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OF THE

MICROSCOPICAL SOCIETY

OF

LONDON.

NEW SERIES.

PLL LILLIA

VOLUME XT.

10ND. ON 2
JOHN CHURCHILL AND SONS, NEW BURLINGTON STREET.
1863.

TRANSACTIONS.

A few words more on Brenzamin Martin. By Joun
Wixuams, Assistant-Secretary.

(Read Oct. 8th, 1862.)

In the introduction to my description of the Martin micro-
scope, read at one of the meetings of the Society during the
last session, I gave some particulars of the.life of Benjamin
Martin, the constructor of that beautiful instrument. I was,
however, unable to give any account of his early life. Since
that time I have met with some additional information
respecting that remarkable man which, although very scanty,
may still be considered of interest by the Society, as supplying
a deficiency in the former account. I have, therefore, with
your permission, to call your attention to “A few words
more on Benjamin Martin.”

Since my last communication I have ascertained that
Benjamin Martin was born of poor but well-conducted
parents, at Worplesdon, a small town or village between
Guildford and Woking, in Surrey, in the year 1704. He
commenced his career in that neighbourhood at a very early
age, as a ploughboy. Having a strong desire to acquire
knowledge, and being gifted with extraordinary perseverance,
he succeeded, by unremitting application, in teaching himself
reading, writing, and arithmetic, and acquired such profi-
ciency that he was able to undertake the instruction of others
in those useful and necessary arts. Having also a strong
inclination towards mathematical and philosophical specula-
tions, after a while he abandoned husbandry, and, devoting
himself to more congenial pursuits, persevered in such a
course of reading and study as, in a great measure, compen-
sated for the want of original education. How he supported
himself during this time is not clear, but it was pos-
sibly by teaching, and he appears to have first employed him-
self in this way at Guildford. About 1735 he settled, as a

VOL, XI. a

2 Witurams, on Benjamin Martin.

schoolmaster, at Chichester; and there, about 1740, as
appears from the advertisement quoted in my former account,
he constructed his pocket reflecting microscope.

His first literary production was the ‘ Philosophical Gram-
mar,’ published without date, before 1735, which was succeeded
by a number of useful introductory works, at the time they
were published of great value to the student. He appears
also, in one part of his career, to have read lectures in
London on various branches of natural and experimental
philosophy, which are said to have been well attended, and to
have given much satisfaction.

I have taken some pains to ascertain the various works
published by Martin, and have appended to this account as
complete a list as I could make out. In the course of the
necessary investigations for that purpose I have met with
several curious particulars connected with them, and relating
either to the author or to their publication, which may, per-
haps, be of some interest. They are chiefly from incidental
notices or advertisements in the works themselves. Thus, in
the ‘Young Man’s Memorial Book,’ published in 1736, at the
end are two separate announcements of ‘‘ Books published for
J. Noon.” In the first of these, which is of an earlier date
than that of the book it is appended to, we read, “ Just pub-
lished, the ‘ Philosophical Grammar,’ &c., &. By Benjamin
Martin.” ‘This was his first work. This announcement is
succeeded by the following :—‘‘ November 20, 1735. Next
week will be published, ‘A New and Complete System or
Body of Decimal Arithmetic,’ &c., &. By Benjamin Martin,”
thus giving almost the very day of the publication of that
work, and also proving that the ‘ Philosophical Grammar’
had not long preceded that date, viz., 1735. In the second
- announcement, which is evidently of the date 1736 (that of
the work in which it occurs), we find, “In the press, and
next February will be published, in two volumes, ‘The Young
Trigonometer’s Complete Guide, &c., &. By Benjamin
Martin.” In the ‘Description of both the Globes,’ &c. (with-
out date, but evidently published after Martin had opened his
shop in London), we find an advertisement or notice, to which
I call attention, as showing how widely spread was the renown
that Martin had acquired as an optician. It is as follows :—
““N.B.—Whereas the Jews, pedlars, &c., in all parts of
England, sell visual glasses with the initials of my name
(B.M.) upon them, and pretend on that account that they
are of my make and were bought of me, I thought it neces-
sary to undeceive the public, by assuring them that I never
sold any to those who hawk goods about the country, they

Witzrams, on Benjamin Martin. 3

dealing in a sort of glass too bad for any but themselves to
recommend, or for any one to buy who knows anything of
optical glass, or has more regard to the safety of his eyes and
the preservation of his sight than the saving of his money.”

In the same work is given “ A Catalogne of Philosophical,
Optical, and Mathematical Instruments, made and sold by
Benjamin Martin, at his shop, the sign of Hadley’s Quadrant
and Visual Glasses, near Crown Court, Fleet Street.”” The
prices are mentioned, and among them we find, “ Large
parlour compound microscope, £3 13s. 6d.; ditto, in brass,
£5 5s.; solar microscope, £5 5s.; Wilson’s ditto, with appa-
ratus, £2 12s. 6d.; ditto, small, £1 7s.; Dr. Lieberkuhn’s
opaque microscope, £2 12s. 6d.; ditto sto, £3 13s. 6d.;
aquatic microscope, £2 12s. 6d.; ; universal compound micro-
scope, £5 5s.; pocket compound ditto, £2 2s.” This list is
curious, as showing the cost of various microscopes at that
time.

Martin also published a few prints, of which a list is given:
They were—‘ Synopsis of Celestial Science,’ 1s. 6d. ; ‘ Orbit of
Comet of 1682 and 1759,’ 1s. 6d.; ‘Wonders of Cometary
World Displayed,’ 2s. 6d.; ‘New Map of the World,’ 1s. 6d.;
‘Map of 460 Miles round London,’ 6d.; ‘Map of 20 Miles
round London,’ 6d.; Transit of Venus over the Sun, J ips rr
6th, 1761,’ ls. 6d.

In conclusion, I append a list of works published by M Ban
between 1733 and 1773, a period of forty years, which I
have endeavoured to render as complete as possible. They
amount to forty, and are:—‘ Philosophical Grammar’ (the first
of his works); ‘ Elements of Geometry,’ 1733 ; ‘Spelling-Book
of the Arts and Sciences, for the use of Schools ;’ ‘ Decimal
Arithmetic,’ 1735 ; ‘Young Student’s Memorial Book,’ 1735;
‘ Description of the Globes,’ 2 vols., 1736; ‘ Memoirs of the
Academy of Paris,’ 1740; ‘Panegyric of the Newtonian
Philosophy,’ 1734; ‘On the New Construction of the Globes,’
1755; ‘System of the Newtonian Philosophy, 1759; ‘New
Elements of Optics,’ 1759; ‘ Mathematical Institutes,’ 1759-
64; ‘The Natural History of England,’ 1759; ‘ Biographia
Philosophica,’ 1764; ‘Introduction to the Newtonian Phi-
losophy,’ 1765; ‘ Institutions of Astronomical Calculations,’
1765; ‘Description and Use of the Air-pump,’ 1766; ‘ De-
scription of the Torricellian Barometer,’ 1760; ‘ Appendix to
Description of the Globes,’ 1766; ‘ Philosophia Britannica,’
3 vols., 1773; ‘Philosophical Magazine and Miscellaneous
Correspondence,’ 14 vyols.; ‘New Principles of Geography
and Navigation,’ 1758; ‘Familiar Introduction to Experi-
mental Philosophy ;’ ‘The Transit of Venus Explained ;’

4. TuLK, on Cleaning and Preparing Diatoms.

‘The Theory and Use of Hadley’s Quadrant Explained ;’
‘The Nature and Construction of Solar Eclipses ;’ ‘ Optical
Essays on Curious Subjects ;? ‘The New Art of Surveying
by the Goniometer;’ ‘The Principles of Pumpwork Ex-
plained ;? ‘The Young Gentleman and Lady’s Philosophy,’
1759; ‘A New Treatise on Perspective ; ‘ System of Optics,’
1740 ; ‘Logarithmologia,’ 1740; ‘Philology and Philosophical
Geography, 1759; ‘Philological Library;’ ‘ Philological
Grammar ;’ Description of both Globes, the Armillary
Sphere,’ &c.; ‘Description of his newly invented Pocket
Reflecting Microscope ;’ ‘ Bibliotheca Technologica.’

This list is taken partly from the works themselves, in
which there are frequent advertisements of his publications,
and partly from summaries in various biographical accounts
of Benjamin Martin.

On Creanine and Preparine Diatoms.
By J. A. Tuxk.

Berievine that a short description of the method of
‘Cleaning and Preparing Diatoms for Preservation,” which
I have found advantageous, may be of some service to those
who are unacquainted with and about to commence the
practice of that art, I am induced to record it; and if it be
found to lighten their labours, and to produce the satisfactory
results I anticipate, my object will have been accomplished.
_ It is unnecessary to state where to look for diatoms, as that
has been sufficiently pointed out by Professor Smith, in his
work on the ‘ British Diatomacez,’ by Dr. Arthur 8. Donkin,
in the sixth volume, ‘Trans. Mic. Soc. ;’ by the editors of the
‘Micrographic Dictionary;? by Mr. Ralph, in the fourth
edition of ‘Prichard’s Infusoria;? by Mr. Roper, in the
‘Trans. Mic. Soc.,’ vol. ii; by Mr. Tomkins, in ‘ Recreative
Science,’ vol. ii; by Mr. Tuffen West, in ‘ Recreative Science,’
vol.i; and by many other experienced writers, who, to-
gether with the above-mentioned gentlemen, have nearly ex-
hausted the subject.

I will, therefore, commence with describing, as briefly as
T am able, a plan for collecting, cleaning, and mounting a
fresh-water gathering, taken from off the mud of a road-side
ditch; and I may remark that any other description of
gathering, guanoes and fossil deposits, may be cleaned and

Tux, on Cleaning and Preparing Diatoms. 5

mounted in the same manner, of course omitting such of
the detailed operations as are evidently unnecessary.
Diatoms are readily collected from the mud when the
latter has only a few inches or no water at all over it, pro-
vided only it is i a moist state; and the plan I adopt, and
which was suggested to me by my friend Mr. Currie, of
Addlestone, is gently and lightly to detach the diatomaceous
stratum lying upon the surface of the mud by the aid of a small,
thin, old, silver salt-spoon, having its bowl-edge in the same
plane as its shank ; thus, the lighter and smaller the spoon is
the more valuable it will be found to be. If carefully per-
formed, by this operation a small portion of the diatomaceous
stratum, in some cases entirely, in others almost entirely,
free from siliceous particles, will be lifted, and may be trans-
ferred into the collecting bottle. It is as well to have in the
bottle some water, into which the spoon can be immersed,
when the forms will readily diffuse themselves in the fluid.
Or if the mud from which the collecting is to be made has
no water over it, but yet is moist, another method of gather-
ing the forms may be adopted, namely, to roll over the
diatomaceous stratum a rather large camel-hair brush,
when the frustules will become entangled in the hairs of the
brush, and may be separated from them by immersion in the
water in the collecting bottle. Having by either of these
means obtained a sufficient quantity of the material, and
suppose it to consist of forms not quite clean, the next
operation is to strain it through a piece of thin silk gauze,
by which means any large pieces of vegetable matter are got
rid of. It should then be placed in a small, unglazed saucer,
with about +” of water above it, and exposed for a few
hours to the influence of the sunlight, which in many
instances will cause the diatoms, which may be known by
their brown colour, to rise to the surface of the impurities ;
and they may then be separated by means of a camel-hair brush
rolled over them in the manner already described. Also in
this case the diatoms may frequently be obtained absolutely
pure, and requiring no further preparation than boiling in
nitric acid and washing in clean water. However, it may be
found that they have not risen to the surface of the impurities,
or if they have, they cannot be collected by the brush free from
silica, in either of which cases the whole of the gathering
in the saucer may be transferred into a large, wide-mouthed
bottle, six inches high and two and a quarter inches diameter
inside, a few drops of nitric acid added to kill the forms, and
the bottle two thirds filled with clean, it need not be distilled,
water, and the whole well shaken. The mass is then allowed

6 Tuk, on Cleaning and Preparing Diatoms.

to subside, and the discoloured water poured off. This wash-
ing operation ought to be successively performed until the
supernatant water remains colourless, for by this means a
great deal of very minute matter is advantageously got rid of.

If itis thought advisable, the washed mass may now be
subjected to the action of boiling sulphuric acid and chlo-
rate of potash, according to the method described by Mr.
Arthur M. Edward, in ‘ Jour. Mic. Soc.,’ vol. vii; or if not, it
may at once be transferred, if of considerabie bulk, into a
Florence flask ; but if of only small amount, into a test-tube
six inches long and one inch diameter, allowed to settle—
the supernatant water being poured off as close as possible—
covered by a quantity of strong nitric acid, sp. gr. 1:5, equal
to its own bulk, and boiled for five or ten minutes. It is
then poured into the large six-inch bottle, which should be
about one half filled with clean water, with which it is well
shaken, allowed to settle for twelve hours, when the acid
water is poured from off it, and a similar amount of clean
water again added to it. Again the fluid is violently shaken
for upwards of five minutes, for the purpose of breaking
down and getting rid of the flocculent siliceous matter or
mucus with which the diatomaceous frustules are generally
connected, and from which they can be completely separated
by no other means that I am acquainted with, and for the
knowledge of which fact | am indebted to the kindness of
Dr. Greville, who communicated it to me.

The mass is again allowed to settle, until the superimeum-
bent water appears tinged only with a slight milkiness; the
water is then poured off. This operation of washing is suc-
cessively repeated until the water, after standing for half an
hour above the settlings and examined under a microscope,
is seen to contain in suspension no very minute siliceous
particles. Any larger particles which may be present will
have subsided along with the forms, and will be got rid of in
the next, the most important, operation.

The mass is now placed in a small, thin, flat-bottomed,
porcelain evaporating basin, say of two and three-quarter
inches diameter and half an inch deep, with so much water as
will half fill the basin; the latter is put upon a table, and its
contents allowed to subside, but not quietly, for during the
subsidence a very gentle whirling or gyrating action is given to
the water, similar to that by which the gold-washer separate;
the gold from the gravel in his round, iron washing-vessel.
The diatomaceous frustules beimg comparatively light and of
large superficial area, are more readily acted upon by the
moving water than the solid, small masses of siliceous matter

Tux, on Cleaning and Preparing Diatoms. *

are, which, in proportion to their weight, are of small super-
ficial area; the consequence is, if the whirling motion is
gradually reduced in force until it is altogether discontinued,
it will be found that the mass has arranged itself about the
centre of the basin, the siliceous particles being below, and
the diatoms lying as a stratum upon them. The latter may
now easily be separated.

Again the slight whirling motion is given to the vessel, when
immediately a cloud of diatoms is seen to rise up from the
mass into the centre of the water. Into this cloud the capil-
lary end of a small dipping-tube, three and a half inches long
and a quarter inch diameter inside, is inserted, at an inclined
angle, when at once a portion of the pure diatoms will enter
it, and from this they may be blown into a small bottle. By
successively performing this operation a very large proportion
of the diatoms may be obtained in a pure state, and fit for
mounting. However, there are certain heavy, compact forms,
which will not readily rise in the whirling process, such, for
example, as Amphitetras antediluviana, Triceratium Favus,
Biddulphia turgida, &c., &c., which will be found at the
bottom of the vessel along with the silica. These may be
advantageously picked out with a fine needle under a simple
microscope.

By a little practice and dexterity in the whirling process,
so as to produce a less or greater amount of motion of the
water, the lighter forms may be collected separate from those
more dense, for the former will rise on a very gentle action
being given, whilst the latter will require rather more motion
to stir them.

The forms thus collected may then be washed in the small
bottle two or three times with distilled water, when they
will be in a satisfactory state for mounting.

It is requisite so to apportion the water in the bottle to
the quantity of forms, as that when the latter are laid on the
cover they appear to be neither too abundant nor too scant.

The slide and the cover about to be used should be made
scrupulously clean, and this is best done by placing on them
a small quantity of a solution of Ward’s washing powder
(a packet of which can be procured at any grocer’s shop for
one penny, and which will be found most useful for removing
balsam or grease from slides), well rubbing them with the
finger, and drying them with a clean cloth. Any filaments
from the cloth should be picked off with a needle under the
microscope.

The cover should then be made to adhere to a slide, by

8 Tux, on Cleaning and Preparing Diatoms.

first breathing on the latter, and then pressing the cover
down upon it with a needle-point.

The bottle contaming the forms is now well shaken, and
the small dipping-tube is immersed into the fiuid to such a
point that the liquid ascends into the tube about half an inch.
The capillary opening of the tube is then made to touch the
middle of the cover, when at once the liquid will diffuse
itself over the latter, but will not overflow its edges. It is
then dried very slowly under a large glass shade, otherwise
the forms will segregate together, after which it is ready for
mounting, either dry or in balsam. I will describe how the
latter operation should be performed.

