. Series II, Vol. ii). The straight bars of silex
by which the central delicate perforated membrane was shown to
be attached to the margin of the areolation now have a trabecular
appearance ; the delicate membrane extends to the edge of the
large areolation, and has perforations more difficult to resolve
than those in the centre. We wish to point out that this is not a
correction of misinterpretation of optical images, but a clear case of
increased resolution, due to an improvement in optical appliances.
Even now we do not wish to lay any claim to finality, but to show
that every advance in perfecting instrumental appliances is at-
tended by an increased gain in our knowledge of structure. In
addition to the new condenser, we have used Professor Abbe's new
compensating eye-pieces, which give sharper images than those of
the Huyghenian construction. Before proceeding further we wish
to record our great obligation to Mr. G. Sturt for the very kind
Way in which he has placed his magnificent collection of diatoms at

42 E. M. NELSON AND G. E. KAROr

our disposal, and for his assistance in naming the specimens. We
are indebted to him for the specimens figured 1, 2, 5, 7, 8, 9.

1. Coscinodiscus centralis exhibits a very beautiful structure.
The bars of the so-called hexagonal, or coarse structure, which are
more delicate than usual, are seen lying over the finer perforated
membrane. In some instances a bar of the coarse structure
bridges over a perforation in the lower structure. Average
diameter of coarse areolation '0000957 inch.

2. Bacteriastrum varians, showing fine, thorn-like points
arranged spirally round the ray. The length of the thorn is
TooV'oo i ncn > assuming it to be one-tenth of the diameter of the
ray.

3. Euphyllodium spatlmlatum. The coarse areolations are filled
up with a structure of very unusual form, some of the minuter
perforations reminding one of telescopic glimpse-objects. Diameter
of coarse areolation, '0000904 inch.

4. Arachnoid iscus Ehrenbergii, showing points projecting into
the areolation from its edge ; some varieties of this diatom have a
more elaborate pattern. Diameter of areolation, *000117 inch.

5. Stalk of Kittonia elaborata, exhibiting a delicate perforated
membrane, covering the bell-shaped end of the pipe. This curious
appendage resembles in miniature the rose of a watering-pot.
Major axis, '00135 inch. The tube-like processes or feet at the
angles of the triceratia have minutely perforated caps to them.
Those on Triceratium fimbriatum are not so easy to resolve.

6. Isthmia nervosa, described above. Major axis, '000274 inch.
There is a very minutely perforated membrane in the smaller
areolations on the hoop of this diatom — a test.

7. Fragment from Briinn deposit. A very beautiful but un-
usual pattern, which we have named the fiddle-pattern, on
account of its resemblance to the / marks on a fiddle. Major
axis, -000202 inch.

8. Fragment from Briinn. Major axis, '000283 inch.

9. Aulacodiscus Slurtii, showing a secondary pattern outside the
primary. In all the examples we have hitherto brought before
you the secondary structure has been inside the primary. This
diatom, however, in common with several of the Aulacodisci, has
its secondary pattern exterior to its primary. Diameter of
primary structure, '0000478 inch.

10. Asterolampra vulgaris. The well-known fine lacework of

Jcvurri. Q. M. C.

B 1.

'/-^*m^>-

Fi g. 4.

;

j *

rr\ f

Fief. . 7.

%£$

m

F i g 9.

1

9

Ser. n.Vol.3. PI. IV.

Fig 2.

•

■

Fig. 5.

Fig. 3.

!-> ^

Fig. 10.

Fig 6.

*Av-w

:■

< *

Fi g. 8.

f

/

F i g 11.

• • •

* ■

• - • • •

• • •

• •• #

• • •

? * * ■

• « •

• ••

• ••

'ria-rop. del

West, Newman &, Co lith.

ON THE FINER STRUCTURE OF CERTAIN DIATOMS. 43

this beautiful form has a still more minute tracery inside each
areolation. How truly marvellous this is when we consider
that the coarse areolation only measures '0000727 inch in
diameter.

11. Aulacodiscus Kittonii. Eight rays. Peru. This diatom
does not resemble the A. Sturtii in the peculiarity mentioned
above, but follows the usual type of diatoms in having its
secondary pattern inside the primary. Delicate structure will also
be noticed between the coarse areolations ; this specimen, there-
fore, is a sort of compromise between the peculiar Aulacodiscus
structure and the usual type. It is very delicate, but not so small
as No. 10, the large areolation measuring "0000798 inch.

The objective used for the work in this and our former paper
was an achromatic oil immersion, T \, 1. 43, N.A., by Powell. The
magnification generally adhered to was 1200 diameters.

44

THE PRESIDENT'S ADDRESS.

Delivered at the Annual General Meeting, 25th February,

1887.

By A. D. Michael, F.L.S., F.R.M.S., &c.

It may be objected that the subject which I have chosen for my
address to-night is not microscopical ; this is to a certain extent
true, but the great use of the microscope is to investigate nature ;
for, although it is possible for man to manufacture articles so fine
in their structure and markings that the very highest powers of our
favourite instrument are required for their examination, yet the
vast majority of his works are so coarse that the assistance of any
considerable amplification is quite unnecessary. It is practically
for nature alone that the microscope is used, and I do not think
that I am going too far if I say that it is applied twenty times
upon biological objects for once that it is employed on all others
taken together ; therefore, no subject which is of deep and general
interest to biologists can be inappropriate for discussion at a
gathering of workers with the microscope such as the present. It
may also be objected that the subject is old ; so are most other
subjects ; what there may be new above the sun we are not told,
but we are credibly informed that there is not anything new under
it; and novelty is scarcely expected in a President's address, it is
usually a review of something that has been done, either of the
work of the year in the particular branch or of something else :
new discoveries are probably more fitly reserved for papers, where
others who are not members of the particular society are more
likely to look for them. But again it may be said, and justly said,
that this question is not only old, but that it has been discussed
and treated of so fully and exhaustively by the very ablest men
that science possesses, both in this and in every other civilized
country, and even in every nook and corner of each country, that
it is utterly hopeless to bring forward any new facts of importance
without fresh discoveries ; or even to put the old facts, or any of

THE PRESIDENT'S ADDRESS. 45

them, in any light which has not been turned upon them over and
over again ; and that it is even presumptuous in a mere amateur
naturalist to dream that he has any chance of doing so : I for one
am not under any such delusion. I am fully aware that everything
I have to say has been said before, and many times before, by those
who could say it far better than I can ; but it has not been said
ad nauseam, for that implies that everyone is weary of it, whereas
it is the characteristic of this particular subject that it does not pall
upon its hearers, and that it still has about it that wonderful
attraction which draws men to it as a candle draws the moths : I
feel that attraction so strongly that I am not inclined to resist it,
but I will rather rely on the existence of a like feeling in my
hearers to make my very stale remarks of interest to them.

You will doubtless before now have concluded that there is only
one subject upon which I can possibly speak as I have done,
namely that upon which the literature has become so voluminous
that in the catalogue of zoological books for sale published by
Messrs. Pietzcker, of Trubigen, after the ordinary headings of
11 Insecta" " Crustacea" " Vertebrata^ &c, will be found a special
division headed " Darwinismus." Now it seems to me that,
although I have not anything new to say, we may spend half an
hour not disagreeably, nor unprofitably, in reviving our recollec-
tions of what has already been said, and of a few of the interesting
facts and features with which the whole subject literally bristles.
Nor is the present an undesirable time for doing so. It is the
general history of important and far-reaching new ideas that they
are at first received with surprise and something like amusement ;
then with bitter hostility, in spite of which they gradually win
their way, if they be sound ; then comes a period of fair considera-
tion, when what is good in them becomes more generally acknow-
ledged, and their cause is won. After this there arises a danger of
a totally different class ; the friends and disciples, through whose
exertions the triumph has been obtained, have in the hour of
struggle acquired an enthusiasm which is not easily satisfied ;
others join them, and the original theory is often pushed far beyond
what its originator ever intended. The idea is all- engrossing,
everything must bend to it, or be explained by it ; and it is apt to
be pushed far beyond its legitimate conclusions. Then, in the
minds of many thinking men, comes a revulsion of feeling. Unable
to follow the exponents of the new idea in their extreme deductions,

46 the president's address.

they arc apt to lose sight of the dividing-line between the original
foundation and the superstructure which later and more enthu-
siastic builders have erected upon it, and to condemn both together;
thus the thoroughly sound original proposition is often endangered
by the eagerness of its advocates. It seems to me that this is
rather the position of the Darwinian theory to-day ; its able
supporters have carried it very far indeed, carried it into many
things which were not originally contemplated, and which, although
they are none the worse for being beyond the original conception,
are certainly different, and may or may not be true. There are,
amongst many others, two main lines in which this may be, and is,
done. Firstly, it is strenuously asserted, by biologists whose
names are sufficient to ensure respect for all they say, that every
consistent evolutionist must admit that the process did not com-
mence at the lowest form of life, but that the springing of life
itself must be accounted for in the same manner. Now, at this
point I am compelled to part company with the evolutionists. I
cannot think that science requires us to believe that of which there
is not any evidence whatever, and the reasons for which must, it
seems to me, be purely speculative and deductive. I fail to see one
iota of evidence of any change of non-living matter into living
matter, except through the agency of life ; and it is, I think,
generally admitted that Dr. Bastian's long and able researches have
not supplied the want. I am not aware that any progress whatever
has been made towards obtaining such evidence, for I cannot
regard the facts of crystallization as in any way analogous to those
of life ; and, until such evidence be supplied, I should prefer to
adopt the Scotch verdict of " not proven." It may be true, or it
may not ; it appears to me that we simply do not know anything
about it. I am fully aware that this is a confession of ignorance,
and of the entire impotence of present science, with regard to the
greatest of all natural questions ; but surely this is not a reason
for putting forward an explanation which cannot be justified by
any proof whatever. It is not the only great problem of nature
which we cannot solve ; indeed, I am not sure that we are not in
the same position as to all the greatest. Who will give us any
sound or reliable information as to what life is, or what is
that subtle something that departs when an animal dies? (Of
course, in accordance with the • rules of this Society, I am
leaving the religious side of this and all other questions

THE PRESIDENT'S ADDRESS. 47

entirely undiscussed and untouched.) Who will give us any
tangible ideas as to the commencement or end of time, or enable
us to conceive either that space is infinite, or that there is a limit
to it ? Bailey, in his poem of Festus, has a passage, " all points
are central to the infinite," that is demonstrably true, but which of
us can really picture to his mind that to which all points are cen-
tral? On the other hand, a limit is beyond our conception. When
our fathers were boys a question was asked of them which is as
difficult to answer to-day as it was then — If you stood on the edge
of space could you stretch out your hand, or could you not ; if you
could where would you stretch it to ; if you could not what would
stop you ? It is, therefore, not any slur upon biological science
that it cannot explain the origin of life, and it cannot surely be
desirable to strain evolution in order to do so until we have some
evidence on the point.

The second path along which Mr. Darwin's followers may be
tempted too far is in the endeavour to explain every biological fact
by survival of the fittest or sexual selection. It may be that there
is such an explanation, but that we cannot discover it. The web
is often difficult to unravel, yet almost every naturalist who
observes a new fact feels not only that there must be some such ex-
planation but also that it is incumbent upon him in particular to
find it out, and there is a feeling of disappointment if he cannot
frame a theory satisfactory to his own mind. We all of us feel
this, and I confess that I, amongst others, naturally think when I
observe something which I had not previously noticed, " Now how
can I explain this ? " but the feeling certainly has a tendency to
produce far-fetched explanations when simpler ones are not easily
found. I will give two or three instances of what I mean, and I
must expressly premise that I do not in any way assert that these
explanations are wrong ; they may all be perfectly correct, but I
quote them simply to show how incumbent men feel it upon them
to give explanations of this nature of obscure phenomena. The
first example I will purposely take from a work of the highest
authority, in which we must all admire both the great ability and
patient study. In Weismann's " Studies on the Theory of
Descent," he gives an explanation of two spots, one on each side
of the third segment of the larva of one of the foreign Sphingidce
(Deilephelct) ; these he calls eye-spots ; they are large brown
spots, surrounded by light and dark rings. When touched, this
Journ. Q. M. C, Series II., No. 18. 5

48 the president's address.

caterpillar does not raise the fore part of its body in the mode
common amongst the larva? of Sphingiclce, but withdraws the first
and second segment within the third, which becomes distended ; and
remains motionless. Weismann considers that this is to terrify an
assailant, and thinks that the third segment would look like an
enormous head with great glaring eyes, and would have a very
alarming effect : he tried putting the larva in a saucer in his
garden ; but the sparrows, after an inspection, thought discretion
the better part of valour and beat a retreat. Weismann suggests
that these eye-spots have been formed by survival of the fittest
out of the smaller ring-spots. It strikes one that when these eye-
spots were rudimentary at their first commencement they cannot
have had a very alarming effect ; also that the theory scarcely
explains the similar spots which sometimes exist on the posterior
segments, and that eye-spots are very like ring- spots which often
exist on nearly all the segments ; and that the withdrawal of the
anterior segments into the more posterior ones is common with
other caterpillars which have no eye-spots, and other arthropods
when alarmed, and may well serve for the protection of the head ;
also that lying still has a family-likeness to shamming-dead. It
must be admitted, however, that the ordinary rearing position of
Sphinx larva? when alarmed is probably a threatening attitude.
Weismann does not say whether he tried if sparrows would eat
other equally large larva?. The other two instances I will take
from papers recently read before our own Scientific Societies. A
zoologist lately submitted to the Zoological Society that the comb
of the cock, and other male gallinaceous birds, was beneficial to the
species because the males were in excess of the females ; and in the
conflicts of the males the comb was a very attackable part, and
enabled them to kill each other more frequently than they would
do were it absent. We might at first think that the apparent
scarcity of the female is due to its more sombre colour, more stay-
at-home habits, and to such remarkable provisions for concealment
in the females of ground-nesting birds as the loss of scent at the
time of incubation, which causes a pointer to pass close by a sitting
pheasant without discovering it ; but Indian ornithologists agree
that the disproportion in the number of males to females is greater
than these causes will account for; while poultry-keepers usually
prefer having three hens to one cock ; but it seems difficult to see
how the comb-theory can operate, as, according to it, the cock with

THE PRESIDENT'S ADDRESS. 49

a large comb would have least, not most, chance of having descen-
dants ; and, again, if the preponderance of males be hurtful why-
has not it or the species died out? The last instance was sub-
mitted, very doubtfully and tentatively, to the Linnean Society.
A botanist, introducing a new fungus which had " a pleasant meaty
smell," suggested that there was some reason to suppose that some
agarics only germinated after passing through the alimentary
canal of animals, and that possibly this smell induced beasts to eat
it, which may be true, but at the first blush it scarcely seems
apparent why a lion should eat fungi, or why a deer or an ox
should be attracted by a meaty smell. At any rate it appears to
me that at present these extreme advancements of the Darwinian
theory have produced a distinct tendency to recoil from it in the
minds of many excellent biologists.

I have purposely used the popular expression " Darwinian
theory," because in the minds of those who are not naturalists it
usually includes two things. If we speak to our non-scientific
friends we shall probably find that most of them by " Darwinian
theory " mean something which Darwin never claimed and never
could have claimed, something the idea of which had arisen in
men's minds long before Darwin, namely evolution; it is really
that, and not Darwin's " survival of the fittest," that is popularly
objected to. I need scarcely point out to you that they are totally
different things. If a man who had not ever seen a watch or a
steam engine suddenly found one in action he would probably con-
clude, without much difficulty, that it had been manufactured by
man, that it had not grown on a tree, or been formed by crystalliza-
tion, but when he came to form a theory as to the precise mode of
manufacture he would probably be very far out. In the same way
it is quite conceivable that evolution might be correct, but that the
beautiful explanation of the mode by which it has been attained,
which we owe to Darwin and Wallace, might be erroneous : but the
converse will not hold good ; if evolution were a myth the explana-
tion would fail of itself. Therefore in considering the Darwinian
theory we must necessarily consider evolution first ; but it may
fairly be said that it is unnecessary to do this, because probably no
biologist of importance now denies the truth of evolution, the sur-
viving objection being confined to those who have not paid any
attention to the subject, but who think that it is somehow degrad-
ing to them to be cousin to a monkey, no matter how many times

50 THE PRESIDENT'S ADDRESS.

removed. This would be a perfectly good reason if I were
addressing a more deeply-learned Society, but ours is one where
we need not be ashamed of amusing ourselves by talking over
some of the interesting developments of life, even if they be gene-
rally admitted.

It seems to me that the one great fact which proves evolution,
and which cannot reasonably be explained in any other way, is the
almost universal tendency of different forms of life to run into
series, both as to species and genera and as to the adaptation of
homologous organs. It is this only which enables us to classify
fauna and flora as we do. Take almost any order of plants or
animals, it matters not what, and we find a great number of more
or less similar forms, similar not merely in the great facts of their
structure, but in all sorts of even trifling points ; these points being
more developed in one species than in another, sometimes almost
rudimentary, but almost always present in some degree. Take
up the table for identification of species in almost any monograph,
and it will strike you at once how the ingenuity of the author has
been taxed to find tangible distinctions between closely-allied
species, and how he is enabled to work down from the general to
the particular by most of the species usually having many, even
trifling, characters in common. The Diptera are excellent ex-
amples ; take up Walker's Diptera and see what occurs even
with the British species : try to identify a gnat which you do not
know ; you will find a long series of species so similar that the
table for identification is appalling. Again, why should the
possession of a bi-lobed tongue furnished with pseudo-trachea be so
much correlated with two effective wings and two poisers, there
are plenty of other forms of sucking mouth ? Why should almost
all Sphinx larvae have a curved spine in the middle of the last
segment of the body ? Why should the number of spines on
the respective segments of the larva of all the species of
Vanessa butterflies be almost constant ? Why should the trachese
be developed into leaf-like organs, the so-called lungs, in all
scorpions and so many spiders and not in anything else ? Why
should two parallel blade-like ridges (the lamella?) run along the
cephalo-thorax of about half the Oribatidce, each ridge bearing a
hair at its end ? Why should a trace of the ridge be found in
almost all the other species, and why should the hair sometimes
persist in the instances where the ridge cannot be detected ?

THE PRESIDENT'S ADDRESS. 51

Why should there be a long tactile hair on the front tibia of almost
all blind A cart ; it is an excellent place for it, but there are other
good places also, and the hair often occurs on the other tibia which
are not such good places ? How can such facts as these, and the
thousands upon thousands of similar instances, be explained except
by community of descent ? An excellent example was pointed out
by Professor Flower in his Hunterian lecture on the subject, viz.,
the reduction in size of the second and third digits in all Australian
Marsupials notwithstanding their widely different habits ; it can
hardly be supposed that the shortening of these two fingers has
arisen separately in all the species. Then, again, the diverse adapta-
tions of the same morphological part tell the same story. The oft-
quoted adaptation of the fore limbs of Vertebrates, is an admirable
example — the leg of a horse, the arm of a man, the wing of a bird,
the anterior support of the wing of a bat, and the fin of a fish being
different forms of the same part, in one case one portion, in an-
other case a different one, being largely developed to meet the wants
of the creature ; but almost any other part maybe taken, although
perhaps the result may not be quite so striking. For instance, the
mouths of insects, the same parts exist in almost all : the mandibles,
the maxillae, the mentum and lingua, the labial, and maxillary
palpi being present in almost all , but often so profoundly modified
that it is difficult at first to recognize that they really are the same
parts, so wonderful are the adaptations to the requirements of the
insect. What plausible explanation except community of descent
can be given for this ? If it did not arise from this cause why
should not the sucking mouth of a butterfly or a gnat be formed
of totally different parts from those in the mouth of a wood-eating
beetle ? Nature does not always utilize the same part for attaining
even a similar purpose in allied creatures ; thus, for instance, in
insects and Acari parasitic on hairy creatures, the apparatus for
holding the hair varies greatly ; in the Pediculus capitis of man the
front leg is furnished with a great falx doubling back like the
blade of a clasp-knife. In the Dispai-ipes and the Trichodactalus of
the humble-bee the same leg has an immense hooked claw, and in
the Myobia of the mouse a strange curved lamina folding round a
chitinous peg, and holding the hair between the two ; but, on the
other hand, in the closely allied Listroplwrus of the mouse it is not
the claw, but the greatly-enlarged maxillary lip, which becomes a
flexible chitinous organ, to wrap round and hold the hair ; and in

52 the president's address.

the Hypopial Nymph of the Dermacarus of the squirrel, and of the
closely-allied form found on the mole, chitinous labia for the same
purpose are developed round a concave furrow at the extreme
hinder-end of the ventral surface.

After this most important of all arguments on the subject I may
refer to other points which, if they have not the far-extended
range, are possibly more striking to many minds ; such a feature is
the existence of rudimentary organs in some species or forms which
are useless and functionless in them, but are effective in allied
creatures. Thus the eyes of Spalax and Chrysochloris among
Mammals, and of Myxine amongst fishes, are hidden beneath the
skin and incapable of receiving luminous impressions, and in the
young of Petromyzon they are actually covered by muscles. Again,
the whales have a rudimentary pelvis and hind limbs hidden
beneath the skin, and among snakes the boa-constrictor has rudi-
mentary hind limbs quite unserviceable. In snakes generally one
lobe of the lungs is rudimentary. In Apteryx the minute wing is
hidden by the long hair-like body feathers. The Chalcididce and
allied families are very interesting in this respect, as even in the
British species we may find almost every stage, from the possession
of four powerful wings hooked together in pairs, as in most other
Hymenoptera, to an entirely apterous creature. In some all four
wings are reduced in size, and this is found in endless grades in
different species. In Mymar the hind-wing is abortive except the
costal nervure, which is shortened, but persists and is attached to
the slender fore-wing by a single hook, forming a supporting piece ;
while in other forms only the nervure exists in all four wings ; and
lastly we find forms where even this is absent. Again, the repro-
ductive organs are instructive. It is difficult, except by descent, to
accouut for the functionless mammae of the male in man, or for
the so-called uterus masculinus, really the homologue of the
Mullerian ducts (or oviducts), of the female ; while, on the other
hand, in rodents, moles, and lemurs, the clitoris is actually per-
forated by the urethra, a singular confirmation of the received view
as to the morphology of this organ. Probably, however, one of
the best instances is the late discovery of a third central eye, use-
less and hidden beneath the skin, in some lizards ; and the connec-
tion of this eye with the so-called pineal gland found in mammals
and even in man himself, which is a small projection of the brain
the use or origin of which has puzzled anatomists to no small

THE PRESIDENT'S ADDRESS. 53

extent. It is a highly interesting fact that rudimentary organs
are almost always larger in the embryo than in the adult. This
brings me to another great argument in favour of evolution, viz.,
the disclosures of embryology, which have led to the enunciation
by Fritz Muller and Ha3ckel of the law that " the ontogeny com-
prises the phylogeny," or in more ordinary language, that the
development of an individual is a sort of record of the development
of the species to which it belongs. This explains numerous cases
which are incomprehensible, except on the supposition of a common
descent, and appeals strongly to the mind. It has always seemed
to me that the most remarkable instance is the well-known one, that
the Xudibranch Mollusca, which have not any shell when adult, yet
possess a well-developed shell like a periwinkle when in their
embryo condition, although they are then within a membrane and
the shell is useless to them. There are, however, hundreds of
other instances. Thus the embryo grubs of Muscidce (Dipterd)
possess a head with antennas and jaws, although these organs
are absent in the hatched larvae. In the embryo larvae of Sphinx
there are ten pairs of abdominal legs, five pairs of which disappear
before hatching. The grubs of bees in the embryo condition have
a head like other Ht/menoptera, and three pairs of legs, but they
similarly disappear. The larva of C/uerocampa porcellus is remark-
able among those of Sphingidte for the absence of the dorsal horn,
but it exists in the very young specimens, but does not grow or
persist. The Acaruut are specially distinguished by the unseg-
mented abdomen, but it is segmented in many of the young larvaa.
The young of the tapir and wild-hog are striped, while the adults
are plain (other allied forms being striped), and the whelps of the
lion and the puma are often more or less striped like so many other
cats. The whale-bone whale has teeth in the fcetal, but not in the
adult condition, and the teeth in the front part of the jaw of the
calf and some other ruminating quadrupeds never cut the gum.
The young blackbird is spotted something like the thrush ; so are
the young of the common (white) gull. The tadpole of the common
salamander has gills, and lives in water ; Salamandra atra lives
high up in the mountains, and brings forth its young fully-formed.
This animal never lives in water in any stage, but if a gravid
female be opened tadpoles with beautifully feathered gills will be
found, which can swim when placed in water ; and there are hun-
dreds of other cases. I will just mention the singular life-history

54 the president's address.

given by Fabre of the larvae of the Sitaris beetle, which he says is
first hatched in the nests of some bees as a minute, active creature
with six legs, long antennas, and four eyes. The male bees emerge
before the females, and the Sitaris larvae jump on to them, crawl
on to the female while pairing, and when that sex deposits its eggs
on the honey the larvae spring on the eggs, devour them, then the
larvae undergo a change, the eyes disappear, the legs and antennae
become rudimentary, they feed on honey, and resemble other beetle
larvae.

It must not, however, possibly be supposed that the development
of the individual is an exact record of that of the species. Weis-
mann is of opinion that if a character is strongly beneficial to the
adult, it has a tendency to be developed earlier in the life-history
as time goes on, and it is difficult to believe that changes which
profoundly affect the adult do not to some extent affect the embry-
onic and immature stages.

Evolution has to consider not only the physical, but also the
mental qualities, and this raises the vexed question of instinct and
reason ; what is the difference if they be different ? We must first
reject mere reflex action, such as laughter when a person is tickled.
Eomanes gives the following definitions : — " Reflex action is non-
mental neuro-muscular adjustment due to the inherited mechanism
of the nervous system, which is formed to respond to particular,
and often recurring stimuli by giving rise to particular movements
of an adaptive, though not of an intentional kind. Instinct is
reflex action into which there is imported an element of conscious-
ness. The term comprises all those faculties of mind which are
concerned in conscious and adaptive action antecedent to individual
experience, without necessary knowledge of the relation between
means employed and ends attained, but similarly performed under
similar and frequently recurring circumstances by all individuals of
the same species. Reason is concerned in the intentional adapta-
tion of means to ends, and may be exercised in adaptation to
circumstances novel alike to the experience of the individual and
that of the species." I should be inclined to put it in homely
language that instinct is the quality which prompts creatures to
perform actions consciously, but without experience, learning, or
thought, so that they perform them without teaching or conside-
ration; and that reason is that which enables them to learn, either
from their own experience or teaching, or to exercise thought

THE PRESIDENT'S ADDRESS. 55

either in adapting means to ends or otherwise. But if we adopt
any such definition is it possible for an unprejudiced observer to
keep a pet dog or cat without seeing by its everyday actions that
it reasons, that it learns by experience how to get what it wants,
and even its owner's habits ; and that it can be taught, sometimes
more, sometimes less, but always something. Putting aside all
wonderful stories it is the constant little ways, generally charac-
teristic of the individual, which impress me most. When I was a
boy I had a Skye terrier, which slept in the kitchen but as soon
as the servants opened the door ran upstairs and jumped on to my
bed. Two bells were rung — one when it was time to get up, the
other for breakfast : at the first the dog never stirred, although I
got up, but at the second the dog instantly jumped off the bed
and left me no peace until I let it out to go down to breakfast.
This surely was not inherited instinct. Space will not allow me
to multiply instances. It may be said that these are animals
altered by generations of association with man ; this only
amounts to saying that they have learnt, which seems to me to be
the essence of the whole thing ; but let us look at wild crea-
tures even low in the scale. Oysters taken from deep water, if
left dry, soon open their shells, lose the water within, and perish ;
but if placed in shallow tanks and occasionally left uncovered by
water for a short time they learn to keep their shells shut, and
live longer. This is turned to great practical account, the oysters
brought to the Paris market from long distances being thus edu-
cated in oyster schools. The razor shells dislike salt ; if it be
sprinkled above their burrows- they come to the surface and quit
them, but if once seized when they do so, and allowed to escape, no
amount of salt will bring them to the surface again (Bingley).
Sir John Lubbock found that both ants and bees could be taught
their way to honey, &c, by repeated journeys, but that if it were
complicated they most of them lost their way the first few jour-
neys, but afterwards went correctly and with apparent confidence.
Forel found that young ants do not know enemies (strange ants),
but that as they grow up they immediately attack an intruder. Lub-
bock found that bees know the hive by its position, and fly to the
place where it had stood if it be removed in their absence. The
mason-bee, according to Blanchard, does not make a nest of its own
if it can possess itself of one belonging to a neighbour, it some-
times even utilizes an empty snail-shell. A wasp, if it finds a piece

56 the president's address.

of paper, often uses it instead of making the paper for itself out of
wood. Mr. S. S. Saunders took the nest of a trap-door spider
with the occupant at home and placed it upside-down in a flower-
pot. In ten days the spider had made a new door at what was
formerly the bottom, but was now the top. Gulls and crows carry
shell-fish to a height and drop them upon rocks to crack them.
The house-martin has manifestly changed its habits, and the
American house-swallow has effected this change within the last
three hundred years. Mr. L. H. Morgan found that the beaver
widens the openings in its dam when there is a flood and narrows
them in drought. The elephant has been seen to blow an object
which is on the ground beyond its reach against the opposite wall
that the rebound may bring it nearer. I think that the Zoological
Gardens is an excellent place to consider this subject, because the
creatures there are wild animals which have had to adapt them-
selves to altered circumstances ; they are not accustomed in nature
to look on man as an organism instituted for the purpose of pro-
viding them with buns and sugar, but the most cursory observer will
soon see how thoroughly most of them have learnt the lesson. One
day I gave a large piece of biscuit to a Falkland Island goose ; it
tried to get it down, turning it different ways, but could not do
so ; it then took the biscuit in its bill and threw it violently
against the stones several times, but it did not break ; finally it
took the piece in its bill and held it in the water till it was soft,
when it quickly disposed of it. I stuck a large bit of sugar
between the wires of the cage of the hybrid paradoxure, a creature
which has a quaint habit of rolling up its long tail in a flat spiral.
It passed its long claws through the wires so as to clasp outside
the sugar, and had a good pull, but the desired morsel would not
come through ; then it tried its teeth and bit off the piece inside ;
then it licked what remained, and finally retired in disgust, and sat
still at the other end of the cage. I now pushed the sugar
further through with the handle of my umbrella ; the paradoxure
instantly saw the change, jumped at the sugar, and pulled it
through with its claws. You may see these things and many
others with numbers of the creatures any day. There is a little
bear that will walk up the perpendicular bars and turn a circle
upon them for a lump of sugar. There is an old crow that pipes
" The miller's wife." There are the ridiculously human Barbary
apes, and finally there is Sally, the bald chimpanzee, the most

THE PRESIDENT'S ADDRESS. 57

amusing and intelligent beast I ever saw. She will poke a straw
through the keyhole or a small gimlet-hole in the boards when
told. She will put a straw as a flower in the keeper's button-hole,
or brush his coat when told. She will keep pence in a hole and
drop them into the keeper's pocket to pay for beef-tea, which she
will drink with a spoon, returning the spoon through any indicated
division of the network, and numberless other tricks, and she is
constantly acquiring new ones. On the 7th of February last I
was there, and she had her arm out of the cage, with the back of
the hand upward. A solitary fly, which had survived in the warm
house, alighted upon it, which Sally evidently wished to capture.
She fixed her eyes on it and drew in her hand and arm very
slowly and gently, and without moving any other part of her body.
She got it nearly in, but as the hand passed through the wire net-
ting it touched, and the fly was frightened and flew ; instantly, quick
as lightning, Sally darted out the other hand and made a grab at it.
She did not catch it, but could anything be more human or more
evidently reasoned ? The conclusion which I draw from all this is,
that whether instinct and reason be separate things or not, or
whether instinct be only reason grown habitual and inherited, yet
that in either case the nature of the mind of the lower animals is
the same as that of man ; and that it is a question of degree and
not of kind ; man and animals may each have both instinct and
reason. The mind of the lowest savage is probably far above that
of Sally, but it seems to me to be only a higher development of the
same thing.

All this may prove evolution to be true, but it does not prove
that Darwin's is the correct explanation of it ; but survival of the
fittest and sexual selection are so familiar to you, and in some form
or other are so continually before you, that I do not propose to
repeat this theory, nor the numerous facts in support of it, but
rather to utilize the little time remaining to me in considering a
few of the points, and the objections and limits to these laws if
any. And firstly let me call your attention to the fact that
Darwin never asserted that these laws explained everything, and
his principal opponents, such as St. George Mivart, did not deny
that they had some operation ; but whereas Darwin assigned them
the principal place, Mivart allowed them only a small influence.
Darwin in his later writings was rather inclined to limit than to
extend these laws. With regard to the existence of the tendency to

58 the president's address.

vary requisite to support Darwin's theory, we are apt to forget how
great this is. We hardly ever saw two human faces exactly
alike, and the same is doubtless true of animals if observed equally
closely. Everyone knows his own dog, and a skilled shepherd
knows each sheep. The two sides of the body usually vary greatly,
so that a man with the two rms the same length and the two legs
similarly corresponding is very rare, and although we are actually
all artificially taught to write the same way, we all write different
hands. Now what are the main objections ? Firstly, to my mind,
both to evolution and the explanation, stands the sterility of
hybrids. It is extremely difficult to answer this, but we may observe,
firstly, that it is only in the case of the Vertebrata and some plants
that we really know whether they are fertile or not ; as to other
groups, we are ignorant on the subject. Secondly, we are apt to
argue in a circle ; we are inclined to take the fertility or sterility
of hybrids as a test of species, and then to cite our classification to
prove that hybrids between different species are sterile. Moreover
the laws of sterility and the reverse contain many things
we do not understand. The Mexican Axolotl has been proved
to be an immature form of Amblystoma, but it is sexually
fertile in the Axolotl stage, and Amblystoma bred from
Axolotl is almost, but not quite sterile, while other Ambly-
stoma are freely fertile. Then there is reason to suppose that a
hybrid can to some extent fertilize one of the original species,
although the embryo does not usually reach maturity. Another
objection, to the explanation only, is the existence of neuter insects.
It is very difficult to see how these can have been produced by
natural selection, as they cannot ever have reproduced their kind.
This difficulty appears to have been so strongly present to
Darwin's mind that it almost shook his faith in his own theory ;
he succeeded finally in satisfying his own mind, but perhaps he was
not as happy in explaining this to his readers as he was in most
other cases. There is the difficulty why similar forms were not
produced in greater numbers by the same conditions. The oft-quoted
neck of the giraffe is a good example ; there are not more vertebrae
in it than in shorter necks, and Darwin reasonably says that it must
have been an advantage to a creature inhabiting a country liable to
drought to be able to browse on the leaves of trees when grass failed,
and that therefore a long neck must have been an advantage, and
have been liable to be increased ; but it is replied that there were

THE PRESIDENT'S ADDRESS. 59

plenty of other Ungulates in the same place at the same time ; why
did not they acquire long necks also? It may be noted that there
almost seems to be something special in the nature of the giraffe, as
it is the only mammal which has horns when it is born. Another
objection is the imperfection of the geological record, and the
absence of intermediate forms. The answer to this seems to me to
be that the geological record is less imperfect than might reason-
ably have been expected ; and that intermediate forms do exist, or
have existed and left traces, in greater numbers than we had a
right to anticipate. Amphioxus is a celebrated instance. The
wing of the young ostrich is covered by curious scale-like plumes,
and has three phalanges to the principal finger instead of the
two possessed by most other birds, thereby approaching reptiles.
The cerebellum in Aplacentia resembles birds in the dispropor-
tionate development of the median lobe, and this is coexistent
with other important bird-like characters ; as, for instance, the
oviparus reproduction and meroblastic ovum of Echidna and
Ornithorhynchus, their possession of a cloaca and of jaws elongated
to form a beak. The double uterus of the Marsupialia, &c. ;
the fossil OdontormcBj &c, or toothed birds ; and the well-known
Archceopteryx, are intermediate forms, and instances might be
multiplied to a great extent did space permit. Everyone who has
attempted any kind of zoological or botanical classification knows
how he has been puzzled by intermediate forms ; but every fresh
form found is taken as a fresh basis, and forms are asked for
intermediate between that and the nearest known ; so that until
the whole chain is completely found, which is not likely ever to be
the case, there must still be a demand for missing links. Again, it
is said that there is not always that steady progress in the geologi-
cal record from the simple to the complex which might have been ex-
pected ; as, for instance, Scudder found an insect as early as the
Devonian furnished with the stridulating apparatus of male locustidse ;
and the highest form of the Molusca, the Cephalopoda, were more
numerous in later geological periods than they are now. On the
other hand, fishes on the whole increase in complexity from the first
to the last geological period, and this is probably the case with the
average of other groups ; but there does not seem to be any reason
why creatures should not revert to a simpler condition if the sur-
roundings rendered it advantageous to them to do so, without that
fact telling against the survival of the fittest.

60 THE PRESIDENT'S ADDRESS.

A very able article appeared in the " North British Review " for
June, 1867, showing how immense were the chances against the
survival of a variation occurring in one individual only. This article
so impressed Darwin himself that in the later editions of his works,
and in u The Descent of Man," he stated that he had become con-
vinced that for a variation to survive it must arise in several
individuals at one time ; but he thought this not unlikely to
occur. The chances are undoubtedly enormously against the sur-
vival of the variation occurring in one individual only ; but then
probably only one variation out of an enormous number does
survive. And it also seems to me that the variations need not follow
a direct line ; two individuals might vary somewhat in the same
direction, although not similarly. The offspring of these two might
be an intermediate form, and this again pairing with a more extreme
variety might produce again an intermediate variety ; thus there
might be soon a number of specimens all more or less varying in
the same direction, and the ultimate outcrop might be considerably
different from the first direction of variation. This would greatly
diminish the adverse chances, for exterior surroundings might well
cause several to vary in the same place more or less in one direction.
The result of pairing cannot always be foreseen ; if two top-
knotted canaries be paired, the offspring is generally bald, but
undoubtedly a variety arising in several individuals at once in the
same place would be much more likely to survive. Then there is
a difficulty how the small beginnings of organs could be useful.
The before-mentioned eye-spots on Deilephela larvse and the
mammary glands are examples of this, and it is a serious difficulty,
as although many things would be useful in their first stage there
would seem to be plenty of others that would be useless. Again, an
allied difficulty is the occurrence of things the utility of which is not
apparent. Certain butterflies have a band of colour with a row of
white spots on the band ; in some localities the spots at the top of
the row are the larger, in other places those at the bottom are so,
yet the varieties although local are constant. . The specimens of
Lycena agestis found on Arthur's Seat, Edinboro', had a minute
white spot on the upper wing not found on any other specimens;
the variety was called Artaxerxes, but bred freely with the ordinary
type. The specimens of Vanessa antiopa found on the Continent
have a yellow border ; the English specimens have it straw-
coloured. The difference between the females of L. agestis and

THE PRESIDENT'S ADDRESS. 61

L. alexis is chiefly in the position of certain inconspicuous black
spots on the under-wing. The butterfly Anosia 2~>lexipus, which is
spreading over the world with such marvellous rapidity, has two
forms, a northern and a southern ; the difference is only in whether
some small spots on the upper-wing are nearly white or light-brown.
It is the northern form that is spreading. It is difficult to see
how utility can have dictated these things, or the brilliant colours
on the inside of many bivalve shells, or the elegant shapes of many
asexual radiolarians, or the abortion of the index finger in the
Potto (Perodicticus), one of the Lemurs. Possibly the direct action
of external circumstances, as opposed to their indirect action through
natural selection, may have more influence than we are at present
inclined to allow. Coster states that young oysters taken from the
English shores and placed in the Mediterranean at once altered
their style of growth, and developed diverging rays like the Medi-
terranean species. Pony breeds have arisen quite separately in
different parts of the world. Great changes take place in the
plumage of parrots when fed on certain fish. The black shouldered
Javan peacock, Pavo nigripennis is considered quite a separate
species, and yet similar birds were bred suddenly in a flock of the
ordinary peacock in England without any known reason. The
peculiar Porto-santo rabbit reverted in England to the common form
in four years. The white-silk fowl reverted to the ordinary fowl in
England in spite of great care. It cannot, I think, be held to
detract from the value and importance of the theory of natural
selection, if we have to admit that it is not the one only cause of
variation. Amongst other probable causes may be mentioned the
inherited effect of use lately advocated by Mr Herbert Spencer, viz.,
that an organ constantly exercised in a particular manner may be-
come abnormally developed in a particular direction, and that such
development, although to a certain extent artificial, might be
inherited by the offspring. Again there is the "physiological
selection " suggested by Dr. Eomanes, which is that the variation
might occur first in the sexual organs causing partial sterility with
the parent form, while individuals of the variety were perfectly
fertile inter se. This would of course require that the variation
should occur in more than one individual, in which case it might
mark off a race which might afterwards vary in other respects.
May we not probably, as far as our present knowledge goes,
reasonably come to the following conclusions ?

62 the president's address.

1. That evolution is one of the great leading facts of nature and
is fairly well established.

2. That survival of the fittest and sexual selection have probably
been the principal agents in effecting evolution of species.

3. That the direct action of external circumstances has probably
had considerable influence, that the other causes suggested may
have assisted, and that almost pure chance may possibly have had
some trifling influence.

4. That it is not improbable that there are other causes which
we have not yet traced which have contributed to the result.

5. That we have not any reason whatever to suppose that life
has arisen out of non-living matter by evolution.

63

On a Fossil Marine Diatomaceous Deposit from Oamaru,

Otago, New Zealand.

By E. Grove and G. Sturt, P.F.R.M.S.

Part III.
Plates V. and VI.

{Taken as read March 25th, 1S87.)

Trinacria ventricosa, n. sp., Gr. and St. — In this species we
have two dissimilar frustules alternating with each other. The
primary valve, as it may be called, has slightly concave sides
with a clear margin. The centre is moderately inflated with a
small circular umbilicus, usually surrounded by a ring of pear-
shaped cellules, the remainder of the surface being covered
with large, irregularly radiating granules. Processes straight,
elongated, like those of Trin. regina, Heib., to which this
valve bears a general resemblance.

The secondary valve has a large inflated centre, leaving at
each corner a flat triangular space, on which is the indication
only of a nodule. Surface dotted with papillae, presenting at
the margin a rugose appearance.

Length of sides of valves usually about , 005' / . From several
specimens observed in contact, it appears that these two forms
belong to the same filament, and that the pseudo-noclules of the
secondary valves meet and are continuous with the processes of
the primary valves, also that the inflations meet one another,
touching at their apices. Frequent.

PI. V., Fig. 1, primary valve ; Fig. 2, secondary ditto ; Fig. 3,
frustular view.

T. ligulata (Grev.), Gr. and St. (Triceratium ligulatum, Grev.,
" T. M. S.," Vol. xii. p. 91, PI. 13, Fig. 9).— Corresponds with
Greville's figure, which is clearly a Trinacria. It is probably
only a small variety of T. excavata, Heib. Length of side, *003 // .
Frequent.

Journ. Q. M. C, Series II., No. 18. 6

64

E. GROVE AND G. STDRT ON

T. pileolus, xzw.juilaiirfica, Grim. — A small form agreeing with
Granow's description and figure ("F. J. L.," p. 16, PI. B, Fig. 56),
excepting in the presence of a central spine. Hare.

ACTINOPTTCHEJ!.

Actincptyckua splendens (Shadbolt), Ralfs. (in "Prit.," p.
840). — Differs in no respect from recent examples. Not fre-
quent.

A. (splendens var. ?) glctbratus, Gran. (" Van Heurck Synop.,"
PL 120, Figs. 6-9). — Through the kindness of L. Hardman,
Esq., we have seen one specimen corresponding very nearly to
the figure of var. incisa (I.e., Fig. 9.)

A. vulgaris Schum., var. maculata, n. var., Gr. and St.- — This
variety comes nearest to var. australis, Grun. ( " Van Heurck
Synop.," PI. 121, Fig. 8), but differs in the size and arrangement
of the apparent spots, especially in the symmetrical group in
each compartment containing the process. The group of en-
larged cells in the striated margin, opposite to each process,
is also a remarkable feature. Diam. about "005". Not un-
common. (PI. V., Fig. 5.)

A. nitidus, Grun., (Heliopelta nitida Grev., " T. M. S.," Vol.
xiv, p. 5, PI. 11, Fig. 18). — A small form, resembling the above
in the character of its cellulation, is abundant.

A. Wittti, Janisch. (A. Sch., " Atl.," PI. 100, Fig. 12).— Not
very rare, "004" to , 006" in diam., with finer markings than those
in Schmidt's figure.

Adinodiscus barbadensis, Grev. (" T. M. S.," Vol. xi, p. 69,
PI. 4, Fig. 11). — Not very rare. Identical with Greville's form.

Craspedoporus el eg ana, n. sp., Gr. and St. — This beautiful
diatom has all the characteristics of Greville's Genus (" T. M.
S.," Vol. xi, p. 68, PI. 4, Figs. 9 and 10), but differs from both
the species described by him. Valve convex, flattened at centre,
with from 7 to 10 large, transversely oval ocelli, each of which
is bisected vertically by a narrow septum or bar. The ocelli
are situated at the outer ends of pear-shaped clear spaces, which
are much shorter than in Greville's figure of C. ralfsii. General
surface granulate, the granules somewhat indistinct in the
centre but arranged in lines between the ocelli and ceasing
near the margin, where there is a clear annular space. Diam.
to -0035". Not very rare. (PI. V., Fig. 6.)

A FOSSIL MARINE DIATOMACE0U3 DEPOSIT. 65

The occurrence in this deposit of the genera Craspedoporus,
Actinodiscus, Porodiscus, and other species, hitherto observed
only in the deposit from Cambridge Estate Barbadoes is an im-
portant fact in relation to the distribution of the Marine
Diatomaceas during the Tertiary period.

Anthodiscus, n. gen., Gr. and St. — Characteristics : Valves
discoid, divided into numerous compartments by depressed,
radial, clear spaces extending from the margin, but not reaching
the centre. Differs from Cosmiodiscus in the fact that the radial
divisions are not merely clear superficial spaces, formed by the
absence of cellules or granules ; but are actual divisions of the
nature of internal septa.

A.floreatus,n. sp., Gr. and St.— Valve circular, -0028" to '003"
in diam., with numerous marginal compartments (14 to 21 have
been observed), resembling the petals of a flower. The com-
partments are granular, slightly elevated at the margin, and
extend inwards for a length of about one -third of the radius.

In the outer edge of each compartment is a depression or
notch, giving a crenulated appearance to the circumference of
the disc. The central portion of the disc, which is flat, has a
clear umbilicus, round which is a zone of granules divided irre-
gularly by clear rays.

At the outside of the granular zone is a slightly depressed
annular clear space, from which spring the granulose compart-
ments or florets.

In frustular view this form is cylindrical, with flat top, and
corrugated or crenulated exterior. (PI. VI., Fig 20.)

Cosmiodiscus Normanianus, Grev. ("T.M. S.," Vol. xiv, p. 80,
PI. 8, Fig. 11). — We do not at present remove this form from
the Genus in which Greville has placed it ; though in the char-
acter of the radial clear spaces, it differs materially from the
other two species described and figured in the same place.
Eventually it may have to be placed in the last Genus (Antho-
discus), or in one of its own. It is not of very rare occurrence,
though usually small. We figure the finest specimen which
has occurred to us, and for which we are indebted to Lawrence
Hardman, Esq. Diam., -0022". Number of compartments, 17.
(PI. VI., Fig. 21.)

It will be seen that at the marginal end of each of the clear
radial dividing spaces, there is a single detached punctum not

66

E. GROVE AND G. STURT ON

shown in Greville's figure. We much regret that, after a long
search, we have been unable to find the only authentic specimen
recorded in his slides, now deposited in the British Museum.