A drop of Canada balsam, taken out of the balsam bottle
on the head of a common pin which has been immersed into
it, is transferred to the centre of the slide, and the cover,
one end of which has first been made to rest on the slide,
gently laid over it, when, by capillary attraction, the balsam
will diffuse itself through the forms and under the whole of
the cover, and yet without extending beyond its limits.
There are these advantages attending this plan: the forms
being next to the glass cover, no considerable thickness of
balsam has to be looked through when they are seen under
the microscope, and by the use of the pin’s head the
quantity of balsam used may be so gauged as to necessitate
no after-cleaning of the slide from superfluous balsam. The
slide is then placed on its edge half an hour or an hour,
when any air-bubbles which may have been entangled by the
forms will have found their way out of the fluid balsam by
the edges of the cover, after which the slide may be put aside
to harden the balsam gradually, or it may be exposed to
"heat not greater than the finger can pleasantly bear, when
the balsam will harden more rapidly.

The preservation of diatoms in a dry state is performed
in the usual manner.

A ring of gold size is made on a slide by means of the
whirling table, and over this a ring of asphalt when the
former is dry. When the asphalt is dry, or nearly so, the
shde is heated until the asphalt becomes soft, when the cover
with the forms on it, as above described, is quickly placed
upon it, and its edges pressed with a needle-point, so that
they adhere to the asphalt at every part. The mounting
may then be finished by placing another ring of asphalt
round the edge of the cover. By this plan the asphalt will
not run under the cover and spoil the preparation.

On the Poorocraruic DELINEATION of Microscopic OBJECTS.
By R. L. Mappox, M.D.

(Read Nov. 12th, 1862.)

On the construction of the microscope, its appendages and
uses, much has been written; still it is to be marked, and
with regret, that the page devoted to its conjoined applica-
tion with photography bears so insignificant a proportion,
when we see that the tendency of the present day is to
employ each for the purpose of scientific observation and
illustration. In a degree, this may have arisen from the
trouble or difficulty peculiar to the study, and the paucity
of attempts to reduce the art to a position calculated to
advance its use. Doubtless, each individual has adopted
methods peculiar to himself, which he has employed for
some supposed, if not real, advantage; therefore, if only
these, so far as they have been made known, were briefly
enumerated, it would considerably guide others, and greatly
tend to facilitate its use.

Yet it seems likely, without aid from opticians, that we
shall be subject to perpetual vibrations, “ without important
additions ;”” nevertheless, it cannot be desired that we yield
to our exigencies by assigning “‘a limit to the discoveries of
future ages,’ prescribe to science her boundaries, restrain
the active and insatiable curiosity of man within the circle of
his present acquirements, and thus rather accommodate his
wants to the narrow spirit of prejudice, neglect, and disap-
pointment, than strive to participate in the common advance-
ment of applied photography.

Unfortunately there is little encouragement given to ad-
vocate its use, even when its usefulness is acknowledged,
and the common remark, that “its employment must be
very limited, for, unless the object to be represented lies in
one plane, you cannot, by the microscope, obtain definition
over its entire surface,’ at once prejudices the question, and
consigns us to still chiefly rely on woodcuts, with their errors,
omissions, and the “distinct folds of their accustomed
drapery.’ It should be remembered we are not in a position
to limit its use, nor assign, without experiment or trial,
the number of diameters an object, whether primarily or
secondarily, can be enlarged, before the eye detects any
offending error; rather would it be in harmony with the
basis upon which the science of experiment has been reared
to first acknowledge the want, then encourage the effort,

10 Manpox, on the Delineation of Microscopic Objects.

and, no doubt, as in the parts now considered necessary
appurtenances to the microscope, we should, ere long, find
the deficiency supplied.

Again, much objection has been taken to the application
of photography for obtaining drawings of microscopic objects,
not simply, as stated, in an optical point of view, but also
from the reason that we are accustomed to learn all we can
of any object under observation by every means placed at
our disposal, these being gathered, as it were, by the draughts-
man, and combined by his skill to represent that which he
has separately observed; whilst in the employment of pho-
tography we must rest content, if in one drawing, with what
we consider the best general view of the object, or some parti-
cular part. Here, however, we have this advantage, there
are no notable mistakes of relative magnitude, distance, or
separation of parts, upon the strict correctness of which
much in scientific observation depends; also, parts incapable
of being easily, if at all, rendered by the hand can by its
use be traced in more than mere outline; for it is possible,
in very many cases, though needing considerable patience,
to obtain some shadows and markings in objects which are
commonly, if not entirely, ignored by the artist, even with
the advantage of continued examination. Whatever may be
his legitimate omissions, all must admire his great skill in
beautiful delineation, and appreciate his work—work which
will, no doubt, increase with the employment of photography
for the purpose here advocated.

The general application of Mr. Wenham’s excellent
arrangement for giving sterecopicity to objects by means of
the binocular microscope will, probably, tend to greatly
alter the ordinary methods of rendering engravings or draw-
ings of microscopic subjects, especially when viewed as opaque
bodies, and we shall then, perhaps, be more ready to appre-
ciate their photographic representation.

If we divide the advantages of photomicrography into
their twofold character, we shall find the one derived from
the facility with which an object can be rendered in its chief
or general aspect, thus affording considerable assistance for
its recognition by others, retaining in its freshness much in-
tact, even in its minutiz, which often becomes greatly
altered when preserved in any of the usual media; whilst
the other tends to an opposite direction, and points at once
to the difficulty experienced when we attempt the photo-
graph of portions or entire surfaces of minute objects with
their details ; the opprobrium and perplexity here combine.

The correctness of the position assumed will, I trust,

Manpox, on ihe Delineation of Microscopic Objects. 11

be in part somewhat verified by the prints for your obser-
vation that accompany this paper. Untouched, unpressed,
prepared with little care, they are simply intended to show
the general and the partial application of photomicrography,
and, however feebly they may represent either, the infancy
of the art must be remembered, and the failings forgotten in
the effort to render them more acceptable.

The midge, sand-hopper, Entomostraca, section of the
pith of Hydrangea, of scalariform duct of Macca or Racca,
the seaweeds, Fragilaria and Zygnema, will sufficiently
illustrate its first application, and the prints of the several
diatoms will show its employment in its second character ;
the former being casually mounted without preparation,
the latter as commonly prepared by microscopists.

The apparatus may briefly be stated as a microscope
attached by means of telescope tubes to an expanding
camera, the whole fixed on a stout board, four feet six
inches long, supported by double triangle legs ; the illumina-
tion is either by a plane or concave mirror, or Abraham’s
achromatic prism, preference being given to the latter; the
condensing lens, a Coddington of small angular aperture.
Strong sunlight, if possible, is employed in all cases; a
slow collodion, iron developer, and the ordinary means used
to strengthen the negative, if, on examination by a lens, the
details be seen sufficiently perfect. Slght obliquity of the
light has generally been attempted, especially when the
surface of the object was not flat. The long eye-piece has
been occasionally used, and I think, gives what 1s commonly
called “ depth of focus,” but certainly at a little loss of defi-
nition. The main difficulty lies, not in obtaining a negative,
but one that, when nicely printed, gives something of the
character of the object when seen by a weak, reflected light ;
for the prints may be said to scarcely resemble objects seen
by transmitted light. In fact, we are hardly yet familiar with
the representation of microscopic objects by its means, and
therefore we rather at once unjustly revert to the illustra-
tion by engraving for a comparison. ‘There is a considerable
danger of producing a weak negative from over-exposure
where the field is not well filled by the object, and especially
if we seek to render the details when the object itself is
coloured. Success appears to me much to rest, ceteris
paribus, in the illumination of the object, im the plans for
which there is a wide field, from ordinary daylight to con-
centrated sunlight, from the mirror to the prism, from
the achromatic to the simple condenser, from direct to
oblique transmitted light, from concentrated to obliquely

12. Manpvox, on the Delineation of Microscopic Objects.

reflected light, to which may be added polarized and artificial
illumination and the employment of coloured media.

Finding how much the appearance of an object may be
altered by the direction of the illuminating pencils, as will be
recognised in some of the photographs of the Coscinodiscus,
&c., where the focus remained unaltered, the plan of deter-
mining the constant focus for a certain objective and object
has been seldom attended to, but in most cases trials
have been repeated until the appearance of the negative
seemed satisfactory, due regard being made for the common
** over-correction’’? where necessary. As the objects are
focussed in sunlight, it must be remembered there is a
chance, without some care, of softening the cementing medium
of the lenses of the object-glasses or of “ firmg” the object.
The advantage of the prism was noticed more than three years
since, and consists in the readiness with which the centring
of the object-glass and condenser can be recognised on its
surface, and a trifling alteration given to the course of the
rays entering them.

A few stereophotographs have been taken by the plan sug-
gested by Professor Wheatstone, also by the method pro-
posed by Mr. Smith; the best negative was fractured by a
fall, but its definition was barely satisfactory. That of the
animal (parasite?) found on the Brittle Star was by the
plan of masking the alternate half of the front lens of the
objective, as also of the Brittle Star, seen by transmitted light.
The print of the former appears rough, as the object was
mounted without other preparation than gentle washing, its
edges being covered by Diatomaceze. No particular scale
has been adopted as regards the magnitude of the image, it
being generally preferred to render the object about the size
usually chosen by microscopists; still many of the negatives
will bear considerable amplification, if required.

However inadequately this subject is now placed before
you, it possesses in itself a sufficient charm and interest to
claim your attention to the extended variety of a “ beau-
teous garniture’ that can be‘made to unfold its exquisite
tracery by the simple means advocated, enable us “ to imitate,
in some faint degree, and to admire, at least, where we cannot
imitate, the perfection” that adorns even Creation’s lowhest
forms.

18

Descriptions of New and Rare Diatroms. Series VIII.
By R. K. Grevintz, LL.D., F.R.S.E., &e.

(Communicated by F. C. 8. Roper, F.R.S.)

PLAGIOGRAMMA.

Plagiogramma Robertsianum, un. sp., Grev.—Valve lanceo-
late, obtuse; costz 2, centrical; striz very fine, about 30 in
"001". Length -0018” to 00380”. (Pl. I, figs. 1, 2.)

Hab. Port Stephen, New South Wales; Dr. Roberts.

Unquestionably distinct, with finer strie than in any
species previously described. Indeed, under a moderately
magnifying power, they are invisible. The frustules vary, to
some extent, in shape and size; the more minute examples
being somewhat elliptical, the larger ones narrower in pro-
portion to their length, and, generally, slightly constricted
below the apices, where a few very minute, raised points are
situated. These come out most distinctly in the front view,
but even then require careful adjustment.

CAMPYLODISCUS.

Campylodiscus ornatus, n. sp., Grev.— Valve uearly circular,
much bent, with two bands of radiating canaliculi, the mar-
ginal one narrow, the inner one much broader, the canaliculi
distant, with two rows of puncta between them ; central space
filled with faint, obscurely moniliform, radiating lines, and bor-
dered with a row of oblong granules. Diameter ‘0056’. (Fig. 3.)

Hab. On Tridacna, West Indies; F. Kitton, Esq.

An exquisitely beautiful diatom, having some relation to
Campylodiscus Horologium, in its circular form, distant cana-
liculi, and intercanalicular puncta; but differing from it in
the much-bent valve and in the double band of canaliculi,
besides various minor points. In the inner band, which is
about twice the breadth of the outer one, the long canaliculi
alternate with very short, imperfect ones, while in the outer band
they are all equal, and correspond in number with the perfect
and imperfect canaliculi, taken together, of the inner band.

Campylodiscus Wallichianus, n. sp., Grev.—Valve circular,
with a defined, broadly linear, central space ; canaliculi about
48, concentric, with extremities very slender, and armed with
minute spines. Diameter -0040". (Fig. 4.)

Hab. Dredged off St. Helena by Dr. Wallich, in from
fifteen to forty fathoms. Harvey Bay, Queensland, and Port
of France, New Caledonia, Dr. Roberts.

14 GREVILLE, on New Diatoms.

This most graceful species in some respects closely re-
sembles my Campylodiscus Normanianus. The form of the
central space is precisely similar, and the number of the
canaliculi is about the same. It is, however, a much more
delicate species. The canaliculi are far more slender ; indeed,
the sharpness and fineness of the lines are most striking at
the first glance. Dr. Wallich correctly remarks, in his notes
upon his St. Helena dredgings, which he has most kindly
placed in my hands, that the canaliculi, when seen in a favor-
able point of view, exhibit themselves as the angular edge of
elevated ridges. In an accurate sketch by him, now before
me, the canaliculi pass quite across the central space, closely
and very minutely beset with spinule; I have also seen a
similar specimen from New Caledonia, but it is an excep-
tional case, as they rarely traverse more than a third of the
distance, and often not so much. ‘The irregularity, however,
of the central markings in this genus are now too well known
to have any influence over specific diagnosis.

Campylodiscus Robertsianus, nu. sp., Grev.—Valve circular,
with an oval central space and prominent radiating coste
of equal length, the ridge of which is composed of minute,
oblong cellules, in pairs. Diameter ‘0050. (Fig. 5.)

Hab. Harvey Bay, Queensland; Dr. Roberts.

One of the most exquisite species of this charming genus.
The valve is bent and concave. The costz or canaliculi re-
semble sharply prominent ribs, along the crest of which are
disposed longitudinally numerous minute, oblong cellules, in
pairs, which in some lights might be hastily taken for short
lines. The nearest ally of this remarkable species is unques-
tionably C. diplostichus, also a native of the Australian seas,
where it was obtained from the stomachs of Ascidians by Dr.
Macdonald. I am indebted to the kindness of Dr. Roberts,
of Sydney, for a series of gatherings from the Southern
Pacific, which, having very recently arrived, are mostly un-
examined. I rejoice, however, in having an early opportunity
of dedicating so well-marked a species to Dr. Roberts, who,
from want of leisure, has been prevented from carrying out
his intention of investigating the Diatomacez of the Southern
Ocean.

Campylodiscus crebrecostatus, n. sp., Grev.—Valve nearly
circular ; canaliculi imperfectly radiating, very numerous, 6
in 001", forming a broad, marginal band, the outer portion
being bent back, so as to form a ridge along the middle of
the band; central space elliptical, closely filled with fine
transverse coste, interrupted by a narrow median line of
blank space. Longest diameter ‘0037". (Fig. 6.)

GREVILLE, on New Diatoms. 15

Hab. Port Jackson, New South Wales; Dr. Roberts.

In a mounted slide presented to me by Dr. Roberts I find
the beautiful Campylodiscus now described. In the dry pre-
paration the valve is of a dark-blue colour. The canaliculi
are fine and sharp, and the separation between the marginal
band and the central space is marked by a very narrow blank
line. The ridge which runs along the middle of the band of
canaliculi is so prominent that, at first sight, there appears to
be a solution in the continuity of the canaliculi, which, how-
ever, is not the case. The costz in the centre are not in the
slightest degree moniliform. It is a robust species for its size.

Navicula Lewisiana, un. sp., Grev.—Valve elongated, linear
oblong; strize very fine, parallel; median line terminating
considerably within the apices in a linear, elongated nodule,
the base of which rests in a socket. Length -0076" to -0122”.
(Fig. 7.)

Navicula, n. sp.? or sporangium of N. rhomboides? Lewis,
‘ Notes of Diatom. of the U.S. Seaboard,’ p. 6, pl. u, fig. 3.

Navicula, n. sp.? or sporangium of N. rhombaides? or N.
fossilis, Enr. Lewis, in ‘Mic. Journ.,’ n. ser., vol. ii, p. 161.

Hab. India (Sunderbunds); Dr. Wallich. Mud from
oysters, St. Mary’s River, U.S.; tidal mud from Savannah
River, U.S.; marsh at Fernandina, Florida; Dr. F. W. Lewis.
Mouth of the River Berbice; Dr. Abercrombie. Sierra Leone,
in gathering communicated by Frederick Kitton, Esq.

Of this diatom Dr. Lewis remarks that “‘it is nearly allied
to Nav. rhomboides and crassinervia, more particularly to var.
B of the first named, and, perhaps, notwithstanding its marine
habitat, ought to be regarded as a variety of one or other of
these species.” Dr. Lewis, however, at the same time re-
gisters it as a doubtful new species, and I am myself certainly
disposed to consider it as really distinct. With regard to
mere figure, the frustules of both Nav. rhomboides and crassi-
nervia are decidedly lanceolate, whereas those of the diatom
now before us have the sides nearly parallel at the middle,
and although gradually narrowing as they approach the apex,
are still, at that part, broadly rounded. And I am not aware
that we have any authority for assuming that the sporangial
condition would cause so radical a change in the frustular
form. In the absence of any such evidence, it appears
to be a safer proceeding to treat it asnew. But the differ-
ence in form is, indeed, the least argument in favour of such
a conclusion. ‘The terminal nodules alone constitute an
essential peculiarity. They are situated at a considerable
distance from the apices, are elongated, apparently cylindrical,
and are, besides, connected in so curious a manner with the

16 GREVILLE, on New Diatoms.

median line, as to render an observation on that organ expe-
dient before proceeding with my description. The term
central or median line is, at present, used with great latitude,
and seems to be held to include, not only the truly simple
central line, which extends longitudinally throughout the
valve, but also, in various instances, two additional lines
which run close to and parallel with it. In the present case
it becomes necessary to distinguish between them, and, until
a better name be suggested, I shall call these additional lines
the extra-median lines. In N. Lewisiana the true median
line, which is very slender, passes to the base, and, as it were,
supports the terminal nodule. The extra-median lines are
very much stronger, incrassated, and somewhat convex oppo-
site the central nodule, and on reaching the terminal nodules
suddenly expand, increase in bulk, and embrace the lower
part of the nodule exactly as a porte-crayon holds a pencil—
a comparison which I perceive, from Dr. Wallich’s notes, we
have both made independently of each other. The frustule
is diaphanous, even under considerable magnifying power,
and the striz strictly transverse and parallel, and so fine that
they cannot be exhibited by the engraver. According to Dr.
Lewis, they are 50 to 60 in ‘001”, while Dr. Wallich makes
them 85 in ‘001”. I confess that I have been unable to
estimate them satisfactorily. In the ‘ Microscopical Journal’
(vol. ii, p. 155, n. ser.) is a partial reprint of Dr. Lewis’s
original pamphlet, in which this species is referred, with a
question, to N. fossilis, Ehr., as well as to N. rhomboides, a
suggestion which does not occur in the original pamphlet
itself. That diatom, however, has, I believe, never been
described, and we only know it by the figures in ‘ Mikro-
geologie’ (pl. 10 I, fig. 6). Judging from these figures, it
is a minute species, with the striz visible and highly oblique,
« few radiating ones being very conspicuous opposite the
central nodule. It seems quite clear, therefore, that it has
no affinity with the very fine and curious diatom under con-
sideration.

I have attempted in vain to render the frustule of N.
Lewisiana stationary under examination, in order to obtain a
drawing of the front view. That, however, given by Dr.
Lewis, “ linear and slightly inflated,” appears to be correct.
In one or two immaterial points this species is subject to
irregularity. The terminal nodules vary in length, and the
forceps-like receptacle is sometimes closed upon the nodule,
while at others it slightly expands. The size of the frustule
is also uncertain. The specimens from Sierra Leone are the
largest I have seen, one in my possession being nearly a

GREVILLE, on New Diatoms. 17

third longer than the individual figured. Those kindly com-
municated by my friend, Dr. Abercrombie, of Cheltenham,
from Berbice, are generally small, and occur along with fine
varieties of N. permagna of Bailey, which I hope to illustrate
in a future paper. In the same gathering is also a long
Pleurosigma, apparently intermediate between P. Baliicum
and P. longinum. (Brightwell, ‘Mic. Journ.,’ vol. vii, p. 180,
plate ix, fig. 7.)

Navicula Johnsoniana, n. sp., Grev.—Valve somewhat con-
vex, elliptical-oblong, with slightly produced, obtuse extremi-
ties, and a transversely rounded, stauros-like blank space in
the centre ; strize very oblique, conspicuously lineato-punctate.
Length 0034” to 0040". (Fig. 8.)

Hab. New Zealand; C. Johnson, Esq. Harvey Bay,
Queensland, in a dredging communicated by Dr. Roberts.

Again I have the pleasure of recording one of the many
discoveries of my esteemed and venerable friend, Mr. John-
son, of Lancaster. It is only recently that he detected the
present diatom in his New Zealand slides, and kindly pre-
sented me with one containing several specimens. I had,
however, scarcely prepared my description before I recog-
nised the same thing in an Australian dredging transmitted
by Dr. Roberts, in which it appears to be exceedingly rare.
It is a somewhat remarkable species, being intermediate be-
tween the genera Navicula and Stauroneis, and I have been
mainly induced to place it in the former, on account of the
nodule being sufficiently definite apart from the rounded
blank space into which it expands on each side, and because
this blank space is unequal, being always larger on one side
than the other, asin many Pinnularie. The most striking
feature in the valve is the conspicuous, remote, oblong
puncta, and the very oblique striz into which they are dis-
posed. The median line is prominent, and there is a
straight parallel row of puncta on each side. A difference
exists between the New Zealand and the Australian examples.
In the former the frustules are oblong, the puncta larger,
and the striz 16 in ‘001."” In the latter the frustules are
elliptical-oblong, the puncta much smaller, and the striz 22
in ‘001’. ‘This is certainly a considerable discrepancy, but_
the recent study of these wonderful little vegetables has led
to the conclusion that far too much importance was formerly
attached to number in the markings, and that it would be
desirable to establish characters, if possible, upon other
grounds. I had prepared drawings of both forms; but not
having room in the plate for both, I have given the Austra-
lian, on account of the more highly developed central-nodular

VOL. XI. b

18 GREVILLE, on New Diatoms.

blank space. In the New Zealand frustules it is very con-
siderably smaller. .

Navicula notabilis, n. sp., Grev.—Valve oval, with extra-
median lines, and near them a parallel uninterrupted line of
minute granules on each side, and with a band of marginal
granules, composed of three or four longitudinal contiguous
series, the intermediate wide blank space obscurely striated.
Length :0020” to :0030”. (Fig. 9.)

Hab. Cook’s Reef, Torres Straits; G. Norman, Esq.

A singularly rich and delicate species, totally distinct from
all that I am acquainted with. The whole valve seems to be
made up of microscopic strings of beads. Even the extra-
median lines which run close to the true median hne are
very minutely punctate. Then comes another straight line
of fine granules on each side, scarcely more distant from the
extra-median lines than they are from each other, not con-
tracted in the slightest degree opposite the central nodule,
and converging just before reaching the ends. Between
these lines and the margin the space is divided into two
equal parts, the one being blank, or at least only obscurely
transversely striated, the other filled up with about four rows
of granules, following the curve of the margin. The two
inner of these rows are distinctly defined ; the others are more
or less confluent. The only variation I have observed is in
size and in the tendency of the smaller specimens to approach
a circular form.

Navicula luxuriosa, n. sp., Grev.—Valve elliptical, some-
what obtuse; strize composed of distinct oblong puncta, so
arranged as to form longitudinal lines contracted opposite

the nodule; the margin, as well as an intra-marginal line or
ridge, also; composed of close puncta. Length -0030” to
0038.” (Figs. 10, 11.)

Hab. Port Stephen, New South Wales, in a dredging com-
municated by Dr. Roberts.

It is utterly impossible for the pencil to convey any idea of
the exceeding beauty of this little object. Under a mode-
rately magnifying power the delicate striation is scarcely
perceived ; but the intra-marginal line at once strikes the

_ eye, as well as the indication of wavy longitudinal lines.
Under a higher power the surface of the valve is seen to be
undulated ; the intra-marginal line, especially, forming a pro-
minent ridge, leaving a sort of channel between it and the
margin. The median is accompanied by parallel extra-
median lines, straight at the sides and converging towards
the ends. Then follow three longitudinal, convex lines of
puncta, contracted opposite the nodule, at which point they

GREVILLE, 0n New Diatoms. 19

occupy a space of about half the distance from the nodule to
the margin. ‘The only species which appears by description
to approach this diatom is N. costata; but on consulting the
figure given by Kiitzing (‘Bacill.,’ plate in, fig. 56), it is
evident that there is no connection whatever between them.
The latter has no extra-median lines, and although the valve
is said to be “ longitudinaliter punctato-costata,” the punc-
tate character arises, not from puncta in the direction of the
transverse striation, but from circular puncta arranged at in-
tervals along either one or two longitudinal lines. The
remarkable intra-marginal line of puncta so conspicuous in
N. luxuriosa is wholly wanting.

Navicula? Cistella, n. sp., Grev.—Valve quadrangular,
about twice as long as broad, the angles rounded and some-
what dilated ; surface marked with delicately punctate, longi-
tudinal lines; transverse striz very fine, parallel. Length,
0015” to 0025”. (Figs. 12—14.)

Cocconeis ? quadrata; Roper, MS.

Hab. Dredged off Lyme Regis, in eight fathoms’ water by
the Rev. J. Guillemard, 1855; F. C. 8. Roper, Esq. Harvey
Bay, Queensland, in a dredging communicated by Dr. Ro-
berts, of Sydney; not unfrequent.

It is not a little imteresting that after I had described this .
ambiguous, minute diatom from the antipodes, I should be
informed by my most obliging friend, Mr. Roper, that it was
actually discovered some years ago on our own shores. The
very accurate drawings made by himself in 1855, and now
lying before me, leave no doubt to be entertained on this
point. But the real nature of the frustule seems to have been
doubtful from the first. Mr. Roper regarded it as possibly a
Cocconeis. The late Professor Smith, to whom specimens
were submitted, could make nothing of it, and would not
venture to refer it to any genus. In now publishing it as a
doubtful Navicula, my object is to attract such attention to-
wards it as may lead to its generic settlement. Looking at the
side view, it is certainly as much like a Cocconeis as a Navicula;
but the front view, which Mr. Roper had not seen, seems to
point more towards the latter. After all, that acute diatomist
may be correct in his conjecture (in Jitt.), that it may belong
to an unknown filamentous form. And, indeed, before I had
communicated with him, I had myself remarked in my MS.,
—$So little, indeed, does the frustule resemble a Navicula,
that in hastily passing the slide across the field of view it
might be taken to belong to one of the Melosiree.” It must
be understood, therefore, that its present position is simply

20 GREVILLE, 0n New Diatoms.

provisional. The valve is somewhat opaque, and varies con-
siderably in size and in relative length and breadth; the ends
are very slightly convex, rounded and inflated at the corners,
and the sides generally more or less convex opposite the cen-
tral nodule, very rarely straight. The longitudinal lines are
curved outwards opposite the nodule, in number about 21 in
‘001’, and most exquisitely punctate. The transverse striz
are fine, and require careful manipulation for their resolution.
The front view has straight sides and ends, the angles
rounded. The whole frustule is very solid and compact.

AMPHIPRORA.

Amphiprora oblonga, n. sp., Grev.—Large; front view ob-
long; wings not deeply constricted; greatest breadth at a
point about half way between the constriction and the ends;
curve of the lateral plates reaching the constriction. Length
0060” to -0085”. (Fig. 15.)

Hab. Harvey Bay, Queensland; Dr. Roberts.

Here is a large Amphiprora, which I cannot refer to any
described species, and yet it may be found eventually to be
merely an extreme aberrant form. Unfortunately, although
I have seen many examples, I have been unable to fix upon
any side view as indubitably identified with it. If I knew
any described species to which I could trace it, even as a
remote variety, I would gladly do so; but the very circum-
stance of this perplexity renders a figure desirable, and I give
it a provisional name, which may be cancelled whenever its
‘relations shall have been conclusively established. Speci-
mens occur much larger than the one figured, and, conse-
quently, greatly exceeding in size A. maxima of Gregory,
with which I was at first mduced to compare it. But that
diatom is very much more broadly truncate, the widest part
being near the ends and the constriction very deep, whereas,
in the present species, the widest part is halfway between the
end and the constriction, and the latter comparatively quite
shallow. The character of the marginal curve im the two
species appears to me to be essentially distinct. It would —
require a careful examination, however, of a long series of
examples of the different species in order to ascertain finally
how much dependence may be placed on the character to be
derived from the curve of the lobes. My own impression is
that a peculiarity exists in the curve of most of the species,

GREVILLE, on New Diatoms. 21

especially when taken in connection with the constriction,
which may be recognised throughout all the variations of
each species. This, however, is only an impression produced
on my own mind after, it must be confessed, a too limited
suite of observations. I find that Dr. Wallich obtained an
Amphiprora at St. Helena, which he also compared with
A. maxima; but he remarks in his notes, written at the
time (accompanied by a very careful sketch), that the curve
of the lobes is different. They appear, indeed, to differ
both from those of A. maxima and the subject of the present
notice.

TRANSACTIONS.

MICROSCOPICAL SOCIETY.
ANNUAL MEETING.

Report of Council.

According to custom the Council have to make their
annual report on the progress and state of the Society during
the past year.

The number of members reported at the last anniversary
was 317. During the past year 383i members have been
elected, making a total of 348. This, however, must be re-
duced by 11 resigned, making a final total of 337. It is with
much satisfaction the Council have to state that no deaths
have been reported during the past year.

The reports of the auditors, and of the library, the cabinet,
and instrument committees, will give the necessary informa-
tion as regards the finances, the additions to the library and
cabinet, and the state of the instruments at present belonging
to the Society.

The Journal has as usual been published regularly, and
circulated among the members.

Report of Committee for investigating the condition and
performance of the Society’s Microscopes.

We have to state that the object-glasses belonging to the
Society are all in serviceable condition, and the best of their
date. Their performance is equally creditable to their respec-
tive makers. But as such improvements have since been made
that they must be considered inferior to what most of the
members are now in the habit of employing—these improve-
ments consisting of increased aperture, more perfect flatness

VOL. XI. ¢

24. Report of Library Committee.

of field, and superior definition—we recommend that a set of
object-glasses, up to + inclusive, be purchased by the Society
for the instruments now in their possession by the respective
makers, and also achromatic condensers; those belonging
to the Society being very imperfect.

In addition to this there is great need for a parabolic
condenser, or some approved form of dark field illumination.

Mr. Ross has made a most munificent offer through Mr.
Reade, stating that, on returning his old instrument, now in
our possession, he will present the Society with d new one,
having the binocular arrangement and all accessories, with
a set of new objectives up to 1th. We have accepted this
offer on behalf of the Society.

Names of Committee,
C. BRooKeE.
EK. G. Loss.
Dr. MILueR.
Rev. J. B. READE.
F. H. Wenuam.

Report of the Library Committee to the Council of the Micro-
scopical Society.

The large additions made to the Library in 1861 have
rendered unnecessary any purchases during the past year,
but your Committee have to report an accession of thirteen
volumes and seventy-nine pamphlets, &c., presented to the
Library since our last anniversary—the number of works
lately acquired being more than the present book-case can
well accommodate. Your Committee, with the sanction of the
Council, are about to procure another, which they trust will
make the entire Library more available for the members.
They also wish again to draw the attention of the members
to the fact, that the three volumes of ‘Original Transactions,’
with many interesting plates, may still be had at the reduced
price of One Guinea.

Jno. Miiyar.
F. W. Rover.

25

Auditors’ Report.

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26 The President’s Address.

The President then delivered the following Address:

The Prestpent’s Appress for the year 1863.

By R. J. Farrants, Esq.

GENTLEMEN,—This is the twenty-third anniversary of the
Society. In the usual retrospect of our affairs for the past
year, the subject which, on this occasion, properly has prece-
dence is the proceedings (and their result) of the Committee
appointed at the last annual meeting to confer with the
Council on ‘the publication of our ‘'Transactions,’ and the
supply to the members of the ‘ Quarterly Journal of Micro-
scopical Science.” Your Committee, having inquired into
the matter referred to them, made a report to the Council,
which led to a conference between that Committee and a
Committee of the Council appointed for the purpose. The
whole subject was fully considered at the conference, and a
course of action recommended to the Council, in conformity
to which they resolved to rescind the agreement then in force.
This having been done, proposals were offered by the editors
of the ‘ Journal,’ to which the Council assented, and a new
arrangement was settled, to take effect from the commence-
ment of the present year. This arrangement the Council
believe to be a fair one, and trust it will be mutually advan-
tageous to the parties interested in it. While it continues in
force the members of the Society will be supplied with a
copy of the ‘Journal,’ together with the ‘Transactions,’ as
has been usual of late years, and our finances be considerably
benefited.

The reports which have been read show a satisfactory state
both as regards members and finances. It is gratifying to
find that the number of members suffers no diminution, not-
withstanding the establishment of numerous provincial socie-
ties with similar objects to our own. The existence, in full
activity, of the Microscopical Societies of Bradford, Hull,
Manchester, Newcastle-on-Tyne, and Southampton, is known
to us by their proceedings published in the ‘ Microscopical
Journal. I hope, however, the Metropolitan Society will
still continue a centre of union to many, if not to all engaged
in microscopical observations. That this hope is not ground-
less is proved by the steady increase of the number of mem-
bers shown by the annual reports of the last ten years.

ee ee”) |! a

The President's Address. 27

In 1853 the total number of members was 207

5» 1854 zs , 298
» 1856 53 fs 241
5. 1858 6 ie 267
» 1860 B ss 985
5» 1862 > 4 317

We now have 337 members contributing to our funds,
many of them contributing also to our ‘Transactions,’ and,
still more, regularly attending our meetings, and taking part
in the proceedings. This increase is not accidental, it is con-
tinuous and regular, and may be fairly referred to the opera-
tion of a cause connected with the constitution and character
of the Society.