ASTEROLAMPREJI.

Asterolampra marylandica Ehr. (Grev. " T. M. S.," Vol.
viii, p. 108, PI. 3, Fig. 164).— Rare.

A. decora, Grev. (" T. M. S.," Vol. x, p. 43, PI. 7, Fig. 6).
— Frequent.

A. vulgaris, Grev. (Z.c, Fig. 19). Abundant.

Arachnoidisce^.

Arachnoidiscus Ehrenbergii, Bail. (" Atl.," PI. 73, Fig. 1). —
Typical, and agreeing with recent examples from California.
Diam. very variable, from # 0022" to 01". Not unfrequent.

A. (Ehrenbergii var.?) indicus E. (I.e., PI. 58, Fig. 6). — Rare.

Stictodiscus Hardmanianus, Grev., var. megapora, Gr. and St. —
Rather smaller than the type, and differing in the large size of
the clathrate cellules, surrounding the central ring of small
granules. This ring is occasionally obsolete. Diam. to , 0045' / .
Frequent. This form seems closely allied to Arachnoidiscus.

8. calif amicus, Grev. var. areolata, Grun. (" Atl.," PL 74,
Fig. 1).— Diam. to -0075".— Not scarce.

8. calif ornicus, var. nitida, Gr. and St. — A small form from
•002 v to '0035" in diam., dotted over with large shining
granules. Margin resembling the type-form, with short broad
lines of plication, and, in perfect specimens, a coarsely striated
rim. Frequent. (PI. V., Fig. 7.)

Melosire^.

Paralia sulcata (Ehr.), Cleve (Orthosisa marina, " S. B. D.,"
Vol. ii, p. 59, PI. 53, Fig. 338).— Very frequent.

Melosirasol. (Ehr.), Kutz. (" Van Heurck Syn.," PI. 91, Figs.
7, 8, and 9).— Frequent.

M. clavigera, Grun. (Z.c, Figs. 1 and 2). — Frequent.

M. borreri, W. S. (" Van Heurck Syn.," PI. 85, Figs. 5, 6, and
7). — A small disc about -002" in diam. with thick walls and
convex surf ace strewn with small scattered granules. Rare. We
place this here with some hesitation.

M. Westii, W. S. (" S. B. D.," Vol. ii, p. 59, PI. 52, Fig.
333).— Frequent.

A FOSSIL MARINE D J ATOMACEOUS DEPOSIT. ' 67

Porodiscus interruptus, n. sp., Gr. and St. — Valve circular,
very convex, with, clear central space about one -third of the
diameter of the disc. The rest of the surface covered with
radiating lines of distinct granules, interrupted near the margin
by a clear annular space, between which and the rim is a narrow
belt of closely-set granules. Margin clear. Diam. to '005".
Rare. PI. V., Fig. 8 (a small example.)

BrigMwellia pulchra, Grun. (" Van Heurck Syn.," PI. 128,
Fig. 9). — Abundant, and very variable in size. Specimens
observed from -0025" to -0075" in diam.

Podosira hormoides (Mont.), Grun. ("Kasp. Meere Diat.," p.
33). — A large coarse form which, but for the absence of the
large puncta, might be classed as P. stellulifera, Grun. Diam.
to '005". Not unfrequent.

P. maxima, Kiitz. (Hyalodiscus, Grun., " K. M. Diat.," p. 33).
— Similar in general aspect to the type-form, but without the
usual traces of an opaque umbilicus. Diam. about '007". Not
rare.

This form comes very near to Coscinodiscus.

Hyalodiscus subtilis, Bail. (" Prit.," p. 815, PI. 5, Fig. 60).—
Varies greatly in size and in the proportionate diameter of the
umbilicus. Forms occur from "002" in diam. with a large
umbilicus resembling H. scoticus (Kiitz.), Grun., to '015" in
diam., with an umbilicus of "0084". The whole surface is
covered with lines of granules about 35 in "001". These large,
coarsely marked forms may be classed as var. robust a.

H. radiatus (O'Meara), Grun. (CI. and Gr., "Arc. Diat.,"
p. 117, also " F. J. L.," p. 41). — Smaller, and not so coarsely
marked as typical forms from Kerguelens Land. Not rare.

H. arcticus, Grun. (" F. J. L.," p. 41, PI. E., Fig. 37).—
Frequent.

Coscinodiscus radiatus, Ehr. (Grun., " F. J. L.," p. 19, and 20,
PI. C, Fig. 1, et seq.) — Frequent, with much variation. The
typical form is present, as well as vars. "major and minor, but
the most numerous variety is C. argus (I.e., p. 20, and " Atl.,"
PL 61, Fig. 2), which passes into C. heteroporus ("Atl.," PI. 61,
Fig. 4) on one hand, and back to C. radiatus on the other.

C. marginatus, Ehr. (Grun., I.e., also " Atl.," PI. 65, Fig. 3).
—From -003' to -0045" in diam., with thick-walled cellules
about 6 in -001".

68 E. GROVE AND G. STURT ON

C. oculus-iridis, Ehr. (Grun., I.e., pp. 24 and 25). — Diam.
observed to "01 2". Cellules at centre about 7 and near the
margin 6 in -001". This is rather coarser than the type-form,
and is nearer to var. borealis (Bail.), Grun. (I.e., p. 25). Scarce.

0. bulliens, A. Sch. (" Atl.," PL 61, Fig. 11, also " F. J. L.,"
p. 20).— Small, about '0025" diam. Frequent.

G. radiosus, Grun. (" F. J. L.," p. 20, also " Van Heurck
Syn.," PI. 132, Fig. 7).— Moderately convex, diam. about •0035' / ,
no umbilicus, cellules radiant, about 15 in "OOl". — Scarce. We
put this here with some hesitation.

C. oamaruensis, n. sp., Gr. and St. Frequent, but usually in
fragments. Large, convex, with small clear umbilicus, sur-
rounded by a ring of cellules. Cellules hexagonal, radial, about
12 in '001 f at the centre, 15 at the margin, close within which is a
ring of puncta about "0004'' apart. At the ends of the inter-
calated lines of cellules are minute puncta, which under a low
power give the disc a somewhat scabrous appearance, especially
towards the centre. Diam. observed up to 'Oil".

This form approaches C. concinnus, but differs in the much
coarser cellulation, which is not punctate, and in the clear
umbilicus.

C. incequalis, n. sp., Gr. and St.— Small, flat, "0025" to •003 //
in diam. Cellules hexagonal, radiant, with a slight tendency to
a fasciculate arrangement, starting from a point not in the
centre of the disc, increasing slightly in size, from 12 at the
centre to 10 in '001" at a point about two-thirds of the radial
length from the centre, whence they decrease slightly towards
the margin, where a distinct ring of very small cellules occurs.
Centre furnished with a few rough excrescences, and usually
with a conspicuous sub-central tubercle.

This species resembles the form figured by Schmidt (" Atl.,"
PI. 57, Fig. 44), but is without the marginal puncta there shown.

G. decrescens, Grun. (" F. J. L.," p. 28, PL C, Fig. 18).—
Small, about "0027" in diam., resembling Grunow's var. repleta.
Scarce.

C. subtilis, Ehr. (Grun., I.e., p. 29, PL C, Fig. 26).— Not
common.

G. subtilis, var. symbolojohora, Grun. (I.e., p. 30, PL T>., Figs.
3-6). — Up to '005 " in diam. Has usually a star of four rays in
the centre. In other respects exactly as G. subtilis. Common.

A FOSSIL MARINE D1AT0MACE0US DEPOSIT. G9

0. Bothii, Gran. (I.e., PL 100, Figs. 20, 22).— Scarce and
smaller than the type.

G. angulatus, Grev. ("T.M.S.," Vol. xii., p. 9, PI. 2, Fig. 11).
--Corresponding closely with Greville's description and figure,
•0025" to '003" in diain., usually with eight, but occasionally
with 10, and even 12 small marginal processes. Very common.

C. Kutzingii, A. Sch. (Gran., " F. J. L.," p. 32, PL D, Fig.
18).— Diam. -0025'/ to -003". Scarce.

G. curvatulus, Grun. (I.e., pp. 30, 31). — A small variety present,
but scarce.

C. eccentricus, Ehr. (A. Sch., "Atl.," PL 58, Figs. 48,49).
— Not scarce, small.

G. minor, Ehr. (I.e., PL 58, Fig. 39). — We class as this a
small form about '001" diam., with cellules arranged somewhat
as in G. eccentricus. Wot unfrequent in the lighter part.

G. concavus, Greg., nee. Ehr. (" G. D. C.," p. 28, PL 2, Fig. 47).
— This form appears to us to be identical with recent specimens
of Gregory's species from the Orkney Islands. Diam. to *0075".
Cellules punctate, six in "001". This appears to be the same
as Greville's C. pulchellus (" T. M. S.," Vol. xiv, p. 3, PL 1,
Fig. 7), found in the Barbadoes deposit. W. Smith's Melosira,
cribrosa ("Ann. Wat. Hist.," Jan., 1857, p. 13, PL 2, Fig. 15),
may possibly be a smaller form of the same. Frequent.

G. elegans, Grev. (" T.M. S.," Vol. xiv, p. 3, PL 1, Fig. 6).—
Type form, very rare.

G. elegans, Grev. var. spinifera, Gr. and St. — Valve with central
conical elevation rising from a circular depression. Centre
filled with crowded fine granules, from which to the margin
radiate lines of larger granules, the spaces between which at
the outside are filled up by short lines, leaving distinct subulate
clear spaces between the marginal and central portions. On
the margin, which is striate, are from 20 to 30 small pro-
cesses. Frequent. Diam., to "0035". This form is akin to
Cestodiscus. (PL V., Fig. 9.)

G. nitidus, Greg. (" G. D. C," p. 27, PL 2, Fig. 45).— Scarce.

G. scintillans, Grev. (" Q.J.M.S.," Vol. xi, p. 230, PL 9, Fig.
6). — Rare.

G. griseus, Grev., var. Galcpagensis, Grun. ("Van. Heurck
Syn.," PL 128, Fig. 7, and PL 132, Fig. 1).— Diam. about '0075".
Scarce. A smaller form, which seems to be typical, occurs rarely.

70

E. GROVE AND G. STURT ON

Striated fragments occur occasionally in this deposit, which
may be fragments of the discs or connecting membranes of
large forms of Coscinodiscus, but at present we are without
certain evidence of this.

Steplianopyxis turris (Grev.), Grun. (Cresivellia, Grev.,
" G. D. C.," p. 64, PI. 6, Fig. 109 ; also "F. J. L.," p. 36).— Not
frequent, but typical.

St. turris, var. brevispina, Grun. (" F. J. L.," p. 35). — Frequent,
usual diam. about , 0016". Length about '0012", with about 10
cellules in # 001". Central group of spines very small and
short.

St. (turris, var. ?) valida, Grun. (" F. J. L.," p. 37).— Very
common. The most abundant diatom in the deposit. Agrees
with Grunow's description, but exceeds the maximum diam.
named by him. Valve moderately convex. Diam. from '0025"
to , 006". Cellules about 3 in 'OOl". Spines usually conspicuous,
curved, and with sharp points, in sub-marginal ring of 10 to 20
in number. In some of the larger specimens the spines are small
or even wholly wanting, as is the case also in the closed-allied
St. superba (Grev.), Grun. (Cresivellia, Grev., " T. M. S.," Vol. ix,
PI. 8, Figs. 3, 5). Such large specimens without spines seem to
us to be identical with Coscinodiscus splendidus, Grev. (" T. M. S.,"
Vol. xiii, p. 44, PI. 5, Fig. 3).

St ferox (Grev.), Grun. {Cresivellia, Grev., " Q. J. M. S.,"
Vol. vii, p. 166, PI. 8, Figs. 15, 16). — A form agreeing with
this is present sparingly ; but as a frustular view shows two
dissimilar valves, one of which resembles in all respects those
figured by Greville, while the other is much less convex, we
cannot consider it as typical.

St. barbadensis (Grev.), Grun. (Cresivellia, Grev., " T. M. S.,"
Vol. xiii, p. 3, PI. 1, Fig. 11). — We place here a species which is
very abundant in this deposit. Frustular views show a pair of
dissimilar valves with broad sutural keels. One valve closely
resembles Greville's figure, but the other is less convex, and
has numerous spines, which are not curved, and are slightly
widened at the ends. The whole frustule bears a resemblance
to St. corona, Ehr. ("Van Heurck Syn.," PI. 83 ter., Fig. 11),
and we agree with Heir Grunow (" F. J. L.," p. 39) that it is
probably a form of that species. Valves '0012* to 0022" diam.
One hemispherical, with a circle of 8 to 12 winged acute spines

A FOSSIL MARINE DIATOMACEOUS DEPOSIT. 71

curved outwards ; the other less convex, with a circle of more
numerous, straight, slightly T-headed spines.

(Note. — The above list by no means exhausts the numerous
forms belonging to Stephanopyxis in this deposit.)

Discs similar to that figured by Dr. O.N.Witt (" Simb. Diat.,"
PI. 11, Fig. 13) as the secondary valve of St. ferox are ex-
tremely common here.

Pyxidicula cruciata, Ehr. (" Prit.," p. 825).— Valve usually
oval. Frequent.

Pyxilla Johnsoniana, Grev. (" T. M. S.," Vol. xiii, p. 3, PL 1,
Fig. 6). — This diatom is described by Greville as having free
frustules, but the fact of our having observed two valves con-
nected by the apiculi, induces us to think that it may be a fila-
mentous form. The apiculi are reduced in thickness for some
distance from the end, at which place they are connected, looking
as if they were spliced together. Frequent. (PI. V., Fig. 10.)

P. dubia, Gran. ("Van Heurck Syn.," PI. 83, Bis, Fig. 12).
— Not infrequent.

P.?? (Pterotheca, Kitt.), aculeifera, Grun. ("Van. Heurck
Syn.," I.e., Fig. 5; also Kitt. in "J. Q. M. C," 1871).— A
variety of this is frequent.

Stejohanogonia danica (Kitt.), Grun. var. (I.e., Figs. 7 and 8).
— This form differs from that figured in "Van Heurck Syn.,"
from the Jutland deposits. The apiculus is more gradually
contracted, the angular costce are more strongly developed,
and very conspicuous in the valvular view. The valve is oval
and hyaline. Frequent.

Xanthiopyxis oblonga, Ehr. ("Prit.," p. 827, PI. 5, Fig. 76).
— Frequent.

X. constricta, Ehr. ("Prit.," Z.c.).— Frequent up to -0025" in
length.

Liradiscus ovalis, Grev. (" T. M. S.," Vol. xiii, p. 5, PI. 1, Figs.
15, 16). — Not frequent.

Goniothecium odontella, Ehr. (" Prit.," p. 864, PI. 6, Fig. 29 ;
also Brightw. in " Q. J. M. S.," Vol. iv, p. 106, PI. 7, Figs. 47, 48).
— A variety of this is very common.

ChcBtoceras gastridium (Ehr.), Grun. var. ("Van Heurck
Syn.," PI, 82, Bis, Figs. 1 and 2). — We have observed several
specimens of a form closely resembling this, but with incurved
awns.

72 E. GROVE AND G. STURT ON

Dicladiacapreolus, Ehr. (Brightvv., " Q. J. M. S.," p. 107, PL 7,
Figs. 53 to 60). — This occurs not rarely, along with forms
resembling Syndendrium diadema, Ehr., which may be the
Sporangia ? of Chcetoceras.

Small discs are also present abundantly, oval or oblong, with
rounded ends, and with a submarginal ring of closely-set
puncta. Frustular views of these show two narrow, somewhat
umbonate valves, one of which has an inflated centre, bearing a
short spine. These may be allied to Thalassiosira Cleve, but
we are unable to come to any conclusion.

Since the publication of Parts 1 and 2 many more species
have been discovered, and further examination has led us to
alter our views as to one or two species hitherto included in
Biddulphia. Of these we now give particulars, excluding such
new forms as we are unable to figure in the plates accompanying
this part, but which will be given subsequently in an appendix.

Cymbellej;.

Amphora furcata, Leud. Fort. (" Diat. de Ceyl.," p. 20, PL 1,
Fig. 11) = A. spectabilis, Greg. (" G. D. C," p. 44, PL 5, Fig. 80).
— Rare.

Cocconeide^:.

Gocconeis costata, Greg. (" Q. J. M. S.," Vol. iii, p. 39, PL 4,
Fig. 10).— Rare.

G. naviculoides, Grev. (" T. M. S.," Vol. xiii, p. 34, PI. 4, Fig.
24). — Scarce.

Mastogloie^.

Orthoneis splendida (Greg.), Grun. {Gocconeis, " G. D, C.," p.
21, PL 1, Fig. 29).— Attains a length of -0055", but has
finer striae than the type form, about 22 at centre, and 18 in
•001" at margin. Not very scarce.

NAVICULACEiE.

Navicula braziliensis, Grun. (A. Sch., "AtL," PL 6, Figs.
23-25). — A few fairly typical examples have occurred. Length
•0045". Striae about 28 in '001". Also a small form with closer
striation (40 in "001") . A form of this species is present
which has sublyrate clear spaces, resembling N, Bailey 'ana,
Grun. (I.e., Figs. 26, 27).

A FOSSIL MARINE PIATOMACEOUS DEPOSIT. 73

N. sandriana, Grim. (A. Sell., "Atl.," PI. 70, Fig. 49).—
Rare.

N. definita, n. sp., Gr. and St. — Valve large, ovato-lanceolate,
with obtuse rounded ends. Strias subradial, about 40 in
'001", occupying a space rather exceeding one-quarter of the
width of the valve, and having a very distinctly defined clear
space on each side of the median line. Central and end
nodules dilated transversely. Varies in length and breadth.
Typical specimen '0077" long, '0022" broad. Not very scarce.
(PI. VI, Fig. 11.)

Ampliiprora rugosa, Pet. (" Diat. de l'lsle Campbell," p. 29,
PI. 5, Fig. 17). — One specimen pretty closely agreeing with
Petit's figure has been brought to our notice by W. J. Gray,
Esq, M.D.

A ? ? cornuta, Chase (" Notes on New and Rare Diat," p. 2,
PI. 1, Fig. 6). — This form, which is certainly not an Amphi-
prora, occurs not infrequently.

FRAGILARIEJ1.

Dimeregramma fulvum (Greg.), Ralfs. (Denticula, " G. D. C,"
p. 24, PI. 2, Fig. 38).— Frequent.

Plagiogramma (constrictum var. ?) nancoorense, Grun. ("Nov.,"
p. 94, PI. la, Fig. 8). — One worn specimen discovered by Herr
Weissflog.

P. neo-gradense, Pantocsek (" Diat. Hungary," PI. 8, Figs. 63
and 71). — Rare.

P. tesselatum, Grev. (" Q. J. M. S," Vol. vii, p. 208, PI. 10,
Fig. 7). — Narrower than the type. Rare.

Stictodesmis australis, Grev. (" Ed. Trans. Bot. Soc," Vol.
vii, p. 535, PI. 13, f. 1-4). — Rare.

Nitzschie^;.

Nitzschia grundleri, Grun. (Cleve, " West Ind. Diat," p. 14,
PI. 4, Fig. 24).— Rare.

2V7 antiqua, n. sp, Gr. and St. — One perfect valve and several
broken specimens have occurred hitherto. The ends suggest
Synedra, but in general appearance and in the character of the
striation, it resembles Nitzschia ; in which we place it with hesi-
tation. Keel narrow w r ith obscure puncta, surface of valve
covered with irregularly arranged dots, which take the form of
short parallel lines about 19 in '001" close to the ventral margin.

74 E. GROVE AND G. STUP.T ON

Longitudinal fold not conspicuous. At each end is an ovate
projection more closely dotted than the rest of the surface.
Length, 016"; breadth, -0007". (PI. VI., Fig. 12.)

RUTILARIEJ;.

Butilaria epsilon, Grev. (" Q. J. M. S.," Vol. xi., p. 228, PI. 9,
Fig. 1). — Rare.

R. epsilo7i, var. tenuis. — Differs from the type in its much more
slender form and smaller central process. The marginal setae
are distinct and wider apart than in the type. The surface
covered with dots forming decussating lines. Scarce. (PI. VI.,
Fig. 13.)

BlDDULPHIEJ).

Biddulphia pedalis, n. sp., Gr. and St. — Valve discoid, '004''
in diam. with 7 to 8 stout marginal processes curved outwards
and upwards. Between each process is a marginal projection.
In the centre of the valve is a large flat umbilicus, surrounded
by a clear annular space, from which branch narrow radial clear
spaces to the base of each process. The rest of the surface is
covered with five close-set, radiating lines of granules, among
which are large puncta, or spines. Below the surface of the
valve, and outside of the circumference, are 14 to 16 feet, or
projections, of a semi-circular form, marked with radial lines.
Not having seen a frustular view, we are unable to say what ap-
pearance these feet or appendages, present in that aspect, and
must await an opportunity for further examination. We are
indebted to W. J. Gray, Esq., M.D., for the only two specimens
of this interesting form hitherto observed. (PI. VI., Fig. 22.)

B. cMnensis, Grev. (" T. M. S." Vol. xiv., p. 81, PL 9, Fig. 16.
— Scarce.

B.podagrosa, Grev., var. (" T. M. S.," Vol. xiv., p. 82, PI. 9,
Fig. 17). — We have met with several specimens of a form resem-
bling this, but with much shorter horns, which are connected by
a keel or web with the inflated centre. There are no traces of
spines or claws on the horns.

B. reticulata, Roper., forma trigona ("Van Heurck Syn.," PI.
102, Fig. 3). — Differs from Van Heurck's figure only in the
slight concavity of the sides. Cellules very distinctly punctate.
Length of side, *0057 // . Scarce.

Kittonia, n. gen., Gr. and St. — Characteristics : Valves with

A FOSSIL MARINE DIATOMACEODS DEPOSIT. 75

stalked processes, terminating abruptly in nodular, discoid, or
cup-shaped expansions, cellulose, but not furnished with claws
or hooks, as in Hemiaulus. Other characteristics, those of
Biddulphia as defined by Van Heurck (" Syn. Texte," p. 203).
Kittonia elaborata, Gr. and St. (Biddulphia elahorata, " J. Q.
M.C.," Vol. ii., Ser. n., p. 325, PI. 18, Fig. 9).— This diatom
occurs frequently in all the samples of this deposit we have
hitherto examined. Specimens vary in size from '007" to '01"
in length, and -004" to -0067" in breadth.

[We take this opportunity of correcting an error in the scale
of measurement attached to PI. 18, Fig. 9, which should be 400,
not 500 diameters.]

K. virgata, Gr. and St. (Biddulphia virgata, I.e., p. 325.
PI. 18, Fig. 11). — Since the above-mentioned figure was en-
graved we have met with a more perfect specimen, of which
we now give a figure (PI. VI., Fig. 23.)

Note. — Having, through the kindness of W. Carruthers,
Esq., F.R.S., of the Nat. Hist. Mus., been enabled to examine
Dr. Greville's authentic specimens of his Biddulphia gigantea
(" T. M. S.," Vol. xii., p. 13, PI. 2, Fig. 9), we find that the
hyaline stalked processes terminate in nodular cellulose expan-
sions larger than the small capitate ends shown in his figure.
We venture to remove the form to this genus under the name
of Kittonia grevilliana.

Cerataulus polymorphus (Kiitz. ), forma minor, ("Van Heurck
Syn.," PI. 105, Figs. 3 and 4). — A small form occurs very
rarely, which we place here. It differs only in the presence of
a small central group of spines, in place of the two shown in
the Fig. referred to.

Triceratium rugosum, n. sp., Gr. and St. — Very similar in
general appearance to Trinacria heibergii, Kitt. (" J. Q. M. C.,"
1871, p. 169, PI. 13, Fig. 6), but differing essentially in the form
of the processes, which are large, club-shaped, and studded with
short spines. Margin convex, extending beyond the edge of the
valve. Surface covered with scattered papillae, presenting a
rugose appearance. Length of side about '005". Rare. (PI.
V., Fig. 4.)

T. coscinoides, Gr. and St. ("J. Q. M. C," Vol. n., Ser. n.,
p. 327, PI. 19, Fig. 13), var. quadrata. — Since describing this
species we have met with a four-angled form of the same.

76 E. GROVE AND O. STURT ON

Triceratium papillatum, n. sp., Gr. and St. — Valve small,
with deeply concave sides, and enlarged rounded ends, slightly
inflated, from which project prominent nipple-shaped processes.
Centre inflated. Surface of valve dotted with scattered grannies,
with a few stout spines interspersed on the central portion.
Length of side, -003". Very rare. (PI. VI., Fig. 14.)

For the specimen from which the figure is taken we are in-
debted to the kindness of Herr Weissflog.

T. bimarginatum, n. sp., Gr. and St. — Valve small, with
straight sides and slightly rounded angles bearing distinct cir-
cular nodules. Central part elevated, bounded by a margin of
closely-set puncta, which form an inner triangle, having sides
parallel with the outer margin. Length of side '0014*. Not
frequent. (PI. VI., Fig. 15.)

T. auliscoides, n. sp., Gr. and St. — Valve small, with rounded
angles and mastoid processes resembling those of Auliscus.
The sides are produced into obtuse angles between the processes
giving an hexagonal appearance to the whole form. Surface
minutely punctate with markings like those of Auliscus pruinosus.
There is an indication of an umbilicus, and the angles are isolated
by an indistinct clear space, giving to the central markings the
form of a concave triangle. Very rare. (PI. VI., Fig. 16.)

We are indebted to W. J. Gray, Esq., M.D., for the specimen
from which the figure is taken.

T. montereyii, Brightw. (" Prit.," p. 856, also "Q.J. M. S.," p.
251. PL 4, Fig. 18). — Not common, but typical.

Aulacodiscus crux, Ehr. — A form of this with three processes
has been observed. A small variety with two processes is not
infrequent, which is not unlike A. probabilis, A. Sch., but
seems to belong to this species.

A. margaritaceus, Ehr. — A beautiful form of this has been
brought to our notice by F. Kitton, Esq. The centre is deeply
depressed, and the exterior elevated after the manner of Gras-
pedodiscus elegans. The diam. is "0095", it has six processes, and
is otherwise quite typical.

A. angulatus, Grev., a variety with four processes, is not very
rare in the lighter density.

Hemiaulus amplcctans, n. sp., Gr. and St. — We place this pe-
culiar form in Hemiaulus solely on account of the general
resemblance it bears to some species of that genus.

A FOSSIL MARINE DIATOMACEOUS DEPOSIT. 77

The apparent absence of the characteristic claws or spines at
the ends of the horns would place it in Biddulphia ; and there
are perhaps better reasons for giving it a genus of its own, but
for the present we leave it here.

Valve resembling in general appearance that of a Hemiaulus,
hyaline, produced at the ends into horns which project at right
angles to the surface of the valve, and are slightly tapering,
with rounded ends. The horns are distinctly cellulate. The
most remarkable feature in this little form is the presence of a
very long, stout central spine, terminating in a bent claw or
fork, by which the spine, projecting from the opposite valve, is
clasped : each spine being embraced or clasped by the fork of the
contiguous valve. The spines appear to be able to move freely
through the forks, so that the valves are sometimes found
near together and at others wide apart. Length of valve
usually about •001'; length of horns about '001"; length of
central spine, '0025'. Scarce. (PL VI., Fig. 17.)

H. ornifhoeephalus, Grev. — The form mentioned under this
name (ante, Part II, p. 11) appears to differ somewhat
from Greville's figure. We append figures of valve and frustule.
(PL VI., Figs. 18, 19.)

Anaulus birostratus, Gran. ("VanHeurck Syn.," PL 103, Fig.
1). — A small form of this occurs rarely. (PL VI., Fig. 25.)

Eunotogramma ? ? bivittata, Gran, and Pant. (Pant. " Diat.
Hungary," PL 26, Fig. 247). — Valve lunate, long, narrow,
tapering, with curved dorsal and ventral margins. Two septa
or vittas nearer to the centre than the ends. Surface dotted
with scattered granules, which are most numerous at the mar-
gins. Not infrequent. (PL VI., Fig. 24.)

We have figured a normal specimen, but have observed some
of much greater length and curvature, .resembling in form
Eunotia lunaris.

Note. — We had named this form Anaulus tenuis, but dis-
covering that it had been found in the Hungarian fossil
marine deposits, and was published in Herr Pantoczek's work
under the name given above, we adopt his nomenclature.

Terpsinoe americana, Bail., (Ralfs in " Prit.," p. 859).

Scarce.

Auliscus pundatus, Grev. (" T. M. S.," Vol. xi., p. 49, PL 3
Figs. 15, 16). — A small form, not uncommon.

78 A FOSSIL MARINE DI ATOMACEOUS DEPOSIT.

A. Greuillei, Jan. ("Guano," p. 163, PI. II., Fig. 11).- Typi-
cal, scarce.

A. (prui7iosus var. ?) confluens, Grun. (A. Sch. " Atl.," PI. 32,
Figs. 6-8.) — Scarce.

A. Hardmanianus, Grev. (" T. M. S.," Vol. xiv, p. 6, PI. 2, Fig.
17). — Small specimens occur rarely.

Clavicula aspicephala, Pant. ("Diat. Hungary," PI. 2, Fig. 15).
— Several fragments of this species have been observed.

PLATE V.

Fig. 1. Trinacria ventricosa, n. sp., Gr. and St., primary valve, 4 $°.
„ 2. „ „ „ „ secondary valve, 5 |°.

3. „ „ „ „ frustular view, 4 £°.

4. Triceratium rugosum, n. sp., Gr. and St., 4 f°.

5. Actinoptychus vulgaris, Schura., var. maculata, Gr. and St., 4 ^°.

6. Craspedoporus elegans, n. sp., Gr. and St., r ^°.

7. Stictodiscus calif omicus, Grev., var. nitida, Gr. and St., 4 f°.

8. Porodiscus interruptus, n. sp., Gr. and St , 5 ,^°.

9. Coscinodiscus elegans, Grev., var. spinifera, Gr. and St., 6 ^°.

10. Pyxilla Johnsoniana, Grev., fruetular view, 4 ^°.

PLATE VI.

11. Navicula definita, n. sp., Gr. and St., 4 j°.

12. Nitzschia antiqua, n. sp., Gr. and St., 3 ^°.

13. Rutilaria (epsilon var.?) tenuis, n. sp., Gr. and St., 8 y°.

14. Triceratium papillatum, n. sp., Gr. and St., 5 £°.

15. T. bimarginatum, n. sp., Gr. and St., 7 ^-°.

16. T. auliscoides, n. sp., Gr. and St., 7 ^°.

17. Hemiaulus amplectans, n. sp., Gr. and St., *^°.

18. H. ornithocephalus, Grev., var. side view, 8 ^°.

19. „ „ frustule, 6 ?°.

20. Anthodiscus fioreatus, n. sp., Gr. and St., 5 f °.

21. Cosmiodiscns Normanianus, Grev., 6 ^°.

22. Biddulphia pedalis, n. sp., Gr. and St., 4 y°.

23. Kittonia virgata, n. sp., Gr. and St., 8 ^°.

24. Eunotogramma ! 1 bivittata, Grun., 5 ^°.

25. Anaulus birosfratus, Grun., 5 °°.

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West.Newman i Co lith.

79

On the Structure of Aulacodiscus Margaritaceus, Ralfs.

By Henry Morland.
(Read March 25th, 1SS7.J

In a paper on "Diatom Structure," which I read before this
Club in May last, I gave the following description of the
structure of the valves of Aulacodiscus margaritaceus of Ralfs :
— "The inner surface consists of a layer with small perfora-
tions, some T 2-£otf i ncn across > ^th thickened borders ; above
this is a framework of tubes (one to each perforation below),
with more or less straight-sided borders. Some of these tubes
have 4, 5, or 6 sides, and they are by no means regular in
shape. As the outward surface is approached the angles get
filled up, and the irregularly-shaped cells end in circular open-
ings rather smaller than the cells themselves."

I have lately been examining this diatom again, but this
time under an oil immersion lens, and find that I must modify
the above description, which, however, is correct so far as the
coarser structure is concerned, but misses the finer details.

I described the irregularly-shaped cells as ending in " circular
openings " on the outer surface. This, I can now emphatically
say, was a mistake, these cells really being closed at the outer
surface of the valve by a very fine siliceous film with markings
very similar to those of Coscinodiscus asteromphalus, Ehr., as
figured by Messrs. Nelson and Karop, a year ago, in our
Journal. With respect to the small perforations on the inner
layer, I find in the examples I have examined that they are
furnished with very short tubes projecting inwards towards
the body of the frustule, these tubes giving a "ringed" appear-
ance to the perforations when the valve is examined direct on
the inner surface. As yet I have been unable to detect any
film across these inner perforations, but there are Diatomists
who seem to be of opinion that these " eye-spots " also are
closed by a membrane, though, perhaps, but very slightly
silicified.

Jouen. Q. M. C, Series II., No. 18. 7

80 THE STRUCTURE OF AULACODISCUS MARGARlTACEUS.

In the case of G. asteromphalus, I consider the markings in
each set of markings, as figured by Messrs. Nelson and Karop,
to be really those of a siliceous film across and slightly within
the mouth of each polygonal cell, as in Aulacodiscus margari-
taceus. If Coscinodiscus asteromjyhalus be examined from the
inner side of valve, " eye-spots " will be seen under a very
medium power.

I think that further and careful examination undei suitable
lenses will show that all valves with " eye-spots " on the inner
surface of valve have their hexagonal, or rather polygonal,
cells, when present, closed on the outer surface, with delicate
siliceous films pierced with sets of extremely fine and minute
perforations.

It must be understood that these remarks of mine in no way
apply to Triceratium favus, respecting which I must make
further examinations before offering a definite opinion relative
to its structure.

81

On a New Arrangement of Growing Slide, designed by the

Rev. A. Pagan, B.A.

Communicated by T. Spencer Smithson.

(Read March 25th, 1887 J

This slide was designed mainly for the purpose of watching
the development of Rotifers and other organisms which require
a constant change of water. The above figures give the
essential points of its construction, which is very simple, and
so far effective as to have enabled Mr. Pagan to observe the
growth of the spores of vohox globator after they had been

82 T. S. SMITHSON ON A NEW ARRANGEMENT OF GROWING SLIDE.

confined to the slide for six weeks, the actual process of
germination taking three days to complete.

Fig. 1 is a longitudinal vertical section of the whole ap-
paratus drawn to a scale of half the actual size ; A is a
wooden stand supporting a glass trough (B), from which a water
supply is conveyed to a slide (D) by a siphon (C). This siphon is
made from an ordinary, capillary, vaccine tube, bent over a
minute gas flame. The water is conve} r ed from the slide by
means of a spout (F), made of blotting-paper, to another trough
or suitable receptacle (E).

Fig. 2 shows in full size an arrangement cut out of blotting-
paper and placed on an ordinary slide; a is a circular hole for
containing the object under observation. This hole is con-
nected by a narrow channel (c) with another hole (ft), shaped as
in the drawing, and so placed beneath the siphon c as to receive a
drop of water as it falls. It is sufficient, however, if the drop
falls on the blotting-paper. A third hole (d) serves to collect
the superfluous w r ater, and also acts as a reservoir when the
slide is under examination with the microscope, water being
applied there from time to time with a camel's-hair brush.

When it is desired to use the instrument the blotting-paper
is wetted and put on the slide, the drop of water containing
the organism placed in the hole a, and the whole is covered
with thin glass up to the dotted line e,. three f-in. square cover
glasses being very suitable for this purpose. The siphon may
now be started, the current being regulated to about one drop
per minute by means of ;i linen thread, unravelled, soaked in
water t<> gel rid of air bubbles, and pushed up the shorter limb
of tlic siphon. The water is drawn off at the other end of the
Blide by three strips of blotting-paper (shown detached at Fig.
3). one 1)i«»;k1 and the other two less than half the width placed
under the broad slip, thus forming a kind of channel for the
water to flow fchronerh.

After a time the blotting-paper is liable to get clogged, and
will not allow the water to filter through ; it must therefore be
changed. To enable lliis to be done, the part used on the slide
is out in pieces in the manner indicated in Fig. 2.

The form of the lid of the trongh V> is shown in Fig. 4 j it
is provided with three holes drilled one inch apart, in order

T. S. SMITHSON ON A NEW ARRANGEMENT OF GROWING SLIDE. 83

that, when desired, three separate slides can be kept under
treatment at the same time.

Mr. Pagan has been good enough to allow me to bring his
invention before the Club, and I have much pleasure in doing
so, as I think it supplies a want that has been long felt by
microscopists, and it is capable of doing a large amount of
valuable work in elucidating problems in the life history of the
many organisms which still remain very imperfectly known,
owing to the difficulty of watching their development during
lengthened periods.

84

PROCEEDINGS.

January 14th, 1887. — Conversational Meeting.

The following objects were exhibited : —

Coryne pusilla (allied to Syncoryne.) ... Mr. P. W. Andrew.

The Scissor Bug, Heterotoma merioptera,} ^ ™ Enock
with drawing of same ... ... )

Lipura, sp. ... ... ... ... Mr. C. Bousselet.

Absorption spectra of Cantharides ... ... Mr. H. J. Waddington.

Embryo (40 hours incubation) of chicken ... Mr. W. Watson.

Actinomycosis in tongue of ox ... ... Mr. G. Western.

An apo-chromatic lin. object glass by Zeiss ... Mr. E. M. Nelson.
Attendance — Members, 32 ; Visitors, 2.

January 28th, 1887. — Ordinary Meeting.

A. D. Michael, Esq., F.L.S., F.R.M.S., &c, President, in the

chair.

The minutes of the meeting of November 21st, 1886, were read and con-
firmed.

The following gentlemen were balloted for and duly elected members
of the Club : — Messrs. E. T. Browne, A. S. Lightwood, and E. Grove.
The following additions to the Library and Cabinet were announced : —
" Proceedings of the Eoyal Society," Nos.
248-9...

f From the Society.

" Proceedings of the Eoyal Society of New")

South Wales" j From the Society.

" Journal of the New York Microscopical")

Society" ... ... ... J " »

" The Botanical Gazette " ... ... ... In Exchange.

" The American Monthly Microscopical")

Journal " ... ... ... )

" Proceedings of the Belgian Microscopical")

Society" ... ... ... j" »

" Proceedings of the Eastbourne Natural")

History Society " ... ... ) " "

" Proceedings of the Canadian Institute of")

Toronto" ... ... ... ...)

85

" Annals of Natural History " ... ... Purchased.

" Cooke's British Desmids " ... ... „

12 Slides prepared by the late Mr. W. T. Loy From Mr. T. Curties.

The President called special attention to the last-named donation, which
consisted of a number of preparations mounted by the late Mr. Loy, for many
years a member of the Club, and one whose manipulative skill was well
known to all those who were acquainted with him. These slides had been
presented to the Club by Mr. Curties, as typical examples of Mr. Loy's
work, and as such the members would no doubt be extremely glad to
possess them, and also to return a special vote of thanks to Mr. Curties for
presenting them.

Votes of thanks to the donors, especially to Mr. Curties, were unani-
mously carried.

The President reminded the members that, in accordance with their
altered rules, the annual meeting of the Club would be held on February
25th, and that it was, therefore, necessary for them to nominate gentlemen
to serve as officers and committee during the ensuing year, such nomina-
tions to be printed upon the balloting papers in the usual manner for elec-
tion at the annual meeting. It would also be necessary to elect an auditor
to examine the accounts to be presented to the annual meeting by the
Treasurer on behalf of the Club.

The Secretary read the following list of nominations by the Committee
as officers : — For President, Mr. A. D. Michael; Vice-Presidents, Professor
Chas. Stewart, Mr. E. M. Nelson, Mr. E. T. Newtfon, Mr. J. W. Groves ;
other officers as before.

On behalf of the Committee, Mr. W. Hainworth was appointed auditor.

The Secretary pointed out that in addition to the four members whose
turn it was to retire by rotation — Messrs. Dadswell, Fase, Gregory, and
Waddington — three other vacancies would occur on the Committee from the
elevation of Messrs. Nelson, Newton, and Groves to the Vice-Presidency, so
that the members were asked to nominate at least enough names to fill up
these seven vacancies.

The President having foimally requested nominations to be made — Mr.
Dadswell was proposed by Mr. S r encer, and seconded by Mr. Dunning ;
Mr. Stokes was proposed by Mr. Parsons, and seconded by Mr. Hembry ;
Mr. Morland was proposed by Mr. Mclntire, and seconded by Mr. Nevins ;
Mr. Sturt was proposed by Mr. Dadswell, and seconded by Mr. Waller;
Mr. Parsons was proposed by Mr. Priest, and seconded by Mr. Vesey ; Mr.
Vesey was proposed by Mr. Hembry, and seconded by Mr. Western ; Mr.
Waddington was proposed by Mr. Dunning, and seconded by Mr. Alpheus
Smith.

As auditor, on behalf of the members, Mr. Hind was proposed by Mr.
Dunning, and seconded by Mr. Alpheus Smith, and unanimously elected by
show of hands.

Mr. E. M. Nelson then said : I have much pleasure in bringing before
you to-night a new microscope which has been made by Mr. C. Baker, and
which I think you will all admit begins a new era in the progress of

86

" microscopy " (see Fig. 5). Yon have before you now for the first time in
the history of the microscope a thoroughly sound full-sized instrnment at
the same price as a student's microscope. I must say that we are all
greatly indebted for the construction of this instrument to the energy and
perseverance of Mr. Charles Lees Curties. I will, if you will allow me,
just go over some of the points adopted in this new microscope. I say
adopted, for in a new microscope there must of necessity be much that is
old in design, Ac. All that can be expected is that some of the points are
to be new. This, therefore, will bo found to be an aggregation of late im-
provements with some uew excrescences added. Let us begin with the foot

Ufl/ufa

Fig. 5.

(a most important part). All microscope feet may be classified under four
heads : 1st. The simple tripod, illustrated by the Powell form. 2nd. The
plate and uprights. A flat plate with pillar or pillars, as in the Beck model,
and a plate with flat uprights in the Andw. Ross. 3rd. The bent claw, a
very common and bad form, used by many makers. 4th. The heavy horse-
shoe, the usual Continental model. The plate and uprights is a good form,
but was not adopted, because it is too heavy and expensive. The bent claw
is a bad form. It is suprising that it has not disappeared long ago. It is
heavy, easily capsized, and while seemingly a tripod, often rocks on four
points. The heavy horseshoe which, until lately, was always fitted to
students' microscopes, has nothing to recommend it. A designer must
indeed be hard up for resources who can only obtain steadiness by weight.
There can be no question but that the tripod in its simplest form is the best.
Of all the ways of utilizing it, that adopted by Messrs Powell and Lealand

87

ia the most efficient, viz., of hanging the microscope in a horseshoe, supported
by three legs ; but for this class of instrument that mode of mounting was
quite out of the question, for cost immediately put it outside the category of
students' microscopes. There is a great difference between the steadiness of
a microscope perched up on the top of its trunnions and one that is hung in
a tripod. This microscope is placed in a kind of stirrup hanging from the
trunnions, a most ingenious device of Mr. Curties. The body is large
enough to take Zeiss' full-sized eyepiece, viz., If in., and is lOin. long when
the draw-tube is pulled out to a mark. When the draw-tube is pushed home
the length is 6*3in., or Continental gauge. It, therefore, will suit both kinds
of apochromatic object glasses. The optic axis of the instrument, when in
a horizontal position, is 8|in. from the table. It has rackwork coarse adjust-
ment, and Campbell's fine adjustment. It is to this fine adjustment that
the instrument owes its origin. The moment Mr. Campbell explained to me
the principle of his fine adjustment, I foresaw the construction of an
efficient students' microscope. The direct-acting screw is only suitable for
low powers and small apertures. I will put it even stronger : delicate
work with high powers and wide apertui-es is not possible with any micro-
scope having a direct-acting screw fine adjustment. The stage is of the
cut horseshoe form, which I had the honour of bringing before you some
little time back. The principal object of this is to enable you to feel your
working distance. A great improvement has been made in the sliding
bar, its guiding lugs being stowed away underneath the stage ; I have no
hesitation in saying that next to a perfect mechanical stage this is the best.
Most of the mechanical stages are so defective in design, and so scamped
in their workmanship, as to be w orse than useless. The substage is fitted
with a tube, having a spiral slot for focussing, which I will pass over,
as I have described it here on a former occasion. There is a novel feature
about the stops for dark ground illumination, viz., there is a three-legged
carrier which Lolds them all. This cariier has a pin in the centre of it on
which the various sized discs fit. The stops, diaphragms, &c, have a
separate 'tube-fitting for them, so that it is unnecessary to move your con-
denser when changing either a stop or a diaphragm. This substage will
carry either of Prof. AbbtS's condensers, or a cheap condenser made
especially for this microscope. The weight of the instrument complete is
7lbs.

Mr. John Mayall, jun., said that knowing well Mr. Nelson's thorough
competence to give a reliable opinion upon any matter connected with the
mechanical construction of the microscope, there could not be the slightest
doubt that the one he had just described had some very excellent points.
Indeed, he thought they might take it for granted that if the instrument
before them had successfully passed Mr. Nelson's criticism, it must be
pretty nearly all right. It occurred to him, however, that the spiral
arrangement employed for focussing the condenser was, perhaps, not likely
to prove quite so true as could be desired, and he should like to ask if Mr.
Nelson had found that it introduced any very great error in centring.

88

Mr. Nelson said he had not observed this to any inconvenient degree
except in cases where very high powers were nsed.

Mr. Mayall thought also that there would be some advantage, both as
regarded strength and appearance, if the arm of the limb was made some-
what stouter — it struck him as being disproportionately light ; but as to the
advantages of the tripod form of foot, he could entirely endorse every word
which had fallen from Mr. Nelson on the subject.

Mr. Karop said he fully agreed with Mr. Mayall that the arm of this and
similar microscopes was too slender. Even if it were in reality strong
enough, it did not give the appearance of being so, which was a fault in the
design. Workmen seemed very much addicted to cutting away the metal,
quite irrespective of anything but figure, and he instanced the case of
surgical knives, where both blade and handle were of a suitable strength,
although where they joined, and where the greatest leverage must occur, it
would mostly be found that the workmen had ground away the steel to a
ridiculous extent, leaving but a thin bridge of metal to take the strain.

Mr. Nelson further called the attention of the meeting to a number of
drawings illustrating the remarkable variety of shapes which he had found
amongst the hairs of a species of acarus. Also to some drawings of in-
teresting fragments of Coscinodiscus and other diatoms.

The President said the number of forms found amongst the hairs of the
Acarina was practically endless — the hairs in Trombidium seemed, in fact,
to vary in almost every species. He felt sure it was unnecessary to say
that they thanked Mr. Nelson very heartily for the communications he had
made to them.

A vote of thanks to Mr. Nelson was then put and carried unanimously.

Mr. John Mayall, jun., then gave an extremely interesting account of
his recent visit to Jena.

The President said that at that late hour of the evening, although it was
not possible to invite any questions to be asked upon the subjects which had
been brought before them, he was quite sure that all present would cordially
respond to the proposal that a hearty vote of thanks be presented to Mr.
Mayall for his very interesting narrative. — Put and carried by acclamation.

Messrs. Schrceder exhibited a new method of showing opaque objects
with the lieberkuhn.

Announcements of meetings, &c, for the ensuing month were then made,
and the meeting terminated with the usual Conversazione, and the following
objects were exhibited : —

Coralline, Clava squamata ... ... Mr. F. W. Andrew.

Serial Sections of Slug, Limax agrestis, cut)

bvMr.J.Underhill J Mr. H. E. Freeman.

Attendance— Members, 41 ; Visitors, 8.

89

February 11th, 1887. — Conversational Meeting.