Happily there are no neon notices; at least, I am not
aware of the death of any member during the year.

I am pleased at being able to speak favorably of the pro-
gress made in the improvement of our collection of objects,
so long an opprobrium to us.

In 1858 the cabinet contained only . 351 slides.

», 1860 the number had increased to 663 _,,
» 1862 the number was... . 882 ,,

And now, by presentations during the year, and some pur-
chases which, for the first time, the Council have been able to
make from the Society’s funds, the number is raised to 1100.

I am also now able to tell you that the Council have de-
termined to appropriate a portion of the balance at their
command to improving the microscopes of the Society. A
committee has been appointed to examine the instruments,
objectives, &c., to settle what is most urgently required, and
to advise the Council as to the best mode of procedure. The
deficiencies at present are confessedly very great, but we
hope soon to have sets of objectives of the best construction,
with the latest improvements, of the eminent makers of the
respective instruments, so that the glasses accompanying
them may again be, what they originally were, the best attain-
able, and examples of what the science and skill of our leading
opticians enable them to accomplish.

And now I have much pleasure in communicating to you a
most generous act of Mr. Ross. When spoken to on this
subject, he spontaneously, liberally offered to present to the
Society one of his best microscopes, with objectives and ap-
paratus complete, to replace the old but excellent instrument
made for the Society in 1841 by the late Mr. A. Ross, his
father. I am authorised to state that an instrument for this
purpose is now in hand, and, when completed, will be pre-
sented to the Society.

298 The President’s Address.

Messrs. Powell and Lealand, and Messrs. Smith, Beck, and
Beck will supply any objectives required of them, at prices
which will leave them no gainers by the transaction, and will
barely cover the cost of production. Messrs. Smith, Beck,
and Beck also write me as follows :—‘‘ Having been informed
that Mr. Ross has promised to present to the Society one of
his best microscopes, complete in every respect, we have con-
sidered whether we should, on our part, make any gratuitous
addition to the above offer (which refers to the hberal terms
on which they will supply any glasses ordered from them) ;
and we have determined not to do so at present. The exist-
ing arrangements of the Society admit of so few and of such
short opportunities for the use of the microscopes by the mem-
bers, that any increase in the present number of instruments
would confer no real benefit in any way. Whenever the So-
ciety may provide fit accommodation for the proper use of
good serviceable microscopes, as well as the means of frequent
access to them, the gratuitous contributions then from most,
if not from all of the makers, will, no doubt, be very con-
siderable. We are quite prepared to do our part ; but probably
a present of more than one stand, or some arrangement of
instruments adapted to the particular wants of the members
generally, would be of more service to the Society than merely
another complete microscope, many of the accessories to which
would probably never be used. That the future of the Society
may be so prosperous as to test this promise of ours to the
utmost, and at no distant period, is the sincere wish of yours
very truly, “ Smitu, Beck, anp BrEcK.”

Last year, on this occasion, I was fortunate in having to
announce the gift to the Society, by Mr. Peters, of his instru-
ment for microscopic writing. Soon after it was known that
this instrument was in the possession of the Society, intima-
tions were given to the Council that it would be an acceptable
addition to the collection of wonderful objects then being
prepared at South Kensington. The Council were led to
believe they would not be justified in withholding from public
inspection an instrument so ingeniously contrived, and by the
use of which such marvellous results had been attained.
Finally, the Council determined on sending it to the Inter-
national Exhibition. It was admitted to the building on
Monday, May 5th; on Wednesday, 7th, a notice of it ap-
peared in the ‘ Times,’ which at once directed public attention
to it; and it continued to excite much interest during the
whole of the time the Exhibition was open to the public.. The
simplicity and completeness of its arrangements were highly
commended by those, foreigners or countrymen, best able

:
E
.
;
;

The President’s Address. 29

to appreciate the difficulties to be overcome, and the admirable
manner in which the task was accomplished. I have much
satisfaction in adding that a medal was awarded to Mr, Peters,
as the award states, for ingenuity of construction. The in-
strument is now, by permission of the Council of King’s
College, in their museum.

The International Exhibition afforded an opportunity of
comparing the microscope stands and glasses of English and
foreign makers. In this competitive examination the English
opticians fully maintained the supremacy which, by general
repute, was assigned to them; indeed, anything nearer to
perfection than a first-class microscope, as supplied by the
principal London houses engaged in the manufacture of these
instruments, can scarcely be expected. The makers, however,
are not content to remain without striving still further to
improve both stand and glasses.

Messrs. Powel and Lealand now regularly supply a =,” ob-
jective, remarkable for clearness of definition, of large but not
extravagant aperture. The demand for these glasses, I am
informed, far exceeds the expectations of the makers: this I
believe is, in great measure, owing to the fact that the com-
bination allows sufficient space between it and the covering
glass to render its use comparatively easy and agreeable,
instead of merely possible.

Mr. Ross has greatly improved his microscope stand by
various additions and alterations. The rotatig stage is
now only one third of its former thickness, and being well
chamfered on its under side, there is a large increase of
working room for all the illuminating apparatus used beneath
the stage; the mechanical stage has been also reduced one
third of its former thickness. By the use of the same
diameter of tube as that adopted by Messrs. Smith, Beck,
and Beck, the whole of the sub-stage, with the apparatus
fitting into it, has been very much diminished in bulk. This
is also one more step towards uniformity of size in the
fittings of first-class microscopes by the various English
makers. Both the circular part of the main stage and also
that of the sub-stage are graduated ; the former enables the
instrument to be used as a goniometer, and the latter will be
found very useful in investigations with polarized light.

To the mirror has been added a double arm, for the more
efficient resolution of lined objects by simple oblique light.

The whole instrument has been reduced more than one
third in weight, and as this has been accomplished by a simpli-
fication of the construction, and reduction of unnecessary
thickness in the upper and moying parts, its steadiness has
thereby not been impaired, .

30 The Presideni’s Address.

Such is a description of the instrument intended for the
Society, which, by the kindness of Mr. Ross, I have had an
opportunity of inspecting and examining.

Mr. Ross has also constructed a new achromatic con-
denser, giving a large field with great intensity, intended for
use with both high and low powers : it adapts to the diaphragm
plate of the microscope, for the modification of the illumi-
nating pencil, and, in combination with the polarizing prism,
will be found a great advantage, as in polarization one half of
the light is thrown away.

The “ Kelner’s Orthoscopic Eyepieces,” though not new,
have this year met witha very greatly increased demand, due
to the recognition of the advantage which their very extended
field gives for purposes of exhibition.

An improved compressor consists of a base plate, across
which is fitted a dovetailed slide, carrying the lower glass.
At one end of the base plate is another short, vertical, dove-
tailed slide, moved by a milled head and screw; and again on
to this, parallel to the base plate, a frame, which holds the
upper glass. Both glasses can be removed for cleaning with
great facility ; the pressure appliec is completely under control,
and as the glasses remain parallel whatever the separation,
the object under manipulation is not slid about by unequal
pressure.

Messrs. Smith, Beck, and Beck remark, ‘‘ The most notice-
able feature of the past year has been, that microscopists are
returning to the use of object-glasses of moderate aperture,
but with the corrections made as perfect as possible.” This
they think ‘‘ may be attributable to the introduction of the
binocular principle, which opens up a new field of observa-
tion amongst general objects which mostly require illumina-
tion from above.’”’ Very few of the better class of instru-
ments, I am told, are now made with a single body, and
great numbers have been returned to the makers, to have
binocular adaptation.

From memoranda kindly furnished by the three firms
above-mentioned, I am able to state that the demand for
microscopes has continued to increase, ‘in spite of the bad
state of trade generally, and the entire stoppage of any
supply to America.” ‘The number of microscopes sold by
these three houses during the year is considerably above
600; “the sale of instruments of the very highest class
maintains its full proportion of increase ;” the number ex-
ceeds 100. One of these houses alone has supplied to the
public during the last year 360 object-glasses of the very
highest character.

The demand for mounted objects for the microscope is, I

The Presidenit’s Address. Ba!

learn, proportionate to the demand for instruments; so great
indeed is it, that it is with difficulty the supply keeps pace
with it.

We have had the usual number of ordinary meetings, with
the usual annual soirée, the full attendance at which may be
accepted as additional evidence of the interest taken by a
large portion of the public in microscopical pursuits.

Our members have not failed to furnish material for con-
sideration and discussion at the ordinary meetings. On one
evening only the Council were not provided with a written
communication to submit to the meeting, and on that occa-
sion the unusual and unexpected deficiency was amply com-
pensated by the valuable observations and interesting discus-
sion elicited on subjects extemporally introduced by the Rev.
J. B. Reade and Mr. H. Deane, which I shall presently have
to notice.

We have had several communications on methods of pre-
paring objects for examination with the microscope :—

1. The first of these was “ On the Preservation and Mount-
ing of Microscopic Objects in Minute Tubes.” By Dr. Guy.
(Read March 12th; published in ‘ Trans. Mic. Soe.’ vol. x,
N.S:; -p. 77.)

The mode of preparing the tube, introducing the object,
and securing it, by sealing both ends of the tube, are
fully and clearly explained, and the classes of objects to
which the method is especially adapted are indicated. Such
are chemical sublimates, as of arsenious acid, antimony ;
some volatile chemical substances, as camphor, iodine, sul-
phur, &c.; small seeds, pollen, and starch, and’small “ cylin-
drical objects, as the antenne of insects, and the stamens
and pistils of most plants.” Minute insects, also, may be
well preserved in this way. The advantages of the plan,
when appropriate, are, the objects are preserved from pres-
sure or distortion, and the necessity of using any preservative
medium is superseded, as the exclusion of air and moisture,
by sealing the tubes at both ends, answers every purpose of
preservation. Specimens of objects thus mounted were ex-
hibited. One particularly remarkable was a stamen of the
rhododendron, which had been enclosed in the tube more
than nine months, and was then as fresh and clear as when
first introduced.

2. “On a Revolving Disc-holder for Opaque Objects.”
By Mr. Richard Beck. (Read June 11th; published in
‘Trans. Mic. Soc.,’ vol. x, N.S., p. 101).

The author gave a short description of the apparatus which
is designed to facilitate the examination of objects under

82 The President’s Address.

Lieberkuhn illumination, and the instrument was exhibited.
It affords ready means of bringing into view any part of the
object under examination: it has many advantages over the
usual forceps attached to the stage, for which it is a con-
venient substitute. The author states that, by the use of
this little instrument, he has “ ascertamed many facts which
he never could satisfactorily determine before.”

A. 8. A paper “On Cleaning and Preparing Diatoms,” by
J. A. Tulk,”” communicated by Dr. Millar, was read
October 8th., published ‘Trans. Mic. Soc.,’ vol. xi, N.S.,

JA,

2 The author gives directions for collecting the diatoms, so
that from the first the gathering may be as free as possible
from foreign admixture. He then explains how all inpurities
unavoidably present may be removed. Finally, he gives full
details of the manner of mounting the prepared specimens
either in Canada balsam, or in.the dry way. Many a micro-
scopist, without doubt, will gratefully acknowledge his obli-
gations to the author for these practical hints.

At our last meeting, when there was no paper, the Rev.
J. B. Reade communicated a method of separating Desmidiz,
which he had practised with great success. It consists in
taking advantage of the endowments of the living organisms,
whence it results that they become firmly attached to ap-
propriate surfaces, while any impurities that may be mixed
with them may be readily diffused through the water which
contains them.

Putting the gathering into a wide shallow vessel, as a
common soup plate, and covering it completely with water,
the whole is set aside for ten or twelve hours, by which time
the living organisms will have become fixed to the surface of
the plate; then, by slightly tilting the plate, and gently
agitating the water, the foreign substances will be diffused
through the liquid, and by pouring off the water, will be re-
moved with it; this may be repeated, if necessary, without
detaching the Desmids. Finally, having added a little clean
water, the Desmids may he gently separated and easily trans-
ferred to the receiving bottle perfectly clean and free from
all foreign matter.

Two papers were read ‘‘ On the Application of Photography
to the representation of Microscopie Objects as seen through
the Microscope.”

4. The first of these, On Micro-Stereography,” by Mr.
J. Smith, was read May 14th.

The plan adopted by the author to obtain match pictures
was to cover in succession the right and left half of the

The President’s Address. 33

objective, and to take a picture in each state. By this, method
he succeeded in getting pairs, which, combined, gave good
stereoscopic effects.

5. The second of these papers, “On the Photographic
Delineation of Microscopic Objects,” by R. L. Maddox, M.D.,
was communicated by Mr. Shadbolt. (Read November 12th ;
published ‘ Trans. Mic. Soc.,’ vol xi, N.8., p. 9.)

The author, admitting the difficulties attending the attempt
to produce well-defined and useful representations of objects
as seen through the microscope, and that pictures so obtained
can at best only give a general view of an object or of some
particular part, still regards the process as advantageous,
because in the pictures there can be “no notable mistakes of
relative magnitude, distance, or separation of parts, upon the
strict correctness of which much in scientific observation
depends; also parts incapable of being easily, if at all, ren-
dered by the hand can by its use be traced in more than mere
outline.” Strong sunlight, if possible, is used on all oc-
casions, though this is attended with the risk of softening
the cementing medium of the lenses of the object-glass. In
the discussion which followed the reading of the paper, the
Rev. J. B. Reade remarked, that the injury of the object-
glass might be avoided by the dispersion of the heat rays,
which could be effected by an arrangement he had long ago
used for that purpose; and Mr Highley suggested that the
heat rays could be intercepted if the illuminating pencil
were made to pass through a solution of alum.

6. A paper “On the Scales of some Species of thysa-
noura,” by Mr. Richard Beck, was read March 12; pub. in
‘Trans. Mic. Soc.,’ vol x, N.S., p. 83.

The author considers the scales of some of these insects
as test objects of great value, as affording the means
of determining the exact condition of a combination as to
the centring of its component lenses, and its corrections for
aberration and dispersion. The proper scales (known gene-
rally as Podura scales) are really obtained from a species of
Lepidocyrtus ; but the precise species is not yet certainly de-
termined. The author mentions the difficulty of finding the
insects, gives the results of his experience in searching for
them, adds instructions for capturing them when their
haunts are ascertained, and for transferring their scales to
the glass which thenceforth is to bear them. He tells us
there is danger of the insects hopping away and effecting their
escape before the transfer is completed, but assures us this
may be secured by a moderate dose of chloroform, which he
administers by dropping a little near them upon the paper

34. The President’s Address.

which has been used to receive them. The vexed question of
the structure of the scales is fully considered, particularly
whether the wedge-shaped markings possess individuality as
little scales, or are mere inequalities on the surface of the
membrane. The opinion of the author is that the markings
are more or less elevations or corrugations on the surface,
which answer the simple purpose of giving strength to a very
delicate membrane. Seven shies illustrating the paper were
presented as an addition to the Society’s collection of
objects.

7. “A Description of a New Parasite in the Heart of the
Edible Turtle,” by Dr. A. Leared, was read May 14, and is
pub. in ‘ Quar. Jour. Mic. Soc., vol. ii, N. S., p. 168.

This parasite, an undescribed species of Distoma, which the
author provisionally names constrictum, was found in great
numbers in the cavities of the heart of the turtle. The
development and migrations of the Entozoa is a subject of
great interest which has not received in this country the
attention it deserves.

The parasites met with by Dr. Leared were undoubtedly
immature animals; their larval condition and the situation
where they were found, in the full current of the blood,
suggest the idea that they were in the act of migrating, for
we can hardly suppose the cavities of the heart to have been
their permanent abode. If this conjecture be correct, it is
the only instance (as far as I am aware) where the animals
have been caught on their journey to the place where they
were ultimately to be developed.

8. A paper “On the Generation of Acari ina Nitrate of
Silver Bath,” by R. L. Maddox, M.D., communicated by
Mr, Shadbolt, was read May 14, pub. in ‘ Trans. Mie. Soc.,’
Vol tac DLS:, op.96.

The facts narrated I think scarcely support the title. All
that is clearly made out is, that the msects were found in
considerable numbers on the surface of the solution.

9. A second paper on the same subject, also communicated
by Mr. Shadbolt, was read Nov. 11. In this it is stated
that the insects were covered with a secretion which appeared
to protect them from the action of the nitrate of silver. How
the insects obtained admission under the circumstances
mentioned is not easy to understand; but remembering how
extensively these little animals are diffused, and the difficulty
of finding any situation entirely free from them, we can
scarcely infer, in the absence of all evidence as to their origin,
that they were propagated and developed in the solution on
the surface of which they were found.