The following objects were exhibited : —
Young Salmon alive
Pollen of Victoria Regia ...
Palate of Garden Spider, JEpiera diadema
Diatoms from Eichmond, Virginia ...
Cirrus of Balanus
Chroococcus turgidus
Diatoms, Auliscus StocJchardti
Secondary markings on Euphyllodium spa-

thulatum and Cocconeis Grevillii . . .
Echinocyamus pusillus from Naples
Laurentian Gneiss from Cape Wrath
Paramcecium oursaria
Fairy Fly, Litus cynipseus

}

Mr. F. W. Andrew.
Mr. E. T. Browne.
Mr, T. Curties.
Mr. C. Dunning.
Mr. J. D. Hardy.
Mr. G. E. Mainland.
Mr. H. Morland.

Mr. E. M. Nelson.

Mr. B. W. Priest.
Mr. G. Smith.
Mr. J. Spencer.
Mr. J. J. Vezev.

Attendance —Members, 47 ; Visitors, 4.

From the Society.
In Exchange.

»

February 25th, 1887. — Twenty-First Annual Meeting.
A. D. Michael, Esq., F.L.S., F.R.M.S., President, in the Chair.

The minutes of the preceding Meeting were read and confirmed.
The following gentlemen were balloted for and duly elected members of
the Club :— Mr. A. F. Tate, Mr. W. F. B. Knight, Mr. F. S. Pim, Mr. Wm.
Gross, Mr. George Paterson, and Mr. Jas. T. Hillier.
The following additions to the library were announced : —
" Proceedings of the Royal Society of New )
South Wales ".. . ... ... ->

" Botanical Gazette "

"Proceedings of the Belgian Microscopical )
Society" ... ... ... )

"Annals of Natural History "
"British Desmids," Nos. 7 and 8 ...
Rainey's " Mode of Formation of Shells of
Animals''

The thanks of the Club were voted to the donors.

Announcements of meetings for the ensuing month were then made, and
the business of the Annual Meeting was proceeded with.

On the motion of Mr. J. W. Reed, seconded by Mr Gregory, Mr J. D.
Hardy and Mr. S. J. Mclntire were appointed scrutineers, and the ballot
was taken for the election of Officers and Committee for the ensuing year.
It was subsequently announced by the President that the whole of the
gentlemen whose names appeared on the printed lists were unanimously
elected.

}

Purchased.

From Mr. Hind.

90

The Secretary read the 21st Report of ihe Committee for the 17 months
ending December 31st, 1S86.

The Treasurer read his statement of accounts for the same period.
It was moved by Mr. Morlnnd, and seconded by Mr. Vesey, " That tho
reports now read be received and adopted, and that they be printed and
circulated in the usual manner."

The President having put the motion to the meeting, it was unanimously
carried.

The President then read his Annual Address.

Mr. E. M. Nelson rose with much pleasure to propose a hearty vote of
thanks to the President for the very charming address to which they had
just been listening. For his own part, he could say that it had been
particularly interesting as dealing with matters which did not ordinarily
come under his notice, taking as he did rather the mechanical side of
natural history subjects. He had been very much appalled by the question
as to what fearful catastrophe would happen to anyone at the edge of
space, but he knew what his duty was when he stood at the edge of time j
and, therefore, at that hour of the evening he would say no more in favour
of a motion which he felt would commend itself to all v, ho were present.

Mr. Waller having seconded the motion, it was put to the meeting by
Mr. Nelson, and carried by acclamation.

The President said he had talked so much already that he would only
now thank the members for the vote of thanks which they had so kindly
passed.

Mr. Weston moved " That the best thanks of the members be given to
the President, Officers, and Committee of the Club for the services they
had so efficiently rendered during the past year and a half."

Mr. John Pearson having seconded the motion, it was put to the meeting
and unanimously carried.

Mr. Spencer proposed a vote of thanks to the Auditors and Scrutineers,
which was seconded by Mr. Enock, and carried unanimously.

A vote of thanks to the Council of University College, for continued

permission to meet in that building, w; s proposed by Mr. Hardy, seconded

by Mr. Dunning, and carried unanimously ; and the proceedings terminated

with the usual Conversazione, and the following objects were exhibited : —

Paludicella JEhrenbergii ... ... ... Mr. P. W. Andrew.

Pollen of Goethea MaJcoyana ... ... Mr. E. T. Browne.

Battledore wing Fly, Mymar pulchellus $ ,| Mr F EnQck
and drawing of same ... ... )

Comose appendices of seed of Strophanthus ~) ,, „ t,

*• -a At • • C Mr - H ' E PP S '

nisjpidus, an African arrow poison )

Attendance — Members, 64 ; Visitors, 4.

91

March 11th, 1887. — Conversational Meeting.

}

The following objects were exhibited : —
Marine Hydrozoa, Pedicellina cernua
Pollen of Goethea makoyana
Seeds of Clematis

Scale of Podura, with dark ground illumina-
tion, Zeiss' apochromatic objective, 6*0 mm.
(iin.), and Abbe condenser, 1.20 n.a.
Oak Apple Fly, Andrieus terminalis, with"

drawing of same
Foraminifera, Cristellaria rotulata, and sec- I
tion of Alveolina quoii ... ... )

Parasite of Tortoise
Diatoms, ActinoptyeJins seductilis ...
Fossil Sponge, Catoptychus agaricoides
Diatoms from Oamaru, Biddu.lpJiia pedalis, n.s.
Negative and prints of Amphipleura pellucida, photographed with Zeiss'
apochromatic 3mm. (|iu.), O.I., N.A. 1-40, and projection eye-piece, by Dr.
E. C. Bousfield and Mr. C. Lees Curties.

Attendance — Members, 39 ; Visitors, 1.

Mr. F. W. Andrew.
Mr. E. T. Browne.
Mr. A. L. Corbett.

Mr. C. Lees Curties.

Mr. F. Enock.

Mr. H. F. Hailes.

Mr. C. K. Jaques.
Mr. H. Morland.
Mr. B. W. Priest.
Mr. G. Sturt.

}>

March 25th, 1887. — Ordinary Meeting.
A. D. Michael, Esq., F.L.S., F.R.M.S., President, in the Chair.

The minutes of the preceding meeting were read and confirmed.
Messrs Isaac Robinson and S. Broad were balloted for and duly elected
members of the Club.

Mr T.F. Smith, 12,Campdale Road, N.W., was proposed for election at the
next meeting.

The following additions to the Library were announced : —

"Proceedings of the Royal Society" ... From the Society.

" Proceedings of the Essex Field Club "
" Transactions of the Northumberland and')
Durham Natural History Society " )

" American Naturalist " ...
" Strasburger's Practical Botany"...
Vol. ii. " Bucton's Larvee," Ray Society
Mr. E. M. Nelson exhibited an adapter for Powell's new achromatic oil
immersion condenser which enables the stops to be more easily changed.
Mr. B. W. Priest read a paper on the " Calcareous Sponges."
Mr. Waller said that the thanks of the Club were due to Mr. Priest for
his excellent resume of this interesting group, and he hoped it would be the
means of inducing more members to take up the study of the sponges
generally. The material was readily obtainable by any visitor to the sea-

In Exchange.
Purchased.

»

92

side, scarcely any mass of algas cast up by the waves being without at least
a few specimens of the ordinary hinds.

Professor Stewart, while cordially endorsing all that had been said by
.Mr. Waller, would rather join issue with Mr. Priest in regard to one
or two points. Firstly, as concerned the position of the radiant canals in
the Sycon figured in his diagram ; and, secondly, as to there being no
recognizable rudimentary nervous system in the Spongiadae. With regard
to this latter, he was strongly of opinion a nervous system did exist. The
external openings of the inhalent inter-radial canals in Lycon compressa
showed delicate hair-like processes of the Ectoderm, each having its axis
traversed by a fine thread of protoplasm derived from a subjacent branched
mecoderm cell. He regarded the hair-like process as a sensory mechanism
which, acted upon by special features in the water, transmitted the impres-
sion to the cell beneath (nerve cell), and from this impulses would be
given off to the contractilecells in its neighbourhood, so that the orifices of
the inter-radial canals might be closed or opened, and the current of
water regulated.

Mr. Priest, in reply, stated his own belief in the possession of a nervous
system by the Calcaria ; he, however, quoted Dr. Polegaeff, a recent observer,
as holding a contrary opinion.

A vote of thanks to Mr. Priest for his paper was put from the chair, and
carried unanimously.

Mr. Morland read a short paper on " The structure of Julacodiscus
margaritaceus"

Mr. Nelson said he had also observed the appearances as described by
Mr. Morland.

A unanimous vote of thanks was passed to Mr. Morland for his com-
munication.

The Secretary then read a description of a new growing slide sent by Mr.
Smithson, of Rochdale.

Mr. Karop said he thought the idea very good, and much superior to the
" hanging drop " arrangement, where the upper surface of the cover glass
frequently got dimmed in the moist chamber, and the dimness was with
difficulty got rid of without disturbing the specimen.

A vote of thanks was passed to Mr. Smithson for his communication.

Mr. Karop then gave a short description of some new Lieberkuhns
exhibited by Messrs. Schroeder, made of Wolfram steel, and which could be
used with magnifications of over 400 diams. The apparatus was exhibited
by Messrs. Schroeder in the room, and he thought was worthy of note.

A vote of thanks was passed to Messrs. Schroeder for their exhibit.

Mr. Karop said there was a little matter he should like to say a few
words about before the meeting broke up, and also to get some information
himself. Mr. Richardson, a member of the Club, had sent him some
deposits containing Diatoms from Scotland, and one of them, from Loch
Kinnord. Aberdeenshire, was very rich in the ordinary lacustrine forms,
such as Epithemia, Synedra, Cymbella, &c, &c. It contained very little
foreign matter, and was easily cleaned. Another deposit, however, from

93

Skye, was mixed with a quantity of white material which resisted all the
ordinary acids, and he supposed was a silicate of magnesia ; at any rate it
gave a milky colour to the washings, and was so fine as not to subside in
any ordinary time. He wished to know how to proceed in such cases.

Mr. Morland had found that alternate treatment with H 2 S0 4 , and liq.
potassae several times repeated was sometimes efficacious in getting rid of
refractory material.

Mr. Karop said he was rather afraid of liq. potassse with diatoms, but Mr.
Morland was a great authority in this direction, and he was much indebted
to him for his suggestion.

Announcements of meetings, &c, for the ensuing month were then made,
and the proceedings terminated in the usual Conversazione, and the follow-
ing objects were exhibited : —

Alga, Yaticheria, sp. ... ... ... Mr. F. W. Andrew.

Mouse Flea, Pulex musculi ... ... Mr. E. T. Browne.

Plant Bug, Calocoris bipunctatus $ ... Mr. F. Enock.

Organisms found in tube of a carbon filter,^

Protococcus, Diatoms Amoeba, Nematoid >■ Mr. G. E. Mainland,
worms, Infusoria, and Rotifer vulgaris )
Moving bubbles in quartz ... ... Mr. E. M. Nelson.

Young tadpole, showing cilia in tufts cover-") Mr Q Rougselet
ing the whole animal ... ... )

Serial set of sections through a young frog ... Mr. W. Watson.

Attendance — Members, 46 ; Visitors, 4.

94

REPORT OF THE COMMITTEE.

February 25th, 1887.

In presenting this, the Twenty-first Report, your Committee
have at the outset to draw attention to the fact that, in conse-
quence of the alteration in the date of the Annual General
Meeting, which will be referred to later on, it is a record of
the Club's affairs for the past seventeen months.

The general status of the Club has remained practically un-
altered during this period.

Twenty-six new members have been elected since the last
report, and 13 have resigned. Death has removed 11, among
whom we have to deplore no less than three past Presidents,
viz., Dr. W. B. Carpenter, C.B., F.R.S., Dr. T. Spencer
Cobbold, F.R.S., and Dr. John Matthews ; the others being
Mr. H. H. Dobson, who officiated several times as Auditor ;
Mr. Scofield, Mr. John Spencer, Mr. Rhein, the lithographer ;
Mr. W. T. Loy, Lieut.-Col. Salkeld, Mr. Henry Davis, and
Mr. W. B. Leighton.

The meetings have been well attended, and a fair number of
valuable papers submitted to them.

The following is a list of the more important : —

1885.
Oct. 23. " On a New British Species of Vaucheria," by Dr.

M. C. Cooke.
Nov. 27. " On some Microscopical Antiquities," by Mr. E. M.
Nelson.

1886.
Jan. 22. " On Spongia fi-agilis," by Mr. B. W. Priest.

" On a New Form of Fine Adjustment," by Mr. E.
M. Nelson.
Feb. 26. " On a Parasite of (lie Mole," by Mr. A. D. Michael.

95

May 28. " On Diatom Structure," by Mr. Morland.

Ditto, by Mr. Deby.
July 23. " On some New Diatoms from New Zealand," Part

I., by Messrs. Grove and Sturt.
Sept. 24. " On the Kola Bean," by Mr. H. Epps.
Oct. 22. " On Zoothamnium arbuscula," by Mr. Spencer.
Nov. 26. " On some New Diatoms from New Zealand," Part
II., by Messrs. Grove and Sturt.

A series of the new Apochromatic objectives, made by Zeiss,
of Jena, was also exhibited at the October meeting by Mr. T.
Curties.

Some interesting informal communications on various
matters were given by the President, Prof. C. Stewart, Mr.
Buffham, and others, which will be found in the Proceedings.

Your Committee, however, desire to impress upon all mem-
bers the importance of bringing forward subjects — not neces-
sarily new — for discussion ; many facts and matters of in-
dividual experience would thereby become known, and much of
the original intention of the Club fulfilled.

The " Demonstrations ' : previously given on some of the
conversational evenings were intermitted in deference to a
generally expressed opinion that several of the series were
better suited to the business of the ordinary meetings. It is
to be hoped, therefore, that similar material will be forth-
coming in the shape of papers.

Subjoined is a list of the additions to the Library, acquired
either by purchase or presented since the last Report : —

Presented by

Dr. Wythe's " Microscopist," 4th Edition ... The Author.

Pritchard*s "Microscopic Objects" Mr. F. Crisp.

Martin's " Experimental Philosophy " ... ... „

"Quekett on the Microscope" (in German) ... „

" Transactions of the Linnean Society " ... ... „

" Eainey on the Formation of Shell, &c." Mr. F. H. P. Hind.

Dr. Braithwaite's " British Moss Flora," Part 9... The Author.

" Science Gossip " The Publishers.

" Journal of the Royal Microscopical Society ... The Society.
" Pi'oceedings of the Royal Society " ... ... „

" Challenger Reports/' Vols. 12-16 ... ... Purchased.

Dr. Hudson's "Rotifera" ... ... ... ... „

Dr. Cooke's " British Desmids," Parts 1-8 ... „

Teall's "British Petrography," Parts 1-10 ... „

Journ. Q. M. C, Series II., No. 18. 8

06

Poulson's " Botanical Micro Chemistry " Purchased.

Piagefc's " Les PectfonlineB," Supplement ,,

" Quarterly Journal of Microscopical Science'' ... „

" Annals and Magazine of Natural History " ... „

"Grevillca ' ... ... ... ••• ••• ••• »»

"American Naturalist" InExchange.

" American Monthly Microscopical Journal " ... „

" Journal of Microscopy" ... ••• ••• ••• >t

" Scientific Enquirer " ... ... ... ... „

Buckler's " Larvee of British Butterflies and -i By Subscription

Moths," Vol. 1 J Hay Society.

Transactions and Proceedings of various

Societies and Sundry Pamphlets

I

Presented.

A supplemental list of books recently added, or a completely
revised Catalogue of all the works in possession of the Club, is
intended to be issued during the present year.

The following slides have been presented to the Cabinet: —

Mr. G. C. Karop ... ... ... 1

„ H. Morland ... ... ... ... ... 2

„ Smithson ... ... ... ... ... ... 2

„ B. W. Priest ... ... ... ... ... 2

*. o. v_>oiiins ••« ••• ••• »•■ ••• ••• o

j , l j . V^ill 1 ••• ■•« ••• ••• ••* ••• *^

J. <>t;i! . , , »•« . , . . .« I o

It having been represented that the date of the Annual
General Meeting in July was an inconvenient one to a large
number of members, notice was given at the ordinary meeting,
in February, that the next succeeding meeting, in March,
would be made special, according to Rule XII, and a proposi-
tion to alter the date submitted to the vote. A slip, convening
a Special General Meeting for this purpose, was therefore sent
to each member, and, after a full discussion, a proposal to alter
the date of the Annual General Meeting from July to February
was carried by a large majority. It was also decided to post-
pone the next General Meeting until the fourth Friday in
February, 1887.

The Excursions during the past season were well attended,
and more than usually prolific; lists of the "finds" will be
found both in the Journal and in the Excursions portfolio.

The Excursionists' Annual Dinner was held at Leatherhead,
on June 24th, Dr. Braithwaite, F.L.S., in the chair. The

97

arrangements, under the direction of the Sub-Committee, gave,
as usual, every satisfaction, and the day being fine, was greatly
enjoyed by those attending.

It is proposed for the future to hold the Annual Winter
Dinner on the Saturday following the Annual General Meeting
in February. The Committee believe that this will be con-
venient both to town and country members, and it will certainly
facilitate the arrangements of the Dinner Sub -Committee.

Permission to hold the meetings at University College has
again been granted by the Council, with their accustomed
liberality and courtesy.

The thanks of the Committee are due to the several officers
for their services in managing the affairs of the Club, and in
conclusion they feel assured that the forthcoming year will
prove no less successful and productive than any which have
preceded it.

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99

On the Calcarea.
By B. W. Priest.

{Read March 25th, 1887.)

It is with some hesitation I bring this paper before you, for two
reasons, first, because you might perhaps think that I can talk only
of that on: absorbing subject, Sponge, which by-the-bye, has taken
naturalists some years to squeeze much information out of, and,
secondly, in dealing with this group, the Calcarea, I cannot avoid
bringing, on the one hand a little that must be to a certain extent
elementary, and on the other hand I am afraid, parts that may
seem a little technical and dry. It is rather a difficult matter to
collect all the information one would wish, and bring it into a small
compass.

If I have not done the subject justice in the little time that I
have at my disposal, I must ask your indulgence for all short-
comings.

The Calcarea, or Calcispongia, are so named in contradistinction
to the Kerdtosa and Silicea, on account of their spicules being
composed of carbonate of lime.

They take the forms of tri-radiates, quadri-radiates, and acerate
spicules, the tri-radiate being the most characteristic.

They occur separately immersed and distributed in the soft tissues
of the Sponge, never collected into fibres or found anastomosed to
form a regular network, as is the case with some of the siliceous
sponges. In consequence of this, after dissolution of the organism,
the spicules fall apart, and being more or less soluble in sea water,
made it doubtful for some time of their being preserved in the fossil
state.

Of the 137 species described by Hseckel, 18 have the spicules
exclusively tri-radiate; 44 tri-radiate and quadri-radiate ; 61
tri-radiate, quadri-radiate, and acerate ; 8 composed exclusively of
quadri-radiates, and only six species have exclusively acerate
spicules.

Journ. Q. M. C, Series II, No. 19. 9

100 B. W. PRIEST ON THE CALCAREA.

The number of species belonging to this group are few, com-
pared with the Keratosaand Silicea, but we keep gradually adding
fresh specimens year by year, for out of the thirty species dredged
by the Challenger, twenty-three were new to science, and within
the last twelve months Mr. Carter has described several new ones
from South Australia.

The late Dr. Bowerbank enumerates only 12 species in his Mono-
graph on the British Sponges ; eight new forms may now be added
to these.

The Calcarea are properly littoral, growing on or hanging from
rocks, seaweeds, corallines, &c, between tide marks, and often
being found in the pools left behind by the tide on our coasts.

In 1828 the Bev. Dr. Flemming placed all the Calcarea then
known under one heading, viz., Grantia, in compliment to Dr.
Grant for the services he had done in working out the physiology
of the group. But as time went on it became necessary to alter
the classification by degrees, as fresh knowledge was acquired,
until it has reached the present stage.

I will not trouble you by going over the various systems, but
state at once how the Calcarea stand as a group from the latest
investigations. I may find it still necessary, perhaps, to retain
familiar names, with regard to the description of species, as time
will not allow me to do more than describe one species in each
family, and that I shall have to condense into as small a space as
possible.

The Calcarea, then, are now classed by the peculiarities of their
canal system, the early development of the mesoderm, the fact
of the mesoderm giving origin to the generative products, and, as
asserted by some naturalists, the absence of nervous elements,
although what a certain structure met with in the examination of
the sponges can be, but a nervous cell development in a rudimen-
tary state or otherwise, I cannot well see.

According to Dr. Polejaeff, they form an isolated group within
the sub-type of an independent subdivision of the Ccelenterata, and
are divided into two Orders, Homocaila and Heterocwla y including
the Family Asconidw of Haeckel, only in the former, and the two
Families Syconidw and Leuconidce (Haickel), in the latter, with the
establishment of a third comparatively new Family, Teichonida, of
Carter.

The Asconidai, from the Greek Ao-kov, a flask or leathern

B. W. PRIEST ON THE CALCAREA. 101

bottle, comprises at present only one genus, Leucosolenia, of Bower-
bank, the knowledge of this Family being very imperfect in com-
parison with the other three, and also being the simplest form of
Calcareous Sponge, whose walls are pierced by simple canals, the
Sponges themselves forming simple sacs, with a completely flagel-
lated endoderm, or inner membrane, the walls being composed of
ectoderm, mesoderm, and endoderm, the formation of which we
shall see further on when treating briefly with the embryology of
the subject. This Family may be simple, branched, or united into
a common stock, Leucosolenia botryoides; (Bk.), belonging to it.

The Syconido?, from the Greek %ukov, a fig, sponges of this
family formerly being likened to the shape of that fruit, comprises
six genera, Sycon (Nissa), Grantia (Fleming), Ute (0. Schmidt),
Amphoriscus (Hasckel), and the two new genera Heteropegma and
Anamixilla (Polejaeff). The Sponges of this Family are mostly
solitary, with thick walls, which are pierced by straight radial
tubes, the latter in some species projecting on the surface as conical
prominences, Grantia compressa and ciliata (Bk.) belonging to this
Family.

The Leuconidce (from Aevkos, white) comprises the following
genera: — Lcucilla and Leucetta (of Hseckel), Leuconia (Bk.), and
the new one, Pericharax (of Polejaeff). These sponges have thick
walls, which are pierced by branched channels, and remind one
more of the complicated water canal systems to be found in the
non- Calcareous sponges, Leuconia nivea (Bk.) belonging to this
Family.

The Teiconidce (Teichojiia, Carter) contains two genera, both,
the latter especially, being comparatively new, viz., Teichonella
(Carter) and Eilhardia (Polejaeff).

The Sponges are peculiar in that the differentiation of the outer
surface is divided into two quite different parts, that bearing oscula
and that bearing pores.

In 1878 Mr. Carter described and figured a species from Aus-
tralia, Teichonella prolifera, a specimen of which was also dredged
at Bognor by the Rev. Henry Fase, I think in 1880, which he
kindly gave to me along with others. I have not heard of its being
found before or since on our shores.

As I mentioned just now, the walls of the Calcareous Sponges
are composed of three layers, the ectoderm, mesoderm, and endo-
derm. The ectoderm, or outer membrane, is composed of flattened

102 B. W. PRIEST ON THE CALCAREA.

polygonal epithelium cells, which cover the whole exterior of the
sponge, and line more or less the incurrent canals, the margins of
the cells being invisible, until treated with nitrate of silver. The
pores which appear on the surface are the inlialent openings, and
are in reality only intercellular spaces, which close themselves,
vanish, and are replaced by new pores, which arise by the separa-
tion of one cell from another.

The endoderm, or inner membrane, consists of elongated cylin-
drical flagellated cells, possessing at their free ends a flagellum,
surrounded by a delicate hyaline marginal membrane, which is
derived from a prolongation of the hyaline plasma, projecting as
a hollow cylinder, resembling the protoplasmic collar of certain
Flagellata, which structure is commonly known as the collar, and
the cells as collared cells. It was from the presence of these
flagellated cells that the late Professor Clark, with some other
naturalists, thought that the sponges were allied to the Flagel-
lata, regarding them as great colonies of the same. These cells,
no doubt, play the part of propelling the currents of water
through the different channels, and likewise take up some of the
nutriment beneficial to the sustenance of the sponge.

The mesoderm lies between the ectoderm and the endoderm,
and is probably derived from the former. It consists of a clear,
jelly-like matrix, in which are to be found irregularly branched or
spindle-shaped ameboid cells. It is in this layer we find the
spicules and reproductive products take their origin. The ova are
naked amaeboid cells, taking their origin from the cells of the
mesoderm, and, as far as the Syconidce are concerned, are vivi-
parous, remaining in the mesoderm and there undergoing develop-
ment ; it is very probable that the same occurs throughout the
Calcarea. The ova, after going through the usual segmentation,
first dividing in two, then four, and next eight cells, by further
subdivision gives rise to a solid cluster of cells, called morula, the
cells forming a single layer about a central cavity (blastula), which
normally is completely closed, but in some instances is known to
be open at the poles.

In the next stage of the Calcarea an amphiblastula is formed,
which consists of a hollow sphere, one hemisphere formed of a
single layer of small, transparent, cylindrical, flagellated cells
(epiblast), the others of large, granular, rounded, and not flagel-
lated cells (hypoblast). It results from a metamorphosis of the

-

B. W. PRIEST ON THE CALCAREA. 103

blastula, the cells of which are partly converted into flagellated
cells, while a few at the base become granular, and produce the
larger rounded cells. It has now become a free swimming larva,
and passes from the parent sponge by the canals and out at the
oscula. After some little time the flagellated cells become
gradually withdrawn or invaginatedinto the hemisphere of granular
cells ; the central cavity of the amphiblastula is obliterated, and
replaced by another, surrounded by the flagellated cells. The
larva or embryo now consists of a sac, with a two-layered wall,
and a central cavity communicating with a mouth. After a while
it settles down on some foreign object, the outer granular cells
become the ectoderm, with its usual characters, the inner flagel-
lated cells, the endoderm, and the mesodermic layer appears
between the two. The embryo now lengthens, pores appear in its
sides, and an osculum opens at the free end, the original opening
bavins: become closed soon after the attachment of the larva. The
spicules now develop in the mesoderm, and it is a curious fact that
they have been seen in the embryo before leaving the parent, in
some cases.

As before stated, the Asconidce are the simplest forms of the
calcareous sponges having a continuous flagellated endoderm,
Leucosolenia bottyoides being an example of this Family, and often
found on our coasts. Some very fine specimens were collected at
the Whitstable excursion of this Club last year (1886). It is
found parasitical on Alga5 and Zoophytes, and in general appear-
ance is arborescent, cylindrical, slightly pedicelled ; surface ap-
parently smooth, cloaca very large, armed internally with spiculated
equi-angular tri-radiate spicules ; spicular ray large and long,
slightly curved ; mouths of cloaca one or more, terminal simple,
and unarmed. Oscula and pores inconspicuous, spicules of skeleton
equi-angular, tri-radiate ; radii somewhat short and stout, rapidly
attenuating. Occurring, as this sponge does, in tufts, it might at
first sight be thought to be one complex sponge, but on careful
examination it will be found to be composed of numerous indivi-
duals clustered together.

The Syconidce come next in order, having their walls pierced by
radial tubes, which tubes are lined by the flagellated collared
cells, and are only invaginations of the gastric wall, the latter thus
being covered with the pavement epithelium only, as occurs in the
ectoderm.

104 B. W. PRIEST ON THE CALCAREA.

Grantia ciliata belongs to this Family, and is certainly one of the
prettiest as well as interesting forms of the Calcarea found on our
coast. It is parasitical on Algae, Zoophytes, &c, and likewise
dredged from eight to ten fathoms. It varies in size, the largest
that has been found being about three inches in length. The
sponge elongately oval, sometimes globular, slightly pedicelled ;
surface papillated, hispid. Cloaca central, cylindrical, nearly as
long as the sponge ; armed internally with spiculated, equi-
angular, tri-radiate spicules; spicular ray attenuated. Mouth of
the cloaca armed with a thick ciliary fringe of very long and
slender acerate spicules ; base of the fringe supported by large,
short and stout fusiform acerate spicules. Oscula simple, very
slightly depressed from the surface of the cloaca. Pores incon-
spicuous. Interstitial cells, distal terminations more or less
obtusely conical, furnished with a ciliary fringe of slender acerate
spicules. Skeleton spicules equi-angular tri-radiate. Besides the
spicular defences of the mouth of the cloaca, there is often a
membrane found at the base of the neck of the cloacal orifice,
forming a sort of diaphragm. It appears probable that besides
being able to close the mouth of the cloaca by the approximation
of the distal termination of the ciliary spicules, it lias also the
power of completely closing it by the extension of a veiling
membrane or diaphragm. In the same way the pores of the
sponge are protected and hidden by similar ciliary spicules, the
mechanism of which is simple and interesting. In the process of
inhalation of water and distension of the distal extremity of the
interstitial cell, the cone of spicules is expanded into a cylinder,
causing the access of nutritive particles to the pores. When the
action ceases a collapse of the cell ensues, and the distal points of
the spicules again approach each other, thus stopping anything
from entering the pores.

We now come to the Leucones, which are modifications of the
Sycones, their flagellated chambers being complete homologues of
the radial tubes; their exhalent canals owing their origin to the
invaginations of the inner cavity, and their inhalent canals re-
garded as homologous with the inter-canals of the Sycones, so
that these families approach nearer to the same type than in the
majority of sponges.

Leuconia nivea, being an example of this Family, may often be
met with, appearing as white crusts on the under surface of rocks

B. W. PRIEST ON THE CALCAREA. 105

between tide marks on our coasts. It is sessile, massive, or coat-
ing ; surface lobular or crested, smooth. Cloacae numerous,
mouths simple, armed internally with very large and stout equi-
angular spiculated tri-radiate spicules, radii attenuated.

Membrane of cloaca furnished abundantly with unicurvo-cruci-
form spicules. Oscula numerous, simple, dispersed over the sur-
faces of the cloaca?. Pores minute. Spicules of the skeleton equi-
angular tri-radiate, very variable in size and stoutness. Spicules of
interstitial and dermal membrane small, acerate, and minute
attenuato-spiculated tri-radiate spicules ; spicular ray short, basal
rays tri-podate. This species never attains to any great size, the
largest I have seen being one sent to me by my friend Mr. Hillier,
of Ilamsgate, and dredged off that coast ; it measures two inches
by one and a quarter.

I now come to the third and last Family included in the order
Heteroccela, viz., the Teichonidce of Carter.

I shall take Mr. Carter's description of Teichonella prolifera as
the example. This species simply consists of parenchymatous
structure, traversed by excretory canal systems, which, beginning
by small branches in the interior, terminate respectively by open
naked mouths at the surface, supported on a staple mass of small
radiates, accompanied more or less plentifully by very large ones,
which, from their much greater size, are rendered very conspicuous.
Thus we have no longer any cortical differentiation on the surface,
nor any cloacal cavity interiorly, but so far simplified structure that
it becomes identical with that of the common run of non-calcareous
sponges.

In general appearance it is vallate, foliate, vertical, plicate, pro-
liferous. Pores invisible to the unassisted eye, scattered over the
surface thickly and generally. Vents slightly marginated, naked,
arranged more or less in single line along the margin only.
Spicules of two forms, tri-radiate and quadri-radiate, both of two
sizes.

Mr. Carter, in his first description of this Family, included a
second species, viz., Teichonella labyrinthica, with the one just
described ; but on examining specimens of the same in the col-
lection sent to him by Mr. Wilson, of South Australia, he finds it
necessary to relegate it to the vicinity of Grantia compressa, still
retaining the specific name.

I have now described as briefly as I could four of the species

106 B. W. PRIEST ON THE CALCAREA.

comprised in the two orders HomocceJa and Heteroccela. The
throe firsl mentioned being frequently met with on our own shores,
and often found growing together, will give anyone interested in
the subject plenty of opportunities for studying their histology.

In preserving and mounting in the dry state the Calcarea, or
portions of the same, small specimens can be selected and mounted
in Canada Balsam in glass colls, fixed to the slip with marine glue,
and also vortical sections done in the same way. To preserve the
spicules of the different species apart from the sponge, heat por-
tions in liquor potassae, when they will soon separate and fall to
the bottom of the vessel, washing well with distilled water and
mounting in Canada Balsam. Do not attempt to mount in gly-
cerine, as, being calcareous, they will be sure in time to dissolve
away.

For examining the soft structures of these sponges, put them
straight from the sea-water into a one-per-cent. solution of osmic
acid, when, on cutting sections tolerably thin, the collared cells,
with their flagellar expanded, will remain intact, and other struc-
tures, which would otherwise be shrivelled up and lost, can be
tolerably well made out with high powers.

To those who would wish to go further into the histology of the
subject, I would recommend them to consult Haeckel's " Mono-
graph of the Calcareous Sponges," Dr. Bowerbank's monograph of
the same, and Dr. Polejaeff's " Report on the Calcarea of the
Challenger Expedition/' to which may be added .Air. Carter's
account of the same from South Australia in the " Annals of
Natural History" for 1886.

The following is a list of Calcareous Sponges found on the
British Coast : —

fj'ucosohnia botrt/oides (Bk.).

Leacosolenia contorta (Bk.).

/. ucosolenia coriacea (Bk.).

Leucosolenia laciinosti (Bk.).

/. ucosolenia lacunosa, var. Hillierii (Carter).

Ascaltis Darwinii (Haeckel).

Clathrina clathrus (Gray).

Gran ti> compre8sa (Fleming)!

Qrantia cili<it>i (Fleming).

Grantin t uxcita (Bk.).

Grantia tessi llata (Bk.).

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B. W. PRIEST ON THE CALCAREA. 107

Grantia ciliata, var spinispicala (Carter).
Aphroceras ramosa (Carter).
Leuconia nivea (Bk.).
Leuconia fistulosa (Bk.).
Leuconia pumila (Bk.).
Leuconia Johnstonii (Carter).
Leucogypsia Gossei (Bk.).
Teichonella prolifera (Carter).
Trichogypsia villosa (Carter).

EXPLANATION OF THE PLATES.
Plate VII.

Fig. 1. Mature ovum of sponge.
,, 2-3. The same in process of segmentation.
„ 4. Blastosphere, with dark granular cells.
„ 5. Free swimming larva with endodermal ciliated cells, and

ectodermal granular cells.
,, 6. Diagram, showing position of a, ectoderm ; b, mesoderm ; c,

endoderm in wall of sponge.
„ 7. Group of Leucosolenia botryoides, Bk.,on weed.
„ 8. A small portion of the sponge enlarged.
,, 9-10. Spicules of the same.

Plate VIII.

Fig. 1. Group of Grantia ciliata, Bk.
„ 2. A large variety of the same.
„ 3. Vei'tical section of Grantia ciliata showing the position of the

radial tubes.
„ 4 to 10. Spicules of the same.

,, 11. Leuconia nivea, Bk., encrusting rock, natural size.
,, 12. Section of the same, showing ampullaceous sacs, with collared

cells in situ, drawn from specimen.
„ 13 to 18. Spicules of the same.
„ 19. Teichonella prolifera, Carter. Upper view showing margin of

lamina and vents.
t , 20. The same, lateral view of vertical section showing excretory

canal systems and vents. (Carter).
., 21-22. The two spicules of the same.

108

On Mounting Media so far as they Relate to Diatoms.

By H. Morland.

(Read April 22nd, 1887.)

The object of my paper this evening is not only to give some
information and to offer some hints relative to the various
media in which the Diatomacess are mounted, but also to
solicit such information and hints in return from those members
who have paid special attention to this subject. I have myself
worked at several of the media to which I shall refer, but
others have never yet come into my hands ; but having seen
slides prepared with them, added to remarks I have heard
made relative thereto, I venture to treat this subject as a
whole. With this explanation, it can be readily understood
that this paper is by no means exhaustive of the subject taken
in hand.

Mounting media, for convenience sake, may be divided into
four classes, viz., Air, Fluids, Resins, and Chemicals. I will
treat of these classes in the order in which I have named them.
Air. — This medium, in consequence of the introduction of
immersion lenses, is now almost out of date ; still, for ordinary
dry lenses, it is as useful now as ever it was, and even for
immersion lenses it answers for those parts of the diatom valve
which touch or are adherent to the covering-glass. Diatoms
mounted in this medium (or in any other) should, as a rule, be
on the underside of the covering-glass. They should be
perfectly dry, and the system of sealing them up by means of
damp cements cannot be too strongly condemned, as in such
case the cover-glasses are certain to get " dewed " in course of
time, the " dew-drops ' in many instances surrounding the
diatoms, and interfering with their due examination; to over-
come this difficulty, 1 always attach my covers by means of
heat to rings of perfectly hard and dry cement on the slide.
Slides with air-mounted diatoms ought to be carefully handled
w lien being cleaned, for if too much pressure be applied to the

H. M0RLAND ON MOUNTING MEDIA FOR DIATOMS. 109

covering-glasses the same will yield to a slight extent, and the
diatoms either get crnshed between the slip and cover, or be
transferred from the latter to the former.

Fluids. — Although certain of these media, such as biniodide
of mercury with iodide of potassium, as well as oil of cassia,
can be obtained with fairly high refractive indices, yet I cannot
too emphatically condemn them for use with the higher powers
of the microscope, simply from the fact that the diatoms will
not remain on the cover-glass, but must necessarily fall to the
bottom of the cell, which consequently must be very shallow,
otherwise the diatoms will be beyond the focus of the objective.
With shallow cells in fluid mounts the diatoms can easily get
crushed on cleaning the cover-glasses. If it were not for these
fatal objections, I should be disposed to regard oil of cassia
very favourably as a mounting medium, as these essential
oils give great brilliancy, but whether they can be effectually
sealed for a permanency I cannot say. I once mounted a slide
in oil of cloves, and it remained perfect for some considerable
time, but eventually a bubble made its appearance. I have
never seen a slide of diatoms mounted in biniodide of mercury
and iodide of potassium, and am inclined to think that this
medium is very little used.-"

Resins. — This class of media is about the most generally
used for mounting diatoms, and for ordinary mounts they will
be found hard to beat ; they differ somewhat from each other
in their way of working, and in their refractive indices. In
speaking of them I will take them seriatim.

Canada Balsam. — This is the oldest and most generally
known of the resin media ; it requires hardening by means of
heat, and if not overdone there is still left a certain amount of
toughness which enables the slide to withstand ordinary fair
handling. The only objection to my mind against this medium
is that its refractive index is not sufficiently high for the new
immersion lenses, that is, for the finer kinds of diatoms ; still,
for the coarser kinds, say four out of five species at the very
least, Canada balsam, taken all round, still remains as good as

* Since writing the above I have learnt, with respect to the solution of
biniodide of mercury and iodide of potassium, that the medium is of such
high specific gravity, viz. 3'02, that any diatoms which fnay chance to be-
come detached will float in the fluid and press upwards against the
covering-glass, instead of falling to the bottom of the cell. — [H.M.]

110 H. NORLAND ON MOUNTING MEDIA FOR DIATOMS.

any other medium yet brought forward. Although balsam is
comparal Lvely colourless in its natural state, it gets to be a very
deep yellow when hardened by means of heat; this colour is,
however, scarcely noticeable when in a very thin layer under a
covering-glass. If over-hardened, balsam becomes brittle, and
the cover is easily detached by a blow or rough usage ; on the
other hand, if under-hardened, not only w r ill the slide be too
tender to handle, but the refractive index will be considerably
lower than should be the case. ^

Styrax. — This is a medium about which a deal of misconcep-
tion exists. As a matter of fact, no styrax, so far as I am aware,
has yet been used as a mounting medium for diatoms or any-
thing else ; but I must explain. The true styrax is a product of
styrax officinale, belonging to the order Styracece. It is a
native of Greece, the Levant, and Asia Minor, and was the
source of the original and classical storax. It has, however,
now wholly disappeared from commerce, and I much doubt if it
be obtainable in this country, its place, so far as our British
Pharmacopoeia is concerned, being now supplied by the product
of Liquidamber orientate, belonging to a totally different order,
viz., the Altingiaceae. This substitute can be purchased at any
chemist's. When getting it " strained styrax " or " styrax
colat " must be asked for. It has a strong resemblance to very
thick treacle, is full of fine dirt, and, I think I may add, of
moisture also. There is yet another false styrax, sometimes
called " American styrax," which is the product of " Liquid-
amber styraciflua " or " sweet gum," a tree found in the
Southern States of America, mostly, I believe, in damp situa-
tions. This latter medium is not, however, obtainable in
England, and it is only comparatively recently that I have been
able to ascertain where it could be obtained in the States, as
even in its native country it is difficult to get hold of. I shall
be happy to give the address to anyone desiring the same.
Like the other false st}Tax, this American styrax is also sup-
plied in a rather dirty state. As the true styrax has no
existence so far as we are concerned, I shall now speak of the
other two media simply as " styrax " and " American styrax."
Both the styraces, which were first introduced by Dr. H. van
Heurck, of Antwerp, can be dissolved in either benzole or
chloroform and afterwards filtered. They are apt to deposit a

H. M0RLAND ON MOUNTING MEDIA FOR DIATOMS. HI

fine sediment in the bottle some considerable time after filtra-
tion, which I consider to be due to the presence of moisture
contracted during the process of obtaining these resins, the pre-
pared media being what I believe is called in the varnish trade
" chilled." If only in small quantity the heat applied during
the process of mounting will drive it off again, but it is better
either to pour off the upper clear portion into another bottle or
to use a " capped balsam bottle ',' with a suspended glass rod for
mounting, and which is never allowed to touch the bottom and
stir up the sediment. Whilst on the subject of this sediment I
may here state that I once had a small quantity of the ordinary
styrax in a pot, which I placed in a cool oven and left there for
some considerable time until it became perfectly hard. I then
dissolved it with difficulty in alcohol, filtered it, evaporated
nearly the whole of the alcohol off again, and thinned it down
to a proper consistency with chloroform. Although very dark
this styrax is as clear now as it was when first prepared, now
over two years ago.

The ordinary styrax is somewhat difficult to harden. The
best way of doing so is by a long continued heat, a considerable
amount of which it will bear, but usually this styrax is not
finished off hard, but merely tough, and I therefore always
strengthen my mounts by the addition of a ring of cement to
the covers. If the styrax be over-heated it becomes charred,
and small specks of carbon can be seen disseminated through it
when viewed under the microscope. Styrax is a very useful
medium for the finer kinds of diatoms, which it shows up much
clearer and brighter than balsam. Some forms, almost invisible
in balsam, are shown up with great distinctness in styrax. For
the coarser kinds of diatoms this medium is not really needed.

American styrax, unlike the other, hardens just like balsam,
but when heated it becomes extremely fluid. Having a high
refractive index it is particularly useful for the finer diatoms.
On account of its fluidity when heated I should be inclined to
confine the use of this medium to the smaller diatoms, lest the
cover should, during the process of mounting, sink down on the
larger forms and crush them.

Balsam of Tolu. — I have never had anything to do with this
medium. I did once think of taking it in hand, but before
doing so I referred to Watts' " Dictionary of Chemistry "

112 H. MORLAND ON MOUNTING MEDIA FOR DIATOMS.

(belonging to a friend of miner), and as something was men-
tioned about crystallization 1 decided to leave it alone. Since
then there have been complaints made about this objectionable
property. On the other hand some microscopists continue to
use it, and seem satisfied with it.

Gum Dammar has also been used as a mounting medium ;
it requires dissolving in some solvent, such as benzole ; its
advantages are that it is colourless and dries quickly ; its dis-
advantage is that when quite hard it is about as friable as
chalk. I consider its proper place is in the preparation of
" ringing" cements to which it gives a nice gloss.

A number of other resins have also been tried, but I don t

know that any of them have shown any advantages over Canada

balsam or styrax, and I am unable to report upon any of them.

Although slides of diatoms mounted in any of the resins will

stand fair treatment, they will not bear any amount of rough

handling. It must not be forgotten that diatom valves are

composed of silex, a brittle substance ; if, therefore, the balsam,

styrax, or other medium be tough, and the cover glass be

rubbed or wiped somewhat roughly, the medium will yield to a

slight extent, but not so the diatom valves, which consequently

will get cracked, though the fragments will continue to be held

in position by the medium in whicli they are mounted. Balsam

slides may be perfectly hard at the edges of the covering glass,

but only tough in the centre part ; if such slides be left to

themselves for a few days in a cool place, the density of the

balsam will become a little more homogeneous in consequence of

the diffusion of the residual solvent in the centre part throughout

the mass, though the outer portion will always remain a little

harder than in the centre, as the solvent gets dried up almost

as soon as it reaches the circumference.

Chemicals. — The sole object of using chemicals as mounting
media, is to obtain a higher refractive index than is afforded by
the resins ; unless such refractive index can be obtained they
have no raison ftetre. So far as my experience of them goes,
they are either difficult to manipulate or they cannot be relied
upon for permanency, with, perhaps, the single exception of
monobromide of naphthaline, which, however, I do not consider
to be any advance upon styrax, as diatoms mounted in this
medium do not exhibit anything like the brilliancy given them

H. MORLAND ON MOUNTING MEDIA FOR DIATOMS. 113

by styrax. I should be disposed to give the palm to phosphorus,
it having an extremely high refractive index. I have never
worked at it myself, but from all accounts it is very difficult of
manipulation ; it requires being dissolved in bisulphide of
carbon, but no more of this must be used than absolutely
necessary, as otherwise the high refractive index is considerably
reduced. Complaints have been made about phosphorus slides
not being permanent, but, on the other hand, I believe that Mr.
Stephenson, who first made use of this medium, has perfect
phosphorus slides in his possession which have been mounted
for some years past. Prof. H. L. Smith's and Dr. S. Meate's
media are both of the same class, having the elements of
sulphur, arsenic, and bromine in each ; slides newly-mounted in
these media are superb, but from what I have heard, and from
my own experience of Dr. Meate's compound, I should say that
neither of them is to be relied upon ; sooner or later a granu-
lation sets in, and it is only a question of how long it will be
before the whole of the mount is thus disfigured. I believe that
some microscopists may be found who may be disposed to think
that some slides mounted in Dr. Meate's medium may prove
permanent, to which I answer that the large number of failures
is more than a sufficient reply ; a medium is not to be depended
upon unless you can rely upon having a larger proportion of
permanent slides than, say, one out of a dozen mounts. It has
struck me that possibly the non-permanency of these two media
is due to the evaporation of the bromine, and that if a proper
cement were found for confining the same, they could then be
used with every confidence in their efficiency.

Prof. H. L. Smith has also introduced two other chemical
media with high refractive indices, but lower than those just
referred to. Of one, called " Stannous Chloride Medium," I
know little or nothing, and am unable to say whether it has
proved permanent or not ; the other medium, a preparation of
antimony bromide and boro-glyceride, is in my hands, as well as
in those of a correspondent of mine in America, a distinct
failure ; at first, all was superb, but after a short time crystals
began to make their appearance and gradually spread all over
the mount, completely spoiling it.

I have seen an account of another chemical medium, viz.,
sulphur in aniline, and thought I would try my hand on same,

114 B. MOIILAND ON MOUNTING MEDIA FOR DIATOMS.

but, to my astonishment, on trying to dissolve the sulphur in
the aniline I found it to be insoluble, though a friend of mine, a
chemist, tells me that sulphur dissolves freely in aniline-
Under these circumstances I am unable to give any opinion on
this medium, further than that if the solution can be prepared
and permanently sealed on a slide it ought to be satisfactory
so far as regards the refractive index, but has the objection of
beinor a fluid.

A medium of high refractive index is certainly a desideratum,
but it must be permanent, and if one could be discovered which
could be prepared and manipulated by any microscopist not
having special knowledge of chemistry, why so much the
better. On the other hand, it is a comfort to the ordinary run
of diatomists to know that there are really only few diatoms
that absolutely require such high refractive media.