The President’s Address. 35

10. “ Descriptions of New and Rare Diatoms’” (series vi).
By R. K. Greville, LL.D. (Communicated by Mr. Roper,
was read May 14th; published in ‘Trans. Mic. Soc.,’ vol. x,
WN..S., p..89).

11. “ Description of New and rare Diatoms” (series viii).
By Dr. Greville. (Also communicated by Mr. Roper, was
read Noy. 10th; published in ‘ Trans. Mic. Soc.,’ vol. xi,
N.S., p. 13.)

Note.—No. vii of this series was not communicated to this
Society. It is published in ‘ Quart. Journ. Mic. Soc., vol.
un, N.S., p. 231.

12. “On some New Species of Diatomacee.”’ By J.
Staunton, Esq. (Read June llth.) Twelve slides illus-
trating the paper were at the same time presented, and are
added to the collection of objects.

13. “On Fungus Destruction of Lozenges in a dry At-
mosphere.” By F. M. Rimmington, was communicated by
Mr. Tuffen West. (Read June 11th; published in ‘Trans.
Mic. Soc.,’ vol. x, N.S., p. 103.)

The point of interest, as remarked by Mr. West, is the
great amount of deliquescence caused by the fungus in a
perfectly dry atmosphere.

B. Vibrio Tritict.—Some interesting facts in connection
with these animals were mentioned to the Society at the last
meeting, by Mr. H. Deane. The long time they maintain
their vitality is well known; how long is not determined.
Mr. Deane has had some diseased wheat for ten years, in
which, when last examined, a year ago, the animals were
found alive and in full activity. He also mentioned a
remarkable fact known to him, viz., that on a particular piece
of land, whenever wheat is grown, it is always infested with
vibrio, no matter what the length of time since the previous
wheat crop, or what crops have been grown in the mean-
time.

Having completed this retrospect of the year, and given a
short account of the thirteen papers which have been read at
our ordinary meetings, it only remains for me to congra-
tulate you on the present state of the Society, and its pro-
spects for the future, and to thank you for the kind support
and assistance uniformly afforded me during the two years I
have occupied the chair I am shortly to resign to the gentle-
man appointed to succeed me,—one whose thorough ac-
quaintance with the mechanical and optical properties of the
microscope, whose familiarity with all the details of microsco-
pical investigation, and whose scientific and general attain-
ments, eminently fit him for the office of President.

36

A Monoerara of the genus Auuiscus. By R. K. Grevitiz,
LL.D., F.R.S.E., &e.

(Communicated by F. C. S. Rorrr, F.L.S., &c., and read March 11th.)

Ir is impossible to be engaged in the study of natural
science at the present time, and especially im the more prac-
tical departments, without being perpetually involved in the
questio vexata, What is a species? Evenin working out the
following monograph of the small genus Auliscus, I have
found myself beset with difficulties; and without doubt
some of my conclusions will be challenged by labourers in
the same field, who hold (with perfect right) what they
assume to be the most orthodox views. But who is to
decide between conflicting opinions? And so the question
again recurs, What is a species? It is singular that what
appears at first sight to be so clear in theory, should be
found practically in the direst confusion. Naturalists of the
greatest reputation are not agreed on even the first step.
Thus, Professor J. G. Agardh, in his ‘Theoria Systematis
Plantarum,’ after quoting various eminent naturalists, re-
marks— “Ex his, que breviter attulimus, satis, credo,
apparet, tres nostre etatis vel excellentissimos nature inves-
tigatores in illa, quam proposuimus, queestione dijudicanda,
inter se dissentire. Schleidenius sola individua, Lindley
species, Friesius species et genera a natura vult constituta,
majores omnes ordines ab arte inventos esse.”

“ A species,’ says Professor Walker-Arnott, “im the Lin-
nean sense of the word .... is formed by our Maker, as
essentially distinct from all other species, as man is from the
brute creation: ‘Species tot numeramus, quot diverse
forme in principio sunt create,’ Linn. It ought neither
for convenience to be united with others, nor be split into
several on account of newly detected diversities of form ;
but the difficulty is to ascertain what is such a primitive
or natural species, and how to characterise it so as to include
those numerous varieties and individuals now existing on the
surface of the globe which have sprung from it, but of which
none may bear greater resemblance to the original or typical
form than they now do to each other.”* This is sufficiently
disheartening ; and Bentham, than whom a higher authority
can scarcely be quoted, is not more encouraging. ‘ The
species,” he remarks, “ in the ordinary traditional accepta-

* ¢ British Flora,’ ‘ Introduction,”

j
:

GREVILLE, on the genus Auliscus. 37

tion of the word, designates the whole of the individuals
supposed to be descended from one original plant or pair of
plants. But this definition is practically useless; for we
have no means of ascertaining the hereditary history of
individual plants. .. . Believing, however, as I do, that there
exist in nature a certain number of “groups of individuals
the limits to whose powers of variation are, under present
circumstances, fixed and permanent, I have been in the
habit of practically defining the species as the whole of the
individual plants which resemble each other sufficiently to
make us conclude that they are all, or MAY HAVE BEEN all,
descended from a common parent.”* Here, it will be per-
ceived, everything ultimately depends upon the judgment of
the observer.

Agassiz speaks with the utmost confidence, and apparently
sees no difficulties at all. “It was a great step,” he says,
“in the progress of science, when it was ascertained that
species have fixed characters, and that they do not change in
the course of time..... Geology only shows that at dif.
ferent periods there have existed different species; but no
transition from those of a preceding into those of the follow-
ing epoch has ever been noticed anywhere... . nothing fur-
nishes the slightest argument in favour of their mutability.
On the contrary, every modern investigation has gone only
to confirm the results first obtained by Cuvier, and his views,
that species are fixed.’’+

In amusing contrast to Agassiz, we have the astounding
deductions of Mr. Darwin, who writes—‘“ I can entertain no
doubt, after the most deliberate study and dispassionate judg-
ment of which I am capable, that the view which most natu-
ralists entertain, and which I formerly entertained, namely,
that each species has been independently created, is erroneous.
I am fully convinced that species are not immutable.... I
believe that all animals have descended from at most only four
or five progenitors, and plants from an equal or lesser number.
. «. Probably ail the organic beings which have ever lived on
the earth have descended from some one primordial form, into
which life was at first breathed.” Alas! for the fixity of species !
The shades of Linnzus and Cuvier are not to rest in peace.

Dr. Joseph Hooker, in his most valuable and interesting
“ Introductory Essay ”’ to the ‘ Flora of New Zealand,’ adheres
to what may be called the popular view of the question, in
assuming that “ all the individuals of a species (as I attempt
to confine the term) have proceeded from one parent (or

* ‘Nat. Hist. Review,’ vol. i, p. 133.
+ ‘Essay on Classification,’ pp. 75—78.

38 GReEvILLE, on the genus Auliscus.

pair), and that they retain their distinctive (specific) cha-
racters.” And he also assumes that “species vary more
than is generally admitted to be the case.””*

In adopting these assumptions, for they express my own
convictions, we still have to acquire a practical insight into
the laws which govern the limitation of species and the
range of variation. So involved in obscurity are those laws,
that one of the most cautious and philosophical naturalists in
America does not hesitate to say—“It is by no means
difficult to believe that varieties are incipient or possible
species, when we see what trouble naturalists, especially
botanists, have to distinguish between them,—one regarding
as a true species what another regards as a variety, when the
progress of knowledge continually increases rather than
diminishes the number of doubtful instances; and when
there is less agreement than ever among naturalists as to
what is the basis in nature upon which our idea of species
reposes, or how the word is to be defined.” + This is strikingly
illustrated in the most recent works devoted to the Flora of our
own country. Scarcely two of our leading botanists take the
same view of what constitutes (in practice) a rigid diagnosis.
In five of the British genera of flowering plants (admittedly
difficult and testing examples), the following differences
occur in two Floras. According to Professor Babington
there are 24 species of Ranunculus, 45 of Rubus, 17 of Rosa,
32 of Hieracium, and 70 of Carex. According to Mr.
Bentham there are 13 species of Ranunculus, 5 of Rubus,
5 of Rosa, 7 of Hieracium, and 47 of Carex; being a dif-
ference in only five genera of one hundred and eleven species.
This extraordinary contrast might possibly be attributed to
certain extreme views entertained by the authors of these
Floras. This may be the case, and parties who differ from
them both will no doubt say so; but who is to decide? The
matter is infinitely complicated by other and equally dis-
tinguished botanists holding not exactly an immediate posi-
tion, but oscillating in a most irregular manner between the
extremes. Sir W. J. Hooker and Professor Walker-Arnott
describe in their British Flora 4 species of Ranunculus fewer
than Babington, and 7 more than Bentham; of Rubus, 34
species fewer than Babington, and 6 more than Bentham; of
Rosa, 2 more than Babington, and 14 more than Bentham ; of
Hieracium, the same number as Babington (32—one extreme
being here reached), and 25 more than Bentham; of Carex,

* ‘Flora of New Zealand,’ “ Introductory Essay,” p. viii.

+ Professor Asa Gray, ‘Nat. Selection not inconsistent with Nat.
Theology,’ p. 5.

a

}
|

GREVILLE, on the genus Auliscus. 39

3 fewer than Babington, and 20 more than Bentham! Well
may the humble student fall back upon the old proverb,
“Who shall decide when doctors disagree’? On the one
side is a war-cry against too many species; on the other an
alleged tendency in the opposite direction. ‘ The time may
ere long arrive,” says Professor Walker-Arnott, ‘‘ when what
are now called genera or subgenera will alone be considered
species, and another Linnzus be requisite to reduce the
chaos to order.’’*

If such difficulties beset the botanist among the higher
orders of vegetation, we need not be surprised to find them
multiplied when we descend to.the more obscure and simple
forms of organized life. Dr. Carpenter has been unable to
discover anything approaching to fixity of species among the
Foraminifera. ‘The impracticability,” he remarks, “ of ap-
plying the ordinary method of definition to the genera of
Foraminifera becomes an absolute impossibility in regard to
species. For whether or not there really exist in this group
generic assemblages capable of being strictly limited by well-
marked boundaries, it may be affirmed with certainty that,
among the forms of which such assemblages are composed,
it is the exception, not the rule, to find one which is so
isolated from the rest by any constant and definite peculiarity,
as to have the least claim to rank as a natural species.” +

The Diatomacee, while not, perhaps, in quite so hopeless a
predicament, are in a very unsatisfactory state, notwithstand-
ing the labours of Ehrenberg, Kiitzing, Smith, Ralfs, and
others. With regard especially to the determination of
species and limits of variation the greatest uncertainty pre-
vails. A few years ago I remarked in another place—“ In
the present state of our knowledge it would appear that
scarcely any one character taken by itself is to be relied on,
and that even a combination of characters which may be
sufficient for the determination of species in one genus may
be unsatisfactory in another; and where groups or sections
happen to be what is called exceedingly natural, the difficulty
is greatly increased. Indeed, it often becomes a question
whether it is best to leave a doubtful variety to embarrass
the diagnosis, or to separate it under a provisional character.
No law can be laid down on this subject which shall prac-
tically be a clear and unerring guide. Among the Diatomacee,
the process of self-division, by means of which any deviation
from the normal condition of a species becomes stereotyped
and perpetuated with inconceivable rapidity, complicates the

* © Brit. Flora,’ “ Introduction.”

+ ‘Introduction to the Study of the Puraminifera,’ p. 56.
VOL, XI.

40 GREVILLE, on the genus Auliscus.

idea of a species to an extent unknown among the higher
orders of vegetables. For example, let a represent a species
of diatom. By some unknown cause one of its progeny, B,
becomes so changed as to constitute a well-marked variety.
Another of its progeny, c, undergoes a different but equally
decided change; and possibly the same thing may occur in
others. Now these varieties or aberrations from the typical
condition may be propagated, according to the late Professor
Smith’s calculation, at the rate of a thousand millions in a
single month. Then, as there is no reason why B and c
should not also have an indefinite number of nonconformist
children, all removed in one character or another a second
stage from the type, and producing duplicates by thousands
of millions, it is manifestly impossible to say where the con-
fusion is to end. But thisis notall. By the process of con-
jugation, what Mr. Thwaites calls ‘sporangial frustules,’
are produced, which are very much larger than the ordinary
size of the parents; and these, it is presumed, multiply equally
freely by self-division, and are equally hable, from accidental
causes, to have their deviation from the normal type perpe-
tuated. Such is the theory; and to arrive at anything like
fixed specific distinctions would seem to be almost a hopeless
endeavour. Nevertheless, by correcting processes unknown
to us, we cannot doubt that the typical characters of real
species are preserved.’’*

There is, besides, another element to be taken into account
connected with the process of conjugation above referred
to. Professor Smith remarks, “Cases have fallen under my
notice which seem to indicate that the further process of re-
production consists in the resolution of the contents of the
sporangium into a ‘ brood’ of diatoms having the same form
and specific characters as the original frustules which origi-
nated the sporangia.”’+ And he adds, in speaking of Cocco-
nema Cistula, “forms of every size intermediate between the
minutest frustule in the cyst and the ordinary frustules en-
gaged in the conjugating process were easily to be detected ;
and the conclusion was inevitable, that the cysts and their
contents were sporangia of the species with which they were
associated, and indicated the several stages of the reproductive
process.” Every diatomist must be familiar with similar
“broods ” of Cocconeides, looking just like broods of young
spiders. Now, the chief point of interest here is, what be-
comes of these broods? How do they increase in size?
Minute as the individuals are compared with the parents,

* «Edin New Phil. Jour.,’ vol. x, new series, p, 26.
+ ‘Brit. Diat.,’ vol. ii, p. 15.

GREVILLE, on the genus Auliscus. 4)

they are enveloped in a siliceous case. It cannot be by self-
division, as they would then be stationary. We are accustomed
to hear of the unsatisfactory state of certain frustules, being
attributed to their probably young condition. This may
be very convenient, but what is meant by it? Is a frustule
which has arrived (by some process or other) at its ordinary
size supposed to become more perfect by successive self-
division? It is evident that all this uncertainty adds greatly
to the labour of determining both species and the range of
variation.

In addition to all that has been said, the following excellent
observations of Professor Asa Gray must not be omitted:
“Everywhere,” he says, “‘ we may perceive that Nature secures
her ends and makes her distinctions on the whole manifest
and real, but everywhere without abrupt breaks. We need
not wonder, therefore, that gradations between species and
varieties should occur. . . . . From the nature of the
case, the classifications of the naturalist abruptly define
where Nature more or less blends. Our systems are nothing,
if not definite. They are intended to express differences,
and perhaps some of the coarser gradations. But this evinces
not their perfection, but their imperfection. Even the best
of them are to the system of Nature what consecutive patches
of the seven colours are to the rainbow.”* Among the
Diatomacee particularly, the maxim Natura non agit sal-
tatim applies with far greater force than among more highly
organized vegetables, rendering the lines of specific separation
very hard to find. So that in the very imperfect state of our
knowledge of these microscopic forms, it would be rash in
the extreme to dogmatise on the subject of species. What
is therefore most required is, a more extensive acquaintance
with the forms of diatomic life. Materials must be accumu-
lated before they can be reduced to order; and, as in all
similar cases, this can only be accomplished at the risk of
encumbering both genera and species more or less with a pro-
visional nomenclature. This has been the inevitable history of
every department of progressive science. Some parties,in their
wholesome horror of doubtful species, seem disposed to assume
that every discovery must be an old friend with a new face ;
and to maintain that all new species or supposed new species,
should be kept in retentis until every doubtful point in their
history and structure is cleared up. This would be to lock
up indefinitely a large number of interesting discoveries, and
to retard the progress of science in this particular department,
which can scarcely be compared with any other. It appears

* “Nat. Selection not inconsistent with Nat. Theology,’ p. 25.

42 GREVILLE, on the genus Auliscus.

to me that the time has not yet arrived when the introduction
of a doubtful species is to be regarded as so serious an intru-
sion. Besides, as I have already observed, it requires almost
as much caution to call a new form a questionable variety of
some known species, as to put it down at once a questionable
species. A series of doubtful varieties is exceedingly incon-
venient by weakening the original definition, especially when
we are only groping our way to what really constitutes specific
difference, and consequently a reliable diagnosis in this very
peculiar tribe.

Avuiscus, Ehr., Bail.

Frustules cylindrical or discoid; valve circular or oval, un-
dulated, with two (three, or four?) opposite circular, flattened,
submarginal processes, and four groups of lines radiating
from the centre; two of them converging towards the pro-
cesses, and two expanding towards the margin.