115

Extract from a Monograph, " Zur Kenntniss der Phycomy-

CETEN."

By Dr. W. ZorF, in the " Nova Acta Acad. Caesar. Leopold.
Carolin. Germ. Nat. Cur." Halle, Bd. XLVII., No. 4.

Translated with the sanction of the Academy by George C. Karop,

M.B.C.S., F.R.M.S.

{Bead April 22nd, 1887.)

Ectrogella Bacillariacearum,* Zopf. An Endophyte in-
festing the Diatom acea3.

The author begins by stating that most observers of the Diato-
macese are aware that this family of the Alga? has enemies among
the Fungi and Mycetozoa. They belong partly to the group of
Monadines, partly to the ChytridiaceEe and Ancylisterc.

He quotes Cienkowski's investigations on Vampyrella, vorax,
which low Myxomycete preys upon Diatoms of all species. Also
Braun and Nowakowski, the former of whom discovered the para-
sitism of Chytridium Lagenula on Melosireae, and the latter found
a form of the same parasitic on Epithgmia Zebra. In these how-
ever, the sporangia are developed externally to the host.

Purely endophytic Diatom parasites were subsequently observed
by Focke, and again by Pfitzer.

Having thus shown that a small series of Diatom parasites is
already known, the complete life histories of which however are
still wanting, the present author proceeds to a description of a new
and fatal enemy of the Diatomaceaa, which also possesses some
special morphological features.

He says : I found the Ectrogella Bacillariacearum in a large-
celled Synedra, growing on the rootlets of Lemna minor, in
stagnant water. About the middle of November it occurred in
such numbers that 75 per cent, of the host-plants from this par-
ticular locality, near Berlin, were attacked by the parasite. In

* From tKTpioyeiv = to eat up or devour.
Jouen. Q. M. C, Seeies II, No. 19. 10

116 W. ZOrF ZUR KENNTNISS DER PHYCOMYCETEN.

subsequent cultivations made in large vessels at the ordinary room-
temperature, hardly a single non-infected specimen could be found
after some time, proving that even the above high percentage
might be exceeded. This is explained by the immense fertility of
the fungus in zoospore production. The disease runs an absolutely
fatal course. As regards other species of Bacillaria being affected
by the parasite, I was enabled to confirm the fact so far that in
each culture a species of straight Synedra, also the curved S.
lunularis, a Gomphonema y and a large Pinmdaria were attacked.
Nevertheless, the fungus appeared to prefer the Synedra?, particu-
larly the larger forms with rich contents, as well as large Pinmi-
larice. At any rate, it was only found in a few of the relatively
small Gomphonemas.

The development was uninterruptedly followed out, as far at
least as the formation of swarm-spores.

It appears to be a special characteristic of these Olpidiea? that,
under favourable conditions of nutrition, their vegetative portion
forms a sac which attains a relatively considerable length. I have
frequently observed individuals whose mycelial sacs extended to
nearly the entire length of the largest forms of the Synedrce under
consideration, that is to say, 200 /x or more. Such like sacs, in the
form of thick vermiform threads, so strikingly resemble the mycelial
stages of many Ancylistea? (particularly Pfitzer's A. Closterii, as
well as many forms of Lagenidinm Rabenhorstii), that at first,
before knowing their development, I was inclined to regard them
as the receptacles of these fungi. They are always unbranched,
probably for the reason that their relative thickness, as compared
with the lumen of the host-cell, allows of too little space for the
development of lateral axes. Under unfavourable conditions of
nutrition, mostly due to more than one parasite occupying the same
foster plant, the mycelial sacs are much curtailed in length,
occasionally becoming reduced indeed to quite short, spindle-
ellipsoidal, or even spherical bodies often of extreme minuteness.
The latter mostly occurs when the parasites invade a Synedra
whose contents have already been more or less consumed by one or
several larger individuals, or when they develop in great numbers
in the host-cell.

For instance, in the rich material at my disposal I often met
with Synedrce in which 20 to 30 were present, yet which at first
only occupied a part of the foster-cell. That these truly dwarf-

W. ZOPF ZUR KENNTNISS DER PHYCOMYCETEN. 117

like forms, in comparison "witli the fullj-developed plants, were
really Ectrogellae, and did not, as might easily have been supposed,
belong to another parasite, was proved by the existence of all
possible intermediate grades, and will also be put beyond all doubt
by the subsequent details of the development. I shall at the same
time show that, singularly enough, these colonies of minute forms
did not reach the interior of the host-cell by migrating through its
investing membrane. As already mentioned, the shape of the
freely-developed sac is vermiform ; where room is wanting however,
the configuration of the individuals is influenced by conditions of
mutual pressure. For instance, the ends of two or more opposed
individuals are frequently tapered off by their forcing their way
like wedges between the walls of the host and a neighbouring
parasite, and this tapering is met with sometimes at one, and
sometimes at both poles. The contents of the receptacles at first
appear finely-granular, later on it is pervaded by great numbers of
closely-packed coarser and highly-refracting corpuscles, so that the
sacs form easily-seen objects. One may also frequently observe
the formation of vacuoles, which often attain to considerable
dimensions. This is not the case, however, in the more robust and
lusty individuals, and appears to indicate an abnormal condition of
the contents.

In consequence of its great delicacy no membrane is apparent at
first sight. It may be easily demonstrated however by means of
staining 1 .

From the Ancylistic-like condition of the mycelial receptacles, at
least in their largest forms, one might expect them to become seg-
.mented by partition walls at the beginning of fructification, but
this does not occur. Even the longest mycelial sacs form only a
single receptacle. The plasma collects after the well-known fashion
round the numerous nuclei to form an equal number of swarm-
spores. These latter are extremely minute, usually from two to
three jx in diameter, rarely more ; they exhibit feeble amoeboid
movements, and are provided with a somewhat highly refractive
tiny nucleus and a distinct cilium. They escape by excretory
ducts, which are, as a rule, already visible as short papillae before
the commencement of swarm- spore formation, and which, later on,
open by mucous degeneration of their apices.

The fact of many excretory ducts being formed in the larger
sporangia is particularly characteristic of Ectrogella (I have counted

118 W. ZOPF ZDR KENNTNISS DEB I'lIYf OMYCETEN.

as many as 10). The medium-sized usually possess from three to
five, sometimes only two, whilst in the smallest one to two at the
most ocenr. Their position is a fixed one, inasmuch as it always
corresponds to the girdle-band (front) view of the diatom cell.
Sometimes they are arranged in a single, sometimes in a double,
row. In the latter case one row corresponds to the anterior, the
other to the posterior surface of the girdle-band.

That this is the case is most readily understood by observing the
valve-view of the Synedra; the excretory ducts will then be seen
lying to the right and left.

Moreover, the excretory ducts are distinguished by the fact that
they are of a much stouter texture as compared with the extremely
delicate wall of the sporangium ; ami, as is shown by the use of a
solution of iodised zinc-chloride, they consist of cellulose.

It is further remarkable that the excretory ducts are not com-
pelled to perforate the siliceous membrane. The pressure, namely,
exerted by one or more parasites as they increase in girth, on the
two valves of the host-cell, causes them to bend outwards, so that
the Synedra now, in a girdle-band view, appears broadest in the
middle ; finally, the frustule dehisces entirely. This process is
completed before the excretory vesicles of the sporangia are ready
to force themselves through the siliceous membrane (if they are
able to do so at all) — indeed, often before the vesicles have arrived
at maturity — so that any necessity for penetrating the membrane is
avoided. Of course, it not infrequently happens that the sunder-
ing of the valves does not take place sufficiently early. But even
in these cases the siliceous membrane is not perforated by the
vesicles. The latter then either do not open at all (and this is not
uncommon), or the swarm-spores are evacuated into the closed
diatom cell. Instead, however, of these imprisoned zoospores
perishing, as is the case in most of the Chytridiaceas, they, pro-
vided of course the host-cell still contains a sufficiency of nutri-
ment, grow to new parasites, having burst or crushed the
degenerated sporangial membrane. These non-immigrated para-
sites, in consequence of their numbers and unfavourable food con-
ditions, always remain in a correspondingly rudimentary condition,
and either retain their spherical form or, at most, become ellipsoidal
or spindle-shaped. They develop into sporangia. The fact that
numerous rudimentary parasites may be present in the long
sporangial sacs, loses its singularity when we are acquainted with

Journ. Q.M.C.

Ser.II.Vol.S.Pl.lX.

.---ptCT^ ^iM i Mi' i' i 'xcc^ra^T^i iTrrrrTn . - i.^ t

G.C.Katojj del.afUrW/opP Nova. Acta. C L.C.G. No.t. Cur. Vol . .-.

<Vest^ewman&.Co. 1 itii.

W. ZOPF ZUR KENNTNISS DER PHYCOMYCETEN. 119

this method of swarm-spore development. The free condition of
the zoospores is strikingly short. As soon as they escape they
make for the nearest Synedra and fasten upon it ; too many as a
rule, often 40 or more. The great increase of the fungus is suffi-
ciently explained by their number and rapid development into
sporangia, which is completed in from 24 to 48 hours.

The effect of the fungus on the host-plant is first manifested by
an alteration in the shape and position of the chlorophyll bands.
They recede from the walls, contract in direction of their length,
and become closely applied to the parasites ; in some instances
they form curved strands or lumps. Simultaneously the nucleus
is dissolved and the plasma contracted. Later on, in consequence
of the pressure exercised by the parasites, the valves fall asunder.

As regards the systematic position of Ectrogella, it may be
determined with certainty by the sporangial fructification. The
form of the mycelial sacs undoubtedly coincides with that of the
Ancylistece ; nevertheless, as the entire vegetative partis transformed
into a single sporangium, and the swarm-spores are spherical and
uni-ciliate, it has a distinct affinity to the Olpidiece. It stands to
Ancylistes, as Olpidiopsis to Myzocytium.

EXPLANATION OF PLATE.

All figures magnified 300 diameters.

Fig. 1. Synedra, with a large and almost fully developed mycelial sac.

2. Synedra, with two young mycelial sacs.

3. Synedra, with numerous nearly mature small parasites, of
various size and shape.

4. Stouter mycelial sac, constricted at its upper third and tapered
at both poles. It contains two vacuoles. At O is seen the
papilliform rudiments of two excretory pores. The valves of
the Synedra are slightly driven outwards by the expansion of
the parasite.

5. Synedra, with one valve separated. The five sporangia are free,
and exhibit various stages of development. At A, the spores
are already mature.

6. Valve view of a Synedra. One (A) of the sporangia shows the
excretory papillae pushed past the separated girdle-band.
A few Ectrogella spores have just fastened on the outer
membrane. A, a single swarm-spore.

7. Girdle-band view of a Pinnularia, with a nearly mature parasite.

8. Empty sporangium, with the excretory pores arranged in two rows.

9. Empty sporangia, the upper having two, the lower only one
excretory pore.

»»

»>

»>

J5

120

On the Structure of the Head of the Blowfly Larva,
and its Relations to that of the Perfect Insect.

By B. Thompson Lowne, F.R.O.S.Eng., F.L.S., &c, Professor
of Biology at the Royal Veterinary College, &c, &c.

(Bead June 24th, 1887.)

The larva of the blowfly is frequently described as acephalic or
headless ; more correctly it is without any chitinised cephalic
shield (Kieferkapsel), for a head is certainly present although in
many respects it is rudimentary.

In the egg, twelve hours after impregnation, the embryo
possesses a head ; in most respects similar to that of an embryo in
which a chitinised head capsule is subsequently developed in the
larva. At this period the head consists of the cephalic fold or
forehead (Vorderkopf), a prolongation of the ventral formative
band (Kevmvulst) over the anterior pole of the yelk. The cephalic
fold is separated from the ventral formative band by a depression
or pit, the future stomodasum or involution from which the anterior
part of the alimentary canal is developed. On either side of the
cephalic fold a lobe-like plate is developed, connected with the
ventral formative band by a narrow stalk. These are the pro-
cephalic lobes of Huxley, and form the lateral and posterior
regions of the head. The antennas are usually developed from bud-
like projections of the procephalic lobes, but in flies the develop-
ment of the antennas takes place at a much later period, after the
escape of the larva from the egg.

Behind the pouch from which the stomodasum is developed the
ventral formative band undergoes segmentation. At first three
segments are formed in the region of the future mouth, the
thoracic and ventral segments being formed at a slightly later
period. A bud-like projection then appears on each side of each
of the three first-formed segments ; the rudimentary mandibles
and first and second maxillae. Subsequently similar buds appear
for the development of the thoracic limbs in those insects in which
such appendages exist in the larva. In the fly, however, no

THE STRUCTURE OF THE HEAD OF THE BLOWFLY LARVA. 121

rudiments of these structures are developed iu the embryonic stage.
Comparative morphology teaches us that the mandibles and
maxilla? are modified limbs, their manner of development being the
same as that of normal limbs.

Much discussion has arisen with regard to the segmentation of
the head in insects. Some regard it as consisting of five, others of
six or more segments. In former days my mind was much exercised
with this and similar problems, but embryology has shown me the
futility of such discussions. There is a close analogy between this
controversy and one, now almost forgotten, on the' vertebral nature
of the skull. Oken and Gcethe initiated the comparison of the pre-
and post-oral structures in insects and crustaceans as well as the
vertebral theory of the skull. Huxley long ago disposed of the
latter question by showing that no initial' segmentation precedes
the formation of the skull as it does that of the vertebral column.
The evidence of embryology is no less decisive, in insects and
arthropods generally ; as no segmentation occurs in the pre-oral
region, and the head consists of an unsegmented pre-oral cap,
developed from the cephalic fold, of two lateral procephalic lobes,
and of three post-oral segments, with their three pairs of lateral
appendages. From the latter the mandibles, maxillae, and labium
are developed. These are, therefore, in serial homology with the
thoracic and abdominal feet. The antennas, on the other hand,
are developed from the non-segmented pre-oral region, and, like
the eyes, have no homologies with limbs. A comparison between
these structures and the post-oral appendages has no more basis in
their developmental history than a comparison of the trabaeculee
cranii with the ribs, or of the sense capsules of a vertebrate with
its limbs.

Almost as soon as the embryonic structures above described are
formed in the egg of the fly, the anterior pair of maxilla? exhibit a
tendency to enlarge and become parallel to each other, whilst the
rudiments of the mandibles and the segment which supports them, as
well as those of the second pair of rnaxilla?, and the segment be-
longing to them, undergo retrograde changes.

These facts were observed and recorded long ago by Dr. Weis-
mann.* Ultimately, as Weismann correctly states, the mandibles
and the mandibular segment disappear. It is not so, however, with
the posterior pair of maxillaa; these coalesce and form a small three-

* " Z. F. W. Z.," Bd. 13.

122 15. T. LOWNE ON THE STRUCTURE OF

lobecl labium ; this and the ventral portion of the corresponding
segment is very apparent in the larva, and remains apparent until
the insect passes into the pupa stage.

Before the escape of the larva from the egg the first pair of
maxilla} become parallel, and project beyond the bead. The pro-
cepbalic lobes disappear so far as tbe external structure of the
embryo is concerned, they become the antennal and optic discs of
Weismann, and, buried in the interior of tbe larva in relation with
the cephalic nerve-centre, remain rudimentary until tbe approacli
of tbe change of the larva into tbe pupa. Lastly, tbe cephalic
cap is reduced to a small triangular plate, which dips down between
the maxilla} and terminates in a point in front of the mouth, in
relation with the chitinised labrum. In the adult maggot the two
cylindrical maxillae are as recognizable as they are in tbe embryo,
or the newly hatched larva. Each is segmented transversely, so
that it consists of an ultimate and a basal portion, and exhibits
an unmistakable identity with a portion of the typical maxillae of
such insects as the cockroach.

Such a typical maxilla consists of a basal joint, tbe cardo ; a
stalk, the stipes ; a blade, the lacinia or mando ; and a hood, the
galea. The galea further consists of two joints which form a
sheath over the lacinia. Lastly, a palpus, of two or more joints, is
supported by the stipes.

I shall now proceed to show that the cylindrical organ, which I
have for brevity hitherto spoken of as the maxilla, represents only
a part of that organ, namely, the galea. Like the galea it consists
of two joints, and like the galea it forms a sheath for the lacinia or
mando.

A careful examination of the blowfly larva shows that the great
lateral hooks lie in a cavity of the galea when retracted, exactly as
the lacinia of a typical insect is enclosed in the galea. On the other
hand the hooks are articulated with a distinct cardo, the H-shaped
piece of Weismann. The other parts of the maxilla, the stipes and
palpus, are, however, indistinguishable.

M. Menzbier * severely criticises certain statements which I

formerly made in my work on the blowfly, f and I admit that in

some measure I laid myself open to his strictures, for I mistook the

great hooks for the mandibles. M. Menzbier speaks of these hooks

as chitinised thickenings in the walls of the mouth, a less excus-

* " Bull. Soc. Imp. Nat. Moscow," T. 55.

t " Anatomy and Physiology of the Blowfly," London, 1870.

THE HEAD OF THE BLOWFLY LARVA. 123

able mistake, as they have no relations with the walls of the month.
M. Menzbier evidently thought that when retracted they lie in
the mouth. Such is, however, not the case ; they lie, as already
stated, in distinct cavities in the galea of the inaxilla?.

The basal joint of the galea of the larva fly exhibits a very
remarkable structure. A series of radiating and dichotomously
dividing groves extends from the lateral margins of the mouth,
and covers a discoid area, occupying nearly the whole of the
under surface of the basal joint of the galea behind and outside
the sac, within which the hook lies. These tubes, although
without rings, bear a strong resemblance to the pseudotracheae of
the proboscis. The whole structure forms a suctorial disc, and is
at least analogous to the suctorial disc of the adult fly. The ter-
minal joint of the galea bears two sensory papilla? connected with
ganglionic sensory nerve terminations. Dr. Weismann regarded
them as the homologues of the antennas and maxillary palpi respec-
tively, an opinion which is clearly untenable if the organ is a galea,
and one which is likewise at variance with Dr. Weismann's own
observations on the development of the organs which 1 have
identified with the galea of the maxilla.

In front of the mouth of the larva a strongly chitinised labrum
is present with a pair of thin membranous margins. Behind, the
orifice is bounded by the three-lobed labium already described.

I am at present engaged in working out the development of the
proboscis of the adult fly, but I will indicate the conclusions to
which I think our present knowledge points, and which I expect to
be verified by further research.

M. Kunkel de Herculais,* in his unfinished monograph on the
genus Volucella, states that the head of the flies is developed from
three pairs of " histoblasts," as he names the imaginal discs of
Weismann ; and so far as my present investigations have gone, I
think M. de Herculais is right.

One pair form the optic and antennal discs of Weismann; these
are in relation with the cephalic or preaesophageal ganglion, and are
doubtless the modified procephalic lobes ; a second pair lie in the
basal joint of the galea, and a third appear to belong to the labium.

The third pair, or labial discs, apparently coalesce around the
salivary duct, a fact known to Cuvier, who regarded them as the
representatives of the mandibles, and one which Dr. Weismann has
verified.

* " Anatomie des Volucelles." Paris — in progress.

124 THE STRUCTURE OF THE nEAD OF THE BLOWFLY LARVA.

M. Menzbier* thinks the bead is developed from six pairs of histo-
blasts, but as be confesses be cannot find them, this may be regarded
as a mere opinion. It cannot be said that the further development of
the histoblasts of the galea has been traced, but these are the largest
in the head if we omit the procephalic discs. Any others which
may exist must be of small size. The conclusion at which I have
arrived is that these form the greater part of the proboscis.

If the above view proves correct, the homologies of the proboscis
and its relations to the larval and embryo states of development
becomes simple. The whole exterior of the proboscis, except the
lab rum, would represent the galeae and stipes of the maxillae, whilst
the edges of the labrum and its apodemes represent the lacinia or
mando. Under this view the position of the maxillary palpi is no
longer abnormal.

With regard to the labium the coalescence of the labial histo-
blasts with the salivary duct indicates that it forms the floor of
the groove between the lips and the basal joint of the proboscis,
that is, the labium is retracted within the galeae of the maxillae, and
these have coalesced behind.

The intimate relation of the salivary duct with the labium of the
larva, and the existence of a suctorial or quasi-suctorial disc around
the mouth of the larva with rudimentary pseudotracheal grooves, are
very suggestive. The existence of a large histoblast or imaginal
disc in this region is not to be overlooked, and I would add the
pharynx of the larva is almost identical with that of the imago.
All these points are distinctly in favour of the view I have endea-
voured to place before you.

It may appear to some that so remarkable a modification of the
maxillaef is improbable, but on this point I will merely observe now
that the maxillae exhibit a wide deviation from their primitive form
in the Lepidoptera, and that the maxilla being serially homolo-
gous with the labium, there is no a priori ground for denying simi-
lar deviations from their primitive form in the two cases. If the
paraglossae of the labium are capable of so wide a modification,
why not the galea of the maxilla ? Hereafter I shall show that the
structure of the mouth-parts of other diptera is consistent with the
view 1 have laid before you.

* Loc cit.

t Brulle — " Researches sur les transformations des appendices dans les
articules " (" Ann. Sc. Nat. ' 3rd ser., torn, ii.) — speaks of the proboscis as
consisting largely of the galea ; either we must admit that the maxillae are
united with each other or with all the other parts of the mouth.

125

On Diatom Structure.

By T. F. Smith.

(Read June 24th, 1887 J

It is not my intention to-night to read an exhaustive paper
on diatom structure; to do so would be to attempt to thresh
out an already well-threshed-out subject, and an insult to the
intelligence of the members of this Club ; several of whom
certainly, and the whole probably, know more about the subject
than myself. There are, however, still a few outstanding
matters in connection with the structure of the more complex
diatoms ; such as the position, and the absence or presence of
certain membranes that still remain in abeyance ; and, possess-
ing several slides, as I do, that seem to me to carry the ques-
tion a step or two further, I thought it might be of interest to
exhibit them here to-night, and give you my own ideas of the
structure shown.

It would be useless, however, to try to get at the finer struc-
ture of diatoms with dry or even water-immersion lenses ; for
however good in themselves, the limit of angle is reached, and
you can get no further ; but Messrs. Swift and Son have
kindly furnished me with four stands and glasses, in addition
to my own, and I am consequently enabled to show you five
of my objects at once, under jV' oil-immersion lenses. Should
you, however, find any deficiency in the manner in which they
are shown, I must ask for your forbearance, as I am new to
the work, and this is the first time I have attempted to exhibit
anything in public, and unfortunately, at a time like this, the
demonstrator is more likely to exhibit himself than the objects.

On May 28th of last year you were fortunate enough to have
two papers on diatom structure read before you in one night ;
one by Mr. Morland, and the other by Mr. Deby ; and, with
the exception of the discrepancy between them of a closed
membrane, or the want of one, those papers may be said to
embody the ideas of general structure brought up to date.

126 T. F. SMITH ON DIATOM STRUCTURE.

Here I should like to stop, but two other papers, with their
plates, have been brought before you by Messrs. Nelson and
Karop, which to me, in some parts, seem to confuse and
unsettle our ideas of structure already fixed, in a certain way,
by the consensus of microscopic opinion.

These drawings of the finer structure of certain diatoms,
admirable as they are as illustrations, give, I am afraid, in
three instances at least, misreadings of the structure, and I
hope these gentlemen will not think me presumptuous if I
venture to point out where I think they are wrong.

In Fig. 1 of their plate, given in the May number of the
Journal of this Club for last year, is a drawing of the finer
structure of Coscinodiscus aster omphalos, and were the figure
only given, there would be nothing more to say, showing
as it does correctly, the finer structure of that diatom, but the
letterpress goes on to say : " This diatom, although consisting
of a single siliceous membrane, has a double structure, viz.,
coarse and fine areolations, the latter within the former." By
this I understand they mean that both structures are on, or
nearly on, the same plane ; but, as a matter of fact, each single
disc of this diatom has three thicknesses of structure, each
differing from the other. You have first the outer membrane,
as figured ; next, underneath this, a layer of hexagonal cells ;
and then an inner plate of so-called eye-spots ; and I can only
account for the outer membrane only being seen by assuming
that the j^" oil-immersion used by these gentlemen had not
working distance enough to allow them to focus through the
whole thickness of the disc. On stand No. 1 you will find a
disc of Coscinodiscus asteromphalos with bits chipped out of the
middle, and you will be able to see for yourselves the different
layers of structure. In the part shown the under membrane
with the hexagons, is intact, but in another part the whole of
the layers are torn through. You will also observe that the
structureless part is the part torn away, proving that the space
between the areolations is the thinnest part of the membrane.

In Fig. 1 of Plate IV. in the last number of the Journal, is a
drawing purporting to give the finer structure of Coscinodiscus
centralis, and here certainly are hexagons, but on the wrong
side of the outer membrane. My mind was greatly exercised
over this figure, as 1 had lately been looking at a great number

T. F. SMITH ON DIATOM STRUCTURE. 127

of specimens of Coscinodiscus, and conlcl not make it fit in any-
how. Hitherto I had found all the structure alike, but here
was something that upset all my generalizations. 'Nature is
variable, but she is not capricious, and it did not seem possible
that two diatoms that, seen through a medium power looked
so exactly alike, could be constructed on such different prin-
ciples.

Not only, however, are the two layers of structure reversed,
but the finer structure of this diatom is missed altogether,
and what Messrs. Nelson and Karop have figured as the fine
perforations, to me are little bosses standing out from the outer
membrane in the position shown, but whether standing on the
hexagons and piercing through, or simply standing on the
membrane itself, I am unable to determine. These bosses I
take to be simply decorative, and agree with other species of
Coscinodiscus, and also with Triceratium favus. The dot shown
in the centre I cannot account for, except as ;i ghost of the eye-
spot just vanishing as the object-glass was focussed down from
the wrong side.

Plus the bosses, I see no difference between Coscinodiscus cen-
tralis and asteromjphalos, except that the former is smaller, and
has the finer perforations so small as to tax the utmost power of
the microscope. On stand No. 2 you will find this diatom, and
the disc is in the same position, I imagine, as the one through
which Messrs. Nelson and Karop focussed — that is, with the eye-
spots upwards. Now, if you work carefully through the disc
you will find, first the eye-spots, next the hexagons, then the
outer membrane, with the large areolations, the floor of which
is filled up with an outer ring of larger perforations, and the
centre with twenty or thirty smaller ones ; and, finally, lowest
of all, four or five little green bosses that occupy the position
that the corners of the hexagons did when in focus.

Another disc, with the outer side up, shows the finer per-
forations distinctly. Another, with little bits chipped out of
the centre, will enable you to study it in section ; and the same
disc will also show you the little bosses plainly, but this time
nearest the eye. I now come to Fig. 11 on Plate IV, which
purports to give the finer structure of Aulacodiscus Kittonii,
and here, I am afraid, it is not a question of reversing the
structure, but misreading it altogether. I may say that I have

128 T. F. SMITH ON DIATOM STRUCTURE.

been using these plates as a test for my own j\" oil immersion,
and, allowing for the difference of N.A. between 1*25 and 143,
was at first satisfied to find that my glass gave on this diatom
the same indications of structure. On a second sitting, how-
ever, I discovered a layer of eye-spots with thickened edges
on the under side ; and my experience tells me that a structure
of hexagonal cells is always built upon the top of these, and
that in spite of appearances this is the structure in this case.
The blacker dots shown in the figure in the shape of hexagons
I take to be spurious, but the lighter ones in the centre not,
being the perforations in the usual covering membrane.

I grant appearances are, at first sight, against me, and it
may seem rash of me to pit myself and my humble glass against
the best manipulators in England, working with the most
advanced optical appliances ; but with all deference, I must
still stick to my opinion that straight-sided cells and not black
dots is the true structure.

This is no new question, as in the April number of the
" Monthly Microscopical Journal," for 1871, is a photograph of
a Coscinodiscus, by Dr. Woodward, of America, and in the letter-
press he says : " On one side the hemispheres are quite a little
distance apart. On the other side they are crowded together,
producing the spurious appearance of a hexagonal framework
with little spherical beads at the corner." After this prompt
suppression of the hexagons by our then greatest authorit}^ on
diatom structure, I find no mention of them until December
4th, 1872, when Mr. Slack expressed a timid opinion that the
hexagons were real, but in order to confine this new teaching
within the limits of the orthodoxy of the day, decided that they
were beaded. But what I particularly want to call your atten-
tion to, as bearing on the structure of Aulacodiscus Kittonii, is
;i discussion that also took place in what Mr. Crisp so aptly
calls " the dark ages," that is, before the advent of oil immer-
sion object glasses, on the structure of Coscinodiscus oculus
iridis, in which Mr. Slack expressed an opinion that each side
of the hexagons was made up of two rows of little beads. Mr.
Slack, no doubt, saw beads, as at that time he and nearly all
microscopists saw beads in nearly all diatom structure ; but
the reason for seeing them was that the true structure was just
outside the grasp of the object glasses of that day, and when

T. F. SMITH ON DIATOM STRUCTURE. 129

you cannot see clearly, you see what you want to see, whether
beads or perforations.

Now, the structure of Aulacodiscus KiHonii is very fine, and
stands to-day in relation to the defining power of the widest
angled oil immersions as Coscinodiscus oculus iridis stood in
relation to the objectives of 1873, just outside the limits of
their power. And as we cannot in this case trust to appear-
ances, analogy should be our guide, and we must argue from
the known to the unknown. Nobody now looking at a Coscino-
discus with an oil immersion would conclude that the hexagons
were beaded, and I think we may reasonably reject the black
dots when we see them in the finer diatoms. Of course, I do
not reject the paler markings, as they are in accordance with
well-known structure, and belong to the membrane on the top
of the hexagons. The inner layer of eye-spots is the only thing
clearly seen ; and, given your layer of eye-spots, to construct
your diatom you place your hexagons on this layer, and then
stretch a fine perforated membrane on the top, and that is all.
But there is other evidence on which I rely, and for this proof
I refer you to the January number of our Journal for this
year, where, in Plate II, figs. 8 and 9, you will find an Aula-
codiscus, which the authors of the paper have named cellulosus.
Fig. 8 is the whole disc magnified 400 diameters, and Fig. 9 a
part magnified 1,000. Both figures show clearly the straight-
sided cells, and Fig. 9 shows fine dots inside the hexagons ;
and although I have not examined the diatom, I have no doubt
but what it will show all the details belonging to the hexagonal
structure, from the eye-spots in the inner layer to the fine
perforated membrane in the outer. Another thing which con-
firms me in this opinion is the centre rosette, which this
diatom has in common with Aulacodiscus Kittonii ; and as far
as my experience goes, this always means the same sort
of structure.

I have not this last diatom under a microscope at present,
but I have a very interesting slide through which I shall be
most happy to pilot you directly. When I bought it, it formed
a symmetrical group, but owing to the slipping of the cover it is
now in fragments, out of which I hope to be able to find enough
to confirm my views. You will see that some of the hexagons
are torn clean away, and some of the bits have turned over, and

130 T. F. SMITH ON DIATOM STRUCTURE.

exhibit the eye-spots nearest the eye, and yon may observe
how exactly alike the appearance is to that of Coscinodiscus.

There now remains, first, the question of the position of the
perforated membrane, which is found on one # side of most
diatoms having the hexagonal structure ; and, second, whether
the eye-spot, which is always found on the other side, is closed
with a membrane or remains a large perforation. With regard
to the former, my own opinion is that the fine perforated
membrane is generally stretched outside the • hexagons ; and
sometimes at a considerable distance from it. I have five
slides here to-night that seem to me to confirm this view, two
of which I have described, and it remains to describe the other
three.

On stand No. 3 is a Coscinodiscus from Richmond, Virginia,
having a spine standing out at each corner of the hexagons,
and considerably above them, but just within the point of the
spines is stretched a very fine membrane. The specimen is
torn, and you will see the free edge of the membrane projecting
beyond the hexagons.

On stand No. 4 is a Triceratium, in which the fine membrane
is chipped off from over parts of three or four hexagons, and if
you study the torn edge of the membrane I think you will see
that it is altogether outside.

On stand No. 5 is a Triceratium with the raised margin of
one side chipped away, and here also, I think, a study of the
torn edge will lead you to the same conclusion. At one spot the
hexagons project beyond the torn edge of the membrane.

On whether the eye-spot has a closing membrane in all cases
I offer no definite opinion; but I have two slides which seem
to prove that in some instances there is one.

In the same slide, from the Oamaru deposit, is a half disc of a
Coscinodiscus, and there is no doubt about the closing membrane
there ; but what is curious about it is, that the centre of each
is granulated as if the process of wearing away was begun. In
other parts the centre is wanting, but the eye-spot has no
thickened edge. One other slide I have with a specimen of a
smashed Coscinodiscus from Jutland. The eye-spots are nearest
the eye, ami in one of the spots is a line membrane torn across,
showing I lie edge most distinctly. This is too delicate an
object to see well with an Abbe condenser.

131

On a Fossil Marine Diatomaceous Deposit from Oamaru,

Otago, New Zealand.

By E. Grove and G. Sturt, F.F.R.M.S.

Appendix.

Plates X, XI, XII, XIII, XIV.

Since the publication of Parts I, II, and III, of this paper a
considerable number of additional species have been discovered,
a list of which we now give.

Amphora tessellata, n. sp., Gr. and St. — Rectangular, ends
rounded. Inner margin straight. Median line incurved with
distinct nodule. Surface covered with large granules, about
11 in '001", arranged rectangularly like those of Plagiogramma
tesselatum. Length of specimen figured '004''. Rare. (PI. X,
Fig. 1.)

A. interlineata, n. sp., Gr. and St. — Oval. Median line gently
incurved, nodules distinct. Stride parallel (about 22 in -001"),
divided longitudinally by a distinct clear space. Length '0055".
The apices of the valve project inwards prominently. Not
frequent. (PI. X, Fig. 2.)

A. subpunctata, n. sp., Gr. and St. — Oval. Outer margin
convex, with stauros. Median line incurved. Striae dotted, about
15 in '001". Space between median line and inner margin
strewn with scattered puncta. Length -005". Rare. (PI. X,
Fig. 3.)

A. contracta, Grun., var. ? — Closely resembles A. Schmidt's
figure ("Atl.," PI. 25, Fig. 62), but has coarser striae (about
14 in -001") . Length -006". Rare. (PI. X, Fig. 4.)

A. obtusa, Greg. (" T. M. S.," Vol. iv, p. 72 ; Vol. v, PI. 1,
Fig. 34). — A large form resembling Gregory's species, but with
coarser striae, about 37 in -001". Length -006". Rare.

Cocconeis nodulifer, n. sp., Gr. and St. — Valve small ; in out-
line and general characteristics resembling C. distorts, Greg.
(" Diat. of the Clyde," p. 18, PL 1, Fig. 23), but distinguished

Journ. Q. M. C.j Series II, No. 19. 11

132 E. GROVE AND G. STURT ON

by the presence of two nodules, situated on the longitudinal
axis of the valve, midway between the centre and extremities.
Longest diameter about -001 5". Rare. (PI. X, Fig. 5.)

Navicula inelegans, n. sp., Gr. and St. — Valve in frustular
view very convex, in outline spindle shaped, usually with an
enlarged centre, but very variable in this respect. Stria? sub-
radial, about 37 in '001", reaching the central line. Owing to
the convexity of the ends, the terminal nodules are not seen in
the valvular view as is the case in Stauroneis acuta, W. Sm.
(This form may be filamentous, and if so should belong to
Diadesmis.) Length of specimen figured about '0057". Not
rare. (PI. X, Fig. G.)

N. margin o-punctata, n. sp., Gr. and St. — Valve resembles
in outline N. jamaicensis, Grev. (" T. M. S.," Vol. xiv, p. 126,
PI. 12, Fig. 23), but differs entirely in other respects. On
each side of the central line the valve is quite devoid of mark-
ings, but at the extreme margin are two rows of granules.
Pare. Length -0048". (PI. X, Fig. 7.)

N, trilineata, n. sp., Gr. and St. — Oval, median line and
nodules distinct. Striae costate, parallel, divided by clear
longitudinal spaces into three distinct groups on each side.
Length -004" ; breadth -0013". Rare. (PL X, Fig. 8).

N. biconstricta, n. sp., Gr. and St. — Valve trinodular, the end
lobes being slightly broader than the central inflation. Median
line and nodules conspicuous. Margin cellulate with short costa3
about 20 in *00 1", not reaching to the centre line. Length -0035" ;
breadth of end lobes -00065". (PI. X, Fig. 9.)

N. dispersa, n. sp., Gr. and St. — Valve lanceolate, with
subacute ends. Median line distinct. Striae obscure (about 55
in "00 1"), reaching to the centre line, excepting at the centre of
the valve, where there is a clear oval space. As the striae
approach the margin they break up into scattered dots, leaving
a submarginal clear space, which is broader towards the ends
than at the centre of the valve. On the margin is a closely
set row of small puncta. Length -0047". (PI. X, Fig. 10.)

JV. margino-lineata, n. sp., Gr. and St. — Valve small, slightly
constricted, with an outline resembling that of N. didyma, Ehr.
Median line and end nodules distinct. Central nodule slightly
dilated. Margin edged with a closely set line of puncta, within
which, separated by a narrow clear line, is a row of very short

A FOSSIL MARINE DIATOMACEOUS DEPOSIT. 133

striae (about 21 in '001"), the remainder of the surface being
quite clear. Length -0035" ; breadth of end lobes -001 // . (PI.
X, Fig. 11.)

JV. lobata, n. sp., Gr. and St. — Valve constricted at centre.
Lobes oblong, with subacute ends. Median line distinct, with
small central and end nodules. Striae costate, conspicuous, not
reaching the median line, and absent for a considerable space in
the centre of the valve. Length "00475" ; breadth of lobes -0012".
(PI. X, Fig. 12.)

N. placita, n. sp., Gr. and St. — Valve flat, oval, with broad
marginal belts of radial dotted striae, about 30 in , 001 // , leaving
between them a lozenge-shaped clear central space. Median
line very distinct with two central terminations rather wide
apart. Length -0023". Breadth -0013'/. This form has some
resemblance to N. patula, W. S. (" S. B. D.," PL 16, Fig.
139), but is broader, and has coarser striae. (PI. X, Fig. 14.)

N. decora, n. sp., Gr. and St. — A very elegant form. Valve
oval, with rounded ends. Median line distinct, terminal nodules
dilated sideways. Striae distinctly dotted, parallel, about 18 in
001", leaving a narrow, clear space on each side of the median
line, which is slightly expanded at the centre. Towards the
margin the striae are interrupted by, first a narrow, and then a
broader clear space, the striae reappearing on the margin in the
form of a row of very short costae. Length "0047" ; breadth
•0019". (PI. X, Fig. 13.)

Donkinia antiqua, n. sp., Gr. and St. — Frustule greatly con-
stricted. Valve ovo-lanceolate with subacute ends, occupying a
middle position in outline betwee D. compacta and D. carinifera
(" Pritchard," p. 921). Median line strongly sigmoid coincident
with the margin at the ends. Central clear space small,
circular. Striae rectilinear, about- 40 in •001". Length of valve
•0077". We regret that, owing to the only specimen of this
form discovered by Mr. R. Rattray having been injured after
this description was written, we are unable to figure this interesting
Diatom.

Biddulphia ? fossa, n. sp., Gr. and St. — Valve flat, oval with
obtuse ends, in outline resembling Anaulus Mediterraneus, Grun.
(Pant., "Hungarian D.," PI. 18, Fig. 160). Processes inconspicu-
ous, scarcely more than slight elevations of the ends of the valve,
covered with finely clotted lines. Surface of valve dotted with

134 E. GROVE AND G. STURT ON

papillae, which are absent from a small circular space in the centre.
Two depressions in the form of clear furrows separate the central
portion from the ends. Length -0034" ; breadth -002". (PI.
X, Fig. 15.)

B. dissipata, n. sp., Gr. and St. — Valve oval, with subacute
ends, convex, with a depressed clear circular space in the centre,
in which is a spine mounted on a small hyaline projection. Pro-
cesses conspicuous, inclined laterally in opposite directions, arising
from slightly bullate inflations, commencing near the centre. Sur-
face, excepting at the clear centre, dotted with small widely sepa-
rated puncta. Length -004" ; breadth -0026". (PI. X, Fig. 16.)

B. vittata, n. sp., Gr. and St. — Valve lanceolate, with central
constriction and acute ends. On each side of the centre are two
transverse vittge, or septa, dividing the interior of the valve into
five compartments. In frustular view the compartments are seen
to be of nearly equal height, the processes projecting but slightly.
The surface is covered with large circular granules, excepting at
the extremities of the processes, which are finely punctate. On
the summits of the compartments are a few scattered spines,
which have disappeared in the specimen from which our frustular
view was figured. Length to -0045". (PI. XI, Figs. 19, 20.)

B* tenera,n. sp., Gr. and St. — Frustule very hyaline, with central
depression bearing a stout spine, and an elevation or inflation on
each side. Processes well developed, similar in form to those of
B. aurita. Valve narrow, oval, with produced extremities. Surface
of the inflations covered with minute dots. Length '0025". (PI.
XIV, Figs. 56, 57.)

B. (Cerataulus ?) rerersa, n. sp., Gr. and St. — Valve oval,
with broadly rounded ends and two mastoid processes placed
on opposite sides (as in Cerataulus turgidus, from which in other
respects it is distinct). In the centre is a group of numerous
small spines, on each side of which is a narrow transverse hyaline
space, the remainder of the surface being covered with exceedingly
fine clots. Frustular view not observed. Length -0025". (PI.
XIV, Fig. 62.)

B. punctata, Grev. — Since our notice of the occurrence
of this species (" J. Q. M. C," Vol. ii, Ser. ii, p. 325), some
frustules have been found in which the conspicuous crenulation of
the connecting membrane (traces of which are apparent in most
of the valves met with in this deposit) is well shown. As this is

A FOSSIL MARINE IHAT0MACEOUS DEPOSIT. 135

absent in Dr. Greville's drawing, we give a figure from an excel-
lent specimen in the cabinet of Dr. Gray. (PI. XIV, Fig. 51.)

B. lata, n. sp., Gr. and St. — Valve broadly oval, with four
slightly tapering processes close to the margin. The surface,
which is moderately convex, is covered with distinct puncta or
small spines. Length of valve •0055'; breadth •0047".

Our figure is given from a magnificent specimen of this fine
diatom in the collection of Herr J. Kinker, of Amsterdam. (PI.
XIV, Fig. 53.)

Cerataulus marginatus, n. sp., Gr. and St. — Valve circular, with
flat upper surface arising from a broad striated base. In the
centre is a group of dots surrounded by an annular clear space,
whence distinct lines of dots radiate to the margin, having between
them numerous subulate blank spaces. The processes, two in
number, are conspicuous, with obtuse ends, and between them, on
each side, on the margin of the elevated portion of the valve, is a
small spine seated on a small nipple-shaped projection. Diam.
•0033". (PI. XI, Fig. 21.)

Triceratium oamaruense, n. sp., Gr. and St. — Valve large,
gibbous, sparsely dotted. The apices are covered with minute
dots, and are cut off from the central portion by curved lines,
which are very distinct at the margins and fade away towards the
middle. Length of side to -0085 ". (PI. X, Fig. 18.)

Note. — This form was described by us in the first part of this
paper (" J. Q. M. C.," Vol. ii, Ser. ii, p. 327) as T. partitum.
Grev., but we have since ascertained from an inspection of
Greville's original examples that it is a quite distinct species.

T. rectangulare, n. sp., Gr. and St. — Valve quadrangular, with
gibbous sides. A distinguishing feature of this form is the large
flat central rectangular elevation, terminating at each angle in a
prominent process or horn. The surface is covered with radial
lines of large granules, except in a small clear central place.
Breadth -004". (PI. X, Fig. 17.)

Note. — Since the above figure was drawn, other specimens
have been observed, in which the processes are club-shaped and
conspicuously spinous. From this it appears that in this species,
as in T. rugosum, Gr. and St. (see below), the valves in each frus-
tule are dissimilar in the form of the processes.

T. rugosum, n. sp., Gr. and St.

Note. — Since describing and figuring this species {supra, p.

136 E. GROVE AND G. STURT ON

75, PI. 5, Fig. 4), we have, through the kindness of F. Kitton,
Esq., inspected a perfect frustule, from which we learn that the
valves differ greatly in the length and form of the processes, those
in the one valve being long and taper, while those in the other
are club-shaped and spinous.

We give a figure of the frustule. (PI. XI, Fig. 26.)
T. cordiferum, n. sp., Gr. and St. — Valve with slightly convex
sides and rounded angles. Processes distinct, circular, hyaline.
Surface of valve closely punctate, excepting where a conspicuous
clear space, having the outline of a heart, divides the central por-
tion from the rest. Length of side -0025". (PI. XI, Fig. 23.)

T. weissflogii, n. sp., Gr. and St. — This species was previously
described by us (" J. Q. M. C," Ser. ii, Vol. ii, p. 328) with
hesitation as T. ccelatum, Jan., from its resemblance to the figure
of that species in A. Schmidt's "Atlas" (PI. 81, Fig. 19). Kecently,
through the kindness of Herr C. Janisch, we have examined an
authentic example of his species, and have come to the conclusion,
in which Herr Janisch agrees, that the two forms are specifi-
cally distinct. We have, therefore, much pleasure in naming the
Oamaru form after the well-known diatomist, Herr Weissflog, of
Dresden, whose assistance has been of great value to us in this
work. Valve nearly flat, with straight sides and slightly rounded
angles. The apices, which are large, and project but slightly, are
covered with delicate points. The centre is sparsely punctate, but
the radiating lines increase in number till at the margin they form
crowded lines. Length of side to -0075".

We figure a specimen of average size. (n. XI, Fig. 22.)
T. pseudo-nerpaturrij n. sp., Gr. and St. — This species was de-
scribed and figured previously (" J. Q. M. C," Ser. ii, Vol. ii, p.
329, PI. 19, Fig. 19) as T. cancel latum, Grev., but since then,
having inspected Greville's authentic specimens, we have ascer-
tained that it is a distinct species. Valve with straight sides, with
a flat central triradiating portion, from which rises an inclined
plane to each apex.

The intersection of these planes with the flat central portion
presents at the margin of the valve the appearance of a short
nerve or vein, two of which are conspicuous on each side. Our
figure is a little misleading, as the " nerves " are made to
resemble papillaa. In the centre of the valve there is usually a
spine, not shown on the figure. The processes are prominent,

A FOSSIL MARINE DIATOMACEOUS DEPOSIT. 137

with rounded ends. Length of side to '003 ". This form is very
common on the deposit.

T. eccentricum, n. sp., Gr. and St. — Valve with nearly straight
sides and very rounded angles. Processes prominent, situated on
one side of the angles formed by the sides. Surface of valve re-
ticulate. Length of side -003". (PI. XIV, Fig. 61.)

T. arcticum, Brightwell.

Note. — Herr Janisch informs us that the large form of this
species previously mentioned (" J. Q. M. C," Ser. ii, Vol. ii, p. 326)
is the same as T. permagnum, Jan., to be described and figured in
his forthcoming work on the Diatomaceas of the Gazelle Expedi-
tion. Through his kindness we have been enabled to examine an
authentic specimen of T. permaguum from Kerguelens Land, and
we have no doubt of the identity of the two forms. A large
quadrangular form of the same with very produced angles also
occurs in this deposit.

The cellulation of these large Triceratia is rather smaller, and
the punctation of the pseudo-nodules more, delicate, than in the
usual form of T. arcticum ; but in all respects they exhibit the
features of the group, and we consider them as large forms of the
species.

T. arcticum, Brightw., forma quinquelobata (T. quinquelobatum,
Grev., " T. M. S.," Vol. xiv, p. 83, PI. 9, Fig. 21).— Scarce.

T. montereyi, Brightwell. — Having met with specimens of com-
plete frustules of this form since we recorded its occurrence, we
figure one showing the extreme convexity of the terminal valves
(PL XI, Fig. 25.)

T.favas, Ehr., forma pentagona. —One or two examples of this
have occurred.

T. grande, Brightw., forma quadrata. — Many of the quadrate
forms of the favus group, which are abundant in this deposit, are
convex, and in all respects, except outline, are so similar to T.
grande that we place them here.

T. stokesianum, Grev. (" T. M. S.," Vol. xiv, p. 8, PI. 2, Fig.
23). — We have met with several specimens of a large Triceratium,
which resembles the form in the Briinn deposit identified by Prof.
Cleve ("J. Q. M. C," Vol. ii, Ser. ii, p. 169, PI. 12, Fig. 5)
with Greville's species.

T.exornatum, Grev. (" T. M. S.," Vol. xiii, p. 9, PI. 2, Fig. 25).
— Scarce.

138 E. GROVE AND G. STURT ON

T. repletum, Grev. (" T. M. S.," Vol. xiv, p. 83, PI. 9, Fig. 18).
— Very rare.

T. plumosum, Grev. (" T. M. S.," Vol. xii, p. 85, PL 10, Fig. 4).
— A form has been observed resembling this in all respects except
that pseudo-nodules are present. We prefer to class it as Gre-
ville's form rather than to introduce confusion by making a new
species of it.

T. condecorum, Ehr. (Schm. "At!.," PI. 76, Fig. 28).—
Scarce.

T. trisulcum, Bailey (" Prit.," p. 854, PI. 8, Fig. 27).— Not
scarce.

T. barbadense (" T. M. S.," Vol. ix, p. 44, PI. 4, Fig. 12).—
This species occurs rarely, but appears to agree with Greville's
authentic examples. The figure above cited is not good, and we
append one. (PI. XI, Fig. 24.)

T continuum, Grev. («T. M. S.," Vol. xii, p. 13, PI. 2, Fig. 7).
— Very scarce.

T. (Stictodiscus) parallelum (Ehr.), Grev. — A form of this with
seven angles has been found by Dr. Gray, and the same indefatig-
able observer has discovered an oval form of the var. gibbosa, with
acute ends, resembling in outline a Biddulphia, of which we give a
figure. (PI. XIV, Fig. 28.)

T. shadboltianum, Grev. (Sch. " Atl.," PI. 80, Figs. 18-20).—
Small forms, with three flat processes, apparently of this species,
occur here.

Lampriscus ? debit, n. sp., Gr. and St. — We place this singular
form in this genus with great hesitation for the present.

Hitherto only two specimens have been observed, and we are
indebted to Julien Deby, Esq., for first calling our attention to it.
It is to be hoped that further examples will be discovered, from
which the true character of this diatom can be ascertained. Valve
circular, with two large marginal processes (?) opposite each other,
between which occur smaller marginal processes (?) unequal in
number (on the one side three, on the other four). The centre is
flat, with a clear umbilicus, on which is a group of spines, the rest
of the surface being covered with curved lines of dots, which con-
verge towards the bases of the processes (?) somewhat as in Aulis-
cus. Diam. -0055". (PI. XI, Fig. 27.)

N.B. — The figure shows the valve as viewed from the inside, as
the specimen was mounted with that side uppermost.

A FOSSIL MARINE DIATOMACEOUS DEPOSIT. 139

Aulacodiscus janischii, n. sp., Gr. and St. — This species has been
hitherto considered by us as A. stoschii, Jan. The first forms
observed were smaller than those which have occurred in samples
of the material obtained since, and closely resembled the figure of
A. stoschii in Messrs. Walker and Chase's work referred to by us
(supra, p. 8). Herr Janisch has, however, kindly allowed us to
examine an original example of his form, and we find that the
Oam aru species differs entirely. We have much pleasure in naming
this fine Diatom after one who has done so much in furtherance of
the knowledge of the Diatom acea3.

Valve large, with moderately convex centre, from which extend
seven bullate expansions, ceasing close to the margin; from the
ends of which project the small cylindrical processes.

Between each expansion there is usually an undulation which is
very conspicuous in the larger examples. The furrows are very dis-
tinct at the processes, but as they approach the centre are gradually
lost on the rough granular surface of the valve, which is covered
with crowded radiating lines of dots.

Diam. to -02". (PI. XI, Fig. 28.) (A small example).

A.janischu, var. abrupta. — This form has usually six processes.
The convex centre does not branch into the bullate expansions as
in the type form, but they rise from its edge and terminate abruptly
on the margin. They are broader at the ends, and more con-
spicuous than in the type. Diam. to '005".

Note. — This form approaches very nearly to A. mammosus, Grev.
(" T. M. S.," Vol. xi, p. 70), of which it may be a six-processed
form.

A. rattrayii, n. sp., Gr. and St. — We at first considered this
species as one of the forms of A.beeveria?, Johns., but further examina-
tion and comparison with an authentic specimen of that rare form
in the possession of our friend, F. Kitton, Esq., have convinced
us that it is distinct. We have much pleasure in naming it after
the well-known diatomist, Mr. R. Rattray, of Dundee, who has
assisted us so materially in the examination of this deposit.

Valve convex, with flattened margin and striated rim. Processes

usually three, small, oval, considerably within the margin. Cellules

hexagonal, about 10 in -001", strongly papillate, closely covering

the surface in radiating lines, with the exception of a small irregular

clear umbilicus. Scattered spines occur giving the surface a

scabrous appearance, especially near the margin. Furrows formed

140 E. GROVE AND G. STURT ON

by two conspicuous parallel rows of cellules. Forms with two pro-
cesses are not infrequent. Diam. -006". (PI. XI, Fig. 29.)

The main distinction between A. beeverice and A. rattrayii is that
the latter bas an hexagonal cellulation, whilst the former is charac-
terized by distant radiating lines of large pearly granules.

A. comberi (Arnott), var. oamaruensis, Gr. and St. — Valve
moderately convex, and not so lurid in colour as the type form.
Processes, in the few specimens observed, three ; small, oval, sub-
marginal. Margin striated. Cellules about 9 in -001", with a
small clear umbilicus, and a small clear space at the base of each
process. Furrows distinct. Diam. about '007". Scarce.

A. elegans, n. sp., Gr. and St. — Valve with convex edges and
rather flat upper surface. Cellules hexagonal, papillate, about 10
in -001", merging into dots at the centre, where there is usually a
small circular clear space. Processes in the specimens observed,
5, 6, or 7, narrow, prominent, cylindrical. No clear space at the
base of the processes. Furrows represented by the walls of two
adjacent parallel lines of cellules. Scarce. Diam. about '007". (PL
XII, Fig. 30.)

A. huttonii, n. sp., Gr. and St. — Valve with convex centre and
an undulation between centre and margin. Processes, usually four,
papilliform, submarginal, projecting vertically. Cellules granular,
large, confused in the middle, but passing into distinct radial lines,
which are very conspicuous towards the margin. Surface between
the granules delicately punctate. It has an irregular clear um-
bilicus and distinct furrows, which widen as they approach the
processes. Not scarce. Diam. -004". (PL XII, Fig. 31.)

A. convexus n. sp., Gr. and St. — Valve oval, very convex, with
hexagonal cellules, about 10 in •001", papillate with an umbilical
group of larger cellules.

Processes three, submarginal, enlarged at the end in a spathulate
form, springing from a small clear space. Longest diam. about
•006". Scarce. (PL XII, Fig. 32.)

A. cellulosus, Gr. and St., var. plana. — Differs from the type form
in being less convex, and having (in all specimens yet observed)
four processes only. Not very scarce. Valve usually about *008",
in diam.

A. radiosus, n. sp., Gr. and St. — Valve large, moderately convex,
with a small circular umbilicus of cells, the rest of the surface
being covered with minute hexagonal cellulation, about 9 in '001",

A FOSSIL MARINE DIATOMACEOUS DEPOSIT. 141

arranged in close radiating lines. Processes (in the only specimen
observed) seven in number, small, but conspicuous, and slightly
inflated, arising from a small hyaline space. Diam. 'QV. (PI. XII,
Fig. 33.)

We are indebted to Mr. Rattray for the discovery of this species.

A. spectabilis, Grev. (" T. M. S.," Vol. xi, p. 71, PI. 5, Fig. 16).
An example of this form has occurred, differing only from Greville's
in having four processes instead of five.

Auliscus projnnquus, n. sp., Gr. and St. — Valve circular, with a
clear umbilicus, and two large mastoid processes close to the margin
of the umbilicus. Markings granulose in curved lines, with brilliant
puncta interspersed, diminishing in number as they approach the
margin. Within the margin is a ring of larger puncta. Diam.
•0022". (PI. XII, Fig. 34.)

We are indebted to W. J. Gray, Esq., M.D., for the discovery
of this beautiful Auliscus.

A. lacunosus, n. sp., Gr. and St. — Valve large, slightly oval,
with large mastoid processes close to the margin, at the base
of which on the inner side is a crescent-shaped clear space or lacuna.
Markings very similar to those of A. punctatus, Bail. Diam. *0023".
This form is not infrequent in the deposit. We figure a some-
what abnormal specimen. (PL XII, Fig. 35.)

A. lineatuSj n. sp., Gr. and St. — Nearly circular, with a clear
lozenge-shaped umbilicus, mastoid processes large, circular, or in
some instances somewhat pear-shaped, seated on triangular raised
spaces, the apices of which project inwards. Markings scabrous,
resembling those of A. hardmanii, but differing entirely in the pre-
sence of three diverging ridges or elevations, showing lines on each
side of the centre. Diam. to -005". The form figured has circular
processes. (PI. XII, Fig. 36.)

A. inflatus, n. sp.. Gr. and St. — Valve circular, with clear cir-
cular umbilicus. Processes large, mastoid, seated at the extremi-
ties of a prominent inflation extending along the diameter of the
valve. Markings consisting of fine lines with interspersed puncta ;
a set of curved lines converge from the centre towards each process.
Diam. 0034". (PI. XIII, Fig. 37.)

We are indebted to L. Hardman, Esq., for the discovery of this
very fine form.

Monopsia, n. gen., Gr. and St. — Valve with discoid outline
inflated, the inflation ending in a single mastoid process consider-

142 E. GROVE AND G. STURT ON

ably eccentric. Differs from Aiiliscas chiefly in having one process
only.

M. inammosa, n. sp., Gr. and St. — Valve circular, with broad,
flat, finely striated border (stria? about 55 in 001"), from which
arises a highly convex expansion, terminating in a large circular
process, on which are two rings of large dots. The process is not
central, but is situated much nearer one side of the valve than the
other, and somewhat resembles the mouth of a sack or bag tied up
and leaning to one side. The surface of the expansion is covered
with markings resembling those of Auliscus pruinosus, converging
to the base of the process. Diam. -003". Rare. (PI. XIII, Fig. 38.)

Huttonia, n. gen., Gr. and St. — We place under this name two
species which appear to differ from those of any existing Genus,
but further observation is necessary before we can define the Genus
in which we propose to place them, and which we have named after
Prof. Hutton, of Christchurch, New Zealand.

H. alternans, n. sp., Gr. and St. — Valve oblong with rounded
ends, moderately convex, having at the ends, on the alternate sides,
flattened appendages, which have somewhat the appearance of
processes viewed laterally. Surface of valve covered with fine
puncta. Length to -0063". (PI. XIII, Fig. 39.)

H. virgata, n. sp., Gr. and St. — Valve similar to the last in out-
line, but with much coarser puncta, which are interrupted by broad
transverse clear spaces irregularly placed. Length of the only
specimen observed •0042". (PI. XIV, Fig. 55.)

Actinoptychus {glabratus var.?) elegantulus, n. sp., Gr. and St. —
Valve small, with large clear centre, from which hyaline rays extend
for some distance between each compartment. Margin hyaline,
with large clear spaces between each process. Processes small,
seated on a small, crescent-shaped, hyaline space, connected with
the centre by a narrow ray. Surface of the undulations covered
with delicate decussating lines of strife. Rare. Diam. *0025".
(PI. XIII, Fig. 40.)

A.pulchellvs, Grun., var. tcncra. — Small, with numerous compart-
ments, and a large clear centre. The undulations are conspicuous,
and the small but distinct processes arc situated in small clear
spaces at the ends of the elevations, which terminate abruptly.
On the summit of each elevation is a clear radial line, the
remainder of the surface being covered with fine decussating stria?.
(PL XIII, Fig. 41.)

A FOSSIL MARINE DIATOMACEOUS DEPOSIT. 143

A, undulatus, Ehr. — Small forms of this occur with extreme
rarity.

A. (undulatus, Ehr. var.?) constrictus, n. sp., Gr. and St. — Valve
with three undulations and three distinct processes. In the margin
of the valve there is a constriction of the inner edge of the margin
at the end of each of the rays, which gives to the form a very
distinct appearance. The compartments are more sparsely cellulose
than is the case in A. undulatus, Ehr. Diam. -0033." (PI. XIV,
Fig. 63.)

A. simbirskianus, A. Sch. — An example of this has occurred.

Porodiscus hirsutus, n. sp., Gr. and St. — Valve, with clear cir-
cular central space, about i of the total diameter, the remainder of
the surface being covered with papilla which are very much coarser
than in P. interrvptus, and are not interrupted near the margin as
in that species. Diam. -0027". (PL XIV, Fig. 54.)

Asierolampra uraster, n. sp., Gr. and St. — Valve rather coarsely
reticulated, the interior extremities of the cellular compartments
angular with slightly rounded ends. Centre, of a few large cells,
connected by a radial line with the apex of each compartment. It
will be observed that in the specimen figured, which is the only one
observed, there are two radial lines connecting one of the compart-
ments with the central cells. This is probably abnormal.

The clear spaces between the compartments are broad and taper-
ing, ending considerably within the margin, and showing at the
termination of each an indentation (possibly a spine ?). We are
indebted for the only specimen of this species to Dr. Gray.
(PI. XIII, Fig. 42.)

Anaulus ? subconstrictus, Gr. and St. — We place this singular
form here for the present with some hesitation.

Valve narrow with slightly expanded ovate ends, which are
separated from the central portion by distinct septa. Surface
covered with dots, which in the centre are arranged radially. In
frastular view, the valve, is very slightly constricted and has rounded
ends. On the ventral side, at each end of the valve, there is
apparently a folding over of the membrane or cell wall partly
closing the interior. Length '0045'. (PI. XIV, Figs. 59, 60.)

Hemiaulus dissimilis, n. sp., Gr. and St. — In this form the con-
tiguous valves are dissimilar. We figure a frustule, one of several
which have occurred to us, from which it will be seen that one
valve resembles that of Hemiaulus, with the usual processes or

144

E. GROVE AND O. STDRT ON

horns terminating in spines ; while the other has inflated ex-
tremities, but without horns or spines. (PI. XIII, Fig. 43).

77. amplectans, var. major. — Differs from the typical form (supra,
p. 76, PI. 6, Fig. 17) in the greater length of the valve, and in
being covered with granules instead of being hyaline. (PI. XIII,
Fig. 44.)

H. augustus, Grev. (" T. M. S.," Vol. xiii, p. 30, PI. 3, Fig. 12) —
Several specimens have been observed, which agree with Greville's
figure, excepting that there is only one spine, projecting inwards
at the extremity of each horn.

// ? te unicornis, Grev. — We figure an example which has occurred
to us of opposite valves of this species in conjunction, showing that
the connection between the frnstules is effected by an interlacing
of the horns, and not, as in the true Hemiaulidoe, by the junction
of terminal spines or claws. (PI. XIII, Fig. 45.)

Note. — This being so, it appears that Greville was right in his
doubt as to whether this and other allied species described by him
(" T. M. 8.," Vol. xiii, p. 29) rightly belong to Hemiaulus. "We
take the opportunity of correcting an erratum on page 11, supra,
where " tenuicornis " is printed " tenuiformis."

Trinacria simulacrum, n. sp., Gr. and St. — This singular form
is frequent in the deposit, but further investigation is required
before it can be ascertained whether it really belongs to the Genus
in which we placed it provisionally. It has been suggested that it
may be an inner or secondary valve of T. Kinherii, A. Sch.
("Atl.," PI. 112, Fig. 21), but we think, if this were so, we should
have met with the true valves of that species ; which has not been
the case. (PI. XIII, Fig. 46.)

T. ventricosa, Gr. and St. (supra, p. 63, PI. 5, Figs. 1, 2, 3).
— Having, through the kindness of Dr. Stolterfoth, obtained a
complete frustule of this form, we give a figure showing a pair of
primary and secondary valves in situ. (PI. XIII, Fig. 47.)

Coscinodiscus centralis, Greg. (" G. D. C," p. 29, PL 3, Fig. 49).
— In a sample of the deposit obtained recently, several examples of
what appears to be this form have occurred. Diam. -006".

C. oblongus, Grev. (" T. M. S.," Vol. xiv, p. 4, PI. 1, Fig. 9).—
One specimen has been observed by F. Kitton, Esq., in this deposit,

Terpsinoe americana, Bail., forma trijona (Pantocsek, " Hung.
Diat.," PI. 6, Fig. 53). — A form very similar has been found by
Mr. F. Marshall.

A FOSSIL MARINE DIATOMACEOUS DEPOSIT. 345

Melosira oamaruensis, n. sp., Gr. and St. — This species, which is
abundant in the Oamaru deposit, belongs to the same group as M.
Sol. Ehr., and M. clavigera, Grun. The form, when touched,
readily breaks up into two discs, which differ from each other. We
give figures of both. The primary disc has a smooth margin, and
a clear centre, slightly raised. The margin is adorned with a ring
of closely set spathulate costal, in length about i th the diam.

The secondary disc has a crenulate margin, and a border of
dotted striae, within which the costze are indicated by an annulus of
detached lines. Diam. to -006". (PI. XIII, Figs. 48, 49.)

Pyxilla ? reticulata, n. sp., Gr. and St. — Single valves of this
little Diatom are not uncommon, but we have hitherto not observed
any complete frustules. Valve circular, slightly convex ; in frus-
tular view cylindrical, longer than the diameter. The whole surface
is hexagonally cellulate. (PI. XIII, Fig. 50.)

Stoschial punctata, n. sp., Gr. and St. — We place here a form
which, judging from the figure of S. palacea, Grun. (" V. H. Syn.
Belg. Diat," PI. 128, Fig. 6), appears to have affinities with the
Genus. The surface is covered with small scattered granules.
Length -007". (PI. XIV, Fig. 52.)

Tricerativm sexajiartitum, n. sp., Gr. and St. — A single speci-
men of this, for which we have to thank Herr Janisch, reached us
while correcting the proof of this paper. The valve has an
hexagonal outline, with obtusely rounded processes. The centre
is slightly depressed, and from this proceed very fine, thickly-
crowded, radiating lines of granules. Still liner granules cover
the processes, on each side of which are indications of internal
veins. Frustular view not yet observed. Diam '00345". (PL
XIV, Fig. 64.)

Corrigenda.

Opportunities of inspecting authentic examples of rare species
which have, since the publication of the earlier parts of this paper,
been afforded to us by the kindness of William Carruthers, Esq.
F.R.S., F. Kitton, Esq., Herr Janisch, and other friends, have
convinced us of the necessity of making a few changes in the
names recorded. These changes have, for the most part, been
indicated in the text, but we now give a summary of them. Our
readers will be so good, therefore, as to cancel —

146 E. GROVE AND G. STURT ON

Biddulphia elaborata, n. sp., putting in its place Kittonia elabo-
rata, n. sp.

Biddulphia virgata, n. sp., putting in its place Kittonia virgata,
n. sp.

Aidacodiscus stoschii, Jan., putting in its place Aulacodiscus
janischii, n. sp.

Aulacodiscus beeverice, Johnst., putting in its place Aidacodiscus
rattrayii, n. sp.

Aulacodiscus comber i, Arnott type, putting in its place Aulaco-
discus comberi, Arnott, var. oamaruensis.

Aidacodiscus decorus, Grev., putting in its place Aulacodiscus
elegans, n. sp.

Aulacodiscus notatus, n. sp., putting in its place Aulacodiscus
barbadejisis, Ealfs., " Pritch.," p. 939.

Triceratium cwlatum, Jan., putting in its place Triceratium
weissfiogii, n. sp.

Triceratium cancellatum, Grev., putting in its place Triceratium
jiseudo-nervatum, n. sp.

Triceratium partitum, Grev., putting in its place Triceratium
oamaruense, n. sp.

Auliscus barbadensis, Grev. var., putting in its place Auliscus
lineatus, n. sp.

In our notice of Triceratium grande, Briglitwell (" J. Q. M. C,"
Ser. ii, Vol. ii, p. 326), we gave as a synonym T. favus, var.
maxima, Grun., but not having seen authentic specimens of the
latter, we do not feel assured of the identity of the two forms, and
desire to note the large convex form so abundant in this deposit
simply as T. grande.

We desire to record that since our first description of Pseudo-
rutilaria monile, specimens have occurred in which the number of
cells on either side of the centre is equal ; also specimens in which
the number on one side exceeds that on the other by more than
one.

We also request our readers not to attach too much importance
to the statements in the earlier parts of this paper as to the rela-
tive abundance of the various species. Subsequent examinations
have shown us that the relative numbers of the species vary in
every different piece of material, even from the same lump. One
Diatom, however — Stephanopyxis valida, Grun. — asserts its pre-
eminence in number in every sample we have examined.

A FOSSIL MARINE DIATOM ACEOUS DEPOSIT. 147

PLATE X.

Fig. 1. Amphora tessellata, n. sp., Gr. and St., 4 £°.

2. „ interlineata, n. sp., Gr. and St., 4 ^°.

3. „ subpunctata, n. sp., Gr. and St., 4 ^-<?.

4. „ contracta, Grun. var., 4 ^°.

5. Cocconeis nodulifer, n. sp., Gr. and St., 8 ^°.

6. Navicula inelegans, n. sp., Gr. and St., 6 y°.

7. „ margino-pxinctata, n. sp., (-Jr. and St., 4 s°.

8. ,, trilineata, n. sp., Gr. and St., 4 f °.

9. ,, biconstricta, n. sp., Gr. and St., 4 ^°.
10. „ dispersa, n. sp., Gr. and St., 4 ^°.

„ 11. „ margino-lineata, n. sp., Gr. and St., 4 ^°.

„ 12. ,, lobata, n. sp., Gr. and St., 4 a°.

„ 13. ,, decora, n. sp., Gr. and St., 4 2°.

,, 14. „ placita, n. sp., Gr. and St., 4 £°.

15. Biddulphia fossa, n. sp., Gr. and St., 4 y°.

16. „ dissipata, n. sp., Gr. and St., 4 y°.
„ 17. Triceratium rectangulare, n. sp., Gr. and St., 4 fl°.
,, 18. ,, oamaruense, n. sp., Gr. and St., 2 f°.

PLATE XI.

„ 19. Biddulphia vittata, n. sp., Gr. and St., valvular view, 4 ^°.

>, 20. „ „ „ frustular view, 4 2°.

„ 21. Cerataulus marginatus, n. sp., Gr. and St., s ^°.

„ 22. Triceratium loeissflogii, n. sp., Gr. and St., a |°.

j> 23. ,, cordiferum, r». sp., Gr. and St., 4 £°.

,, 24. „ barbadense, Grev., 4 £°.

„ 25. ,, motileregii, Bright w., 4 £°.

» 26. „ rugosum, Gr. and St., frustular view, s ^°.

„ 27. Lampriscus (?) debit, n. sp., Gr. and St., s e°.

„ 28. Aulacodiscus janischii, n. sp., Gr. and St., ' 2 \°.

29. „ rattrayii, n. sp., Gr. and St., 4 2°.

■»

j>
»»

j>
j>

1>

5>

;>

PLATE XII.

„ 30. Aulacodiscus elegans, n. sp., Gr. and St., s ^°.

„ 31. „ huttonii, n. sp., Gr. and St., 4 a°.

» 32. „ convexus, n. sp., Gr. and St., 4 ^°.

» 33. „ radiosus, n. sp., Gr. and St., 2 |°.

„ 34. Auliscus propinquus, n. sp., Gr. and St., 4 fl°.

„ 35. ,, lacunosus, n. sp., Gr. and St., 5 2°.

» 36. ,, lineatus, n. sp., Gr. and St., 4 f °.

PLATE XIII.

„ 37. Auliscus inflatus, n. sp., Gr. and St., 5 ^°.

„ 38. Monopsia niammosa, n. sp., Gr. and St., 4 ^.°.

„ 39. BZuttonia alternans, n. sp., Gr. and St., 6 ^°.

Journ. Q. M. C, Series II., No. 19. 12

148 A FOSSIL MARINE DIATOMACEOUS DEPOSIT.

Fig. 40. Actinoptyclius (glabralus var. ?) elegantulus n. sp., Gr. and St.,

500
1

„ 41. A. pxilcliellus, var. tenera, Gr. and St., 5 ^°.

„ 42. Asterolampra uraster, n. sp., Gr. and St., 5 %°.

„ 43. Hemialus dissimilis, n. sp., Gr. and St., 4 ^°.

,, 44. ,, amplectans, var. major, Gr. and St., 4 £°.

j, 45. ,, tenuicomis, Grev., view of valves in conjunction, 4 ^°.

„ 46. Trinacria simulacrum, n. sp., Gr. and St., 4 £°.

„ 47. „ «ventrico$a, Gr. and St., frustular view, 5 &°.

„ 48. Melosira oamaruensis, n. sp., Gr. and St., under valve, 4 %°.

» 49. „ „ „ „ upper valve, 4 ^°.

„ 50. Pyxilla reticulata, n. sp., Gr. and St., 7 £°.

PLATE XIV.

„ 51. Biddulpliia punctata, Grev., frustule, 3 4°.

„ 52. Stoschia (?) punctata, n. sp., Gr. and St., 2 ^°.

„ 53. Biddulpliia lata, n. sp., Gr. and St., 3 |°.

„ 54. Porodiscus hirsutus, n. sp., Gr. and St., z \°.

„ 55. Huttonia virgata, n. sp., Gr. and St., e ^°.

,, 56. Biddulpliia tenera, n. sp., Gr. and St., valvular view, 4 -J°.

» 57. „ ,, „ „ frustular view, 4 ^°.

„ 58. Triceratium parallelum, var. gibbosa, Gr. and St., s \ °.

„ 59. Anaulus subconstrictus, n. sp., Gr. and St., valvular view, 4 |°.

60. „ „ ,, „ frustular view, 4 |°.

61. Triceratium eccentricum, n. sp., Gr. and St., 5 ^°.

62. Biddulpliia reversa, n. sp., Gr. and St., 5 ^°.

„ 63. Actinoptyclius (undulatus, Ehr., var. ?) constrictus, 5 %°.
„ 64. Triceratium sexapartitum, n. sp., Gr. and St., 5 ^°.

•5

55

Joirrn.Q.M.C.

Set II. Vol. 3 Pl.X.

Wee t, We miaa & Co li Lb -

JorUTIL. Q.M. C.

Ser.Il.Vol.3.Pl.XI.

j.hbh.

Journ.Q.M.C.

Ser.II.VoL3.Pl.XII.

W"est,Newmaji& Co.Hth.

Journ.Q.M.C.

Ser.II.Vol.3Pl.XILr.

^Vest, Hewnu*rL&.CoJtt4i

Jo-urn. Q.M.C.

Ser.lI.Vol.3.Pl.XIV:

~Vfee t. Bewman &Cc.Tit3i.

149

List of Diatomace^e Found in Loch Kinnord Kieselguhr,
by the Rev. George Davidson, Minister of Logie-Cold-
stone, Dinnet, Aberdeenshire. (Extracted from " Trans.
Edinburgh Geological Society.")

Recently a number of Diatomaceous deposits found in various
parts of Scotland have been worked for commercial purposes,
amongst other things in the manufacture of paper, the material
being mixed with the ordinary pulp to give body and gloss. Most
of the material which is called Diatonrite, is very rich in Diatoms,
that from Loch Quire deposit, for instance, containing as much as
88'732 per cent. That from Loch Kinnord, Aberdeenshire, has
been carefully examined by Rev. George Davidson, of Logie-
Coldstone, and, as a list of fresh-water forms in a readily procur-
able and easily cleaned material will no doubt be of interest to
many microscopists, it is printed in extenso below. The original
list is, moreover, quite out of print.

Epithemia

turgida, Ktz.

Eunotia

impressa, var. ;

5>

gibba, Ktz.

Grun.

5)

sorex, Ktz.

>>

formica, Ehr.

J)

zebra, Ehr.

»

nodosa, Ehr.

J>

ocellata, Ktz.

5>

pectinalis, Dillw.

)5

gibberula, Ktz.

>>

undulata, Sm.

)5

alpestris, Ktz.

5J

tetraodon, Ehr.

)>

ventricosa, Ktz.

>>

ventricosa.

J)

Hyndmanii, Sm.

))

bigibba, Greg.

))

granulata, Ktz.

>>

diadema, Ehr.

V

proboscidea, Ktz.

>>

camelus, Ehr.

V

globifera, Heib.

>1

monodon, Ehr.

Eunotia

arcus, var. incisa,

Ehr. „

Faba, Ehr.

>>

uncinata, Ehr.

»

lunaris, Breb.

>>

gracilis, Sm.

i)

triodon, Ehr.

j)

major Sm.

5>

op. (?)

minor

150

>>

>>

?>

Cymbella Ehrcnbcrgii, Ktz.
„ cuspidata, Ktz.

,, Scotica.

,, hercynica, Sell.

Atlas, ix, 30, 31.

,, pisciculus, Greg.

„ turgida, Greg.

„ navicuUfo?inis,Amd.

„ sp. (?) Atlas, ix, 56.

„ obtusiuscula, Ktz.

,, augustata, Grun.

,, Norwegica, Grun.

,, acutiuscula, Grun.
cequalts, Sni.
(Navicula) Cesatii

(Rhab.).
Anglica, Lagerst.
Amphora ovalis, Ktz.

,, lineata.

Cocconeis placentula, Ehr.

,, Helvetica, Brun.
Achnanthidium flexellum, Breb.
lanceolatum, Breb.
Jaclcii (?).
Cyclotella operculata, Ktz.

,, rotula, Ktz.

„ Kutzingiana, Thw.

„ papillosa, O'Meara.

,, antiqua, Sm.

Surirella nobilis, Sm.

,, splendida, Ktz.

„ linearis, Sm.

„ tenera, Greg.

,, constricta, Ehr.

„ craticula, Ehr.
Tryblionclla angustata, Sm.
Cymatopleura apiculata, Priteh.

„ elliptica, Breb.
Nitzschia augustata, Grun.

,, denticula, Grun.

55
57

5J
55
55

Nitzschia linearis, Sm.

sigmoidca, Sm.

parvula, Sm.
Navicula divergens and vars.,Sm.

acuta, Ktz.

nodosa, Ehr.

stauropAera, Grun.
„ gibba, Ktz.
,, viridula, Ehr.
,, /zrma, Ktz. and Grun.
„ /i^fos, Ralfs.

mesotyla, Ehr.

laivissima, Grun.

sp. (?) Atlas, 44,51.
,. nobilis, Ktz.
,, follis, Ehr.
„ rhomboides, Ehr.
,, amphioxys, Ehr.
,, major, Ktz.
, , mormonorum, Atlas,

44, 24.
„ diceph&a, Ehr.
,, rar. stauroneiformis.
„ Brebissonii, Rabh.
,, viridula, var. major.
„ rupestris, GruD.

;5

55

55

5.'

55

35

iridis, Ehr.
,, viridis, Ktz.

,, interrupta, Ktz.

cuspidata, Ktz.

augustata, Sm.
,, ovalis, Sm.
„ Americana, Ehr.

„ cocconeiformis,

Greg.
,, scrians, Ktz.

,, ajftnis, Ehr.
,, borealis, Ehr.
„ limosa, Grun.

,, radiosa, Rabh.

151

Navicula cardinalis, Ehr.

,, divergens, var. Mul-
lensis, Greg.

,, semicruciata, Ehr.

,, gracillima, Pritch.

„ polyoma, Breb.

,, amphigomphus, var.,

Atlas 49, 31. „

„ fulva, Ehr.

,, punctata, Ehr.

sp. (?) Atlas, 44, 51.

,, bacillum, Ehr.

,, stauroptera, var.,
Grim.

„ sp. (?) Atlas, 43, 25

■a pygmwa, Ktz.
,, scutelloides, Sm.
„ tumida, Sm.

„ acrosphceria, Breb.
„ Hitchcockii, Ehr.
,, Braunii, Grun.
„ injlata, Ktz.

,, leptogongyla, Ehr.
„ sp. (?) Atlas, 45, 28.
„ spharophora, Ktz.
,, termitina, Schm.
,, commutata, Schm.
„ crassinervis, Breb.
„ ex His, Grun.
„ rhyncocephala, Ktz.

„ lacustris, var. /3. Greg.
,, oculata, Breb.
„ mesolepta, Ehr.
„ amphirhynchus, Ehr.

„ Zellensis, Grun.
„ serians, var. minor.

„ hemiptera, Ktz.
undid at a, Greg.
nodulosa, Grun.

3J

>>

stomatophora, Grun.

Navicula rhombica, Greg.
Stauroneis phamicenteron, Ehr.
anceps, Ehr.
dubia, Greg.
acuta, Sm.
linearis, Ehr.
Pleurosigma attenuatum, Sm.
lacustre, Sm.
,, Spencerii, Sm.
Synedra ulna, Ehr.
„ biceps, Ktz.
,, capitata, Ehr.
„ lunaris, Ehr.

,, ladians, Ktz.

,, linearis, Sm.

„ longissima, Sm.

,, atv/5, var. tenuissima,
Ktz.
Cocconema lanceo latum, Ehr.
cymbiforme, Ehr.
cistula, Hemp.
,, parvum, Sm.
„ Helveticum, Grun.
Gomphonema acuminatum, Ehr.
,, tnsigne, Greg.

,, dichotomum, Ktz.
„ constrictum, Ehr.
,, subtile, Ehr.
„ vibrio, Ehr.

,, Hebridense, Greg.
„ Brebissonii, Grun.
„ intricatum, Ktz.

,, turris, Ehr.

„ geminatum, Ag.
„ cygnus, Ehr.
,, tenellum, Ktz.

,, elongatum, Grun.
Fragilaria capucina, Desm.
„ lapponica, Grun.

„ virescens, Kalfs,

>>

5>

152

Fragilaria var, exigua, Grim.
„ construens, Grun.

j>

undata, Sm.
Tabellaria fenestrata, Lyngb.
Stenopterobia anceps, Grun.
Encyonema gracile, Rab.

lunula, Grun.

ca>spitosu?n, Ktz.
Denticula tenuis, Ktz.

j>

n

Denticula injlata, Sm.
Tetracyclus lacustris, Ralfs.
Melosira crenulata, Thw.
Campylodiscus noricus, Ehr.
Stephanodiscus minutulus, Grun
Odontidium mutabile, Sm.
Mastogloia Grevillei, Sm.
Ceratoneis arcus t Ktz.

153

PROCEEDINGS.

April 22nd, 1887.— Ordinary Meeting.

A. D. Michael, Esq., F.L.S., F.R.M.S., &c, President, in the

Chair.
The minutes of the preceding meeting were read and confirmed.
Mr. T. F. Smith was balloted for and duly elected a member of the Club.
The following donations were announced : —

" The American Naturalist " In exchange.

" The American MonthlyMicroscopical Journal " „

" The Journal of the New York Microscopi- ^
cal Society" ... ... ... ... J

" Science Gossip " From the Publisher.

Report of the Smithsonian Society ... ... From the Society.

" Journal of the Royal Microscopical Society " „

Report and Proceedings of the South London")

Microscopical and Natural History > ,,

Society ... ... ... ... j

Report and Proceedings of the Essex ■*

Natural History Society ... ... ) "

" The Quarterly Journal of Microscopical ->

c . „ i Purchased.

Science ... ... ... ... )

Cooke's " British Desmids "

" Annals of Natural History "...

" The Microtomist's Vade-Mecum "

The thanks of the Club were voted to the donors.

Mr. H. Morland read a paper " On Mounting Media, so far as related to
Diatoms."

Mr. Stokes said he had tried one or two of the preparations mentioned by
Mr. Morland, but so far as his experience went the unfortunate part was,
that though it was easy to get a medium suitable in other respects, the
difficulty was to keep it, because as a rule most of them had a great effect
upon the cement, and after a time they were sure to get out. So far as he
could see, dry mounts or Canada Balsam were the only kinds to be de-
pended upon ; with the others it was only a question of time — how long
they would stand.

Mr. T. C. White said that he quite agreed with what Mr. Morland had
said concerning styrax ; he had tried it, and found that after a time it be-
came granular. He had thonght it might be a good plan to make a very dense
solution of borax in glycerine, so thick as to be almost like a jelly, but he
found that however well it answered at first, crystals were sure to form
afterwards, and, of course, spoilt everything.

Professor Stewart said that in making a recent examination of a number

>>

»>

154

of Mr. Stephenson's slides, mounted in phosphorus dissolved in bisul-
phide of carbon, he found that there was nothing the matter with them,
although many of them had been mounted as long as 12 years ago. Had
there been any leakage there would, of course, have been a conflagration.

Mr. Sturt said he had tried, with success, a mixture of styrax and
Canada Balsam, in which the Aulacodisci, Triceratium favus, and others,
showed up splendidly. This medium would be found a very good one for a
number of diatoms for which styrax alone was too highly refractive.

The President said he had some little experience of styrax as a mounting
medium, althongh not as regarded the mounting of diatoms ; but his im-
pression was, from specimens which Dr. Gray had shown him, that when it
was obtained in a pure state it was a very admirable medium for mounting
a large proportion of diatoms. Dr. Gray had informed him that he actually
boiled the styrax upon the slide v\ ith the diatoms in it, so that apparently
the application of great heat did not always result in carbonizing. In his
own experience he had found it unsuitable, because the objects which he
desired to mount would not stand great heat, and on this account he had
been obliged to abandon it, althongh he had hoped it might be of great use
in mounting minute dissections of very clear chitinous objects, which were
otherwise somewhat difficult to see. As regarded the material itself, there
seemed to be no doubt that different samples varied in many respects to
such an extent as to give an impression that there must be more than one
species of plant from which it was obtained. One or two lots crystallized
all over the slides, whilst others did not show much tendency towards
crystallization ; but from whatever cause this difference might arise, it
seemed that the tendency to crystallize could be reduced to a minimum by
macerating the styrax in a succession of warm waters ; this was, however,
too troublesome for most persons to carry out. The styrax which gave the
crystals was much lighter in colour than the other kind, and on this
account, if it could have been obtained free from them, it would have
proved a more valuable medium. He had found that this light styrax was
extremely difficult to dissolve in any medium which would take up a large
quantity, so that when a mount did dry there was often very little of the
resin left under the cover-glass, rendering it necessary to frequently run
in more; and, on the whole, he found that it gave so much trouble that he
had to abandon it altogether. He must say, however, that for diatom
mounting where heat could be safely used it appeared to be a great advance
upon Canada Balsam. In the matter of mounting with phosphorus, it was
well known that Mr. Stephenson had been very successful, but it was un-
doubtedly very awkward stuff to handle by those who were inexperienced
in the art of using it.

Mr. G. C. Karop read a translation of a paper from the German, relating
to a Parasite infesting the Diatomaceaa. The subject appeared to him to be
rather a new one, and, therefore, worth bringing before the Club, as it
would be interesting to know if anything of the kind had been seen in this
country. If those members who went to their excursions felt interested in
the matter, he thought they might find the subject to be one which
merited investigation.

155

Mr. Sturt said it was well to notice that the species seemed chiefly con-
fined to Synedra.

The President thought the subject was one which might repay investiga-
tion, and expressed the thanks of the Club to Mr. Karop for translating
the paper.

The President said there was one small subject which he had been
requested to mention, and that was that some time ago a little alteration
was made in the wording of the tickets which were placed beside the ex-
hibits on the tables on their evenings of meeting. The alteration con-
sisted of the addition of a line, in which gentlemen were requested to enter
any points of special interest in their objects to which it was desired that
attention should be directed. Some members used this and others did not,
and the point he wished to urge upon them was that whenever they brought
anything which was either new or of special interest, if they would kindly
fill up the paper with a rather more detailed description than simply the
name of the specimen, it would not only prove useful to other members
present, but Mr. Hailes would be able to select such cases as might have
special value for insertion in the Journal ; and by this means a useful record
might be preserved. As it was, a great deal of information was given in
conversation which dropped out of their proceedings from the want of
some means by which it might be recorded.

Mr. E. M. Nelson exhibited and described a new photo-micrographio
apparatus.

Mr. T. C. White said he quite concurred with Mr. Nelson as to the
advantage of having the whole of the apparatus mounted upon one base-
board, because then whatever vibration took place it equally affected the
whole of the apparatus, and so did not blur the picture. He should like to
know from Mr. Nelson if, in addition to diatoms, he had tried any patho-
logical sections, because these were what he found to be the most difficult
class of subjects. There could be no doubt whatever as to the superiority
of photography for the purpose of delineating objects, because however
well a person might draw, it took far less time to photograph, and the de-
tails were sure to be entirely reliable. He took a photograph, a few days
ago, in half an hour, which would have taken anyone at least a day to draw
as minutely perfect as the picture came out.

Mr. Stokes asked if it answered better to increase the eyepiece power or
to increase the distance from the eyepiece in order to obtain a greater in-
crease in the size of the picture ? Which would give the sharper print ?

Mr. Nelson said he had as yet done nothing with the apparatus except
diatoms, and of these he had only taken about two or three subjects.
Until he succeeded in getting the finest detail which he could see or draw,
he intended to go on with one thing ; after this he hoped to do all sorts of
other things beside. As regarded increase of size, it was Professor Abbe
who said that where the distances could be obtained it was the lowest eye-
piece which was the best to use.

A vote of thanks was returned to Mr. Nelson for his communication, and
after announcements of meetings for the ensuing month had been made, the

156

proceedings terminated with the usual conversazione, and the following
objects were exhibited : —
Melicerta conifera
Culex pipiens, $ & Q, without pressure,

showing muscular structure, &c.
Fresh-water Diatoms from Mendip Hills,
Mi riil ion circtilare, Gomphonema Fracji-
lariir, &o. f &c. ...
Eggs and Larvae of Cat-Flea

}

Mr. F. W. Andrew.
Mr. F. Enock.

Mr. G. E. Mainland.
Mr. C. Rousselet.

Attendance — Members, 44 ; Visitors, 2.

May 13th, 1887. — Conversational Meeting.

}

The following objects were exhibited : —
Nostoc commune ...
Section of Human Retina...

Diatoms, Anthodiscusfloreatus, Sfc., from Oamaru
Head of Queen Bee, Apis mellifica, with ex

planatory drawing
Ova of Perch, embryo six days old
Thick section of Gall, showing curious cellular )

L/1SSU6 ••• ••• ••• ••• ♦ • • J

Diatoms from Florence (fresh water)
„ Rutilaria tenuis ...
,, Actinoptychus splendens, in balsam,
with £in. O.G. and Liaberkiihn...
A Photo-micrograph of Aniphipleura pellucida~)
X 700 diam., taken with an oil immer. -j\ I
O.G., 1*43 N.A., and 3rd power projection i

cj fc3~]-/lfc!Ot5»«» ••• ••• ••• ••• j

Radiolaria. Challengeron diodon, and C.

Willemosii, from a Hyalonema sponge
Paludicella Ehrenbergii ...
Diatom, Myopsia mammosa, from Oamaru
Type slide of Diatoms from Pensacola Bay,~)

Florida ... ... ... ... ... )

Attendance — Members, 14 ; Visitors 2.

May 27th, 1887. — Ordinary Meeting.

A. D. Michael, Esq., F.L.S., F.R.M.S., &c, President, in the

Chair.

The minutes of the preceding meeting were read and confirmed.

The following additions to the Library were announced : —
" Proceedings of the Canadian Institute " ... In exchange.
4< The Botanical Gazette" ... ... ... „

"The American Monthly Microscopical Journal" ,,

" The American Naturalist " ... ... ... „

}

»-

]

Mr. F. W. Andrew.

Mr. E. Carr.

Mr. C. G. Dunning.

Mr. F. Enock.

Mr. W. Goodwin.

Mr. G. C. Karop.

Mr. G. E. Mainland.
Mr. H. Morland.

Mr. E. M. Nelson.

Mr. B. W. Priest.

Mr. C. Bousselet.
Mr. G. Sturt.

Mr. W. Watson.

157

" Proceedings of the Watford Natural His-

tory Society" ...

}

In exchange.

»>

" Science Gossip "

" Annals of Natural History " Purchased.

" British Desmids," concluding part ... ... „

The Secretary read the following note from Col. O'Hara, accompanying a
photograph of a worm found in a preparation of the poison of Bungarus : —
" Dear Sir, — In looking over some slides of snake poison, which I pre-
pared in India, I find in one, in the clear poison of Bungarus arcuatus, or
ceruleus, a parasitic worm, almost invisible by transmitted light. As it is a
curious locality to choose for one's habitat, I send you a photo of it, by
polarized light, which may interest the members of the Q. M. C. I send it
unmounted."

The President remarked that it was certainly a very singular habitat for
a parasite, because the Bungarus was well known as one of the most
dangerous and poisonous of the Indian snakes, from 2,000 to 3,000 persons
annually being killed by it.

Mr. H. M. J. Underbill gave a description of the anatomy of Spiders,
illustrating the subject by means of diagrams, and numerous mounted pre-
parations and sections exhibited under the microscopes provided for the
purpose in the room.

Mr. B. T. Lowne regretted that he had unfortunately arrived too late to
hear the whole of Mr. Underbill's paper, but with regard to the latter portion
he should be very glad to have some further information, and should
specially like to hear a little more in detail about the eyes. To mention one
point, he should like to know whether Mr. Underhill had observed a distinct
line of fibrous tissue separating the upper layer of cells from the layer of
cells lying below ? He had himself paid some attention to these subjects,
and had found the layers so separated in S alliens, but in some others it was
absent. His own view was that this layer was a connective tissue layer
separating the optic from the nervous portion of the eye.

Prof. C. Stewart said that Mr. Underhill had brought the views which he
held so clearly and so fully before them that it was hardly necessary to
supplement what be had said. In speaking, however, of the heart, he seemed
to have had some difficulty in making out the valves, and, therefore, of ex-
plaining their action. He should himself have thought that they were the
same as those of ordinary insects, and that their structure was as usually
described in the text books, the organ consisting, in fact, of four chambers
communicating with each other, before and behind, provided with valves. It
was not so easy to see their action in all insects, but in the Ephemera they
were seen very clearly. With the binocular microscope especially, an
observer could see through the tissues and clearly watch the action of the
pair of valves at each end, two of which guarded the orifice in front and two
the orifice behind.

The President said he also had been struck with the observations of Mr.
Underbill about the heart on account of the difficulty which he seemed to
have met with in connection with the matter, and because his remarks ap-

158

peared to exclndo tho opinions of foreign arachnologists who had worked
out the subject and had communicated the results. He remembered more
particularly a paper by Prof. Claparede in which he described at some
length the circulation and the structure of the heart, and illustrated the
subject with figures, but the conclusions he came to were not the same as
M r. Underbill's. Prof. Claparede, on the contrary, thought there was both a
forward and a backward aorta, and that the current divided at the heart,
going partly backward and partly forward, though he thought the main
current was the backward current. The observations upon which his con-
clusions were based were made on very young living spiders. He fancied
that there was also a somewhat elaborate paper by Prof. Berkau on the
same subject, in which he confirmed, on the whole, the observations of Prof-
Claparede, but attributed the sucking action to the action of the trophi. A
paper had also appeared by Prof. McLeod, of Louvain, on the sucking
action of the Araehnida, in which he had drawn the whole thing with
extreme skill, attributing the sucking action to the oesophagus and the
sucking stomach. He remembered being considerably interested and pleased
with this paper at the time he read it. He was not sure that he quite
understood Mr. Underbill's remarks as to the movement of the blood cells
in the lungs, but thought he seemed to take the different lamina? to be
entirely detached organs. In the same paper to which he had referred Prof.
McLeod had described the pillars joining the different gills, and had figured
them rather carefully. He remembered that when he saw Mr. Campbell's
specimens and sections of spider's lungs, they came to the same conclusion
that there was some connection between the laminae, but they could not
quite decide whether they were pillars or not— this was prior to the appear-
ance of Mr McLeod's paper, though he did not think Mr. Campbell had ever
published anything upon the subject.