It is remarkable how much uncertainty appears to exist
with reference to the species of this small genus. This has
been owing partly to our ignorance in not knowing what part
of the structure furnished the most trustworthy characters,
and partly to the very small number of examples in collec-
tions. So little are the American species of my late lamented
correspondent, Professor Bailey, understood, viz., A. radiatus,
pruinosus, punctatus, and celatus, that Dr. Lewis remarks—
““They vary much in their markings, and occasionally ap-
proach so near each other in general character as to make it
very doubtful whether they ought to be kept apart.” ‘This
want of confidence in Professor Bailey’s species has induced
me to reproduce figures of the whole of them, as those which
accompany his original descriptions are extremely vague and
deficient in detail. It is true, however, that some of the Aulisci
do sometimes resemble each other so closely as to render the
task of discrimination exceedingly difficult. Until recently
the number of processes was regarded generically as two.
A. pruinosus, indeed, not unfrequently occurs with three.
Within the last two months, however, not only has another
species been discovered with three, but two species with four
processes; one of these will be found described as 4. John-
sonianus ; the other is not in a sufficiently perfect state
for description, although several valves of it have been seen,
all of them showing tolerably distinctly the alternate pro-
cesses of the subjacent valve; so that the disc is ornamented

of ees isk

GREVILLE, on the genus Auliscus. 43

with a circle of eight visible processes. It seems doubtful,
therefore, whether some species may not actually possess three
or four processes.

* Radiating lines costate (not punctate). Valve mostly
oval, or slightly oval; in the first three species occa-
sionally circular. “

Auliscus sculptus (Smith), Ralfs; valve circular or inclining
to oval, with indistinct umbilicus, and two lateral rounded
depressions ; costz in four sets, radiating from the centre,
two of them converging to the processes, and, along with the
rounded depressions, forming a well-defined 4-lobed figure or
quatrefoil; the costz within the depressions strong, few, un-
equal, quite. smooth (no apiculi), and appearing to terminate
abruptly within the edge of the cavity; marginal coste strong,
distant ; diameter ‘0020” to -0035”. (Pls. II & IIL, figs. 1—3.)

Auliscus sculptus, Ralfs in Pritch. Inf., 1861, p. 845, pl. vi,
fig. 3.

Enpodiscus sculptus, ‘Sm. Brit. Diat., vol. i, p. 25, pl. iv,
fig. 42; ‘Mic. Dict.,’ pl. xu, fig. 31.

Hab. Poole Bay, 1851; Professor Smith; Barking Creek,
on the Thames, F. C. 8. Roper, Esq.; Ipswich, F. Kitton,
Esq.; Penzance, J. Ralfs, Esq.; Westport Bay, Ireland, G. M.
Browne, Esq.

I have been quite unable to discover any strongly definitive
character between this, the earliest known species, and the
one immediately following; and those naturalists who are
influenced by what has been called a “righteous horror’ of
uncertain species would, no doubt, be in favour of their union ;
but im that case we should have fig. 1 at one end of the series,
and fig. 6 at the other, which would surely be an extreme
view. ‘The single desire to study these two species, and the
singular deficiency of materials, has alone caused a twelve-
month’s delay in the preparation of this small monograph.
I have at length, however, in addition to an ample series of
A. celatus, had an opportunity, through the kindness of Mr.
T. G. Rylands, and other friends, of examining a considerable
number of the present species; and the result is, on the
whole, satisfactory to my own mind, although it may not be
equally so to others who have not had the same opportunity
of tracing minute differences. It will be at once perceived
that there is no difficulty in referring specimens, as they ordi-
narily occur, to their respective places. It is only where
exceptional frustules approach each other that any embar-
rasment is experienced. ‘The principal features in A, sculp-

44. GREVILLE, on the genus Auliscus.

tus, as compared with A. celatus, are as follow :—1. The form
is usually circular, while in A. celatus it generally tends to
oval. 2. The lateral depressions are deeper. 3. The coste
within the depressions are strong, unequal, not radiating
symmetrically, like a fan, but generally pomting in different
directions, and apparently terminating abruptly before reach-
ing the outer curved edge of the depressions. 4. A much
greater tendency in the costz of the depressions to anasto-
mose. 5. The entire absence of apiculi. This character,
although a minute one, seems to be of importance. I have
examined very many examples of 4. celatus, and never found
apiculi wanting, excepting in one instance, which I have
given at fig. 7. Occasionally there are, in A. sculptus, a few
narrow, transverse cellules, formed by anastomosis, just be-
neath the outer curve of the depressions; and sometimes a
transverse costa is visible, followmg the line of the ridge
below its summit, from which branch off at right angles the
strong coste which proceed to the margin. This transverse
costa is probably always present, concealed within the margin
of the cavity, as the marginal coste are certainly not (all of
them, at least) continuations of those within the depressions.
Mr. Ralfs, under A. ovalis, in Pritchard, remarks—“ The
truncated processes do not, in general, correspond exactly
with the longer diameter of the valve, but are placed a little
on one side in opposite directions.” This I have ascertained
to be the case in all those species which deviate from the
circle. If a straight line be drawn through the middle of
the valve in its longest diameter, the two processes will in-
variably be seen more or less on the opposite sides of the
line; and such is the rule with our present species itself,
whenever it assumes a slightly oval form.

Auliscus celatus, Bail.—Valve slightly imclining to oval
(must rarely circular), with indistinct umbilicus ; radiating
costee next the margin, strong, distant ; central area 4-lobed,
2 of the lobes composed of finer costz converging to the pro-
cesses ; the intermediate lobes depressed, containing radiating,
often more or less anastomosing lines, and studded with
minute apiculi, which are sometimes confined to the outer
edge of the lobes. Diameter :0022” to :0065”. (Figs. 4—7.)

Auliscus celatus, Bail.—‘ Notes on New Species of Mice.
Organ.’ (‘ Smithson. Contrib.,’ vol. vii), p. 6, figs.3,4; Ralfs,
in Pritch., 1861, p. 845.

Hab. In sand washed from West India sponge, and in
soundings from Mobile Bay, U.S.; Prof. Bailey. Mud from
New London Harbour ; Delaware River mud, rare, U.S.; Dr.

Lewis. Californian and Ichaboe guanos, C. Johnson, Esq.
3

GREVILLE, on the genus Auliscus. 45

R.K.G. Bolivian guano and Monterey stone, G. M. Browne,
Esq. Bass’ Straits, C. Johnson, Esq. ; New Zealand, G. M.
Browne, Esq.; Harvey Bay, Queensland, New Caledonia,
and Woodlark Island, in dredgings communicated by Dr.
Roberts; R.K.G.; Brodick Bay, Island of Arran, R. K. G.
Having already referred to this species under the previous
article, I am not called upon to enter into many additional
details. The most essential character, perhaps, resides in
the apiculi, which are sometimes so numerous as to render
the whole area of the depressions quite rough, surrounding
even the umbilical space; while, in other cases, they are few
and scattered, or occur only. on the ridge or outer curve
of the depressions. Typical specimens seem to exhibit two
or three minute apiculi or tubercles on the coste, following
exactly the curve of the depression. In the Arran example
(fig. 4), which much resembles A. sculptus, there are very
few apiculi, and they are so situated; but, in addition to
this character, the radiating costz of the depressions are
continued to the margin. The range of size is extraordinary.
Those from Ichaboe guano, obtained, I believe, only by Mr.
G. M. Browne and myself, are so far beyond the average
dimensions, that it is probable they may be sporangial. I
am not disposed to place any reliance on the presence or
absence of anastomosing lines among the coste of the de-
pressions, as they appear to be sometimes nearly, if not quite
absent. A few may be occasionally perceived in the neigh-
bourhood of the umbilical space; while they are sometimes
so numerous as almost to amount to reticulation, only being
too irregular to deserve that name. Not unfrequently
the depressions, instead of forming semicircular lobes, unite
with the umbilical space, and resemble an oblong bar
stretched across the valve, scarcely dilated at each end, and
rough with apiculi. The depressions are considerably more
shallow than in the preceding species, or, in other words,
the undulation of the surface is less prominent. No cha-
racter of any value can be obtained from the marginal
costee, which, although generally distant, are sometimes
double the ordinary number. A very fine valve, kindly com-
municated by Mr. Brightwell, and obtained from sponge
sand, without any specified locality, and named A. sculptus,
I take to be the present species. There are, indeed, no
apiculi, but the coste within the depressions pass into a
perfect anastomosing network, unlike anything I have seen
in A. seulptus ; and the marginal cost are very numerous,
Auliscus elegans, n. sp., Grev.—Valve circular, with a
small, round umbilical space ; radiating coste proceeding to

46 GREVILLE, on the genus Auliscus.

the processes, widely converging and forming obcordate
groups ; centrical spaces between the umbilicus and the mar-
ginal coste, more or less minutely reticulated. Diameter
0032". (Fig. 8.)

Hab. Patos Island guano, C. Johnson, Esq.; R. K. G.

Surface of the valve much undulated. Processes large,
with a broad border. ‘The sets of costee leading to the pro-
cesses suddenly converging. The space between the umbi-
licus and the costee of the margin, extending so as to partially
enclose the converging sets, being filled up with a network of
minutely anastomosing lines. Marginal costz less robust
than in either of the preceding species. The umbilical space
is distinctly defined ; but there is no conspicuous quatrefoil.

Auliscus racemosus, n. sp., Ralfs, MS.— Valve nearly
circular, with definite umbilicus and row of marginal puncta ;
costee converging to the processes delicate, terminating im
little clusters of minute granules on each side of and below
the processes. Diameter 0024". (Fig. 9.)

Hab. Barbadoes deposit, Cambridge estate, C. Johnson,
Esq. Communicated by J. Ralfs, Esq.; R. K. G.

An interesting little species, of which several specimens
exist. It is not improbable that a larger number of ex-
amples would show some difference in the amount of the
punctation ; for there are indications of puncta within the
marginal circle, and the lateral sets of radiating lines which,
in the specimens before me, terminately shortly im faint
granules, may, in other cases, be more fully developed. But
the character derived from the clusters of granules termi-
nating the costz, is so distinct and remarkable, as to leave no
doubt regarding the validity of the species.

Auliscus reticulatus, n. sp., Grev.— Valve broadly oval, with
indistinct umbilicus; marginal radiating coste forming a
rather narrow border, within which the whole area is divided
into 4 lobes; the lateral ones very large, and filled with
a reticulation of anastomosing lines; converging lines also
often anastomosing. Diameter ‘0035. (Fig. 10.)

Hab. Cape of Good Hope, G. M. Browne, Esq. From
Melobesia, on Haliotis tuberculata, Peru, F. C. S. Roper,
Esq.

In the large proportion which the internal 4-lobed space
bears, to the entire valve this species differs from all the pre-
ceding, and in the very large comparative size of the lateral
lobes, it differs most remarkably from its nearest allies,
certain extreme varieties of A. celatus. The marginal coste
form a narrow band, often narrower than in the individual
represented in the plate; and the line of separation between

GREVILLE, on the genus Auliscus. 47

this band and the depressed lateral lobes is sharply defined ;
the transition from the strong, simple, somewhat distant
coste to the network of anastomosing lines being quite
abrupt. The processes are small, and situated very near to
the margin. .In afrustule from the Cape of Good Hope the
reticulation is confined to the side lobes of the quatrefoil ;
but in the beautiful Peruvian specimen figured, which belongs
to my friend Mr. Roper’s cabinet, it extends to the lobes
connected with the processes, in which, however, the con-
verging cost preserve their distinctness; the reticulation
being produced by sharp lines anastomosing transversely at
different angles.

Auliscus mirabilis, n. sp., Grev.—Valve broadly oval, with
large, definite umbilical space, and marginal border of oblong
cellules, each cellule penetrated at the base by a short line ;
area within the border, with the exception of the converging
coste, more or less filled with a reticulation of anastomosing
lines. Diameter :0040". (Fig. 11.)

Hab. Monterey stone; G. Norman, Esq., G. M. Browne,
Esq., R. K. G.

An exquisitely beautiful diatom, and rare as beautiful. It
was first brought under my notice by Mr. Norman, but his
specimen had unfortunately sustained some superficial injury.
That subsequently supplied by Mr. Browne leaves nothing to
be desired. My own specimen is a fragment. The general
effect of the ornamentation of the valve is exceedingly rich,
and resembles a lace pattern; indeed the whole might be
transferred with little modification to lace manufacture. The
processes are large, very conspicuous, irregularly circular,
with a very broad unequal border. The umbilical space de-
fined, and oval in the direction of the processes. The costz
which converge to the processes very clear and sharp; those
which radiate towards the margin anastomosing, so as to fill
the lateral space even to the sides of the processes with an
irregular network. The structure immediately within the
margin is quite peculiar, being composed of a close row of
large oblong cellules, penetrated by a small line or spine,
which reaches past the middle of each cellule.

Auliscus ovalis, Arn.—Valve oblong-oval; cost all deli-
cate, several of the lateral ones opposite the umbilicus crested
near the margin with minute apiculi. Long diameter -0040”.
(Fig. 12.)

_ Auliscus ovalis, Avrn.—Ralfs, in Pritch. Inf., 1861, p. 846.

Hab. Algoa Bay and Peruvian guanos; Ralfs, F. Kitton,
Esq., Prof. Walker-Arnott, G. Norman, Esq., R. K. G.

The form of this species is alone sufficient to distinguish

48 GREVILLE, on the genus Auliscus.

it from all others. The radiating cost are all slender and
somewhat faint; those passing from the umbilicus to the
processes widely converging ; some of the lateral ones rough
for a short distance from the margin, with very minute api-
culi. Umbilicus rather indistinct. Processes-generally very
large, not truly circular, but often tending to a very obtusely
triangular figure, sometimes very broadly ovate.

** Radiating lines punctate or scabrous. Valve strictly
circular (except in A. punctatus, which is nearly so).

Auliscus pruinosus, Bail—vValve circular, with a large,
smooth umbilicus ; radiating lines all minutely scabrous, be-
coming close and numerous towards the margin. Diameter
"0055". (Fig. 13.)

Auliscus pruinosus, Bail.‘ Notes on New Sp. of Mic.
Organ.’ (‘Smithson. Contrib.,’ vol. vii), p. 5, figs. 5—8.
Ralfs, in Pritch. Inf., 1861, p. 845. (PI. vi, fig. 1.) (Bad.)

Hab. In estuaries, &c., from Massachusetts to the Gulf
of Mexico; Prof. Bailey. At Black Rock, Long Island ;
Dr. Lewis. Var. with three processes in Savannah River
mud; Dr. Lewis. Georgia; F. Kitton, Esq.

A most charming diatom, scarcely to be recognised by the
published figures. In none of the specimens which I have
seen is there any trace of the bevelled edge described by
Professor Bailey, and which in his figure has the appearance
of a broad border. Nor are the processes so very remote
from the margin; but this I apprehend to be a variable
character in several of the species. The most graphic idea
I can give of the general appearance of the valve, arising
from the numerous plumose, rough lines, is that conveyed by
the term frosted—a disc of the most exquisite and sym-
metrical frost-work. The umbilicus is a clear, circular, blank
space, from which the lines radiate, at first rather widely,
but soon approximating from the addition of intermediate
lines, like the lamellae in many Agarici, become fine and
extremely numerous as they approach the margin. When
closely examined they are seen not to be punctate, but
rather resemble delicate scratches on glass, the roughness
of the edges causing the frosted appearance. The processes
are large and handsome, with a broad border. I have availed
myself of Mr. Kitton’s kindness, and given a representation
of the three-process variety from a splendid example in his
cabinet.

Auliscus radiatus, Bail. ?—Valve circular, with obsolete um-
bilicus, and striated marginal border ; lines all regularly and
conspicuously punctate, those converging to the processes

GREVILLE, on the genus Auliscus. 49

forming a narrow, obovate group, those radiating to the
margin straight. Diameter 0045". (Fig. 14.)

Auliscus radiatus, Bail.? ‘Notes on New Sp. of Mic.
Organ.’ (‘ Smithson. Contrib., vol. vii), p. 6, fig. 13?

Hab. In mud, New York harbour, and in the mud of the
Hudson River at West Point; Rockaway, Long Island,
U.S.; Prof. Bailey. Fossil at Kaighu’s Point, New Jersey ;
New London harbour, U.S.; dredged, Dr. Lewis.