Mr. Underhill said that Mr. Lowne had just looked at his specimen and
found that the fibrous separating layer of the eye was not present in it. The
diagram w r as not taken from the eye of an Epeira, but from some other
species, and he had not cut any sections of the eyes of Salticus. As
regarded the circulation of the blood, he did not wish to contradict Prof.
Claparede, whose paper on the subject he had not seen, but, of course, if he
said he had seen it go in both directions, no doubt it did so. It was, how-
ever, very difficult to see, and it was possible that a mistake might be made
from seeing it apparently moving in both ways, so that anyone looking at it
in one direction would see it moving both ways, though there was really only
a backward current. The movement of the heart was very clearly seen in
spiders, the pulsations going along the heart like waves. As to the valves,
he was quite aware of what the text books said about them, but that con-
stituted his difficulty, because he could not find them, although he would not
say positively that there were none. The salivary glands were situated one
in each jaw. The gills were attached at one end, but were free at the other
end, and were not quite free at the sides. As for the pillars which the
President mentioned having Been, he could not help thinking that some
small hairs musi have been mistaken for pillars, or else the sections which

159

he examined were imperfect ; if an improper section was taken these would
be likely to appear to be pillars.

A vote of thanks to Mr. Underhill for his paper was then proposed by the
President and carried unanimously.

A paper by Mr. B. T. Lowne was, owing to the lateness of the hour, de-
ferred until the next meeting.

Announcements of meetings, &c, for the ensuing monti were then made,
and the proceedings terminated with the usual conversazione, when the
following objects were exhibited in illustration of Mr. Underbill's paper
under a series of microscopes provided by Mr. C. Baker and other
members : —

Section of Lycosa, showing brain, heart, gills, liver, silk glands, &c.

Small spider, unnamed.

Eyes of Lycosa.

Section of eye of Lycosa, showing lens, vitreous body, and retina.

Spinnerets of Hair Curler Spider, Cinijio similis.

Threads of Cinijio.

Spinnerets of Clubiona, showing silk tubes.

Nest of spider, Theridion.

Calamistrum or " comb " on hind leg of Cinijio.

Foot of Web -walking Spider, Epeira.

Foot of Ground-walking Spider, Dysdera.

Attendance — Members, 39 ; Visitors, 5.

June 10th, 1887. — Conversational Meeting.

The following objects were exhibited : —

Diatoms, Biddulphia Baileyii ... ... ... Mr. F. TV. Andrew.

„ Kittonia elaborata ... ... ... Mr. H. Morland.

Bacillus tuberculatus, with new cheap German")

4 0.G.N.A.84 j Mr. E. M. Nelson.

Type slide of Oamaru diatoms, mounted by )

HerrKniker ) Mr. G. Sturt.

Section of Retina, showing rods, cones, &c. ... Mr. W. Watson.
Attendance — Members, 24 ; Visitors, 0.

June 24th, 1887. — Ordinary Meeting.
Chas. Stewart, Esq., F.L.S., &c, Vice-President, in the Chair.

The minutes of the preceding meeting were read and confirmed.
The following gentlemen were balloted for and duly elected members of
the Club :— Mr. Francis W. White and Mr. William Thos. Wilson.
The following donations were announced : —

A Series of Papers From the Royal Dublin Society.

" Proceedings of the Belgian Micro- (

scopical Society " ... f From the Society.

"Journal of the R.M.S."

" The Botanical Gazette " In exchange.

160

r In exchange.

" Proceedings of the Natural His-
tory Society of Glasgow "
" Annals of Natural History " ... Purchased.

Professor B. T. Lowne gave a resume of his paper " On the structure of
the head of the Blowfly larva, and its relations to that of the perfect insect,"
which he illustrated hy diagrams drawn upon the black-hoard as he pro-
ceeded, apologising, however, for the absence of other diagrams which he
had not yet been able to complete.

The Chairman was sure that the members would agree with him that they
were not only'greatly indebted to Mr. Lowne for bringing this subject before
them, but also for not having brought up his series of diagrams, because a
diagram drawn upon the board, and developed as the speaker proceeded,
illustrated a subject far better than could be done by pointing to a compli-
cated diagram. Mr. Lowne had made the view which he took of the matter
so plain that he was quite sure it would be clearly understood by all who
had listened to it, and he should be glad to hear any remarks from anyone
present upon this "object of the microscope,'' than which few were more
interesting or more common. He thought he understood Mr. Lowne to say
that what was commonly spoken of as the tongue — or hypo-pharynx — of
the cricket or the cockroach was not actually homologous, but was serially
homologous to the proboscis of the blowfly.

Professor Lowne said this was so ; though functionally the same, the two
organs were developed from different parts.

Mr. Tebbs said he should like to ask Mr. Lowne how it was that in the
gnat the labium appeared to be quite a complete and independent organ ?
In Bombylius they had them also quite separate, and in the sucking flies the
same thing also occurred. In tracing them down it was found that the
lancets became less developed until, in the blowfly, they were enclosed in
the labium. Mr. Lowne seemed to have been taking an extreme case with-
out bringing into relation with it the intermediate stages. In the bee there
was a complete set of maxillae, and so on down to the extreme case of the
blowfly where they had no function.

Professor Lowne thought it would be admitted that if he was right in the
case of the blowfly the correctness of his view in connection with all the
other flies would necessarily follow. He thought that in the case of the
gnat and of Bombylius, the parts referred to by Mr. Tebbs were
the modified galea of the maxillag. In Asilus the labium was clearly dis-
tinct from the lips of the proboscis. In Tabanus the whole of the structures
were so modified that he was puzzled as to what was the actual condition ; he
had, however, no doubt that in the proboscis they had the galea. In the
bees, the tongue was a perfectly distinct structure, and there was no doubt
in his mind that it was a labium. With regard to the lancets they might go
on discussing the subject, but without conclusive results until they knew
what they were developed from. They had been called mandibles, but he
entirely dissented from that view, thinking it far more likely that they were
paraglossae. It was certain, however, that there was no other means of find-
ing out what they were except by tracing out their development.

161

A vote of thanks to Professor Lowne for his admirable paper was proposed
by the Chairman, and unanimously carried.

Mr. T. F. Smith read his paper "On Diatom Structure, ' which he illus-
trated by a number of choice specimens, exhibited under microscopes in the
room.

The Chairman said that the criticisms which Mr. Smith had offered in the
course of his paper were no doubt quite capable of being answered by those
whose views had been opposed. Diatom structure was undoubtedly extremely
complicated, and where, as in these cases, the conditions of observation gave
rise to questions of considerable difficulty, they naturally led to differences
of opinion, which were by no means lessened by the way which people had
of seeing what they wanted to see.

Mr. E. M. Nelson thought they had enjoyed a great treat that evening by
having a diatom paper from a new source ; to him, certainly, it was a great
pleasure to welcome a new worker in a field which was admittedly so
surrounded with difficulties. To get a proper notion of diatom structure
was important from a botanical point of view, but not less so as affording
the means of determining the correct interpretation of microscopic images,
because in all cases they were met with questions of dioptric difficulty.
They bad-far too few workers in this very interesting and important field.
As to his remarks upon Asteroniphalus, Mr. Smith was perfectly right to
criticise the paper as he had done, because it was certainly misleading on
account of its not being clearly stated that it intentionally dealt with
the finer structure only. The writers were perfectly conversant with the eye-
spots, but did not render this plain, and the matter was further complicated
by the wording of the paper, which ought really to have had the second
paper tacked on to it. He did not wonder, therefore, that Mr. Smith thought
they had gone wrong. The specimen which Mr. Smith was showing under
the name of Coscinodiscus centralis was really not centralis, but conscirms,
a totally different form from centralis, in which the bar cuts right through
the middle. The next one was quite new to him. The next was an extremely
beautiful specimen of Triceratium, and he thought he might say it was the
finest he had ever seen ; they were quite agreed as to the structure of this.
In Aulacodiscus Kittonii he had seen the eye-spots, and he should be happy
to show Mr. Smith anything which he had, and to work out the subject
together for the good of science. The diatom namers seemed to go rather
by the shapes than by structural differences ; the slide of centralis which he
had was one which had been very carefully and independently named.
Personally he felt very much obliged to Mr. Smith for his paper, and for the
many beautiful specimens with which he had illustrated it.

Mr. Morland said he had been looking at some of Mr. Smith's slides, and
could say that the one called centralis was really Coscinodiscus hiangulatus ;
it was so called because where the edges turned over there Avere two angles
formed ; centralis was much finer. It would be found in Smith's " Atlas of
the Diatomacea?," and also in " Castracane on the ' Challenger ' diatoms."

Mr. Karop said he was very pleased indeed to have heard Mr. Smith's
paper, which was one which ought to give rise to a good deal of discussion.

162

He thought Mr. Smith went wrong in arguing from analogy in such cases
where one of the difficulties met with was the fact that personal equation
was sure to come in, and where that was so he supposed it was scarcely
possible to get people entirely to agree.

Mr. Smith said, with regard to his having thought that Mr. Nelson and
Mr. Karop knew nothing about the matter, he was misled by the letterpress,
which went on to say that the diatoms consisted of one siliceous membrane.
As to the naming of centralis, he had gone by his general knowledge, and of
the many specimens which he had examined in no case had he found a bar
as described by Mr. Nelson. He got a specimen some time ago which had
been mounted by Wheeler, but which he had found too thick for his purpose ;
he, therefore, got another slide by another mounter, and found that as
regarded species it was precisely the same. As regarded Kittonii, the matter
was one which he could not at present solve, and he thought it was only by
analogy that it could be solved.

The thanks of the Society were unanimously voted to Mr. Smith for his
paper, and for the exhibition of the specimens in illustration.

Announcements of meetings and excursions for the ensuing month were
then made, and the proceedings terminated with the usual conversazione,
when the following objects were exhibited by Mr. Smith in illustration of
his paper : —

Coscinodisctis asteromphalos, in section, bits chipped out of centre.

Coscinodiscus centralis, showing finer structure, and little bosses at corners
of hexagon.

Coscinodiscus, sp., from Richmond, Virginia ; with broken edge membrane
showing over edge of hexagon.

Aulacodiscus Kittonii, showing eye-spots and hexagons.

Triceratium, sp., from Hungary, showing fine membrane torn off portions
of hexagons.

Triceratium, sp., from Oamaru deposit, showing broken membrane over
hexagons.

Coscinodiscus, sp., from Jutland, showing membrane in eye-spot.
Coscinodiscus, sp., from Oamaru deposit, with granulated membrane in
place of eye-spot.

The following objects were also exhibited : —

Rivularia articulata ... ... ... Mr. F. W. Andrew.

Section of garden spider, Epiera)

diadema, showing the internal '

.., , , V Mr. F. Enock.

anatomy, with an explanatory

drawing ... ... )

Mounted Rotifer, Limnias cerato-\ -** ™- w n i„ n
phylli 5 ... ... ... J

Attendance — Members, 3G ; Visitors, 5.

163

On Diatom Structure.

By T. F. Smith.

(Bead July 22nd, 1887.)

Plate XV.

It will be within the recollection of the members of this Club
that when I exhibited here last month what was presumed by me
to be Coscinodiscus centralis I was met, on the authority of Mr.
Morland, with the objection that it was not Coscinodiscus centralis
at all, but concinnus or, I think, angulatus. I did not at the time
profess to have knowledge enough of the species of diatoms to
decide that question, and even if I had done so the principal point
would still remain doubtful, whether the diatom fio-ured bv Messrs.
Nelson and Karop and that exhibited by myself were identical.

Since then Mr. Morland has given me a slide, mounted by him-
self, which he considered was Coscinodiscus centralis, and Mr.
Sturt has lent me the slide from which Mr. Karop's drawing was
made, and I am now in a position to state that, whatever may be
the names of the two specimens, they certainly are not the same,
and the structure is altogether different. Having stated this fact,
my surmises about their having mistaken one structure for another
and focussing through the wrong side of the diatom, falls to the
ground, and I now beg to express my regret to these gentlemen for
challenging their reading of the structure before making quite sure
that we were not speaking about different diatoms.

I am now, however, in a position to speak with certainty about
the specimens I show to-night and theirs being identical ; and,
having examined them carefully, I am still of opinion that the
perforated membrane in Messrs. Nelson and Karop's drawing is
shown on the wrong side of the hexagons. There is no question
this time of focussing from the wrong side of the diatom, but, I
think, of taking too deep a focus and of failing to take note of what
was outside before the image disappeared. I find it very easy to
get the appearance shown in the figure, and it would be easy to sit
down half a dozen times and rise up again from the microscope

Journ. Q. M. C, Series II., No. 20. 13

164 T. F. SMITH ON DIATOM STRUCTURE.

without suspecting it not to be the true structure. It is no reflec-
tion, therefore, on these gentlemen's skill that they have produced
this appearance ; but there is an evolution of a knowledge of
structure as well as an evolution of structure, and it has taken me
a matter of nine months to arrive at my present ideas of the
structure of the diatom in question. This diatom was perfectly
familiar to me in appearance, although not in name, and I have
spent many hours in trying to spell out the meaning of the ap-
pearance it presents, but it is only lately, after a study of fractured
specimens, that I am able to remain satisfied with my reading.
Having convinced myself.it now remains for me to try to convince
others, and for that purpose I have two specimens of Coscinodiscus
centralis here to-night, one being from the slide given me by Mr.
Morland and the other from a spread slide of the Nottingham
Deposit, mounted and lent me by Mr. Cole.

I have also endeavoured to draw the structure that you may know
what to look for, and decide for yourselves whether it is correct when
identifying it under the microscopes. In PI. XIV., figure 1 shows
the centre of the disc, and is supposed to be seen with the outer
membrane removed and looking down on the inner layer of eye-
spots. Figure 2 shows the outer perforated membrane, the relation
of the different parts of which 1 will try to point out on the black-
board. In doing this I am obliged to make a more symmetrical
arrangement than what is seen in the diatom, to conceal my want
of skill in drawing. The hexagons in the specimens seem to be
thrown together anyhow, but when I also drew them anyhow and
tried to put on the superstructure the result was deplorable. You
draw first your hexagons and then place a round dot at each
corner large enough to conceal the junction. These dots represent
the imperforated part of the outer membrane, and form a ring of
six on the top of each hexagon. Now draw another circle in the
centre of each ring of dots, bring down a star-like point from the
circumference of each dot to the outer edge of the inner ring, and
the membrane is complete. There are indications of the centre
circle having two or three perforations like those shown by Messrs.
Nelson and Karop, but I have not put them in my drawing as it
would tend to confuse the structure. Figure 3 in my drawing
shows a part of the disc with four or five of the hexagons torn out
of the centre, and Figure 4 the same part with some of the outer
membrane remaining projecting over the space from which the

T. F. SMITH ON DIATOM STRUCTURE. 165

hexagons are wanting. I am sorry to say this last drawing is as
bad as can be, and fails altogether to convey the appearance of the
torn structure under the microscope. That part in the microscope
can be readily seen from its being paler, proving that the dark
colour of the ring of spots is due to the hexagons ordinarily under-
neath. This is all I have to say about this diatom to-night, but
there are other appearances that I have lately seen that I have not
embodied in this paper because they are new to me, and I am not
sure how far they are true. I shall be pleased, however, if the
members will look at it for me and give me their opinions.

There now remain two little matters connected with my last
paper that I should like to mention. The first is my opinion that
the figure of Aulacodiscus cellulosus given in the Journal by
Messrs. Grove and Sturt confirmed my views of the structure of
Aulacodiscus Kittonii, although I had not examined it. Since
then Mr. Sturt has kindly lent me the slide, and I find the
structure is exactly what I said it would be, viz., an inner layer of
eye-spots, with hexagons stuck on the top, and an outer perforated
membrane on the top of the hexagons.

Secondly, I exhibited a Coscinodiscus with an outer perforated
membrane, stuck on the top of the spines which project one
from each corner of the hexagons. The specimen was a fractured
one, and did not show the membrane all over, but my reason for
choosing it was that it showed the broken edge of the membrane
projecting over the hexagons. One gentleman that night could
not conceive a membrane being in that position, and thought it was
part of another diatom slipped on to the one I was showing. I
tried to convince him that it was not so, but don't think I suc-
ceeded. Since then I have had a conversation with Mr. Morland
on the subject, and find that he also is sceptical and puts down the
appearance to a granulation of the medium in which the diatoms
are mounted. I may state that some time ago I had a bit of a brush
with Mr. Morland in the " English Mechanic ' : on the existence
of a structureless membrane on the inner side of Arachnoidiscus,
and must admit that in that encounter I came off second best, and
this, I suppose, is what makes him think I am again in error. Both
these objections are perfectly legitimate ones, and having advanced
my opinions it is my duty to prove my case. To do this I have
brought the same slide to-night, and am fortunate enough to have
here specimens not far from each other, one showing the broken

1 ('»(» T. F. SMITH ON DIATOM STRUCTURE.

edge of the membrane and the other with it over the whole diatom.
This, I hope, will satisfy both class of objectors, as it meets the
points of each.

EXPLANATION OF PLATE XV.

Fig. 1. Coscinodiscus centralis. Central part. Outer membrane sup-
posed to be removed.
„ 2. Same diatom. Outer membrane only.
„ 3. Same diatom fragment. Inner layer only, with piece torn out

of centre.
,, 4. Same as Fig. 3, with torn outer membrane projecting over cavity
underneath.
Object glass used, Swift and Son's ^\ inch oil immersion and D. eye-
piece. Magnification about 1,400 diameters.

M

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I Vol. 3. PI. XV

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167

Do PORODISCUS INTERRUPTUS AND CRASPEDOPORUS ELEGANS

BELONG BOTH TO ONE FoRM ?

By H. Morland.

(Read July 22nd, 1887.)

Last gossip night I exhibited a slide containing specimens of
Porodiscus interruptus and Craspedoporus elegans, two new species
of diatoms described and figured by Messrs. Grove and Sturt in
the third part of their paper on the marine diatomaceous deposit
from Oamaru, New Zealand.

In the centre of this slide was a frustule, on one side of which
was a valve of P. interruptus, and on the other, one of Craspedo-
porus elegans. I am sorry to say that as yet I have only found
one such frustule, and thinking it quite possible that one valve
might have got jammed into the hoop or "connecting zone" of
another valve, I deemed it advisable to examine this frustule
critically before finally mounting it, as in consequence of having
but one such specimen I could only show it in one position.
First I decided upon mounting it showing " side " view, as in such
position the two valves could readily be recognized by focussing
first on the upper valve and then downwards on to the lower one.
Having come to this decision, all that remained for me to do was
to examine the " front " view of this frustule, which I had to do
11 dry," and under a i-inch objective (285 diameters) ; as far as I
could judge, it was a true frustule. However, I still further tested
it by passing it in and out of a drop of water (necessary for free-
ing it from adherent sand and fragments), and found it behaved
exactly the same as I have found other frustules to behave ; but
whilst examining it in this manner I had to do so under a lower
power, a |-inch, of about 60 diameters.

The valves of both these forms, roughly speaking, are shaped
somewhat like a watch-glass ; in the frustule their convex sides
both point one way, Porodiscus interruptus having the convex side
outwards, and Craspedoporus elegans having the same side towards
the interior. Arguing from analogy only, I should be inclined to

168 ON PORODISCDS INTERRUPTDS AND CRASPEDOPORUS ELEGANS.

think that this diatom is, or was, a parasitic form, growing some-
what after the manner of the Cocconidece, Craspedoporus elegans
being underneath.

As tending to confirm my observations of this frustule, I may
add that since I mounted it I have found a valve of Craspedo-
porus elegans with the " connecting zone " still attached, the same
being on the convex side of the valve, in a similar relative position
as in the frustule.

Should other diatomists examining this deposit be so fortunate
as to find frustules of these forms, either confirming or refuting
my views, I shall be glad if they will favour this Club with
information respecting the same. As, however, these forms are
scarce, it is possible we may have to wait some time before
receiving such information ; when valves are scarce, perfect
frustules are still scarcer.

The present is, I think, a good example of how difficult it
is to correctly describe a fossil diatom when the same is not
represented by living specimens. The Oamaru deposit, from
which I obtained my specimen, contains also another diatom, of
which the frustule has dissimilar valves. I refer to Trinacria
ventricosa. At first sight these valves would be considered as be-
longing to totally different species, but, fortunately, as this form is
rather common in the deposit, complete frustules, with the two
dissimilar valves in situ, are to be found without much difficulty.

169

Notes on a Species of Orthezia found in Kew Gardens.

By Edward T. Browne.

(Read August 26th, 18S7.)
Plates XVI., XVII.

At the Conversational Meeting of the Club in July I had the
pleasure of exhibiting an insect which I had found in the Economic
House, Kew Gardens.

I labelled the insect at the meeting " A supposed Dorthesia,
allied to the Aphis and the Coccus," obtaining this information
from Westwood's " Introduction to the Classification of Insects."
On page 450, Vol. ii, he writes : —

" In Dorthesia the antennas of the male are very long, but simple,
and the abdomen terminated by a thick pencil of very delicate
white seta? ; and the female is covered with elongated flakes of a
waxy secretion, which, in some exotic species in my collection,
are nearly an inch long. I possess males belonging to the
genus Dorthesui, the wings of which are nearly an inch in ex-
pansion."

In the insect-room at South Kensington Natural History
Museum, I found several species of the genus Orthezia, but they
all slightly differ from the one I obtained at Kew.

From the inquiries I have made there is no doubt about the
insect being an Orthezia, and I believe it is a new species.

There is a slight confusion about the name of the genus. In
Westwood it is written Dorthesia, but by later writers Orthezia ;
the latter form is correct, for the genus is named after l'Abbe
d'Orthez ; and by an error the d' was joined to the word Orthez,
making it D orthez.

The genus Orthezia is closely allied to the Aphis and the
Coccus ; it is a true plant-louse, and found in many parts of the
world.

There is not much difficulty in observing the habits of these
creatures. I kept some in a cork-cell, without food, for over three

170 E. T. BROWNE ON A SPECIES OF ORTHEZIA.

weeks. Two females, after having spent three weeks in a cork-cell,
were chloroformed, and mounted as dry objects. I was greatly sur-
prised, on looking at the slide a week afterwards, to find one of the
females alive, and twenty young Orthezia, all alive and doing
well.

The Orthezia which I am exhibiting to-night were first seen
about twelve months ago, on a Strobilanihes, a Chinese plant,
which has been in the Economic House about three years.

The insects have gradually been spreading, in spite of measures
taken to annihilate them. Now they may be found on Scutel-
laria, and other foreign plants in the adjoining house. • A pecu-
liarity of the genus Orthezia is the secretion of wax. Round
the body there is a waxen fringe, and the females possess a
large egg-pouch, or marsupium, which grows gradually from
the extremity of the abdomen. The eggs are laid inside the
marsupium, and their number increases in proportion to the size
of the Douch.

By this arrangement the eggs furthest from the abdomen are the
first laid, and, consequently, first hatched. At the extremity of
the marsupium, on the upper surface, there is an opening, through
which the young Orthezia crawl.

In some specimens only a very small opening exists at the
extremity of the marsupium, not large enough for the young to
crawl through. When this occurs I find a square opening is made
near the abdominal end of the marsupium, but I cannot say how
this opening is made ; to all appearance it looks as if it were
broken, or gnawed.

On opening the marsupium the eggs and the young Orthezia are
seen. The eggs, when first laid, are white, but afterwards become
light brown. They are wrapped up in fine waxen fibres, resembling
cotton-wool. In a good-sized marsupium about 20 eggs may be
found, together with several young.

The young Orthezia are scarcely visible to the naked eye,
and they spend their early days in the marsupium, using it as a
place of protection. Often they may be seen crawling about
their mother, and when danger threatens they crawl inside the
pouch.

When young, there is a slight fringe of wax round their bodies,
and a few waxen tufts on the middle of their backs.

I saw a young one go through the process of changing its skin.

E. T. BROWNE ON A SPECIES OF ORTHEZIA. 171

The old skin splits along the back, and then the young one
gradually backs itself out.

The males possess wings, and are destitute of the waxen cover-
ing. In Westwood's " Introduction to the Classification of
Insects," Vol. i, Plate I, there is an engraving of the male of
Orthezia cata phr actus . The male I found at Kew (caught flying
about near the food plant) differs considerably from the one figured
in Westw T ood. The insect is much smaller, and there are only two
waxen threads from the extremity of the abdomen. In Orthezia
cataphr actus there is a large bunch.

Mr. Douglas, who has written several papers on Orthezia, whicli
may be found in the Entomological Society's Transactions for
1881, states that the larvae of males of Orthezia urticce are like those
of the females in form, and are only distinguished from the females
by two projecting posterior lamina?.

I have not yet discovered this form of the male among the Kew
species. I have shut up separately many Orthezia, without the
marsupium, in hopes of discovering a male, but within a fortnight
the marsupium has begun to form.

At the end of the third week my insects have generally died of
starvation, as I am unable to obtain food for them.

During the past eight weeks I have seen many dozens of young
Orthezia born, but not a single winged male has made its appear-
ance. Probably the Orthezia?, following the custom of their rela-
tions, the Aphides, produce all females for many generations. I
must express my thanks to Mr. J. W. Douglas for his kind
response to my inquiries, and I shall take the liberty to quote from
his kind letter the valuable information contained in it. He says :
" I am greatly obliged to you for the Orthezia ; it appears to me
to be quite new, but I am not sure that the absence of lamella? on
the thorax is normal, for all of them in the tube are more or less
broken. I have stated all I know about Orthezia in the Entomo-
logical Society's Transactions, and previously in the ' Entomolo-
gists' Monthly Magazine.' There is one species (American,
Walker) that I do not know, and there is one species figured by
Cornstock, in his report for 1880, which is not yours." It is my
intention to forward more specimens to Mr. Douglas, as he
possesses better means of identifying the insect than I do. I also
feel much indebted to Mr. S. J. Mclntire for the help he has given
me in collecting specimens.

172 E. T. BROWNE ON A SPECIES OF ORTHEZIA.

PLATE XVI.

Fig. 1. Orthezia insignis,' male, X 30 diam.
n 2. „ „ female, X 30 diam.

„ 3. Leg of male, x 125 diam.
,, 4. Tips of antenna of male, X 125 diam.
„ 5. End of abdomen of male, showing double setae, X 125 diam.

PLATE XVII.

Fig. 6. Female Orthezia, waxy secretion removed by soaking in benzole,
X 30 diam.
„ 7. Under side of same, X 30 diam.

„ 8. Marsupium of female laid open and showing eggs and young in situ,
X 30 diam.

Joum.Q.M.C.

Ser. II Vol.3. Pl.XVI.

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Journ.Q.M.C.

Ser.Li.Vol.3.Pl.XVIL

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173

On a New Eye-Piece.

By E. M. Nelson.
(Read October 28th, 1887 J

Having given for some time past a good deal of attention to
eye-pieces for telescopes as well as microscopes, and having lately-
contrived one which has surpassed any I have yet seen in the
sharpness of its defining power, I thought a short account of it
would prove of interest to the Club.

Until lately there have been among microscopists only two
kinds of eye-pieces in general use — the Huyghenian and the
Kellner, but a little while ago Professor Abbe introduced what
are known as compensating eye-pieces. Of these three forms the
Kellner may be dismissed by saying that although it possesses one
achromatic lens its defining power is undoubtedly bad. The
compensating eye-pieces, while being absolutely necessary to some
of the apochromatic series of objectives and beneficial to others,
improve the definition of ordinary objectives.

With regard to all my previous work with achromatic singles,
doublets, and triplets, &c, I may say that I have not succeeded
in producing any combination giving definition equal to the
Huyghenian. But the increased definition obtained by the com-
pensating series caused me to re-open my investigations.

The action of the Huyghenian eye-piece is that of an under-
corrected lens balancing an over-corrected image ; the strange thing
is that the compensating system of eye-pieces, being all over-
corrected, should give better results. After going into the matter
I came to the conclusion that the Huyghenian system sacrifices
definition to flatness of field, this latter quality being one in which
the compensating eye-pieces are eminently deficient. Now we
know that a single convex lens having the least aberration has its
radii 6 : 1, and the outstanding aberration is Sf= — i| XI.

But the aberration of a plane convex is not much greater if the
plane side is to the focus as Sf= — |- L 2 , but if the convex side is
towards the focus Sf becomes = — f- y -l, or about four times as much.

174 E. M. NELSON ON A NEW EYE-PIECE.

This is in illustration of what I have frequently urged, viz., that
every microscopist should see aberration by making images of a
lamp flame on a piece of paper with the field lens of one of his low
eye-pieces, turning first the convex and then the plane side to the
focal point on the paper.

Another very instructive experiment is the reading of a micro-
photograph of printed matter with a plano-convex lens, reversing
the lens and noticing the effect. p IG q

With the convex side to the photograph the
printed matter is quite misty, and the field is
fairly flat, but with the plane side the field is very
much curved, and the print in the centre of the
field becomes black, the fog going off. I there-
fore thought that if I reversed the eye-lens of
the Huyghenian eye-piece (see Fig. 6) I should
get increased definition at the expense of flatness of field. Nor
was I disappointed, for I found on trial that I got material increase
of sharpness in the centre of the field, the margin being quite out
of focus.

This out of focus part I stopped out by making the diaphragm
smaller, so reducing the size of the field from 16in. to 8in., which
leaves it still larger than that given by the compensating ones, and
quite large enough for all practical purposes.

Therefore, if anyone is desirous of improving the definition of
his eye-pieces, all that is necessary is the inversion of the eye-lens
and the contraction of the diaphragm. Of course it is only advis-
able to treat eye-pieces of less than lin. focus in this manner, as a
large flat field is of paramount inrportance with the lower eye-
pieces, and the loss of definition is not so apparent. The best
result I have obtained with this plan is by achromatizing the eye-
lens. The one which I have here to-night is the best eye-piece I
have ever seen. It is of 12 power, and gives sharper pictures than
one of Zeiss' compensating series of the same power, which was
carefully selected from several sets. This eye-piece works perfectly
with the 24 mm. and 3 mm. Zeiss apochromatic objectives. You
will notice there are only two surfaces to work in the simple form
and four in the achromatic form, against seven in the compensating
eye-piece.

175

On a Small Portable Binocular Microscope and a Live Box.

By 0. Rousselet.

(Read October 28th, 1887.)

I have been asked to bring before you a small microscope which
has been made to my order.

I have long felt the want of a portable binocular for the purpose
of showing objects effectively when away from home, here at our
meetings for instance, without having to carry the very heavy weight
of the large instruments. The portable monocular microscope
did not, as a rule, allow me to exhibit objects to my satisfaction,
as a certain class of them are seen to so much greater advantage
with the binocular.

Several forms of portable binocular have been made by various
makers, but they are mostly very elaborate, and consequently very
expensive. My aim has been to have it as simple as possible
without sacrificing any of its essential qualities ; the result is here
before you, and I may state that it certainly gives me every satis-
faction. There is necessarily a great deal about it that is old, and
I will therefore confine my remarks to a few of its principal points.

The foot is the well-known sliding tripod ; the total length of
the tubes is eight inches, which is as short as they could be made
without causing a strain to the eyes ; the diameter of the tubes
is only a little over one inch, but the tubes carrying the eye-pieces
are wider at the top, and receive the B eye-pieces of my large
microscope ; this is of importance, because with small eyepieces
the field of view is greatly reduced, and the result is not so satis-
factory. The stage is simple, and has a broad but very thin sliding-
stage, which moves very smoothly. The condenser, also, belong-
ing to my large microscope fits in an adapter, which is screwed on
to the stage below, and it is focussed by a spiral motion, which
brings it up just above the stage if required.

There is no tail-piece, the mirror being carried by a double-
jointed arm fixed at one corner of the stage, which allows it to be
brought above the stage for the illumination of opaque objects ; for

176

C. ROUSSELET ON A SMALL PORTABLE

this purpose the concave mirror has a very short focus (l-|in.), and
acts as a very effective silver side-reflector. The focussing' is effected
by a good coarse rack-work ; a fine adjustment was not required for
my purpose, as I can work very well with a ^in. objective without
it, but it could be added if thought desirable. The stand is very
light, but sufficiently steady for all practical purposes.

The whole is packed into a small case, which, when quite com-
plete, weighs just under 61bs.

Fig. 7.

I have also to bring to your notice a live box which has been
made to my order, which for pond life certainly works better than
any other contrivance of the kind I have seen. The old live box,
which has done duty for so long, has the very great defect that the
object placed thereon is totally out of reach of the substage con-
denser, and, therefore, incapable of being properly illuminated.

Some years ago Mr. Swift made an improvement by fixing the
glass plate, on which the object is placed, nearly flush with, the plate
of the live box, as is shown in the above woodcut (Fig. 7). But this,
however, introduced another defect, that was, that any objects placed
in the box could be examined, over the whole field, only with low
powers, whilst with high powers only those objects placed near the
centre could be reached. Now, it is very frequently desirable to
examine an object witli a high power after it has been found with a
low one, and we all know how very fond living creatures are of
getting to the edge of the drop of water in which they are placed,
and to shift them to the centre is frequently a very tedious work,
and is often fatal to the animal.

To remedy this defect, I have had a live box constructed in which
the glass tablet is somewhat reduced in diameter, but the outer ring
is enlarged sufficiently to allow any high power to focus to the very
edge of the glass tablet, and the result is very satisfactory. An
object lying anywhere in the live box can be reached by the con-
denser from below, and by both low and high powers from above;
besides which, it acts as a very good compressor, capable of fixing,
without hurting, the smallest rotifers, and, when you know how to

BINOCULAR MICROSCOPE AND A LIVE BOX. 177

do it, it is also possible to get a rotifer in so small a drop of water
that it is unable to swim out of the field of view of a quarter inch
objective. I have had it in constant use for animals of all sizes, from
the smallest infusoria to tadpoles, and I hope it will be found equally
useful to my fellow pond-hunters.

I have also a small screw compressor, made on the same prin-
ciple ; it is very simple, and effective, and allows of regulating the
pressure to a nicety.

178

On the Finer Structure of Butterfly and Moth Scales.

By T. F. Smith.
(Read October 2&th, 1887J

At the last Conversational Meeting of this Club I exhibited the
scales of Amathusia Horsfddii as showing the villi figured by Dr.
Royston-Pigott in the " English Mechanic."

Allow me to say here that I know nothing about butterflies
beyond recognizing one when I see it flying, and then I am not
sure it is not a moth. But we are all familiar with the appear-
ance of the scales, and that, under suitable powers, they nearly all
present the same general appearance — longitudinal and cross-
ribbings. But this is only in a certain focus ; in changing the focus
the whole appearance alters, and the field becomes filled with
dots. I know nothing more unsatisfactory than to rise up from
the microscope in a state of fog and feel that you are no nearer to
a knowledge of the structure than when you sat down. This,
however, was the condition of my own mind until very lately, and

I have no doubt it is also the condition of many other observers.

The battle of the scales was fought out very fiercely about a
dozen years ago, when Dr. Royston-Pigott claimed to have dis-
covered beading in Podura and Lepisma scales, and, although very
little is heard of the matter now, it is not because it was settled,
but because the combatants ceased from sheer exhaustion. On the
Podura scales I have never detected the slightest appearance of
beading, but the other day, on Lepisma scales, I came across the
exact appearance figured in the ninth volume of the " Monthly
Microscopical Journal," and I have not the slightest hesitation in
asserting, first, that the appearance as shown in Fig. 4 of Plate

II of that volume is faithfully portrayed, and, secondly, that it
is false. It is well to know sometimes where a reputation was
wrecked, and I beg leave to show you on the blackboard how it
happened.

T. F. SMITH ON THE FINER STRUCTURE OF BUTTERFLY SCALES. 179

It is pretty well known that most insect scales are formed by
two membranes, sometimes plain and sometimes corrugated, and
that in the Lepisma the two corrugated membranes cross each other
at an angle, giving it the appearance of spines. In addition to
that there are very fine cross-ribbings, the same as on most butter-
fly scales, but except in some of the smaller scales are nearly all
torn and hang about in all directions. If you imagine a lady's
antimacassar with long, plain bands from end to end, and most
of the cross stitches between them torn, you will have the ap-
pearance presented by one of the membranes of the Lepisma scale.
The other corrugated membrane crosses this one at an oblique
angle, and where any part of the fine cross-ribbings cross the
oblique markings there is the appearance of beads. Dr. Pigott
claimed these beads as a proof of the advancing definition of
object glasses, and within certain limits he was right, but it re-
quired the definition of the oil immersion to complete the evidence.

But while there is a boldness in asserting the presence of a
certain structure on imperfect evidence, there is also a boldness of
denial, and this is exemplified in a paper read before the Royal
Microscopical Society in about 1874, by Mr. Mclntire, on butterfly
scales, in which he correctly figures the beading or villi, but calls
it pseudo-beading. I am afraid, however, it cannot be explained
in this manner, as microscopical ghosts will rise from anywhere
they are conjured up, but on butterfly or moths scales will rise
from one side only, proving to me that they have a real presence.
This small beading will rise on the surface of nearlv all the scales
I have examined, but it is impossible to connect them with the
cross-ribs in the finer ones, even with the widest-angled oil immer-
sion, but in the scales of the Amathusia they are plainly seen to
stand on them, and the structure is large enough to remove all
doubt. As nearly all scales present the same primary structure, is
it a very far-fetched conclusion to arrive at, that the fine beading
of the minute scales is fastened on in the same manner, even if
you cannot see the connection ?

The scales of A mathusia are very interesting from their connec-
tion with historical microscopy. On the 20th of December, 1848,
Mr. \Varren De La Rue read a paper before the Microscopical
Society on the scales of this butterfly, in which he mentions and
draws the beading as seen by him on the cross-ribs. Illustrating
the paper is a fine plate showing the whole scale magnified 800

Journ. Q. M. C, Series II, No. 20. 14

180 T. P. SMITH ON THE FINER STRUCTURE OP BUTTERFLY SCALES.

diameters, and on another plate a part of the same scale magnified
1,900 diameters, and drawn from that to a further scale of 4,400
to 1. I don't know a better object than the more magnified draw-
ing, with which to measure the progress that has been made since
that date, with even dry objectives. The drawing shows the
structure as shown by Ross' T y objective, considered at that time
and for a long time after a king of glasses, but does not show the
villi, although " an irregular net-like covering " was apparent to
the observer, which he set down as pigment cells. To-night I show
the same object under a dry £", just made for me by Swift and Son,
and of which the new optical glass forms a component part. For
the purpose of comparison with the drawing I have forced up the
glass to 1,900 diameters, and the villi are there seen plainly stand-
ing up from the crossbars.

The scales of Ainathusia are mounted dry, but the three other
scales which I show are mounted in Canada balsam, and I am
indebted for them to Mr Hinton, of Varley Road, Upper Hollo way,
without whose aid I could not have shown the structure to-night.
By this method all here is plain, while a scale mounted dry will
give only the barest indications.

Allow me here to give my ideas of the structure of the different
scales shown under the four microscopes. On the first stand is
the Amathusia, which gives the key to all the others, and the
structure in this I will try to show you on the blackboard. It is
very simple ; longitudinal ribs running from end to end of the
scale; cross-ribs at regular intervals, and rising from these two
or three beads, some of which seem to stand close on the cross-
ribs and some to rise from them with a stalk. On the second stand
is a coarse reticulated scale of Morpho mencJaus, and I want to call
your attention to the contrast between the coarseness of the main
structure and the beautiful minute beads with which it is outlined.
On the third stand is a scale of Papilio mcmnon, and nothing-
can exceed the beauty of its structure. Instead of a single cross-
bar at regular intervals connecting the long ones, they are con-
nected by a beautiful interlacing pattern, from which rises
numerous minute filaments not more than the 100,000th of an
inch in diameter. On the fourth stand is the scale of a moth
(Zygoma trigonilla), and here the structure is quite different. I can
see no trace of cross- ribbing, but from the inner part of the mem-
branes of the scale, I think, a tufted structure springs, which, in

T. P. SMITH ON THE FINER STRUCTURE OF BUTTERFLY SCALES. 181

appearance, is not unlike the hairs on the leaves of some plants.
The scale is somewhat rounded in section, and this internal growth
seems to be the means of keeping the two membranes apart.

With regard to pigment cells, I do not think there are any, as I
have never been able to trace any such between the two membranes.
Dr. Pigott, in last Friday's " Mechanic," like Silas Wegg, " drops
into poetry " and says, " All pigment is pure figment," and in this I
agree with him. In conclusion, I beg to say that I am not wedded
to any opinions expressed in this paper, but am ready to change
them on receipt of evidence. I have not had the time to become
master of all the facts, and no doubt will have to modify some of
my opinions on further investigation.

182

On the Histology of the Muscles of the Fly and their
Relation to the Muscles of Vertebrates.

13y B. Thompson Lowne, F.R.C.S., Lecturer on Physiology in the
Middlesex Hospital Medical School, &c.

(Read November 2Uh, 1887.)

Our knowledge of the comparative histology of muscles has been
much retarded by the fact that authors have been slow to recognize
that the striated muscles of different forms of animal differ greatly
from each other. Thus the blow-fly exhibits three distinct types of
striated muscle, two of which differ materially from the ordinary
striated muscles of the mammalia.

In mammals three forms of muscles are well known, non-striated
muscle, heart muscle, and striated muscle. With the first of these
the present paper is not concerned ; the two last exhibit transverse
striation. In heart muscle, the nuclei are situated in the centre of
the fibre, and there is no investing sheath or sarcolemma, whilst in
the skeletal muscles there is a distinct elastic investing sheath to
each fibre, and the nuclei are placed immediately beneath it.

A transverse section of such a skeletal muscle fibre shows that it
consists of a number of prismatic columns, surrounded by an inter-
columnar substance ; thus the section is mapped out into irregular
fields, fields of Cohnheim.* The transverse sections of the columns
when highly magnified appear dotted with minute highly refractive
points. This appearance has been differently interpreted by
different observers; Schwann *f demonstrated the existence of
moniliform fibrillae, and I am inclined to regard these bright points
as the sections of the ultimate moniliform fibrillae of Schwann.
The moniliform fibrillar are cemented together into prismatic rods
or fibrils by an interfibrillar cement material ; the fibrillae are the
muscle rods of authors, and form the principal or contractile sub-
stance, whilst the cementing medium is the intermediate sub-
stance (Zwisehen-substanz) of Rollett. \ The columns of
united moniliform fibrillae are the " colonnettes " of Viallaines,§

* Virchow'a Archiv., Bd.34. f Strieker, " Comp. Histology," Vol. iii.

X Strieker, I.e. § " Ann. Sc. Nat. Zool.," Gth ser., Tom. 14.

B. T. LOWNE ON THE HISTOLOGY OP THE MUSCLES OF THE FLY. 183

the intermediary substance between the columns forming the line
or boundaries of Cohnheim's fields is muscle plasma, and is
continuous with the nucleated layer immediately within the sarco-
lemma.

I regard the muscle fibres of the heart as colonnettes, the trans-
verse section of a single fibre representing a large field of
Cohnheim.

The above view of a muscle fibre appears to be borne out by
a comparative study of the three forms of striated muscle fibre
which exist in the blow-fly and other insects, and I should describe
a striated muscle fibre as consisting of one or more columns of
primitive fibrillar cemented together, forming one or more colon-
nettes. In the ordinary mammalian muscle fibre a number of
colonnettes are embedded in a nucleated plasma, and surrounded by
a muscle-sheath.

All the varieties of striated muscle in the fly possess the above
characters, but it is only in the larva that the fibres correspond with
those of the mammalia, in which numerous colonnettes are em-
bedded in plasma, and surrounded by a membranous sheath, sarco-
lemma, with the nuclei of the plasma immediately beneath it.

It is noteworthy that the muscles which we might be tempted to
regard as the most highly differentiated form of contractile tissue
exist only in the insect in its larval condition, when development is
but little advanced above the vermiform type.

Physiologically, the muscles of the larva of the fly have, how-
ever, the same functions as in the higher vertebrata ; they con-
tract powerfully, and the duration of the contraction is compara-
tively long ; fatigue does not supervene rapidly. Such muscles
respond to a second stimulation immediately after contraction, and
the contraction is tetanic, not clonic.

With regard to the ultimate structure of the colonnettes, or
bundles of ultimate fibrillar, the optical appearances differ much,
according to the method of illumination and the kind of objective
used. It is easy to make out alternate dark and light bands. With
my immersion ^g, the bright bands, in specimens fixed with osmic
acid, appear very narrow and well defined, and the dark bands
appear to consist of dark prisms, separated from each other by very
fine bright lines running in the direction of the fibre ; but with a
quarter, and the same illumination, the dark and light transverse
bands change places with each other, the bright bands becoming

184 B. T. LOWNR ON THE HISTOLOGY OF

diffused and broad, whilst the dark bands become narrow, and
minute bright dots appear in a line in the centre of the dark band.

Such appearances indicate, to my mind, difraction phenomena,
and are not inconsistent with the structure which I have indicated
above, the transverse stria} arising either from the moniliform con-
dition of the primitive fibrillse, or from an alternation of more and
less highly refractive material in the fibril itself.

In the imago of the fly two totally distinct forms of muscle
exist, which possess well-marked histological characters differen-
tiating them from the muscles of the larval insect. These two forms
of muscle were recognized by Dr. Weismann,* by myself, f and more
recently by M. Viallaines.J They have been distinguished by the
last-named author as the muscles of the wings and the muscles of
the limbs. Neither term is very fortunate, however. All the
muscles of the imago, including those which move the wings, ex-
cept in the vibratory movement of flight, belong to the second
kind ; I shall, therefore, speak of them as the ordinary muscles of
the imago, and I shall designate the first kind as the muscles of
flight.

The muscles of flight occupy the greater part of the thorax.
They consist, as M. Vialkines§ has pointed out, of enormously
enlarged colonnettes, and are entirely devoid of any investing
sheath. In transverse section each muscle consists of a few
gigantic fields of Cohnheim, each dotted over with a regular and
close punctation of minute highly-refracting granules. In optical
longitudinal section each fibre is seen to consist of very fine more
or less distinctly beaded fibrillar, embedded in a ground substance
of low refractive power, in which rows of very small oval nuclei are
distributed.

The ultimate fibrillas exhibit alternate dark and light bands,
which may be regarded, perhaps, as the expression of the monili-
form character of the fibres, or possibly of an alternation of sub-
stance ; for although the beading of the fibres is often distinct, in
other specimens it is not recognizable.

M. Ranvier|| believes the fibrillar of the wing muscles are capable
of still further subdivision. I am unable to determine that such a

* Weisrnann, " Zeitscli fur ration Med.," Bel. xv., p. 60.
f " Anatomy of the Blowfly," 1870, London.
X L.c.

| " Lecon (TAnutomie General sur le System Mnsoulaire,"' Paris, 1880.

THE MUSCLES OF THE FLY. 185

division can be effected, but if it can it does not show that the
fibrils are not morphological elements of the tissue ; they are per-
fectly distinct, and are sufficiently separated by the interfibrillar
ground substance to be clearly differentiated with the highest
powers in thin sections.

Physiologically, these muscles are distinctly differentiated from
all other forms of muscle tissue ; their contraction is vibratile, and
corresponds to artificial incomplete tetanus. That is, their con-
traction may be described as consisting of a prolonged series of
single contractions, like those of heart muscle, but with a refrac-
tory or fatigue period of extremely short duration. If we regard
the interfibrillar material as nutrient material, its abundance
between the contractile fibres is explained in relation to the
physiological properties of the muscle.