The diatom described under this name by Professor Bailey
is, he says, “‘a minute species, presenting the characteristic
mastoid processes of the genus Auliscus, but having no dis-
tinct umbilicus, and having only slight indications of the
peculiar curved lines of the preceding species” (A. celatus).
His figure is also that of a minute species, and exhibits not
the very slightest indication of any curved lines at all. It
will be perceived, from the specimen which I have figured
from Mr. Kitton’s cabinet, that it is anything but minute;
that the lines which converge to the processes are quite evi-
dent and well-defined, and that there is a remarkably con-
spicuous border, which does not appear in Bailey’s figure, nor
is it referred to in his description. Under these circumstances
I should, perhaps, be justified mm regarding our present
diatom as distinct. Mr. Kitton, however, is decidedly of
opinion that they form one species, and I therefore leave the
question undecided until some information be obtained of
Prof. Bailey’s species. In the event of the one before me
being ascertained to be truly different, I wish it to bear the
name of Baileyi. In Mr. Kitton’s specimens there is no
distinct umbilicus, but an indefinite space, irregularly filled
up with puncta. All the lines are composed of a single row
of minute puncta, the lateral ones not plumose, but straight.
The border is very striking, beimg composed of an imner line,
and the space between it and the margin crossed with rather
distant striz. It seems scarcely credible that if such a border
existed in the examples which Prof. Bailey obtained from
three localities, he should have overlooked it.

Auliscus punctatus, Bail.—Valve nearly circular, with sub-
distinct umbilicus; whole surface more or less punctate,
but generally so irregularly that it is difficult to trace the
radiating lines. Diameter ‘0030’. (Figs. 15, 16.)

Auliscus punctatus. Bail. Notes on New Sp. of Mic.
Organ.’ (‘Smithson. Contrib.,’ vol. vii), p. 5, fig. 9. Ralfs,
in Pritch. Inf., 1861, p. 845.

Hab. “ Often associated with A. pruinosus in the stations
given for that species,’ Prof. Bailey. Rice-field mud,
Savannah river, rare; Dr. Lewis. Patos Island guano; C.
Johnson, Esq. Monterey Stone; F. Kitton, Esq.

50 GREVILLE, on the genus Auliscus.

This species is in a very unsatisfactory state, and it may be
doubted whether specimens have been seen in a really perfect
condition. Taving myself had no opportunity of examining
many individuals, I can say but little regarding it. In one
example now before me, the puncta are so disposed over the
entire surface that not the very slightest trace of a line
of any kind can be perceived. Inone specimen figured, the
radiating lines are partially visible. Ina valve I have from
Virginia there are comparatively few puncta, and the
characteristic lineation is of course conspicuous. The late
Professor Bailey compared A. punctatus with A. pruinosus, and
supposed that it might prove to be a variety of that species.
He remarks, however, that “ the sparsely punctate basis of
the one (pruinosus) with the closely punctate surface of the
other (punctatus) appear to offer a sufficient distinction
between them.” I apprehend that if these two species are
to be compared at all with each other, a better criterion exists
in the totally different character of the punctation.

Auliscus Peruvianus (Kitton), Grev.— Valve circular,
with close radiating lines of very minute puncta, and a row
of marginal apiculi; processes very small, each surrounded
by a cirelet of minute apiculi. Diameter about 0039”.
(Fig. 17.)

Auliscus Peruvianus, Grev.—‘ Trans. Mic. Soc.,’ vol. x,
p- 25, pl. i, fig. 6 (very coarsely engraved).

Eupodiscus? Peruvianus ; Kitton, MS., Ralfs, in Pritch.
Inf., 1861, p. 938.

Hab. Peruvian and Californian guanos; F. Kitton, Esq.,
Dr. Macrae, C. Johnson, Esq., R. K. G.

As I have already mentioned in the tenth volume of the
Society’s ‘Transactions,’ Mr. Ralfs first imdicated the re-
semblance of this diatom in certain of its characters to an
Auliscus. <At first sight it has far more the aspect of a
Eupodiscus, under which genus it was published. The very
small processes, the total absence of any umbilical space, and
the equal manner in which the surface is filled up with what
appears to be uniform straight lines of puncta, all tend to
convey the impression of a Hupodiscus. It is not until the
radiating lines are carefully examined that some of them are
seen to follow the usual curved and converging course to the
processes. In other respects the species is distinguished by
well-marked characters, the most conspicuous one being a
rather close series of marginal apiculi. A small, irregular
circlet of more minute apiculi also surrounds each of the pro-
cesses, and, what I believe has hitherto escaped observation,
there is on one side of each process a tubercle larger than the
apiculi, and at about the same distance. Minute apiculi

GREVILLE, on the genus Auliscus. 51

are likewise remotely scattered over the surface of the valve,
which, in certain lights, resemble diaphamous points, and are
very liable to be passed over. Specimens, however, sometimes
occur in which these raised points are very numerous and
visible, and towards the margin especially, give quite a rough
appearance to the valve.

*** Radiating lines, exceedingly fine and crowded, and
sometimes more or less very minutely granulose. Valve
strictly circular.

Auliscus Macreanus, n. sp., Grev.—Valve circular, with a
thick, prominent margin, and small, indistinct umbilicus ;
radiating lines all exceedingly fine; minute intra-marginal
puncta scattered between the large, broadly-oval processes.
Diameter -0040". (Fig. 18.)

Hab. Ceylon; Dr. Macrae.

One of the finest of Dr. Macrae’s discoveries in the Indian
seas, and strikingly distinct. The processes are very large,
and touch the margin, which is highly raised. A row of
minute puncta is situated immediately within the margin, and
halfway between the processes additional puncta form an
irregular belt, while two little clusters on each side are found
midway between the margin and the centre.

Auliscus elaboratus, n. sp., Ralfs, MS.—Valve circular ;
centre minutely granular, giving off numerous very fine con-
verging lines, which, as they approach the processes, are in-
terrupted by a circular ridge, surrounding at some distance
each process; whole surface more or less minutely granular.
Diameter :0044”. (Fig. 19.)

Hab. Barbadoes deposit (Cambridge estate) ; kindly com-
municated by Mr. Ralfs.

A most peculiar species. The radiating lines excessively
fine; the centre completely filled up with a minute granula-
tion. Processes in the specimens now before me three ; each
surrounded by a circular ridge, which encloses a space about
as broad as the diameter of the processes themselves; and
the fine lines passing over the ridge catch the light, or pro-
duce a slight shadow, and thus cause the appearance of a sort
of halo round each process.

Auliscus Johnsonianus, n. sp., Grev.—Valve circular, with
minutely granular centre, and very fine, obscure, converging
lines; processes (4) with striated border. Diameter ‘0034”.
(Fig. 20.)

Hab. Barbadoes deposit (Cambridge estate) ; C. Johnson,

sq.
The striated horder of the processes is of itsclf sufficient to
mark this species; but it is also distinguished (if the cha-

52 GREVILLE, on the genus Auliscus.

racter be permanent) by the presence of four processes. One
other species belonging to this marvellous deposit has occurred
both to Mr. Ralfs and myself with the same number; and as
those of the subjacent valve are nearly as visible as the four
in the upper valve, there is the singular effect of a circle of
eight processes. Our specimens of this latter species are all
unfortunately more or less injured in the superficial sculpture.
The plumose lines in A. Johnsonianus are even finer than in
A. elaboratus, but are otherwise very similar, and have also
the same very minute granular character.

**** Whole surface of valve widely reticulated.

Auliscus Ralfsianus, n. sp., Grev.—Valve circular, with the
whole surface covered with a wide and lax network, the spaces
within the interstices showing minute puncta, arranged in
radiating and converging lines, Diameter :0045”. (Fig. 21.)

Hab. Barbadoes deposit (Cambridge estate); C. Johnson,
Esq.

Perhaps this may be considered as the most extra-
ordinary species in the whole genus, and I have the greatest
pleasure in dedicating it to my highly valued friend and fellow-
labourer, Mr. Ralfs. . In all the rest the prominent superficial
sculpture is characteristic of the group; the radiating or plu-
mose arrangement of the lines, especially those which curve
and converge from the centre to the processes, being more or
less evident. But in the present case the observer is startled
by, at first sight, perceiving nothing but a loose, wide, brown
network enveloping the whole valve, with the exception of
the processes. An attentive examination, however, shows
that within the reticulations there are puncta or minute cel-
lules, arranged in the manner common to the genus. The
processes are almost marginal, nearly circular, and very large.

The following species are unknown to me, and cannot be
established without additional information :

Auliscus Americanus, Ehr.—It is impossible to say what
this may be from Ehrenberg’s figure (Microg. pl. xxxviii (14),
fig. 2), which is doubtless incorrect, as no space is left for any
converging lines between the centre and the processes.

A. gigas, Ehr., Microg., pl. xix, fig. 63. A fragment too
small and imperfect.

A. cylindricus, Ehr.—No figure published.

A. polystigma (Coscinodiscus), Ehr., Bericht Berl. Akad.,
1844, p. 78. No figure published.

Roper, on the genus Licmophora. 53

At fig. 22 I have given a figure of a specimen observed by
Mr. G. Norman in shell cleanings from Japan. I do not
venture, on the strength of a single specimen, to describe it
as a distinct species. It comes nearest to A. celatus, but
differs in the sharp and diffused character of the punctation,
and especially in the presence of puncta on the converging
lines.

On the genus Licmornora (Agardh).
By F.C. S: Koren, F.L:S., ‘&c.

(Read March 11th, 1863.)

TuxE microscopic forms of Algz of the order Diatomacez,
although slightly alluded to in the works of Dillwyn in 1809,
and, with respect to a few genera, more carefully investigated
by Dr. Greville, in the ‘Scott. Crypt. Flora’ and ‘ British
Flora,’ and since then in the papers of Messrs. Ralfs and
Thwaites in the ‘Ann. Nat. Hist.,’ had not been made the
subject of any special work in this country, until the liberal
guarantee offered by Messrs. Smith and Beck induced the
late Professor Smith to publish the result of his labours in
that hitherto neglected branch of science; as although in
the earlier editions of Pritchard’s ‘Infusoria,’ a portion of
Ehrenberg’s descriptions of the Diatomacez, with copies of
his figures, were given, these were so imperfect and meagre,
and included so many foreign forms, that they were of little
use to elucidate our British species.

Our native microscopists, although universally admitted to
have the best instruments, and therefore the best means of
investigation in their hands, had treated the siliceous epi-
derms of the Diatomacez more as objects for testing the
powers of their respective instruments than with any endea-
vour to arrive at a satisfactory conclusion as to their relative
habits, modes of growth, or position in the scale of nature.
The labour of reducing to anything like a system the varied
and often widely discordant opinions on these minute forms
of the vegetable kingdom was thus left almost entirely in
the hands of continental observers, and the works of Agardh,
Kiitzing, Ehrenberg, Nitzsch, De Brebisson, and others, show
the patience with which—with the imperfect instruments at
their command—they reduced the chaos previously existing
to something like order. But the difficulty of giving accurate,
or, at least, generally recognisable descriptions of such minute
forms is so great, that though the voluminous works of Kiitzing
and Ehrenberg are invaluable in determining those species

5A Rormr, on the genus Licmophora.

which present constant and strongly marked peculiarities,
a vast number of the forms included in their genera, in the
absence of authentic specimens, are now quite unknown, and
can neither be determined by their specific characters or
figures. The difficulty thus presented to the English ob-
server may be estimated by the fact stated in the preface to
Professor Smith’s ‘ Synopsis,’ that, out of the 224 species
included in his first sub-tribe, not more than twenty had
been previously recorded by native observers, and of the
remainder a very large proportion are only doubtfully to be
referred to the outline figures of Ehrenberg and Kiitzing.
The appearance of Professor Smith’s researches at once
obviated the great difficulty the English diatomist had to
contend with; and affording a sure foundation to start from,
brought a host of observers into the field, attracted by the
great beauty of the hitherto neglected frustules of the tribe,
by the abundance with which they are found in almost every
locality, and especially to the field thus offered by a more
careful examination of marine and foreign collections for
the description of new species or varieties of those already
known.

The great advantage Professor Smith’s work offers over
that of all his predecessors, consists in the determination
he formed, and to which, except in a few cases, he adhered,
not to admit species unless he had an abundant supply of
material for investigation ; in the beauty and accuracy of Mr.
Tuffen West’s illustrations; but chiefly to his own authentic
slides being made available to the publicfor nearly all the species
described in the ‘Synopsis.’ The value of his work, there-
fore, as a basis for further observation, is far greater than
that of any of his predecessors; and though, had his life
been spared, he would doubtless have availed himself, in
another edition, of the extended researches he originated, to
modify some of his species, and probably also some parts
of his classification—still, the greater part of those species
he has included in the ‘ Synopsis’ are well authenticated, can
be readily recognised, and will form a sure ground work for any
future writer on the subject.

That in a first attempt to describe our native species of
these minute and lowly organized forms of life, so few errors
should have occurred is truly remarkable, when it is remem-
bered how little was known of the variations arising from
habitat; of the influence of the temperature of the water, and
the effect of salt, brackish, or fresh water on the form and
marking of the frustules; of the astonishing rapidity with
which slight structural peculiarities might be perpetuated by
the process of self-division ; and that, except in a few genera,

Rover, on the genus Licmophora. 55

no observations had been published as to the laws of develop-
ment and the propagation of the plant.

It is not at all surprising, therefore, that in attempting to
avail himself of the meagre specific characters and mere out-
line figures of his predecessors, in the endeavour to reduce as
far as possible the overloaded nomenclature and synonymy of
the tribe, some errors should have crept in, which at the
present day can be to a certain extent cleared up; and I pro-
pose on the present occasion to show that in the genus
Licmophora, though the author of the ‘Synopsis’ appears
to have referred to what are, or what he supposed to be,
authentic specimens for the determination of the species, yet
by some oversight, not readily accounted for, the names of
the only two species included in the genus are reversed. The
Licmophora splendida of the ‘Synopsis’? is in fact the
L. flabellata of all previous writers, whilst what is referred
to as L. flabellata, Ag., is the true L. splendida, Grev. Itis
also perfectly evident to any one who will carefully examine
the allied genera Podosphenia and Rhipidophora, and compares
the species and synonymy of the ‘Synopsis’ with the
works of Kiitzing, Ehrenberg, and Agardh, that great con-
fusion exists as to the limits and specific characters of those
enumerated by ProfessorSmith; and though I have beenunable
at present to obtain a sufficient series of authentic specimens
to arrive at any satisfactory conclusion on the doubtful points
in these genera, I hope on a future occasion to be able to
elucidate them and lay them before the Society.

With the genus Licmophora, however, the case is different,
for by the kind assistance of Dr. Walker-Arnott, who first
directed my attention to the point, and also of Dr. Greville, I
have been able to study a variety of gatherings, including
authentic specimens both from Agardh and Kiitzing. Dr.
Hooker has also permitted me to examine the original MSS.
of Capt. Carmichael, and the specimen of his Echinella venti-
labrum, on which Greville’s species of ZL. splendida was I
believe originally founded ;* and as I had in my own collection

* That this is the case is tolerably certain, from the fact that in 1827
Dr. Greville, in the ‘Scot. Cryp. Fl.,’ only describes the Lvillaria flabellata
from Capt. Carmichael’s specimens ; in 1838, in the ‘Brit. Fl.,’ he includes
this under Agardh’s name of Licmophora flabellata, and also describes a new
species as L. splendida, the only specimens mentioned being those of Capt.
Carmichael. Now, as Capt. Carmichael in his herbarium has only two
species, which he called Hehinella flabellata and L. ventilabrum (the latter
having broadly cuneate valves, as in Dr. Greville’s Z. splendida), there can
be little doubt that they are identical, and I hear from Dr. Greville that he
has no doubt the reason for his adopting a new name for the species was,
that, though the specimens came into his possession, he had not the manu-
script descriptions to refer to, and, therefore, did not adopt Carmichaei’s

VOL. XI. e

56 Roper, on the genus Liemophora.

authentic slides of Professor Smith’s of both species, I have
been enabled to satisfy myself, and I trust any one who will
investigate the subject, of the peculiarities which are the true
characteristics of each.

As I have had no opportunity of examining any living
specimens, I am unable to determine, with any degree
of certainty, whether there ought to be two or only one
species in the genus, though this is a point which is open to
much doubt. Kiitzing divides it into five, but his L. fu/gens
is the Synedra fulyens of Smith, and his ZL. divisa I believe
identical with Rhipidophora Dalmatica, and L. flabellata and
Meneghiniana are evidently the same species ; so that in fact
he has really only two, L. flabellata and L. radians.

Professor Smith states that he only gives, “in accordance
with the authority of his predecessors, two species of the
present genus; but he is far from satisfied that they are truly
distinct.”* In all the gatherings I have examined, I can
detect no structural peculiarity that is not common to both,
and certainly there is no difference in the form which will
allow the F.V. of one to be called “ rounded at the upper ex-
tremity,”’ while the other is said to be “truncate ;” nor are
the valves of one “attenuate at the larger extremity”
whilst the others are ‘ rounded,” as stated in the specific
characters by Professor Smith, and illustrated by the figures
233 and 234, in t. xxxu, vol. 11 of the ‘ Synopsis.’