The last type of muscle which I shall describe is the ordinary
muscle of the imago.

These differ from the muscles of the larva in consisting of a
single hollow colonnette ; the cavity is an axial canal, which en-
closes a row of nuclei. The fibre is further provided with a more
or less distinct investing sheath or myolemma.

In transverse section such fibres exhibit the same appearances
as a field of Cohnheim. The nuclear canal, however, sends off
stellate cracks in many preparations, which partially separate it
into segments.

As with the primitive colonnettes of the larval muscle, optical
longitudinal sections give variable appearances. I will not decide
whether the fibre is divided into transverse segments, each con-
taining a nucleus, by the so-called membranes of Krause ; but I
am clear that the myolemma adheres very closely to the fibre, and
more firmly* between the closely packed nuclei of the central canal
than opposite to them, so that it sometimes separates opposite the
nuclei, and gives an appearance indicative of Krause's membranes.
The fibre exhibits longitudinal striae, the expression of the ultimate
fibrils, which appear as bright dots in transverse sections. The
dark and light alternate discs are beautifully seen, and rows of
bright highly-refractive dots appear in the light discs dividing
each into two.

* In this part of the fibre its demonstration is difficult. M. Viallaines
considers it to be less developed and thinner at these points, and adherent
to the intermediate (light) discs.

IffG B. T. L0WNE ON THE HISTOLOGY OF

The nearest approach to the ordinary muscle fibres of the imago
in the insect is the heart muscle of a vertebrate, although the
characters of the two arc sufficiently distinct, and the insect muscle
is a more elaborately differentiated structure. The physiological
character of the ordinary muscles of the imago is not completely
understood, and evidence is still desirable on this subject. I
believe its contractions are clonic, like those of the heart muscle,
rather than tetanic, a sharp, sudden, but not a sustained contrac-
tion, and that it is differentiated from other forms of muscle, both
morphologically and physiologically. My reason for regarding
it as susceptible of powerful single contractions rather than
tetanic contraction, is that the muscular movements of the limbs
in insects are effected by sudden jerks, which are well seen when
the thoracic ganglion is crushed, and the structure of the joints is
such that sustained muscular exertion appears to be unneces-
sary. The curved mandibles of insects once driven into their
prey hold by their mechanical construction, so an insect clings
rather by the spinous appendages of the limbs than by sustained
muscular power.

In gold-stained preparations of muscle a network of fibres has
been demonstrated,* consisting of very regular transverse networks
corresponding to the membranes of Krause, united by fine longi-
tudinal fibres ; and it has been recently supposed that the contrac-
tion of the muscle is due to the contraction of the longitudinal and
its elongation to the contraction of the transverse fibres. If this
were the case, the transverse networks being the stronger, the elon-
gation of the muscle should be a more powerful act than its con-
traction. Possibly the networks are due to the coagulation of the
muscle plasma, or they may be an intermuscular nervous plexus, a
supposition which has some support from the structure of the
electric organs of fishes, and the intern" brillar nervous network of
non-striated muscle.

In conclusion, I would draw attention to a remarkable similarity
between muscle fibres and capillary blood-vessels. The myolemma
of the former, like the wall of the latter, consists of endothelial
plates cemented together, both contain a coagulable fluid, muscle
plasma, and blood plasma, and in both there are solid corpuscular
bodies, muscle rods in the one, blood corpuscles in the other. The

* C. F. Marshall, " Quarterly Journal of Microscopic Science," 1887.

THE MUSCLES OF THE FLY. 187

developmental history of the two structures is also remarkably
similar. Both are developed from cells with numerous nuclei,
some of which form the tubular wall, whilst others become con-
verted into muscle rods in the muscle, and blood corpuscles in the
capillary. The development of the fibrillee of the muscle from
nuclei is no longer doubtful in insects at least, and the fibrillee may
be regarded as united muscle rods.

I shall reserve for a future paper some observations on the
muscle fibres of the dorsal vessel and alimentary canal in insects.

188

On the Disintegration op Diatomaceous Deposits.

By M. Guinarp, Corresponding Member of the Belgian

Microscopical Society.

Translated from the u Bulletin de la Societe Beige de Microscopic"

Many means of disintegrating the fossil diatomaceous deposits
are known. Amongst others, one has been lately indicated by M.
J. Brim. The plan recommended by the learned Genevese Pro-
fessor is based upon the recrystallization of sulphate of soda, but
the operations necessary for obtaining complete success are too
delicate, and exact many precautions difficult to realize practically,
the most essential, to obtain saturation with sulphate of soda, being
the heating of the water to about 33° C, and the consequent use
of the thermometer in the vessel serving as a water bath.

I would point out a salt which I believe has not yet been sug-
gested for this operation, and which by reason of its easy manipu-
lation may be of use for the disintegration of diatomaceous deposits.

This method consists in introducing some fragments of the
deposit into a tube, covering them to the depth of about two centi-
metres with crystals of common commercial acetate of soda (not
pure), and finally adding thereto one or two drops of water. (For
operating on a larger scale the proportion of water is five cubic
centimetres to 100 of the salt.) The tube is then plunged into a
water bath, and when the water is near the boiling point the salt
will dissolve. The deposit absorbs the solution of acetate of soda
and is left in the hot water for about ten minutes, the tube then is
withdrawn from the bath, and the solution allowed to cool, or if it
is desired to quicken the action, the tube may be plunged into a
vessel of cold water. A minute crystal of acetate of soda is then
dropped into the solution, which owing to this supersaturation will
suddenly crystallize. This operation may be repeated two or three
times with the same solution, and it is rarely that the deposit will
not be perfectly reduced to powder.

By these means I have procured the disintegration of the most
refractory deposits, such as those from the Isle of Fur, in Jutland,

M. GUINARD ON DISINTEGRATION OF DIATOMACEOUS DEPOSITS. 189

but I have found six successive operations necessary to obtain a
good result.

There only remains now to add water in excess to re-dissolve the
crystallized salt, to empty the whole into a suitable vessel, and to
add a large quantity of water.

This method has been communicated by M. Parmentier, Pro-
fessor of Chemistry to our faculty of science, who has occupied
himself specially with the phenomena of the supersaturation of
salts.

Another substance which may be found serviceable, and which is
used in the arts to detect stones cracked by frost, is hyposulphite
of soda, but the manipulation is more delicate. However, I
indicate the process here, but give the preference to the acetate of
soda process.

Hyposulphite of soda melts in its water of crystallization ; put
this salt into a capsule, heat it in a water bath to 48°, the salt will
deliquesce. Plunge therein the deposit before heating, and when
the solution shall be liquified and re-cooled add a small crystal of
hyposulphite of soda, re-crystallization will take place, and the
deposit will be disintegrated ; re-melt again and add water in
excess, then decant. It will be understood that this operation
must be repented if success is not at once obtained.

190

PROCEEDINGS.

July 8th, 1887. — Conversational Meeting.

J

The following objects were exhibited : —
Melicerta ringens
Orthesia $ , sp. allied to coccidce, and form

ing a kind of marsupium in wax ...
Diatoms, Porodiscus interruptus

Craspedorus elegans... ... ... „ „

Arachnoidiscus JShrenbergii, show- ^
ing fine points projecting in- I
wards from the areolations, |
j'jth oil imm. O.G. ... J

Attendance — Members, 16 ; Visitors,

Mr. F. W. Andrew.

Mr. E. T. Browne.
Mr. H. Mori and.

Mr. T. F. Smith.

July 22nd, 1887. — Ordinary Meeting.

E. T. Newton, Esq., F.G.S., Vice-President, in the Chair.

The minutes of the preceding meeting were read and confirmed.
The following gentlemen were balloted for and duly elected members of
the Club : — Mr. Richard James Cowling and Mr. George Pearce.

The followiug additions to the Library and Cabinet were announced : —

From the Editor.
In exchange.

>»

>>

Mr. Alfred Allen.

»>

>>

" Science Gossip "
" The Botanical Gazette ''
" Annual Report of the Brighton and Sussex )
Natural History Society "... ... )

" Journal of Microscopy "

" The Journal of the Postal Microscopical (

Society" ... ... j

" The Scientific Inquirer " ...

" My Microscope " ... ...

" Report of the Smithsonian Institution " ...
The thanks of the Club were voted to the donors.
Mr. T. F. Smith read " Some Additional Notes on Diatom Structure."
The Chairman said it had no doubt given great satisfaction to the
members to know that they had amongst them a gentleman who, when he
found he had made a mistake, was willing to come down and acknowledge
it at the meeting. It was a thing which he feared very few men, even
amongst those high up in the ranks of science, were desirous of doing.
Mr. Morland said as he had not yet had the opportunity of seeing the

Mr. Roper.
In exchange.

191

specimen referred to by Mr. Smith, he could not give any opinion about it
at that moment, but he should like to point out that he had not been quite
properly quoted as to having said the " medium." What he said was the
" cement," meaning what the diatoms were fixed with, and which sometimes
by its contraction would produce granulations which might under some
conditions be mistaken for markings. As a general rule the markings on
diatoms were regular, or if not so there was some system about them which
he might almost call a regularity of irregularity, compared with which the
effects of the granulations of cement or other substances would be con-
spicuously irregul r. It was in practice very difficult to get rid of foreign
matter entirely from a diatom, and frequently, after many attempts, he
had given up all hopes of doing so, and on mounting the specimen he found
that the irregularity had disappeared under the process when seen in the
ordinary way. He thought, however, it was possible that when viewed with
a different kind of illumination, under immersion objectives, the irregularity
might still be perceived.

Mr. Karop said as the holiday season was coming on he should not be
likely to trouble much about the finer structure of diatoms for a month or
two. He thought, however, that the matter of an inner and outer mem-
brane was one which might give rise to some misconception, because it
might very often be imperfectly silicified, and therefore might by the
treatment with acids be unequally acted upon so as to produce appearances
which would very likely be mistaken for apertures of different kinds by
different observers.

Mr. Smith said that as the objects were exhibited in the room members
could easily see for themselves what had been described. He thought a
great deal of the difficulty arose from the imperfect adjustment of the
correction collar of the objective.

Mr. Henry Davis called attention to a fish parasite, Gyrodactylus elegans,
which he had found upon some sticklebacks from the River Lea, and which
he proceeded to describe by means of drawings on the black board.

The Chairman said that he was sure the members would be much
obliged to Mr. Davis for bringing this subject before them, and he hoped
some of them would be able and willing to follow it up.

Mr. J. D. Hardy said that he did not recognize this creature from the draw-
ing and description given, but should be very glad to hear in what part of
the Hackney Marshes it could be found.

Mr. Davis, in reply to this question and also to further questions from Mr.
Hardy and Mr. Parsons, said that as regarded the adult forms he could see
the development of the hooks taking place in the egg. He did not find the
parasites himself, but his little boy got them one day during an expedition
with a net and pickle bottle, and having asked to be shown the circulation in a
stickleback's tail, he put one of the fish under the microscope for the purpose,
and then found it to be infested with the parasites. Having a weakness
for Rotifers, he wanted to make this out to be one, but was unable to do so.

Mr. Morlancl read a paper " On Porodiscus interniptus and Craspedoporus
elegans"

102

The Chairman said anything from Mr. Morland on the subject of diatoms
was sure to be of interest, and though he did not himself give much atten-
tion to objects of this kind he might say that it seemed a very extraordinary
thing that two such utterly opposite things should belong to the same
species. It showed how careful persons should be not to hastily make new
species from the observation of differences in the markings alone, though it
was not very often that anyone had the good fortune to find the two valves
together as Mr. Morland had done.

Mr. Smith said it was quite possible for a valve to be found which had a
different pattern on different sides, in illustration of which he drew a
diagram upon the board of a specimen of Airfacodiscus as he had seen it
under a 1 V m * immersion objective.

Mr. Morland said this was not a question of difference of structure on
different sides, but rather that of two distinct valves of the same species.
There was a distinct space seen between the two, with a bubble of air
between them. He could give another instance in the case of Cocconeis,
recent specimens of which could be found in situ.

Mr. Karop said that the specimens exhibited the other night had all the
appearance of being genuine valves belonging to one and the same frustule.

The thanks of the meeting were voted to Mr. Morland for his communi-
cation.

Announcements for the ensuing month were then made, and the proceed-
ings terminated with the usual conversazione, and the following objects
were exhibited : —

Head of " Devil's Coach Horse," Ocvpus")

i •«, , i *. a I Mr. F. Knock.

olens, with explanatory drawing ... )

Diatoms, Coscinodiscus centralis, from Sheer-")

... ... ... s Ut - t - w - Smith -

„ Coscinodiscus centralis, from Not-)
tingham (Maryland) deposit )

Attendance — Members, 27; Visitors, 0.

August 12th, 1887. — Conversational Meeting.

The following objects were exhibited by Mr G. E. Mainland: —
Pupa of the Hessian fly, Cecidomyia destructor, and the stigma and
pollen of Phlox, sp.

Attendance — Members, 15 ; Visitors, 0.

August 26th, 1887. — Ordinary Meeting.

.J. G. Waller, Esq., F.H.A., in the Chair.

The minutes of the preceding meeting were read and confirmed.
The following additions to the Library were announced : —

" Proceedings of the Koyal Society " ... ... In exchange.

" The American Monthly Microscopical Journal " ,,

193

"The Journal of the New York Microscopical^) j n exc ^ ano . e

» • • ... ••• ••• J

97

• • •

}

Society

"The Botanical Gazette"

" The Scientific Inquirer ; '

" The American Naturalist," two parts .

" Proceedings of the Belgian Microscopical
Society

{; Proceedings of the Geologists' Association " ...

" Transactions of the Wagner Free Institute of )
Science, Philadelphia"... ... ... )

Series of Papers from the Manitoba Historical")
and Scientific Society ... ... ... )

" Annual Report and Proceedings of the Liver-
pool Science Association "

}

a

>i

" Journal of the Pioyai Microscopical Society " From the Society.
" Annals of Natural History " ... ... ... Purchased.

Mr. E. T. Browne read a paper on a new species of Orthezia (Orthezia
insignis) found in Kew Gardens.

The Chairman invited discussion on the paper, and called on Mr.
Mclntire, whose name had been mentioned in Mr. Browne's communication.

Mr. Mclntire thought he could add nothing to Mr. Browne's remarks.
He congratulated the members on having secured so promising an inquirer
into the secrets of the microscope.

Mr. Freeman remarked that he had brought a specimen of Orthezia ob-
tained from Sphagnum Moss on a Scotch Moor, which it was interesting to
compare with the new species. In the Scotch insect the waxy secretion
was disposed in an even manner, like plates or scales. There was no en-
largement at the end of the body to form an egg pouch. The specific name
of this one was Cataphractus, " armed at all points."

Mr. Hardy desired to make a few remarks in further explanation of Mr.
Davis' paper, read at the last meeting, on the parasite that gentleman had
found on the stickleback. Mr. Davis had written to him that it was
Gyrodaetgliis elegans. It was figured and described in the " Micro-
graphic Dictionary," also in Cobbold, and in the tC Linnean Transactions"
of 1860. He would, however, add a few observations he had made on
examining the creature more carefully to complete the description given by
Mr. Davis.

Mr. Hardy shortly described what he had observed, illustrating his
remarks by drawings on the black-board.

Announcements for the ensuing month having been made, the meeting
concluded with the usual conversazione, at which the following objects were
exhibited : —

Rotifer, Pedaliou mira, from wet moss ... Mr. F. W. Andrew.
Plant-Bug, Orthezia cataphractus ... ... Mr. H. E. Freeman.

„ ,, insignis n.s. $ and $ )

, Tr n, -, C Mr. E. T. Brow T ne.

from Kew Gardens ... ... ... )

Attendance— Members, 30; Visitor, 1.

194

September 9th, 1887. — Conversational Meeting.

ia")
J

1

The following objects were exhibited : —
Red spider, Tetram/chus telarius
Puparium of the Hessian fly, Ceeidomyia

destructor (Say.) in situ in barley straw
Radiolaria, Orosphceria Huxleyii, from

Davis' Straits, H.M.S. Valorous, 1875
Diatoms, Coscinodiscus concinnus
,, FJoscularia regalis ...
„ Megalotrocha albo-Jlavicans ...
Flint with Entomostraca, &c, from the Pur- )
beck, Swanage, Dorset ... ... )

Diatoms, Arachnoidiscus ornatus, showing a^
series of radial plates on inner >
side of disc ... ... ... )

„ Eupodiscus argus, inner side show
ing fine granulated membrane
Head of Tcenia, from a dog ...

1

Mr.

E.

T. Browne

Mr.

F.

Enock.

Mr.

H.

F. Hailes.

Mr.

H

. Morland.

Mr.

C.

Kousselet.

>j

jj

Mr.

G.

Smith.

Mr.

T.

F. Smith.

i>

Mr. W. Watson.

Attendance — Members, 33 ; Visitors, 3.

From the Society.

September 23rd, 1887. — Ordinary Meeting.

A. D. Michael, Esq., F.L.S., F.R.M.S., President, in the Chair.

The minutes of the preceding meeting were read and confirmed.
The following gentlemen were balloted for and unanimously elected
members of the Club :— Mr. F. T. Hughes and Mr. B. T. Lowne, F.L.S.,
F.E.C.S.

The following additions to the Library were announced : —
" Proceedings of the Belgian Microscopical

Society"...
" The American Monthly Microscopical Journal''
" The Botanical Gazette "...
" Proceedings of the New York Microscopical'

Society"...
" Hooke's Micrographia Eestaurata " ...
The President said that the last-named donation was an old work, the
text of which was now for the most part obsolete, but it had still a certain
amount of interest from the references made to it by other writers. The
plates were also of some value, and were certainly very creditable to the
time at which they were produced. It was a very desirable book for the
Society to possess, and he had much pleasure in moving a vote of thanks
to Mr. Leaf for his donation.

This proposal having been seconded by the Secretary was put to the
meeting and carried unanimously.

'}

In exchange.

)»

From Mr. C.J. Leaf.

195

Mr. Morland said there was a matter which he should like to bring before
the meeting, in reference to the paper which had been contributed to the
Club by Messrs. Grove and Sturt ' ; On the Oamaru Diatom Deposit," and
printed in the last number of the Journal, with five plates in illustration.
He felt that a paper like that deserved some special recognition on the part
of the members, and, therefore, he asked leave to move the following
resolution : — " That the thanks of this Club be, and are hei-eby, tendered to
Messrs. Grove and Sturt for the very excellent papers they have contributed
to its Journal ' On the Diatomaceae contained in the Oamaru Deposit,' of
which the five plates contained in the last part have been prepared and
executed at their sole cost."

Mr. Karop said he had great pleasure in seconding this resolution, and the
President having formally put it to the meeting it was carried by acclamation.
There being no paper forthcoming, and the Chairman's appeal for observa-
tions from members upon any matters of interest which might have come
before them during their holiday trips, meeting with no response, the ex-
cursions, &c, for the ensuing month were announced, and the proceedings
terminated with the usual conversazione, the following objects being
exhibited : —

Sida crystallina... ... ... ... ... Mr. F. W. Andrew.

Ophiocoma neglecta ... ... ... ... Mr. E. T. Browne.

Flower of ~Erythroxylone coca ■ ... ... ... Mr. H. Epps.

Plv.mateUa repens ... ... ... ... Mr. C. K. Jaques.

Asplanchna priodonta ... ... ... ... Mr C. Rousselet.

Attendance — Members, 38 : Visitors, 4.

October 14th, 1887. — Conversational Meeting.

The following objects were exhibited : —

Melicerta janns Mr. F. W. Andrew.

Gizzard of beetle, Otwrynckus sulcatus ... Mr. E. T. Browne.

Parasite of the Hessian fly, Semiotellus) , T „ „

, . •" } Mr. F. Enock.

destructor ... ... ... ... )

Mouths of various beetles, with labrum, &c.,~) ,, ^ ^. ,

' J- Mr. F. Fitch,
removed ... ... ... ... J

Tomato '* cnss," Aleurodes vaporariorwm ... Mr. J. D. Hardy.

Diatoms, Trweratiutn Weissii... ... ... Mr. H. Morland

1

Dermal plates of a fossil sponge, Stelletites\ „ B W P •
callodiscus ... ... ... ... J"

Various rotif era Mr. C. Eousselet.

Scales from wing of Amatliusia Horsfeldii,'

showing " villi" of Dr. Eoyston Pigott
Crystals, Benzoyl sulphonic imide (saccharine) Mr. H. J. Waddino-ton.
Autheridia and globules of Charafragilis ... Mr. W. Watson.
Attendance — Members, 40 ; Visitors, 2.
Journ. Q- M. C, Series II., No. 20. 15

A Seibert ]So. III. O.G. used as a simple.

r \ Mr. E. M. kelson,
microscope

'J Mr. T. F. Smith.

19G

October 28th, 1887.— Ordinary Meeting.

A. D. Michael, Esq., F.L.S., F.R.M.S., &c, President,

in the Chair.

The minutes of the preceding meeting were read and confirmed.
Mr. Thomas Buckney and Mr. W. C. Westerton were balloted for and
duly elected members of the Club.

The following additions to the library were announced : —

" The Quarterly Journal of Microscopical") p . v, a
Science" ... ... ••• ... j

" Journal of the Royal Microscopical Society " From the Society.

" American Monthly Microscopical Journal " In Exchange.

"Grevillea" ... ... ... ... ... Purchased.

" Proceedings of the Royal Society "... ... From the Society.

" Proceedings of the Hertfordshire Natural") T -^ ,

. „ > In Exchange.

History Society " ... ... ... J

" Proceedings of the Croydon Microscopical")
Society" ... ... ... ... j

u Proceedings of the Essex Natural History")
Society" ... ... ... ... j

'* Botanical Gazette'' ... ... ... ... „

" Proceedings of the Bristol Natural History

Society"
" The American Naturalist'' ... ... ... ,,

"Annals of Natural History " ... ... Purchased.

Vols, xx and xxi. — " Reports of Challenger")
Expedition" ... ... ... ... )

Mr. E. M. Nelson exhibited a new portable microscope recently made from
his drawings, and described the advantages it offered for field, table, and
exhibition purposes. He also read a paper " On a new form of eye-piece,"
and illustrated the subject by diagrams.

On the motion of the President a vote of thanks was passed to Mr.
Nelson for his eminently practical and useful communications.

The Secretary described a new form of portable binocular microscope,
designed and exhibited by Mr. Rousselet, also a new live box and com-
pressor ium, by the use of which an object could be examined in any part of
the field.

The thanks of the Club were returned for these communications.
Mr. T. F. Smith read a paper " On the finer structure of Butterfly and
Moth Scales," which he illustrated by diagrams and specimens exhibited
under several microscopes.

Mr. E. M. Nelson said he felt much indebted to Mr. Smith for bringing
down these scales for exhibition ; they were beautifully shown and were
well worth attention. In the scale of the moth the resemblance to the
stellate hairs of plants was very noticeable. The beading on the scale of

1

>»

197

Menelaus he had seen before. The other he had gone over carefully with an
oil immersion, but did not get more than Mr. Warren de la Rue had
obtained ; but on focussing lower down he fancied there was evidence that
the objective gave the image of the lower side as well as of the upper side-
Mr. Stokes said, with regard to the statement of " pigment being
figment," he might say that a friend of his had been getting the colour out
of some of the scales, and he found that the colours obtained differed in
various kinds of butterflies and moths.

Mr. Smith said he had never seen any trace of pigment cells himself, but
there were in some instances some little tubes found which possibly might
contain something of the sort. The coarser scales were simply composed
of one membrane.

The President said it would, of course, be unfair to in any way
criticise or judge of the matter before them without having first
examined the objects to which Mr. Smith had called attention ; but,
so far as his own observations went, he thought there could be little
doubt that in most cases scales were double, and it frequently happened in
such cases that one surface gave one image and the other one gave another,
the ordinary appearance being the result of a combination of the two. In
most cases this was an interference image, just the same as might be pro-
duced by placing two surfaces of muslin, or other perforated material, one
over the other. A great variety of patterns might be produced in this way,
and it had always struck him that many of the patterns on scales were due
to this kind of interference. He had also noticed how common it was, that
when a person came to ox amine with high powers, surfaces which had
previously been supposed to be smooth, he discovered that they were
not so.

The thanks of the Club were unanimously voted to Mr. Smith for his
paper.

The President said that, according to the agenda, a paper by Mr. Lowne
was to have been taken next. As, however, their time had so far expired
they proposed, with Mr. Lowne's concurrence, to postpone the reading of
this paper to their next meeting.

Mr. Morland read a reply to a criticism in the Royal Microscopical
Society's Journal for the current month, on his paper on " Mounting
Media, so far as they relate to Diatoms."

The Secretary announced that he had received applications for assistance
of members at the Soirees of the Croydon, and South London Microscopical
Societies, both of which, however, were arranged to take place on the same
evening. Meetings of the Club for the ensuing month were also mentioned,
and the proceedings terminated with the usual conversazione, and the
following objects were exhibited : —

Pelomyxa palustris Mr. F. W. Andrew,

C amp odea staphylinus Mr. E. T. Browne.

Hydra vulgaris Mr. H. A. Crowhurst.

Parasitic fly, Callimome regius J ... ... Mr. F. Enock.

Section of eye of butterfly, Pieris brassica ... Mr. H. E. Freeman.

198

Asplanchna Bright icellii, with ephippial or"| ^ c R, usseleL

winter egg )

Pork measle, Cysticercus cellulosa ... ... Mr. W. Smart.

Scale from wing of butterfly, Amathusicr\

Horsfeldii, showing the " villi " of Dr. t Mr. T. F. Smith.

Royston Pigott ... ... ••• )

Scale from wing of butterfly, Papilio memnon, \

showing same... ... ... ... j

Scale from wing of butterfly, Morpho mene-

laus, showing same
Scale from wing of moth, Zggcena trigonil la,]

showing same...

Attendance — Members, 49 ; Visitors, 5.

'} -
'} -

199

On the Structure of Butterfly and Moth Scales.

By T. F. Smith.
{Read November 25th, 1887.)

At the last ordinary meeting of this Club I read a paper on the
structure of butterfly and moth scales, and exhibited some speci-
mens showing the villi discovered by Dr. Koyston-Pigott. There
was no doubt in my own mind about the villi, nor, I think, in the
minds of any of those who saw them ; but the specimens had been
far too short a time in my possession to allow me to speak posi-
tively of their position, although I expressed an opinion that, in one
instance at least, they were between the two membranes of the
scale.

Since then, however, I have been able to examine torn specimens,
and have now no hesitation in asserting that this is the structure
in all cases. If you come to think about it you will see that it is
almost impossible it should be otherwise, seeing that these little
filaments are often not more than the 100,000th of an inch in
diameter, and could not stand the wear and tear during the insect's
life, unless protected in some such manner.

Of course, if there were positive evidence that the villi were out-
side the membranes there would be an end of all speculation at once,
but to me all the evidence so far points one way, and that in an
opposite direction. In no single instance have I seen them project
beyond the outline of the scale even when twisted on itself, and it
would be impossible but what some would project so if outside.
But what I chiefly rely upon is the evidence of torn scales, such as
the specimen I have brought here to-night for your inspection, and
which will, I think, convince you that the villi are inside and not
out.

The scale under the microscope is from Urania rhypheus, and it
happens to be a scale of Urania in which the villi were figured, as
pseudo-beading, by Mr. Mclntire, about a dozen years ago in the
" Monthly Microscopical Journal." The villi on this scale differ
from many in not being so numerous, but appear in well-defined

Journ. Q. M. C, Series II., No. 21. 16

200 T. P. SMITH ON BUTTERFLY AND MOTH SCALES.

rows some distance apart. In the specimen shown to-night the
under corrugated membrane, with the cross-bars, has been torn
away from a considerable part of the scale, but has left the upper
smooth membrane intact. Now this upper smooth membrane, from
its thinness, is optically non-existent when mounted in balsam, un-
less you can focus on the broken edge ; but its presence is
apparent here from some of the villi remaining attached to the
under side. Had the whole of the villi remained intact it would
have pointed to the probability of their being outside ; but as the
most of them are gone they were evidently torn away with the
under membrane. There seem to me, then, to be two points
settled. First, that all butterfly and moth scales have certain
projections or villi, springing from their surfaces ; and that,
secondly, these projections are contained between the two mem-
branes of the scale. They assume various forms, consisting in
some cases of little tufts branching from one root or point ; in
others of little rods tapering at one end, which run straight from
one membrane to the other ; in others they have a distinct stem
with a rounded head ; and in others are simply bosses standing on
the ribbings and cross-bars.

I assume their purpose is to separate one membrane from the
other, and the villi are more or less pronounced in character
according to the distance the membranes are separated. They
differ, even in the same scale, and are always largest in the quill,
which they keep expanded by interlacing in all directions.
Various also, is the manner in which they are distributed in the
scales of different species, and I don't think diatoms themselves can
show more distinct forms.

Dr. Pigott, in his papers on this subject, has spoken many times
of isolated beading in the scales, and his last paper to-day almost
deals exclusively with this point. My own opinion, however, after
a careful examination of many scales, is that there is no isolated
beading, but that in all cases they spring from the ribs or the
cross-bars.

201

On the Formation op Diatom Structure.

By E. M. Nelson.

{Read January 21th, 1888.)

Plate XVIII.

I have some misgivings in bringing this matter a second time to
yonr notice, neither would I do so had I not lately found some
fresh examples which throw additional light on the subject.
Further, I believe we are on the verge of a new departure in
the field of microscopical work, viz., illustration by means of
lantern pictures from photo-micrographic positives. I have brought
a lantern with me to-night, and have chosen this as my first sub-
ject, illustrated by photo-micrographic positives of my own manu-
facture.

My first picture is that of a portion of Coscinodiscus Janischii
(Plate XVIII., Fig. 1), a drawing of this I have already exhibited
here. It shows an increase of structure from the centre to the
margin, an areolation is at first indented by the formation of a
process, in the next areolation, counting towards the periphery
the process is longer, in the next it has nearly reached the
opposite side of the areolation, in the next row you will observe
that the single areolation has become two ; these increase in size
and divide again. This to my mind indicates a growth from the
centre outwards.

Now we come to a series of six photographs of fragments in the
Briinn deposit.

The first, Fig. 2, you will probably recognize as the one with the
fiddle / mark described in the paper " On the Finer Structure
of Certain Diatoms," by Mr. Karop and myself.* Before passing
on let me ask you to notice the accuracy of Mr. Karop's drawing,
the identical areolation being easily recognizable.

In Fig. 3 the areolation becomes more circular, the central cut
in the/ has joined the openings at the ends which causes it to

* " Journ. Q. M. C," Ser. ii., Vol. iii., No. 18, PI. IV., Fig. 7.

202 E. M. NELSON ON DIATOM STRUCTURE.

assume the appearance of a somewhat oval areolation with two
tree-like processes in it.

In Fig. 4 the tree-like expansions at the end of the processes
are much diminished, and in some the boughs are altogether want-
ing, the processes then taking the form of a pollard willow.

In Fig. 5 there is no expansion at all on the top of the process.
The process is a mere spike projecting into the oval areolation.

In Fig 6 the process or spike has disappeared, leaving only a
small indentation at the margin of the areolation.

In Fig. 7 you have a clean oval and regular areolation which
resembles that on Isihmia nervosa, but without secondary structure.

Hitherto I have been either unable to rind, or unable to resolve,
secondary structure in this diatom. It should, however, be very
carefully watched, as it is undoubtedly an interesting point, whether
the areolation is first formed and the secondary structure is a sub-
sequent growth or not.

In the first instance we have an illustration of the increase of
silex and of the diatom generally, and in the other six the growth,
so to speak, of the areolations.

It may be said that Fig. 7 shows the elementary structure, and
Fig. 2 the most highly developed. I have no evidence to bring
that that is not the case, but I can only give it as my own opinion
that the reverse is what has really taken place.

Joum.Q.M.C.

Ser.IIVoLIEPl.mil.

208

On some New Appearances in Podura Scale.

By T. F. Smith.

(Taken, as read, January 27t7i, 1888.J

I beg to call the attention of the members of the Club, to a new
appearance of the Podura which I do not think has yet been re-
corded. On searching over a slide of this scale the other day with
an oil immersion, to see if I could not produce Dr. Pigott's beading,
I was struck with one that displayed entirely new features. You
all know the optician's appearance of this scale, with the exclama-
tion marks, blue or red, according to the corrections of the glass,
and with a light streak in the middle, more or less extended as
the aperture is larger or smaller. But in the specimen before me
the usual markings had vanished, and in their stead the whole
scale was studded with very slender spines with round heads, and
the pointed ends stuck into the scale like a lot of pins stuck loosely
and anyhow into a paper, and instead of being blue or red were a
pure white. At first I thought there were two sides to the scale,
and this was the wrong one, but I soon discovered that this scale
was tight against the cover, and that all the scales so placed had
the same appearance.

Since then I have examined many scales on several slides, and
am now strongly of opinion that the notes of exclamation markings
are spurious, and that the light streak is the true appearance,
which has hitherto been seen with the darker outline on each from
taking too deep a focus.

It is a well-known fact that an oil immersion objective works
only with its full aperture, when an object mounted dry is well on
the cover, and this in itself should be sufficient evidence that the
appearance the object presents, under these circumstances, is the
truer one. Then, again, the pin-like looking spines are not more
than half the diameter of the exclamation marks, and the image is
always at its smallest when in focus ; never larger. Another fact
which guides me in my estimation of the structure is the observa-
tion of a hair with small projecting spines. Here was structure of

204 T. P. SMITH ON SOME NEW APPEARANCES IN PODURA SCALE.

which there could be no doubt, and the same point of the correction
collar that gave the sharpest image of this hair gave also the
sharpest image of the spines on the scale. Still another proof.
To bring the notes of exclamation marks out well requires a deal of
management of the light, and are best seen with the smallest
apertures of the condenser ; but no amount of light will obliterate
the new ones or prevent them from standing out sharply from the
general blaze. I may say that the two smallest apertures of my
condenser always give false images, and in general work I never
use them.

I have brought two specimens of the scale for your inspection to-
night, and have placed one under a T ^" oil immersion and the other
under a new dry ■§-". The scale under the y 1 ^-" is doubled up near
the quill, and the pointed ends of two or three of the spines have
forced their way through the membrane and project by themselves
some considerable distance. On the companion scale under the
dry -g" you may develop some very respectable beads by using the
smallest aperture of the condenser, but they instantly vanish when
the light is restored. I have tried the same experiment on the
same scale with the oil immersion, but it has too much aperture
even then to lend itself to the falsehood.

Since writing this paper I have spoken to Mr. Pringle — a no
mean authority on micro-photography — and he tells me that some
time ago he photographed this scale as presenting the same ap-
pearance I have been trying to describe to-night, and got severely
sat upon in consequence. What I have been calling pins he calls
French nails, but the difference is not great.

205

Notes on Villi on the Scales of Butterflies and Mothb.

By Dr. Royston-Pigott, M.A., F.R.S.

(Bead January 27th, 1888.)
(Abstract.)

The resolution of these difficult objects is a capital introduction
to the study of the minute structure of disease germs, and I can
strongly commend it to the attention of microscopists who have
neglected this department of natural history. Dr. Gabbett, of
Eastbourne, has made a large collection of germ slides, and has
succeeded in cultivating some very interesting micrococci closely
agglomerated in single layers. Each point appears perfectly
circular, and is finely edged with a minute jet black ring. The
thickness of this minute black test ring may be estimated at ■g-g-^ow
of an inch. But when the micrococci occur in several layers they
can scarcely be resolved, and no test rings are visible. This fact
demonstrates the extreme difficulty of resolving the minute bead-
ing existing in subjacent layers, as, for example, in the test
Poduras.

Many of the villi in butterfly and moth scales are pawn-shaped,
possessing a base and a spherical summit. This form was the first
one discovered, with exceeding difficulty, on the scales of the Red
Admiral Butterfly.

The scales of Amathusia Horsfeldii gave clearer indications,
but their extreme delicacy permits of no pressure being applied, as
it flattens and distorts them. After seven years' prosecution of the
research, I was rewarded with finding an entirely new vein, which
has proved very rich in material, in moths of the Zygcena tribe.* It
is rather difficult to arrange all their complicated forms methodi-
cally, and I shall therefore first sketch generally some of their re-
markable appearances.

* There are about 100 species of this 'genus scattered over many
countries. Mr. Hinton, Vorley Koad, Holloway, has prepared a number
of slides, at my recommendation, showing many forms of beading, ribbing,
and villi. Mr Watkins, of Painswick, has also supplied me with 40 species
of Zygcena.

206 DR. ROYSTON-PIGOTT ON VILLI ON

Occasionally they are seen to lie flat upon the basic membrane,
and to be connected by cross ramifications, interlacing in an extra-
ordinary manner. At other times the bases of the villi are ciliated,
forming, reticulations, resembling ancient hieroglyphics or archaic
writing. Their thickness varies from ^-5-5-^ to tWooo °^ an mcn >
and their length is sometimes prodigious.

The villi principally observed at present take the following
forms : —

I. Beaded Villi.

II. Embossed Villi.

III. Pillar Villi.

IV. Ciliated Villi.

V. Connected Villi.

VI. Banana or Bunched Villi.

VII. Spinous Villi.

VIII. Tall Villi.

Out of about 400 preparations (dry mounts) of scales obtained
from all parts of the world, I propose to select a few which with good
object glasses give some startling results. I should here premise
that when the heads of the villi make contact with the cover
glass they always produce black circular discs more or less minute.

I. Beaded Villi. Papilio erectheus ; male ; Australia. Hind
wing of butterfly. Powell's l-12th oil N.A. 1*43. Innumerable
black contact heads of villi on dark red scales, which generally show
brilliant test beads, glittering with extraordinary beauty and pre-
cision of form. Between open ribs are scattered irregularly re-
markable isolated beads, varying much in size. With very fine
object glasses these beads exhibit jet black or blue black circular
margins and bright focal discs.

II. Embossed Villi. Zygoma lonicera. Some of the dark
scales of this moth display amazingly large embossed villi of
irregular shape. The long scales are the most beautifully marked,
and the villi are in places much prolonged. The scarlet and steel
grey scales show unusual thickness, and when the ribs lie upwards
the spots or villi appear a long way below them, attached to the
other or unribbed membrane. But even the little short grey scales
reveal very long filamentous villi developing into villi broad and
and black. Zygoma lavendulce exhibits also most extraordinary
irregular villi on dark scales.

III. For Pillar Villi examine scales of Papilio philenor. The

SCALES OF BUTTERFLIES AND MOTHS. 207

pillars appear to support the membranes of the closed sac, and often
bright beads are seen accompanying the villi. The effects below it
are very striking in different focal planes.

IV. Ciliated Villi. Delicate hairlets spring from the base of
the villi, assuming fantastic forms, spiral, anastomosed, contorted,
twisted, spreading, rising and falling in different focal planes,
which (when compressed by a touch of the object glass) adhere
flatly to the unribbed membrane.

V. Connected Villi. Impossible to describe in writing without
elaborate plates.

VI. Banana or Bunched Villi. Several villi appear to start
from one root, and branch up like a bunch of bananas, i.e., before
they have been squeezed down. These branches define beautifully
with two black margins ; yet I judge them to be solid, transparent
filaments. Some of the Zygoma scales exhibit very strange- look-
ing bunches attached to one root, apparently piercing both the
upper and lower membranes, thus securing firm pillar attach-
ments.

VII. Spinous Villi. Zygoma minos. Abrupt short cross-bars,
being villi flattened down. There are two sets, one for each mem-
brane. The very delicate pale scales show up the best.

VIII. Tall Villi. Zygoma ephialtes. Most curious hair-like
appendages on under side of scales. Large bases to villi. Double
ribbing occasionally, which twist together the lower ribs into odd
shapes. Cylindrical fibres embodying most grotesque forms all
along the median line. Rather tali mushroom-like villi.

208

Parasitism.
Address of the President, A. D. Michael, F.L.S., F.R.M.S.

{Delivered Feb. 24th, 1888.)

Among the descriptions which explain the nature of the objects
shown at this, and most other, microscopical societies, there pro-
bably is not any more frequently found than "parasite of some
creature," as, for instance, of the horse or the fowl. This is natural
enough, for parasites are usually, and almost necessarily, of small
size as compared with their hosts, and fall within the range of those
studies which cannot be pursued without the aid of a microscope ;
moreover, the worker with that instrument, while he shares the
horror of parasites which is common to most civilized human beings,
still feels irresistibly attracted by their curious and exceptional life-
histories, and has a strong tendency to collect and exhibit them.
Possibly familiarity breeds indifference. I well remember that
when our late lamented President, Dr. Cobbold, exhibited living
larvae of that terrible entozoic worm, "the Bilharzia" at the Lin-
nean Society, he could not understand why men were not particu-
larly anxious to approach his microscope and bottles. In the lists
issued by the dealers in microscopical objects will be found long series
of parasites and their eggs ; yet probably not one in fifty of those
who exhibit and deal in these things ever really considered what he
meant by a parasite, and the greater number would be somewhat
astonished if they were informed that, according to the views ex-
pressed by eminent authorities, most of the creatures which they
exhibit are not parasites at all ; while many animals are entitled to
that appellation which are not included in our exhibitors' lists. It
may, therefore, be worth spending half-an-hour in endeavouring to
obtain rather clearer views as to what a parasite is, and in reviving
our recollection of a few of the more interesting forms of parasitic
life. We have to ask, lstly, can we define the popular idea of a
parasite ? 2ndly, does it agree with the scientific idea, or rather
with any of the scientific ideas? 3rdly, if it do not, which, if
either is correct? It is strange to see how men's views have varied

THE PRESIDENT'S ADDRESS. 209

in this matter, and from what opposite standpoints authors have
attempted to classify parasitic forms of life.

A parasite is denned in Jameson's edition of Johnson's diction-
ary as being " one that frequents rich tables and earns his welcome
by flattery." This probably corresponds with the derivation of the
word from Tapa, beside, and oItos, food, but it does not appear al-
together applicable to a Tcenia or an Ichneumon. Jenkens' lexicon
comes somewhat closer to our notions ; it states a parasite to be
" a hanger-on ; a plant or animal living on another." These
probably are not works in which we should expect to find any great
scientific exactness ; let us therefore see what have been the
opinions held by those who have endeavoured to regard the matter
from a strictly scientific basis. General works on parasites are not
numerous, yet there are some to be found, although they are chiefly
confined to the parasites of man. Saint-Fargeau, one of the earlier
writers, says, " The parasite is he who lives at the expense of
another, eating his host's property but not his host." This has a
certain quaint resemblance to Johnson's idea, but if such was ever
the received view it has been somewhat widely departed from.

" Parasites," says Kiichenmeister, " are independent organized
beings, descended from peculiar animal or vegetable patents, which
require, in order that they may be enabled to complete their de-
velopment, growth, or reproduction, to take up their abode, either
constantly or temporarily, in or upon a second animal or vegetable
organism of a different kind from which they derive their nourish-
ment.' 1 This definition is getting very close to the ordinary idea,
but it scarcely seems quite consonant with the fact that Kiichen-
meister appears to treat bed-bugs, fleas, blow-flies, gnats, and mos-
quitoes, as parasites of man.

Van Beneden, in his well-known work, which is still probably the
best on parasites generally, does not put his definition in any single
sentence, but his opinions are evidently exactly opposite to those of
Saint-Fargeau ; he says, " Those creatures which merit the name
of parasites feed at the expense of a neighbour, either establish-
ing themselves voluntarily in his organs or quitting him after
each meal like a leech or a flea." It is evident that Van Beneden
does not consider a creature to be parasitic unless it does eat its
host; but he considers that it must not kill him, at all events not
at one meal ; those which do not eat the host he calls " mess-
mates," or " inutualists ; " thus, according to him, a leech, a flea,

210 THE PRESIDENT'S ADDRESS.

a gad- or Tsetse-fly, a vampire bat, and every other animal which
ever consumes any living portion of another living animal without
killing it, is a parasite, while the Ricini, the feather-eating Mallo-
phaf/a, and the Dermaleichi, which form the bulk of the microsco-
pical preparations of parasites, are not parasites at all, because they
do not eat the host, but only keep its hair, skin, or feathers clean.

Mr. r. Geddes, in the " Encyclopaedia Britannica," scarcely de-
fines animal parasites, although he classifies them, but he includes
the Mallophaga.

Megnin, one of the latest writers on animal parasites, says,
" Parasites are beings which live at the expense of other living
beings." He includes the gnats and that class of creatures, but he
also includes the Ricini.

The popular idea is probably intimately connected with the
question of position ; a creature which lives upon or in another
living creature is regarded as a parasite whether it eats its host or
not, and a perfectly free-living animal, which only attacks some
other being when it is in want of a meal, is not looked upon as
parasitic. I cannot help thinking that some definition founded
more or less upon the popular idea is, after all, the best. Let us
take the gnats and mosquitoes as excellent examples ; they un-
doubtedly do attack us and suck our blood when they have a chance,
but as a rule they are vegetable feeders, and probably of the enor-
mous numbers of these annoying Diptera which are born only a very
small proportion ever taste blood at all ; they are not most abun-
dant where animals are numerous, quite the contrary. The midge
swarms to such an extent in many of the wildest glens of the
Scottish Highlands that it is hardly possible to stay in the
places on a summer evening, unless provided with midge-
masks. The mosquito is generally supposed to be a specially
southern creature, but this is incorrect ; there is probably no place
on the face of the earth where it is found in such count-
less myriads as in the Tromsdal, a romantic uninhabited valley in
Norway, considerably north of the Arctic circle. This valley is
almost without vertebrate life, and is only visited by the Lapps, for
a few hours at a time, when they drive their tame reindeer down
from the mountains for the inspection of such visitors by the
steamers as are prepared to pay for the sight, and have telegraphed
to the agent in Tromso to bespeak it ; but in the bright and busy
little town of Tromso itself, which is only divided from the Troms-

THE PRESIDENT'S ADDRESS. 211

dal by a narrow arm of the sea, a mile or so wide, I was assured by
the natives that the mosquito is comparatively scarce. What a
very small proportion of the Tromsdal mosquitoes can ever have
sucked blood, and yet it is suggested that they are parasites.
Again, take a leech, although here the question is more diffi-
cult. It is admitted on all hands that a lion is not a parasite, it
kills its prey and eats it ; but it is said that a leech is, because it
docs not kill its prey; but if it happen to attack a very small
creature it probably does kill it, and surely the question of whether
it is a parasite cannot depend on the size of the particular creature
attacked. On the other hand, it seems very odd to be told that the
Mallophaga and Dermaleichi, which live all their lives, in every
stage, upon particular birds, and will not live elsewhere, are not-
parasitic. Of course it clearly is not necessary in order to con-
stitute parasitism that the residence of the parasite upon the host
should be permanent ; it may be temporary only ; but it does seem
to me that it must be more than seizing the so-called host in order
to make a single meal. Confining ourselves for the moment to
animal parasites upon animals, may we not say that a parasite is
a creature which, at the time spoken of, is residing in a permanent
or temporary manner in or upon another living creature, and is
existing at the expense of or by the assistance of the host. Of
course no general definition is likely to be exhaustive, or quite to
meet every case ; for instance, the well-known British parasitic
anemones, Sagartia parasitica and Adamsia paliata, are found, the
former on the back and the latter round the mouth of univalve shells
which have lost their molluscous tenants and have been taken pos-
session of by soldier-crabs ; it may be said that the anemone does
not live upon the crab, but only on the roof of his house. There is,
however, a singular instance of one of the foreign crabs which usually
has an anemone adhering to each large claw, and goes about waving
them in a manner which doubtless renders the Actinia's fishing
operations very easy.

Another difficulty, however, occurs far more serious than such
small points as that last named ; there are vegetable parasites as
well as animal. Milne Murray, in the " Encyclopaedia Britannica,"
says " the name of parasites has been given to those plants which
are nourished wholly or partially at the expense of other living-
organisms," and this seems fairly to express what is the ordinary
idea, both scientific and popular. Not only are such plants as the

212 the president's address.

Mistletoe, the Orobanche, and the Dodder regarded as parasitic,
but the fungi of favus and ringworm, the muscadine of the silk-
worm, the pathogenic bacteria, &c, are looked upon in the same
light ; although they are parasitic, not upon other vegetables, but
upon animals ; and it certainly would appear strange if such forms
as Saprolegia were not considered parasitic when attacking the
Salmonidce, but other allied species when attacking vegetables in a
similar manner were parasitic. On the other hand, Van Beneden
has very properly said that if vegetables feeding upon living
animals are parasitic, then it is unscientific not to consider animals
which feed upon living vegetables as also parasitic ; and he conse-
quently suggests that there are more animals which are parasitic
than which are not so. It may be well worth considering whether
it would not be better to confine the term parasites to organisms
which are parasitic upon other organisms belonging to the same
natural kingdom ; if this be not done, and if we admit with the
various writers that in order to be a parasite it is not necessary to
reside upon or in the host, that it is not necessary to feed entirely
or usually on the host, or always on the same host ; or that all
individuals of the parasitic species should ever seek assistance from
the host at all, occasional repasts by scattered individuals being
sufficient, then we should arrive at the somewhat startling con-
clusion that most animals are parasitic, and that the non-parasitic
are rare exceptions almost confined to predatory creatures. The
caterpillar would be parasitic upon its food-plant ; the bee and the
butterfly upon the flowers they suck ; the cow and the sheep upon
the grass they eat ; and we cannot be sure that even man himself
might not be held to be parasitic upon such organisms as fruit-
trees and Brussels-sprouts.

Now let us glance shortly at how parasites have been classified.
Van Beneden first separates messmates, which he divides into fixed
and free ; then he separates mutualists, which he does not divide ;
finally he comes to parasites, which he divides into those which are
free during their whole lives, those that are free while young, those
that are free when old, and those which are not ever free. Leuckart
distinguishes first between ecto- and endo-parasites; the former he
divides into two sections, viz., temporary and permanent ; the latter
into three sections, viz. : (1) those having wholly free-living
embryos ; (2) those having embryos passing through a different
host ; and (3) those without any free-living period passing their

THE PRESIDENT'S ADDRESS. 213

whole existence in one host. Kossmann attempted what may be
called a physiological classification, viz. : (1) Dios?notici, or vege-
tative, without independent digestive organs ; (2) Digestorii, with
independent digestive organs, and these latter are divided into
Sedentarii and Vagantes. Mr. Geddes classifies according to the
nature and degree of the parasitism into commensualists ; parasites
within the same species, and hyperparasites. Megnin divides para-
sites into two great classes, viz., harmless and hurtful ; and, indeed,
no better summary of the different views can be given than the
well-known quotation from Terence, Quot homines tot sententice.

I will now refer to a few of the varied and curious forms which
parasitism assumes.

Amongst the order of beings to which I have paid the most
special attention, namely the Acarina, there are numerous examples
of almost every kind. Unquestionably the best known is the itch-
mite (Sarcoptes Scabiei), which has brought itself very un-
pleasantly under the notice of the human race. It is a true
parasite, living its whole life in or upon one individual, and feeding
upon the substance of its host. The literature relative to this tiny
creature is so voluminous that Fiirstenberg's summary of it occupies
172 closely-printed folio pages of his book, and has rightly been
called a marvel of human labour ; and yet Fiirstenberg wrote in
1861 and the literature has been rapidly increasing ever since. It
is curious that in his magnificent work Fiirstenberg carefully draws
every species of itch-mite as having two pairs of chelate mandibles,
a thing not only incorrect in itself, but also entirely unknown in the
whole order of Acarina. I do not propose to add to the mass of
printed matter on this not very attractive subject, and will simply
remind you that it is an error to suppose that cleanliness is an
entire protection against this unwelcome visitor. It doubtless
assists considerably ; but although the adult, egg-bearing female
lives in burrows in the skin and is probably rarely transferred, yet
the immature forms and the young adults live on the surface, and
being minute, hyaline creatures, not visible to the naked eye, may
be passed from individual to individual by the morning newspaper,
the handle of a door, the clothes from the wash, or in a thousand
other fashions. Luckily, now that the disease is understood, a cure
can be effected with absolute certainty ; but amongst animals,
which cannot rub each other with sulphur and the like, the result
is different, and the largest and fiercest carnivora are sometimes

214 the president's address.

killed by a Sarcoptes, not from injury to any important organ ; they
simply die worn out by want of rest. In the French Army, after
the Franco-German War, the disease spread so suddenly amongst
the cavalry horses as to become very serious, and in this case, and
that of some other animals, as the camel, it was found that the
disease could be more or less communicated to the human atten-
dants, although it did not proceed far with them, soon dying out
without remedies.

A marked contrast to the Sarcoptes is offered by the only other
Acarine true parasite of man, the Demodex folliculorum. This
curious little being, with its short legs and its long tail, is a per-
manent parasite, but a harmless one. It lives calmly from genera-
tion to generation inside the sebaceous follicles of our noses and in
our ears without our usually having the least idea of its presence.
It appears, however, to be otherwise in the pig and one or two
other animals, in whose skin a Demodex breeds in such quantities
as to produce a diseased state.

A curious and very doubtful temporary parasite of man is the
so-called harvest-bug. If we go for a walk in late summer amongst
long, very dry grass we shall probably come home with an itching
on the calves of our legs, which will soon become intolerable. An
ordinary examination will possibly not disclose anything except
the result of our own scratching ; but careful study with a good
lens will reveal a number of small white pimples with a minute
scarlet demon seated on the top of each. This demon is the young
hexapod larva of some species of Trombidium, for he may belong to
any one of several species. A drop of turpentine will probably dis-
lodge him ; if left alone he will die a natural death in two or three
days. He is the Lcptus antumnalis of the earlier writers, who sup-
posed the six-legged mites to be separate genera, not knowing that
they were simply the larvae of the eight-legged mites. Why these
predatory creatures should leave their happy hunting-grounds
among the grass to fasten on to my leg I never could quite under-
stand ; it does not agree with them, for they die there. If they
were older they would have learnt wisdom, for the nymphs and
adults of the same species are not ever found adhering to the skin.
The irritation produced must probably result from some poison, not
from any wound so minute a creature can inflict ; and looking at
their close relationship to spiders, and their similar mode of life,
this seems probable.

THE PRESIDENTS ADDRESS. 215

The ordinary Ixodes j'inaceus, called the dog-tic, seems to me to
bear somewhat the same relation to the harvest-bug that Demodex
does to Sarcoptes. If entitled to be called a parasite at all it is a
very temporary one. It lives in the ferns and bushes apparently
on vegetable food, but will undoubtedly attach itself to any passing
animal. Many authors consider that this creature produces irrita-
tion, so I suppose it must with some. Personally, I have often
found it on my arms after a day in the woods, but have not ever
found it out except by sight. It drives its rostrum, with the two
rows of great recurved hooks, right into the skin, and it is sur-
prising that the wound should not be more felt. Authors say that
if a drop of turpentine be placed on the Ixodes it will withdraw its
rostrum, and I suppose it must be so ; but those that have favoured
me with their attentions have not been kind enough to do this, and
I some time since received from Miss Ormerod a piece of ox-hide
which had come from South Africa in spirit. It had three very
large Ixodidce, close together, so firmly fixed in it that I had to cut
deeply into the hide with a dissecting-knife in order so release the
rostra. The bite of all the British Ixodidce is not painless, if I may
trust the assurance of a well-known entomologist, who told me
that on one occasion when he put his hand into a swallow's nest to
search for beetles the Ixodes inside bit like a dog. The severity of
the bite of the allied Argasidce is well known.

You will find numerous other Acari treated as parasites of man
by various writers ; as to most of which it need only be said that
many Acari which are not parasitic are very small and very quick,
and very apt to get into unexpected places.

One of the most curious forms of limited parasitism found
amongst Acarina is that of the Hypopus. In the collection of this
Society will be found a slide of a large flea with numerous Hypopi,
which were supposed to be inside it. A careful examination will
show that this is an error, and that the Hypopi are only between
two segments of the abdomen, being in the part where the anterior
edge of a segment is drawn within the posterior edge of the pre-
vious segment in a telescopic manner, thus providing a place of
shelter for the A cams. The Hypopus is usually a minute creature,
flat on thev entral surface, but entirely covered by a smooth, arched,
dorsal., chitinous carapace ; its hind legs end in hairs like those of
the itch-mites, and its mouth is rudimentary, consisting only of a
short, closed, membranous tube ending in two bristles. It is

Journ. Q. M. C, Series II, No. 21. 17

216 the president's address.

curious to see what different views acarologists have held as to the
nature of these animals. All the earlier writers considered them
to be distinct organisms, and gave them generic and specific
names. Dujardin first suspected that they were only forms of
gome other known creatures; he found them abundant with and
on Gamasidce, and expressed his conviction that Hypopus was a
young Gamasus. Gerlach was probably deceived by the hind legs
and the parasitism, and declared them to be adult itch-mites.
Gervais, without giving any reason, classes them as adults of the
genus Tyroglyplms; this is somewhat strange, because they do
not look in the least like Tyroglyphus. Gervais does not profess
to have made any discovery, and yet it is the first instance in which
the connection, which really exists, between Tyroglyphvs and
Hypopus, is referred to. Claparede followed this idea up. He
was not a man to put forward anything without reasons ; he had
previously been studying Hoplophora, one of the Qribatidce. In
this creature the nymph is soft and white, the adult hard and
chitinous. Claparede now took to rearing one species of Tyro-
glyphus. He got plenty of larvae and nymphs, plenty of adult
females, but no adult males ; but he did get a number of hard,
chitinous Hypopi, and he satisfied himself that each of these
emerged from a soft white Tyroglyphus-nymiph, leaving only a cast
skin behind it. What could be more convincing ? Claparede
announced his discovery that Hypopus was the male of Tyro-
glyphus. Unfortunately this was disproved even before it was pub-
lished. Robin and Fumose happened to be studying the same
Tyroglyplms at the same time ; the Swiss and the French
naturalists were working in entire ignorance of one another's
labours. Robin and Fumose published their results a few days
first ; they had found and bred the male in abundance, but it had
not struck them that the Hypopus belonged to the same life-
history. Next came Megnin, who, as the result of experiments in
which he alternately allowed his breeding boxes to get dry and
then supplied fresh pieces of fungus, came to the conclusion that
Tyroglyphus-nym])h.s had the power of changing into Hypopi when
drought or other circumstances were unfavourable to their exis-
tence as Tyroglyphi, and of changing back again when circum-
stances were once more propitious. Afterwards Andrew Murray
brought forward the somewhat startling theory that Hypopus was
a ferocious internal parasite, which entirely eat up its host, the

THE PRESIDENT'S ADDRESS. 217

Tyroglyphus-\\ym\)\i, leaving nothing but the skin. Finally,
Haller came nearest to the truth when he said " Hypopial form is
a travelling-dress." Some years ago, during a short stay in a
country house, I was struck by the fact that almost every fly, or
other small moving creature, which came out of the cucumber-bed
was laden with Hypopi to sueh an extent that I called the flies " the
emigrant ships," and yet Tyroglyplius was swarming and evidently
thriving in the hot-bed. I easily satisfied myself that the Hypopus
really was an immature stage of the Tyroglyplius, but the circum-
stances did not seem to admit of Megnin's explanation. I was
thus led to undertake a series of experiments, too long to be
detailed here, by which I think I proved that Hypopus is a stage
occupying the period between two ecdyses of the Tyroglyphus-
nymph, and which, although it does not occur in all individuals, is
a perfectly normal condition, not induced by any adverse circum-
stances, but forming a provision of nature for the distribution of
the species far more efficient than any adopted by the Tyroglyplius
form, which would die if carried by the fly into hot sunshine or
warm dry places. Here, then, we have an instance of a parasite,
if that name can really be applied to it, which resides temporarily
upon the host, but requires nothing from him except conveyance
to " fresh fields and pastures new ; ' the host is really the
emigrant ship, as I used to call it. Another curious acarine para-
site, whose parasitism is of a somewhat allied nature, is Uropoda
vegetans. This creature looks rather like a large Hypopus at
first sight, but even a cursory examination will show that it is a
very different being. Its mouth organs, instead of being rudi-
mentary, are more highly developed and complex than those of
any of the Acarina, except its brother Gamasids. It possesses
tracheae which are absent from Hypopus, but like that creature it
only uses its host to convey it to suitable food. It is predatory,
living upon very minute insects and Acari. The small quantity of
fecal matter, which passes from the minute round anus of this or
other closely-allied species, soon hardens on exposure to the air,
and by this it is attached to the host ; the attaching matter, of
course, increases in quantity, but it does so by adding to the length,
not the thickness, of the stalk. Thus the Uropoda is at last attached
to the host by a long thin stalk, which keeps host and parasite
some distance apart. The host is most commonly a beetle, and
the Uropoda, when attached to one of the beetle's legs, has an ex-

"..18 the president's address.

cellcnt opportunity of using its long agile mandibles for capturing
its prey when the beetle is grubbing in the earth or dirt where they
abound. Slightly similar instances occur in other orders of beings,
thus the young Anodont, a bivalve mollusc, attaches itself to its
parent, or else to some fish, by a very long cable, which proceeds
from the foot ; and which persists through life after its use is over
in some mussels and pinnae, and is known as byssus. In the
gills of these Anodonts live the larvae of some species of Hydrach-
nidce, many of which are parasitic in the larval, but not in the
adult state. Parasitism is common among other members of the
Gamasidce besides Uropoda, but its nature varies considerably ; in
some cases the adult male, which is the most powerful and best
developed creature, is not parasitic, although the females and
young may be so ; and it is still a doubtful question whether these
seek only conveyance from their host or actually feed upon his
substance. Many arguments favour the latter view, but it is
difficult to see how a whole swarm of Gamasids manage to find
sufficient nourishment on the hard chitinous coat of such an
animal as the common dung-beetle, Geotrupes stercorarius. Some
Gamasids certainly seem to be true parasites ; thus many of those
found on bees die if removed from the bee, while others do
not. Two Gamasids which are unquestionably parasites, living
all their lives upon the same host, and feeding upon him, are
Dermanyssus avium, abundant in our poultry yards, and the
PterojHus of the bat, which latter is supposed to differ from all
other Acarina in having an octopod larva ; an allegation which it
seems to me must be received with caution. It shows how little
the Acarina are understood even by first-rate naturalists ; that
Van Beneden apparently supposes that Pteroptus does not belong
to the order. Another quaint acarine parasite of the bat is the
Otonyssus, a difficult creature to classify, which is generally found
on the ears of the bat, most often three or four clinging to the
extreme edge of the ear, and probably not any elsewhere. It seems
odd that the numerous parasites of bats should be so very special.
Neither Pteroptus, Otonyssus, nor the extraordinary Nycteribia
have any very close allies elsewhere. Another curious acarine
parasite of the bat, however, is in a different position — the Myobia
chiropteralis — which was first described in a paper read at this
Society, although a well-marked species, is closely allied to the

THE PRESIDENT'S ADDRESS. 219

Myobia of the mouse and mole. It is interesting to find this
relationship between the parasites of the mouse and bat, consider-
ing how closely-allied (zoologically) these creatures are, and how
widely different are their habits. In the Myobia the front pair of
legs are short, and armed, not with claws of the ordinary form,
but with large, strongly-curved, chitinous blades, which curl round
a chitinous peg, holding a hair of the mouse or bat between the
two, and forming one of the most efficient organs for the purpose
which I know of. In the Listrophus of the mouse and rat the hair
is held by a somewhat similar apparatus, formed, not by the claw,
but by the edge of the largely-developed and flexible maxillary lip ;
and, again, in the Hypopi of the Glyciphagus (Dermacarus) of
the squirrel and the mole it is the recurved posterior edges of the
dorsal and ventral plates, where they overlap, that perform the
same office of holding the hair. Most, but not all of these are
true parasites, living all their lives upon the same host, and feeding
upon him. Very different in kind is the parasitism of the great
sub-family of Analgince or Dermaleichi, which live their whole
lives upon the feathers of birds, and die if removed for any length
of time ; but they do not feed upon the substance of their host, they
simply serve to keep his feathers clean ; at least this is the opinion
of those who have studied the group, and it is upon this fact that
the name Analges is founded. The universality of the law was
stoutly disputed by a South African ostrich farmer, with whom I
once corresponded, who declared that the Dermaleichi increased in
such numbers upon his ostriches that if the parasites were not
killed (by sulphur, &c.) the birds died. If, however, they be
beneficial, as is apparently the case in the majority of instances,
they would then belong to Van Beneden's " mutualists," and not
be classed by him amongst parasites at all. The number and
variety of species in this group are very great ; they are most
imperfectly known, although the researches of Dr. Trouessart
among the bird-skins in the French Museums have lately made us
acquainted with a very long list of them. The occasional enormous
development of one pair of legs, and the strange forms of the
hinder extremity of the abdomen in the males of many of these
Acari, would hardly be believed without being seen ; but probably
the most interesting circumstance about them is that the female is
fecundated before the last change of skin, and that the egg-bearing

220 in k president's address.

female is often totally different in appearance from the same
creature at the earlier period when fecundation takes place. This
has heen called " Pedogenesis," and an instance of it occurs in a
parasite which is not an Acarus. The crustacean once called
Praniza is parasitic, and is fecundated at that stage, but it is the
young of the free-living Anceus, and the eggs are laid in the latter
condition. A curious connection exists between the Dermaleichi
and another small group of Acarina, the Cheyleti ; oddly enough,
Van Beneden gives eruditus as the parasitic species. All the
Cheyleti are predatory creatures, living on small, soft-bodied Acari
and Insects, and are constantly searching for them. This leads the
free-living kinds, of which eruditus is one, into all sorts of
localities, and it has been described by authors who were not
acquainted with its inquisitive habits as a resident in very strange
places ; but there is one small group of the Cheyleti which probably
really may be called parasites ; they are Cheyletus parasitivorax, C.
heteropalpus, &c. These live permanently upon birds, but only to
devour the Analgince, by which the bird's feathers are infested.
Here, says Megnin, is an " auxiliary parasite," a sort of exaggerated
mutualist, whose parasitism consists only in ridding his host of
other parasites. This appears to be so, but if the Analgince be
really beneficial parasites the position of the Cheyletus may be con-
siderably modified.

It is not only on the feathers of birds that acarine parasites
exist. Lamina sioptes gallinarum and Cytoleichus sarcoptoides live
in the air-chambers, and on the serous membranes in such numbers
as sometimes to kill the host, while the singular Harpirhynchus
nidulans is found in the follicles at the roots of the quills, and the
still stranger nymph of Syringophilus bipectinatus, with its tarsi
terminated by a whole bunch of hooks, is found inside the quills
themselves. There are plenty of other acarine parasites, but I will
only refer to one which Professor Allman discovered in such an
unexpected place as the nares of the seal. It is called Halarachne
Halichceri, and has lately been carefully studied by Dr. Kramer.

I will now very shortly refer to a few only of the very numerous
interesting parasites which are not Acari, but I shall wholly omit
the intestinal worms, because, although these, from their life-
histories, are the most curious of all, yet so much has been written
about them of late, and so much said about them at this Society,

THE PRESIDENT'S ADDRESS. 221

that the most singular facts are probably familiar to all my
hearers.

Among insects, although the fleas of hairy animals are certainly
parasites, yet I hardly think that the flea of man can be admitted
into the fraternity ; but there are two little incidents relative to
this species which seem to me amusing. The first is that Van
Helmont, an early writer, seriously gives a receipt for manufac-
turing them, as if they were pomade or cake ; the second is that
Van Beneden gravely discusses whether they might not advan-
tageously be used instead of leeches, and whether it would be
worth while for that purpose to import the very large specimens
found at Cette and Montpellier. He appears to forget that the flea
produces an irritation which people are foolish enough to object to.
Possibly, however, he was only laughing at homoeopathy. I have
always thought that the Ornithomyia is a very curious parasite. It
is a dipterous insect, with well-developed and serviceable wings, yet
it lives a thoroughly parasitic life upon birds, only using its wings
occasionally to shift from one host to another ; but it can fly well.
It is said occasionally to attack man, and a nocturnal incursion
which a number of specimens made many years ago into the
military hospital at Louvain created rather a panic among the
inhabitants. Parasitic creatures are apt to be very imperfectly
developed, but in this insect not only are the claws and mouth-
organs powerful and complex, but also the internal organs are
magnificently developed. I do not know any other dipterous
species which makes so fine a slide for showing the optic and other
ganglia, and the internal organs generally. The Ornithomyia has
several near relatives which are not provided with wings, the
ordinary sheep tick (Melophagus ovis), the Lipoptena of the stag,
the Braula cceca of the bee, are allied creatures ; but are all
apterous. The Ornithomyia often exhibits a good instance of
hyper-parasitism ; the Anoplura and Dermaleichi of the bird
frequently leave it and attach themselves in considerable numbers
to the fly, where they appear disproportionately large. I do not
think that parasites of parasites are so common as some people
suppose. A Hypopus found on humble-bees is also found on the
Gamacids which infest them. These two instances may be called
accidental parasites, but Pagenstecher found Nematodes on the
Nicothoe of the lobster, and the Taenia cucumerina of the dog has

222 the president's address.

its temporary host in the Trichodectes of the dog ; and probably
there are plenty of instances amongst the entozoic worms.

Another dipterous parasite, which is amusingly quick in the
ways of the world, is the Tachinaria. The fossorial Hymenoptera
lay their eggs in burrows, and providently provide a store of the
living larva) of other insects, which they bury for their young to
eat when hatched ; but while the prudent mother is thus engaged
the Tachinaria slips into the burrow, lays its eggs on the pro-
visions, and departs. The dipterous larvse are hatched first, so
that before the young bee or wasp is born its larder is emptied,
and the thief has gone forth rejoicing in its ill-gotten goods, and
leaving its Hymenopterous neighbour to starve. Some of the
Hymenoptera, however, are not easily excelled in the ingenuity of
their parasitism. Mr. Enoch has often shown us his skilful pre-
parations of the beautiful little Polenema ovulorum, which lays its
eggs inside those of the common Cabbage- Butterfly. This charm-
ing little atom has a relative very like it, which has managed to
adapt its fragile wings, with their long fringes, to an aquatic, or
semi-aquatic, life ; and lays its eggs inside those of the beautiful
dragon-fly, Agrion virgo.

The crustacean parasites are very remarkable. It is chiefly
among them that there occurs that strange form of parasitism —
that while the female is a true parasite upon another animal, the
male is practically parasitic upon the female ; but, on the other
hand, in Nicothoc, where the female has become a mere bunch of
digestive and reproductive sacks, the male is a free-swimming
creature. This degeneration of the female parasite into little more
than an egg-sack is very remarkable amongst crustaceans, but is
by no means confined to them ; the same thing occurs with the
mollusc Entoconcha and other creatures. Among strange crusta-
ceans may be mentioned an Isopod Bopyrus, the female of which
lives under the carapace of the prawn, the male being free, &c. ;
the Phryxus paguri discovered by Eathke, the female of which is
found attached by its back to the abdomen of the Pagurus, thus
sharing the shelter of the shell which the latter has taken posses-
sion of. The male of this creature is one of those that is parasitic
upon the female. Another Isopod, the Cymotliue, lives in pairs,
male and female, in the bucal cavity of fishes {e.g., the Stromatea) ,
not to devour its host, but to share his dinner. Those that live in

THE PRESIDENT'S ADDRESS. 223

the mouth of the flying-fish are so large as to fill up the greater
part of the cavity. Another Isojiod, the Icthyoxenus yellinghausu,
hollows out a comfortable residence for himself and his wife in the
coats of the stomach of one of the cyprinoid fishes. The crustacean
is said to penetrate from the outside, behind the abdominal fins, and
through the skin. The Pinnotheres, a crab, lives in the mussel and
other bivalves, and has been said to go out hunting, and bring his
meals home with him and share them with his host ; this probably
requires confirmation : if it be true, it certainly is quite opposed
to some of the definitions of a parasite. The barnacles are very
strange parasites. They do not usually want to feed on their host ;
they only want to be carried into good places where they may fish
for themselves ; and as creatures of this nature attach themselves
in such numbers to rocks, to ships, to floating wood, &c, it does
not seem very strange when we find some genera of them, as Tubi-
cinella, Coronula, Platylepas, and Chelonobia, adhering to whales,
sea-snakes, turtles, and even to the manatee ; but what does seem
odd is that as a rule a species of barnacle adheres to one species of
whale, and to that only. The Gallce also are cirrihipedes. They
are parasitic on crabs and lobsters, adhering to the abdomen, but
have become so degenerate from their parasitism that they have
but few organs left.

One of the worms, Odontobius, which also only desires to pick
up passing scraps, seems to have a better idea of where to place
itself on the whale than the barnacle has, for it is found on the
whalebone, and a more favourable situation can hardly be imagined.
A polyp, Mnestra parasites, has a very quaint notion of how to
attain the same object, for it plants itself firmly on the head of a
gasteropod, Phyllirhoa bucephala, and it caused considerable dis-
cussion among zoologists when discovered.

It is scarcely necessary to say that there are not any parasites, in
my sense of that word, among the higher vertebrata, for that sense
will not include either the vampire-bat, or the small Egyptian
plover which keeps the teeth of the crocodile clean, or the Pique-
bceuf, which seeks its dipterous prey on the back of the buffalo ;
but amongst fishes there certainly are cases very like parasitism ;
these are mostly very well known. The Ttemora attaches itself by
its suckers to a shark, or to some other fish which swims better
than it does itself. The fishes Fierasfer Hornei and Enchelyophis

224 the president's address.

vermicularis live in the digestive cavities of holothurians. Fish
live in sea-anemones, and Oxybeles lumbricoides lives in a star-fish;
the young of Caranx trachurus frequent the cavities of the medusa
Chrysaora isocela, and there are plenty of other instances of asso-
ciation between fish and medusse. Some authors might call this
parasitism, and some might not, but of one thing we may be certain,
viz., that like all the other creatures which I have mentioned to-
night, whether they be called parasites, messmates, mutualists, or
anything else, they are not less wonderful nor less interesting than
other forms of organic life, and that the study of them will amply
repay everyone who has the time to devote to that pursuit, and
the inclination so to devote it.

225

PROCEEDINGS.
November 11th, 1887. — Conversational Meeting.

]

The following objects were exhibited : —

Freshwater sponge, Spongilla fluviatilis ... Mr.

Gizzard of Cricket ... ... ... ... Mr.

Amoeba princeps... ... ... ... ••• Mr.

Hydra fusca, with spermatic, and ovarian
capsules

Whirligig beetle, Gyrinus natator, showing
aerial, and aquatic eyes ... ... )

Ephippian egg of Daphnia, resting stage ... Mr.

Group of Diatoms ... ... ... ... Mr.

Eyes of fly, Anthomyia... ... ... ... Mr.

Actinoptychus anmrfatus ... ... ... Mr.

Amphipleura pellucida, with Powell and'
Lealand's oil imrn. achro. condenser, and
Zeiss' apochromatic | O.G. N.A. 1*40 and \
Nelson's eye-piece x 1,000 diam. Francis' j
method of intensifying by Nicol prism )

Antarctic radiolaria, H.M.S. " Challenger,"
1,950 fins

Stephanoceros EicJiJiornii ... ... ... Mr.

Section of Lily bud Mr.

F. W. Andrew.
E. T. Browne.
E. Dadswell.

5>

}

Mr. F. Enoch.

J. D. Hardy.
G. Hind.
G. E. Mainland.
H. Morland.

Mr. E. M. Nelson.

Mr. B. W. Priest.

C. Kousselet.
W. Watson.

Attendance — Members, 49 ; Visitors, 4.

November 25th, 1887. — Ordinary Meeting.

A. D. Michael, Esq., F.L.S., F.R.M.S., President, in the Chair.

The minutes of the preceding meeting were read and confirmed.
Mr. John J. Lewer was balloted for and elected a member of the Club.
The following additions to the Library and Cabinet were announced : —
" Proceedings of the Canadian Institute " ... In exchange.

" Journal of the Essex Field Club " „

" The American Monthly Microscopical )
Journal" ... ... ... ... )

" Proceedings of the Belgium Microscopical-
Society "

" The Botanical Gazette " ...

" Proceedings of the New York Microscopical)
Society" ... ... ... ... J

One Slide of Cysticercus Celluloses

'}

5>

)>

»»

>;

From Mr. Smart.

226

The thanks of the meeting were voted to the donor.

The Secretary said it had often been found a matter of inconvenience
when live objects were brought by members for distribution, that others
wore unable to take them home on account of not being provided with
bottles. lie had therefore asked the attendant to provide a supply of
bottles, which members could purchase, if required, for l^d. and 2d. each.
Some small boxes for slides could also be obtained from him on similar
terms.

Mr. C. L. Curties exhibited and described two new microscopes by Zeiss,
one of which was furnished with a centering stage, rack and pinion to the
condenser, and a clamping screw to the fine adjustment, by means of which
it could be thrown out of gear and so saved from risk of injury whilst
travelling ; the other was mounted upon a triangular brass bar, which could
be raised or lowered so as to alter the height of the body. It was also fur-
nished with an iris diaphragm with ten leaves.

Mr. Curties also exhibited to the meeting some remarkable photo-
micrographs of Pleurosigma Angulatum and Amphipleura Pellucida, taken
by Dr. Roderick Zeiss with the new apo-chromatic objectives.

The President hoped the members would examine these photographs after
the meeting, as they were certainly amongst the most remarkable yet pro-
duced, certainly showing both longitudinal and transverse lines on Pellucida,
The iris diaphragm was also worth attention.

Mr. Karop thought it was a most unfortunate thing to have added that
very rough method of raising the body of the microscope. He could not
see at all what was the good of it, and it would be sure to (t wobble " after
it had been a short time in use.

Mr J. D. Hardy exhibited a simple form of growing slide, in the construe-
tion of which he had used one of the ordinary compressors. It was intended
as an intermittent slide, since the circulation had to be stopped whilst the
contents of the slide were being examined under the microscope.

The thanks of the meeting were voted to Mr. Curties and Mr. Hardy for
their communications.

Mr. B. T. Lowne gave a resume of his paper " On the Histology of the
Muscles of the Fly," which he freely illustrated by drawings on the black-
board.

Prof. Chas. Stewart said he had listened with much pleasure to the clear
and lucid manner in which Mr. Lowne had explained his subject, and had
laid before them certain views concerning it. For his own part, not having
made muscle structure a study for many years past, his knowledge of it was
probably somewhat antiquated ; but regarding the subject from the stand-
point of his own sub-fossilized views, he should rather have fancied that
what had been spoken of as nutrient-plasma was really continuous with the
protoplasm on the surface. He should look upon this largely as being pro-
toplasmic, and that all the other was but a modification of it. He should
also be disposed to think of the complex parts as being derived from a
modification of the cell rather than from the nucleus. He thought, too, that
this protoplasm was no more nutrient than the other, though it was no doubt

227

likely that nutriment might be diffused through it, regarding it as the living
material of the structure. A little doubt seemed to have been thrown by Mr.
Lowne as to the existence of Krause's membrane, but he thought this was
quite plainly to be seen, and that there was no difficulty in showing it.
Having drawn a diagram upon the board, he pointed out that a fibre showed
dark and light portions as described, and that in the dark portion a middle
dark line could very readily be demonstrated — this was Krause's membrane.
He thought it was certainly not due to any optical effect, but to the existence
of a different material, and that the rods were separated by a more abundant
quantity of plasma. In each little group of these rod-like structures there
was another differentiation producing light patches, which were probably due
to more or less fusiform expansions. He had not seen any evidence of the
continuity of the rods across the clear spaces. Here they always seemed to
be interrupted, the clear space beiDg crossed by Krause's membrane. He
thought, however, that he should only be expressing the feeling of the mem-
bers of the Club, as well as his own, by hoping that Mr. Lowne would give
them a demonstration of the subject on one of their gossip nights, in which
case he should be very pleased to bring up some of his ancient specimens for
comparison.

Mr. Karop thought the evidence as to the existence of Krause's membrane
was not very conclusive. The fact that a small nematode worm had been
seen to crawl up inside a fibre, the substance of which closed up again after
it, seemed to show that this so-called membrane was not a membrane at all
in the general sense of the term.

Professor Stewart thought this would be quite possible supposing the
membrane to be viscous and not solid. In such case a nematode might
pass through just as a penny could pass through the film of a soap-bubble
without rupturing it, or as white blood corpuscles passed through tissues
There was no need to suppose that the worm passing through necessarily
made a hole, except in the sense in which a suicide was said to " make a
hole in the water."

Mr. E. M. Nelson said he had been examining muscular fibre, not with
any idea of studying it physiologically, but just to see what could be done
with it optically. For this purpose he took a portion of the muscle of a pig
and selected an ultimate fibril measuring in section not more than the
tiooo mcc 5 an d in which, if the bands were all the same size, they would
have measured the gg-spo inch. Drawn upon the black-board, he showed
that this fibril was ^crossed by a number of lines, some being white, others
dark, black, or very black, and so fine that in some cases they almost
appeared beaded. — It was a fact that some people always saw beads in a
horizontal line if only it was fine enough. He tried this object just in the
same way as he did diatoms, and was quite sure that there were no con-
tinuous vertical lines running down it, but there was something of a waxy
appearance, which might divide it into three.

Mr. T. F. Smith said he had no physiological knowledge of the subject,
but he had examined an ultimate fibre, the diameter of which was about
the 30000 inch, and drew on the board the appearance which it presented to

228

him. He quite agreed with the remark that when a person looked at fibres
of this sort in large bundles he could make anything he liked out of them.
The President said he had been greatly interested in this paper and in the
discussion to which it had given rise. It was well known that Mr. Lowne
had devoted himself largely to insect anatomy, so that the points raised
were of extreme interest. Personally, however, he could add nothing to
what had been said, as the subject was one which was outside his own
department of study. If he recollected rightly there was a reference to it in
Professor Schafer's anatomy of a fly's leg, where it was stated that in the
duller bands there were certain rod-like substances which had highly refrac-
tive, somewhat swollen ends, lying in the lighter bands, and his view was
that these were detached structures lying within the darker band, the en-
larged ends appearing as black spots in the lighter band, so that in each
lighter band there was a double row of dots. He also mentioned that during
the contraction of the muscle, when the lengths of the rods shortened, the
size of the darker spots increased considerably, so that the light band became
a dark band in consequence of the greatly increased size of the dark ends.
His view was that these rods were entirely detached from those of other
bands, and were not connected by any intervening lines as Mr. Lowne had
shown. If, however, Mr. Lowne could demonstrate "what he had
described it would be a highly interesting addition to their knowledge of the
minute structure of muscle.

Mr. B. T. Lowne said, with regard to the appearances which were found
in minute structures of this kind, everyone would, of course, take his own
view of what he saw. For his own part he regarded them largely as inter-
ference phenomena, and in this opinion he was certainly strengthened by
what Mr. Nelson had stated to be the result of his observations. They
would find that there were a hundred different opinions as to what these
appearances meant. They had been described over and over again, and they
were so exceedingly minute that he could not place much importance upon
observations upon muscle of ordinary mammals. Neither should he insist
strongly upon what he saw in the muscles of the fly, except for the fact that
the wing muscles were ten or fifteen times as large as those of any mamma-
lian. It had even been said that they were resolvable into minute fibrilhe,
and there was so distinctly a continuous line that he had no doubt whatever
as to its existence as a fact. With regard to nutrient material, perhaps it
was rather a popular mode of expression, but he regarded the functional part
as represented by the longitudinal bands, and thought the material which
kept them going was perhaps the protoplasm. He thought it was now
universally admitted that muscle nuclei split up into rods. This might be
wrong, but it was certain that the nucleus gradually disappeared under the
formation of the rods ; and it seemed, therefore, as if there must be some-
thing analogous between the two formations. What he meant to say was
that the nucleus was concerned somehow in the formation of the rods, and it
was quite certain that the nucleus disappeared and the rods took its place.
What he wanted shown was that diffraction could not account for the
appearances. The structure which he had observed appeared at least to be

229

•}

Mr. F. W. Andrew.
Mr. E. T. Browne.
Mr. C. Lees Cnrties.

mechanically possible, and there seemed no doubt whatever that the trans-
verse markings were an index of the rapidity with which the muscle was
capable of contracting.

The thanks of the meeting were then unanimously voted to Mr. Lowne for
his communication.

Mr. T. F. Smith read a paper " On the structure of Moth and Butterfly
Scale," supplementary to that read at the previous meeting.
The thanks of the Club were voted to Mr. Smith for his paper.
Announcements of meetings, &c, for the ensuing month were then made,
and the proceedings terminated with the usual conversazione, and the fol-
lowing objects were exhibited : —

Volvox with parasitic rotifer, Proalis para.

sitica'.

Floscularia ornata

Photo-micrograph, Spine of Echinus, taken")

with Bakers 2in. O.G. )
„ Amphipleura pellucida,'

partly resolved into
beads, sent by Dr.
Zeiss, and taken with '
his 3*0 mm. apochro-
matic O.G. N.A. 1.30._
,, P. angutatum X 490(0

from Dr. Zeiss, and
taken with his 2*0 mm r
apochromatic O.G.

N.A. 1.30 J

Head of " Devil's coach-horse " beetle,")

Ocypus olens, with drawing ... j

Section of eye of Blowfly, prepared by Mr. )

Underbill ... ... ... i

,, eye of Pieris brassica, do. do. ...

„ eye of Spider, do. do.

Circulation in Anacharis

Fresh-water Oligochata, sp

Kotifera, various

Scale of Moth, Urania rhypheus, showing villi
Type slide of diatoms from Oamaru ...

Mr. F. Enock.

Mr. H. E. Freeman.

»>

Mr. G. Hind.
Mr. G. E. Mainland.
Mr. C. Kousselet.
Mr. T. F. Smith.
Mr. W. Watson.

Attendance— Members, 48 ; Visitors, 3.

230

December 9th, 1887. — Conversational Meeting.

The following objects were exhibited :—
Stichotricha remex
Actinomycosis, in tongue of Cow
Fairy fly, Camptoptera papaveris
Beetle, Mezium sulcatum
Hemiaulus ampleetans ...
Raphidioplirys elegans ...
Ultimate muscular fibre of Pig
Beetle, Ptilinus pectinicomis . . .

Attendance — Members,

38

Mr. F. W. Andrew.
Mr. C. Lees Curties.
Mr. F. Enock.
Mr. G. E. Mainland.
Mr. H. Morland.
Mr. C. Rousselet.
Mr. T. F. Smith.
Mr. W. Watson.
Visitors, 7.

: !

»

>j

»>

December 23rd, 1887. — Ordinary Meeting.
A. D. Michael, Esq., F.L.S., F.R.M.S., President, in the Chair.

The minutes of the preceding meeting were read and confirmed.
The following gentlemen were balloted for and duly elected members of
the Club:— Mr. W. Barnes, Mr. Fredk. Goslett, and Dr. G. W. Royston-
Pigott.

The following additions to the Library and Cabinet were announced : —
" The Botanical Gazette " ... ... ... In Exchange.

"The American Monthly Microscopical")
Journal" ... ... ... ... )

" Proceedings of the Canadian Institute of,

Toronto"
" The American Naturalist " ...

" Science Gossip " ... ...

" Journal of the Eoyal Microscopical Society "

"Proceedings of the Royal Society "

" Annals of Natural History "

"Grevillea" ... ...

Twenty-four Slides prepared by Mr. Hinton...
The thanks of the Club were voted to the donors.

The Secretary called attention to a prospectus recently received from the
publisher of the " Naturalists' Directory,'' Boston, Mass., U.S.A., accom-
panied by a request for names suitable for insertion with particulars as to
the special branch of science taken up, and whether it was desired to make
exchanges of specimens, &c. It appeared to him that for some purposes this
would be found a very useful book.

The President said that this was no doubt a very useful publication to
naturalists, who could by its aid ascertain the names and addresses of

From the Editor.
From the Society.

Purchased.

>>

From Mr. T. F. Smith.

231

persons in all parts of the world who were working at the same subjects as
themselves, and with whom they could, if they desired, readily place
themselves in communication.

Mr. H. Morland read the following extract from a letter dated December
19th, 18S7, from Herr E. Weissflog, of Dresden: — "Among the diatoms
picked out from the Oamaru deposit I had one small frustuleof Craspedo-
porus elegans ; when dry it was difficult to see the different structure of both
valves. Before mounting it I passed it in a drop of water ; the latter soaked
into the frustule and both valves separated readily. They confirm fully
your view about this form ; one valve is Craspedoporus elegans, the othei
Porodiscus inter ruptus?

Mr. Karop thought it was very interesting that Mr. Morland's observation
should have been confirmed in that way. When looking at the specimens at
the time they were exhibited in illustration of the paper, he had remarked
that they seemed to be too good a fit to be the result of casual occurrence.

The thanks of the meeting were voted to Mr. Morland for his communica-
tion.

Mr. T. F. Smith read the following supplementary note to his paper on
<f Butterfly and Moth Scales " read at the ordinary meeting of the Club in
November last : — " It was not my intention to have said anything more on
' Butterfly and Moth Scales,' but since reading my last paper I have found in
the ' Monthly Microscopical Journal ' a paper read before the Boyal Micro-
scopical Society on May 3, 1871, by Dr. R. L. Maddox, in which he treats the
subject somewhat exhaustively and arrives at the same conclusion as myself
as to the nature and use of the little ro<l-like bodies between the membranes.
His language is as follows : Speaking of the two membranes, he says — ' The
inner was made up of a coarser and darker material with also pigmentary
deposit, in the substance of which the framework of the longitudinal ribs is
fixed, projecting somewhat on the free surface of the membrane facing the
opposite one ; but besides this, the longitudinal ribs especially, if not the
cross-bars, appear to be attached to the opposing surface of the outer, or next
membrane if three, by minute more or less wider or narrower vertical pro-
jections or septa — so that the ribs are bound to each other by cross-bars and
to the opposite membrane by short columns or attachments at very different
points.' Now, of course I should have found this out before reading my
last paper instead of after, and my only excuse is that there is no indication
of this structure in the three plates that accompany the paper, and coming so
soon after Mr. Mclntyre, who figures the structure but calls it false, I did
not read the letterpress until too late. I am sorry that I should have treated
this presence of the rod-like bodies to keep the two membranes apart as a
new discovery, and take this earliest opportunity of acknowledging my
mistake."

The President said that no one could avoid occasionally putting forward
as new something which had already been published, because an exhaustive
search of all that had been published on any subject was for most persons a
matter ol impossibility. When, however, such a thing had occurred the
proper thing to do was what Mr. Smith had done — but which persons of
Journ. Q. M. C, Series II., Xo. 21. 18

232

great note sometimes omitted — namely, to take the earliest opportunity of
acknowledging the fact in the same place as that in which the statement had
been made.

The President said that as there were no other papers before the meeting
he would gay a few words about a slide which he had brought down for
exhibition. The object was not one which he had seen put up as a micro-
scopic object, and although it was a very common thing and was shown in
almost every biological work, it was not everyone who had seen the thing
itself — he referred to the Spermatophore of one of the Cephalopoda— thz
common Squid. These creatures were common on the extreme western
coast of England during the late summer and autumn, at which time
they appeared to come in shore, and were then eagerly sought for by
fishermen on account of the value attached to them as bait. Having
described the process usually adopted in fishing for Squid, the points of
interest connected with the specimen exhibited were illustrated by a diagram
drawn upon the black-board.

Mr. Morland inquired what medium was employed for mounting this
object.

The President said the best thing for the purpose was diluted glycerine or
glycerine jelly.

Professor Chas. Stewart said he quite agreed with the President that this
was an extraordinarily beautiful object, and one also very full of interest.
It could be readily obtained from the common Squid, and when mounted in
glycerine jelly and illuminated with a parabola or spot lens its features
were brought out exceedingly well. It was worth mentioning, however, that
glycerine jelly had an inconvenient way of developing large vacuoles in the
middle of the slide, which in course of time necessitated remounting.
Some year or two ago specimens of this object could be obtained stained and
mounted in balsam— he believed they came from Zoological Station at
Naples— but when prepared in this way they were certainly not such
beautiful objects. Perhaps the most remarkable Spermatophore was that
of a small species of Tremoctopus from the Mediterranean, which had
about 100 suckers close together upon the hectocotylus. On examining one
of these he found a rather remarkable thread, which was sticking out from
the great respiratory orifice. On tracing it, it was found to come out of the
genital opening, and on being drawn out he found it extended to a length of
two feet, and at one end there was the special armature which had been
described by the President. He thought it was rather an extraordinary
thing to find one of such remarkable dimensions, especially in the case of
one of the smallest of the Octopods.

Mr. Karop said that though the President had mentioned the chief use
made of these creatures here was for the purpose of bait, on the Italian
shores the people ate them with avidity, and also sold them as food. He
moved a vote of thanks to the President, which was unanimously carried.

Announcements of meetings for the ensuing month were then made, and
the proceedings terminated with the usual conversazione, and the following
objects were exhibited : —

233

Cordylophora lacustris... Mr. F. W. Andrew.

Crystals of Acetanilide Mr. E. T. Browne.

Achyla prolifera, on dead larva of Corethra ) ^ T q -^ Mainland.
plumicomis ... ... ... ••• )

Sperrnatophore of Squid, Loligo vulgaris

Muscular fibril of Pig ...

A collection of various Rotiferae

Scale of Moth, Callimorpha dominula, show-
ing villi

Attendance— Members, 36 ; Visitors, 2.

Mr. A. D. Michael.
Mr. E. M. Nelson.
Mr. C. Rousselet.

Mr. T. F. Smith.

January 13th, 1888. — Conversational Meeting.

The following objects were exhibited :—
Crystals on cork of sherry wine bottle
Eggs of Sea Loach
Chelifer, sp.
Bugula turbinata
Triceratium Weissflogii
Nest of Trap-door Spider, from California . .
Exuvia of Dermestes larva
Photo-micrographs
Entomostraca, JBosmina longirostris ...

Attendance— Members, 28 ; Visitors, 2.

Mr.

F.

w

. Andrew.

Mr.

E.

T.

Browne.

Mr.

J.

J.

Kern.

Mr.

G.

E.

Mainland

Mr.

H

, Morland.

Mr.

S.

H.

Needham

Mr.

E.

M

, Nelson.

Mr.

C.

Rousselet.

January 27th, 1888.— Ordinary Meeting.

A. D. Michael, Esq., F.L.S., F.R.M.S., &c, President,

in the Chair.

The minutes of the preceding meeting were read and confirmed.
Mr. W. S. How was duly elected a member of the Club.
The following additions to the Library and Cabinet were announced : —
" The Microscope," Nageli and Schwendener... From Mr. Frank Crisp.

"Essex Dene-holes" „ Essex Field Club.

"American Monthly Microscopical Journal" In Exchange.

" Botanical Gazette '' ...

" Journal of the New York Microscopical)

Society " ... ... ... ... j

" Journal of Microscopy "

" Journal and Proceedings of the Royal)

Society of New South Wales " ... )

"Proceedings of the Eastbourne Natural)

History Society " ... )

" Proceedings of the Belgium Microscopical)

Society" ... ... ... ... j

"Annual Report of the Ealing Natural"

History and Microscopical Society "

»

3»

»

From the Society.

>>

'}

234

" Science Gossip" From the Publishers.

"Annals of Natural History " ... ... Purchased.

Ten Slides from Mr. E. T. Browne

The thanks of the Society were voted to the donors.

The President said that, as the next ordinary meeting would be their
Annual Meeting, it would be necessary according to their rules to elect
auditors of their accounts, and also to nomina