The only real difference that can be detected in dried or

prepared specimens is, that certainly
Fig. 1. some gatherings consist of frustules
a 6 broadly cuneate on the 8.V., and widely
club-shaped on the F.V. (fig. 1, a, 4);
and at the same time, as far as our
present evidence goes, this is combined
with comparatively short valves, a shorter
and less dichotomously branched stipes,
and, perhaps, some difference in the
arrangement of the endochrome, as shown
in fig. 234, t. xxvi, vol. i of the ‘Sy-
nopsis.’
This last peculiarity, however, may
arise from the time of year in which the
specimen was gathered, as the ocelli or

specific name. It is curious that, according to the ‘ Infusionsthierchen,’ p.
221, Ehrenberg had, in 1828, and again in 1831, in the ‘Abhandl. der Akad.’
of Berlin, described a small form under the name of “ Eehin. splendida,’ but
this also was unknown at the time to Dr. Greville, and 1 have only included
it in the synonomy of his species with much doubt.

* ‘Syn. B. Diat.,’ vol. i, p. 85.

8

ry

Rorgr, on the genus Licmophora. 57

circular bodies which are seen in the contracted endochrome
of some gatherings appear more as if they were the com-
mencement of the reproductive process than merely a simple
contraction of the endochrome itself. The fact has been
noticed by other writers, but it is a point on which I place
little reliance as a specific character, and can only be cleared
up by a careful comparison of living specimens.

In contradistinction to these decidedly cuneate valves,
there are others, and from the number of gatherings I have,
and also from its being the first recorded,

I should imagine by far the most widely dis- Fie. 2.
tributed, with valvesnarrow, linear-cuneate a

on the 8.V., club-shaped but attenuate on
the F.V. (fig. 2, a, 6), almost invariably
and sometimes considerably longer than
those of the cuneate form, with along and
much branched stipes, and altogether a
larger and more robust plant than the
other.

Now, if these peculiarities are per-
manent, and not the result of habitat
or local influences, there is considerable
probability that they ought to rank as
distinct species, or, at all events, as well-
marked varieties; and as far as my present
information extends, I am inclined to
think that the latter is the most correct
classification ; but this is a point that can
only be cleared up by a more extended
examination of livig specimens, and for
the present I shall merely give the best
specific characters I can to the two
species of Agardh and Greville, with the
synonymy as far as I have been able to
trace it satisfactorily, with a few remarks on the gatherings
on which my conclusions are founded.

Ss

Genus. Licmornora, Ag.

Frustules cuneate, stipitate, flabellate at the summits of
the stipes ; stipes dichotomously branched ; incrassate, valves
convex, elongated, and traversed by a longitudinal median
line.

1. Licmophora flabellata, Ag.

Frustules linear-cuneate, truncate; F. V. club-shaped,
but attenuate, stipes much branched; tufts usually three to
four lines in height.

58 Rorsr, on the genus Licmophora.

Marine on Zostera and small Algee.

Syn. Licmophora flabellata, Ag., Consp., 1830, p. 41.

a = Hooker's Br. Fl., 1833, p. 408.

> nA Wyatt’s Fl. Danm., vol. v, No. 234.
3 5 Har., Br. Alg., 1841, p. 206.

5 33 Kiitz., Bac., 1844, t. 12, f. 1,.2, 3, 4
op S 53 .1hcgs De Ale., 1849, p- 113.

45 __, hy. Ger, 1845, p. 108.

welitia flabellata, Grev., Sc. Che: Fl, 1897, t. 289.
Kehinellu flabellata, Carm. MSS., 1826.

55 Ss Ehr., Infus., "1838, $ail9; fee

55 Bail., Sil. Jour., 1842, <5) Alii me BE

Licmophora Meneghiniana, eal Bac., 1844, p: 123.

a wil laeie e., Consp., 1830, p. 4d.

"6 Ag., SRG: Alg. Kur., 1835, t. 2.

_ splendida, W. Smith, Syn., 1853, t. 26, f. 233.

‘i Ralfs in Pritch. ‘Inf., 1861, aes

Meridion radians, Ag., Sys. Alg., 1824, p. 2 (in part).
Gomphonema flabellatum, Kiitz., Linnea, 1833, p. 571.

5 argentescens, Kiitz., Lin., 1833, p. 571.

This is decidedly the most common and best known of the
two species or varieties of which the genus is composed, and
is generally noticed as the larger plant. Agardh, m 1824,
in the earliest notice of it, under the name of Meridion
radians, describes it as * frustulis lineari-cuneatis,” and in
the ‘Conspectus,’ in 1830, as “ Plantula magnifica.” Dr.
Greville, in the ‘Scot. Cryp. Fl.,’ vol v, No. 289 (in describing
Ezillaria flabellata), and in Hooker’s ‘Brit. Fl.” p. 408,
states the frustules to be linear-wedge-shaped, and stems
from one third to half an inch in height. Captain Carmichael,
in the MSS. ‘ Algze Appinensis.’ in Sir W. Hooker’s library
at Kew, describes the frustules as “ linearis-cuneatis,” and
calls it the “ largest and most beautiful of the tribe.” Pro-
fessor Harvey, in the ‘ Brit. Alge,’ appears simply to follow
Dr. Greville’s description in Hooker’s ‘ Brit. Fl’ Ehrenberg,
in the ‘Infusionsthierchen, states the frustules to be
“lineari-cuneatis truncatis,” and Kiitzing, in the ‘Bacillarien,’
says, “bacillis gracilibus lineari-cuneatis.” Ralfs, in the
last edition of Pritchard’s ‘ Infusoria,’ evidently follows Pro-
fessor Smith in naming the species, but in describing his L.
splendida, he states it to “ differ from the other species of the
genus by its longer and narrower frustules. I, at one time,
thought that Agardh’s L. argentescens of the ‘Consp. Crit.
Diat,’ p. 41, was identical with Dr. Greville’s splendida, as
he states the valves to have “ frustula cuneata ;” but, at the
same time, he says, “‘the plant is three to six lines in height,”
and from authentic specimens I have had kindly sent me by
Dr. Greville, I find it is certainly the same as flabellata, and
it was probably only separated, as suggested by Mr. Ralfs, for

Roper, on the genus Licmophora. 59

its silvery lustre when dried. Looking at all these previous
authorities, it is surprising to find Professor Smith applying
Agardh’s name of flabe//ata to the cuneate variety, and
uniting in the synonymy, the ZL. radians of Kiitz., which is
the true L. splendida of Greville, with the species described
by Ag. in the ‘ Conspectus,’ p. 41, and the Evillaria flabellata
of Greville, which are identical with the form to which he
gives the name of splendida. There appears to be the same
confusion in the localities given, as the Torbay specimen of
Mrs. Griffiths, and those of Salcombe of Mr. Ralfs, have the
linear-cuneate form, which is the true flabellata, Ag., not the
L. splendida of Smith.

2. Licmophora splendida, Grev.

Frustules cuneate, truncate; F.V. broadly club-shaped ;
stipes branched ; tufts usually one to three lines in height.

Marine on Small Algz and Zostera.

Syn. Licmophora splendida, Grev., Hooker’s Br. Flor., 1838, p. 408.
sf 3 Har., Brit. Alg., 184], p. 206.
Eichinella ventilubrum, Carm. MSS., 1829.
~Licmophora radians, Kiitz., Bac., 1844, t. 11, f. 4.
5¢ a Kiitz., Spec. Alg., 1849, p. 113.
a flabellata, W. Smith, Syn., 1853, t. 26, f. 234, *
s £ Ralfs in Pritch. Inf., 1861, p. 771.
Meridion radians, Ag., Sys. Alg., 1824, p. 3 (in part).
Echinella splendida ? Uhr., Inf., 1838, t. 19, f. 2.

This form, whether it be a different species, or merely a
variety, does not seem to be so well known as that previously
described, but it appears to have been separated by all writers
on the genus since the time of Agardh from its smaller size
and the decidedly cuneate form of its frustules. Dr. Greville,
in the ‘ Brit. Flor.,’ p. 408, says it is “nearly allied to fladel-
lata, but smaller and less divided, and frustules more broadly
wedge-shaped ; tufts two or three lines in height.” Captain
Carmichael describes the frustules as having “‘ terminali latis-
simi,” and notices the peculiar arrangement of the endochrome
as having the appearance of “ bars or ocelli,” which occurs in
some of the gatherings I have, and is shown in tab. xxvi,
fig. 234 of the ‘Synopsis.’ Kiitz. describes L. radians as
with frustules “ cuneatis, basi acutis, apice latioribus.” Mr.
Ralfs copies Professor Smith, but is doubtful if both ought
not to be referred to one species; and yet, with these cha-
racters by the earliest observers of the form, Professor Smith
has applied the name of splendida to the linear-cuneate and

60 Rover, on the genus Licmophora.

large variety, and mixed up the true Licmophora flabellata
of Kiitz. and Echinella flabellata of Ehr. in his synonymy with
the L. splendida of the ‘ British Flora.’

That in many cases there is great difficulty in clearly ascer-
taining the species really described by the earlier writers, I
am quite ready to admit, as we are almost dependent on short
descriptions and imperfectly drawn figures; and even speci-
mens named by Kiitz. and Agardh I have found to be erro-
neous. I have seen a gathering named Rhipidophora grandis,
by Kiitzing, which is the true L. flabellata of Agardh, and of
two gatherings by Agardh of L. argentescens ; one was L. fla-
bellata, the other a mixture ofa large Synedra with a Rhipido-
phora. That Professor Smith’s transposition of the names in
this genus has arisen from some similar cause I have little
doubt, and that, without looking with sufficient care into the
synonymy, he has depended on specimens which have been
erroneously named, or of which the names kad been trans-
posed. It is hardly possible that so careful an observer as
Dr. Greville, after his description of Evillaria flabellata in the
‘Scot. Cryp. Flora,’ and his subsequent account of it as
L. flabellata in the ‘ Brit. Flora,’ could have intentionally sent
the small and widely cuneate form of which he made the
species splendida to Professor Smith, as stated in the ‘Sy-
nopsis,’ as the true flabellata of Agardh. But I am still more
at a loss to understand how in the ‘ Synopsis’ the locality,
“Saltcoats, Dr. Landsborough, from Dr. Greville’s ‘ Her-
barium,’ ”’ could be placed under the splendida, as described
by Professor Smith, as I have had an opportunity of examin-
ing Dr. Landsborough’s gathering, which has the widely
cuneate valves of the true sp/endida of the ‘ Brit. Flora,’ and
is synonymous with the L. radians of Kiitzing. Dr. Lands-
borough, in speaking of this gathering in 1851, two years
prior to the appearance of the ‘ Synopsis,’ says, “This plant
has not been found by any since its discovery at Appin by
Captain Carmichael, till it was got in considerable abundance
by D. Landsborough, junr., in September, 1848, at low water-
mark, in a creek formed by trap-dykes in the parish of Ar-
drossan. Hoping it was the L. splendida I sent it to Dr.
Greville, and was gratified by his pronouncing it that rare
plant. The fans were spread out, in many cases, so as to
form more than a semicircle, the rays numbering ten to
twenty-six. Each ray or frustule was wedge-shaped and a
little denticulated at the top; the upper part was amber-
coloured, and each ray had a lighter-coloured dot in the
middle of this portion. These bright dots formed a crescent
of sea gems. Under this amber-coloured portion there was a

Rover, on the genus Licmophora. 61

pellucid band, the lower part of the fan being amber-coloured,
like the upper.’”’*

With respect to Captain Carmichael’s specimens from
Appin, as far as I can gather from his MSS., the LZ. flabel-
lata, Ag., was described in 1826, and has the long, linear-
cuneate frustules of the true flabellata, not the cuneate form,
as would be imagined by the statement of the ‘ Synopsis ;’
whereas the Echinella ventilabrum, which was, I believe, the
foundation of the L. splendida of Greville, and has the broadly
cuneate valves, appears to have been described in 1829, which
accounts for its non-appearance in the ‘ Scott. Cryp. Flora’:
of Dr. Greville, which appeared in 1827.

With respect to the size of the valves given in the ‘ Synop-
sis,’ there is the same discrepancy as in the other points
noticed, and I should imagine they were both taken from a
mixture of the two forms. Professor Smith gives ‘0033 to
0078 as the length of his splendida, and :0033 to ‘0058 as
the length of his flabellata, or ‘0055 and :0045 as the average
length of each. I have carefully measured fifteen gatherings
of the linear-cuneate variety, from Appin, Cumbrae, and Ayr-
shire, in Scotland; Neyland, in South Wales; Torbay, in
the south of England; Bantry Bay, in Ireland; from the
north and south of France, and Venice; and find they range
from 006 to ‘011. And in nine gatherings of the broad
cuneate variety, from Appin, Cumbrae, and Saltcoats, in
Scotland ; Paignton, Exmouth, and Salcombe, in the south of
England; the north of France, and Venice, the valves range
from 0035 to ‘0051. The average of all the gatherings of
each variety being respectively ‘0073 for the linear frustules
and 0048 for the cuneate forms, showing a considerable dif-
ference from those before quoted from the ‘Synopsis.? The
frustules in the same gathering are generally very persistent
in size, but I have one gathering from Dunbar, named L,
flabellata by Dr. Landsborough, in which the stipes is gone
and most of the valves separated. This contains a mixture of
the cuneate and linear-cuneate varieties, but the former all
range from *0045 to ‘0050, the latter from ‘0065 to :0070, and
there is no evidence to show that they are from the same plant.

From a careful consideration of the foregoing particulars
I can only arrive at the conclusion, that Professor Smith, in
describing the species of Licmophora, by some intermixture
of, or examination of wrongly-named specimens, has reversed
the true names of the species in the ‘Synopsis ;’ and that
both in the measurements, synonymy, and localities given to

* Lands. ‘ Pop. Brit. Seaweeds,’ p. 337.

62 Roper, on the genus Licmophora.

each, some belong to one and some to the other species; and
that the Licmophora splendida of the ‘Synopsis’ is the true
L. flabellata of Agardh, and the L. flabellata the true L.
splendida of Greville.

It is also, I think, clearly proved that the only ground for
considering them as true species is that they differ in the
size and comparative breadth of the frustule and (on the
evidence of several observers) in the size of the plant, but that
there is no decided structural peculiarity. As it is highly
probable that a more extended examination of living speci-
mens may show that this is owing to habitat and the nature
of the plant on which they grow—the larger forms growing
on those that offer a firm and decided support to the stipes,
whilst the smaller may be confined to the weaker and more
filiform algee—I consider that, as far as we at present know,
they ought to be considered rather as varieties than true
species, and that both ought to be classed under the name of
Licmophora flabellata, Ag.

TRANSACTIONS.

Descriptions of New and Rare Diatoms. Series IX.
By R. K. Grevittz, LL.D., F.R.S.E., &e.

(Communicated by F. C. S. Roper, F.R.S.)
(Read May 138th, 1863.)

(Pl. IV and V.)

Tue species described in this paper were obtained from a
sample of Barbadoes earth (Cambridge estate), communicated
a few months ago to my veteran friend in diatomic research,
Mr. Johnson, of Lancaster. Extensively as this remarkable
deposit had been examined, it is most extraordinary that in
the small sample referred to, a host of new things—genera
as well as species, should have been discovered; while it is
equally curious that many forms common in _ previously
examined portions of the same deposit should here be
absent. Some of the most smgular as well as beautiful of
these diatoms are in the hand of my friend and acute fellow-
labourer, Mr. Ralfs, and will enrich the supplement to
Pritchard’s ‘ History of Infusoria,’ upon which he is at present
engaged.

Poropiscus, nov. gen., Grev.

Frustules free, disciform, composed of two discs, united by
an intermediate, ring-like zone; discs very convex, minutely
radiato-cellulate or punctate, with a conspicuous central
pseudo-opening or pore.

This genus is evidently closely allied to Coscinodiscus,
differing chiefly in the remarkable pore-like pseudo-opening,
which is not a mere blank circular space produced by the
absence of cellulation at the apex, but a well-defined, concave,
apparent orifice, provided with a thickened margin. All the
species hitherto discovered—and they are confined to the
Barbadoes deposit—are very convex, with a minute structure
of distinctly radiating puncta (cellules under a sufficiently
magnifying power). In nearly all the species certain of the

VOL. XI.

64 GREVILLE, on New Diatoms.

radiating lines are continued from the margin to the apex,
and divide the disc into- faint but perceptible compartments.
The surface is either plain or armed with variously arranged,
minute spines. The first and last of the following species oc-
curred to myself some years ago, when I was engaged upon the
examination of Barbadoes earth, in working out the remark-
able Asterolampre contained in that deposit; but no others
had been observed, until my friend, Mr. Johnson, commenced
the investigation of the sample of the deposit from Cambridge
estate, which has yielded so prolific a harvest of beautiful
and curious new diatoms. The species of the present genus
not described in this paper will be published by Mr. Ralfs,
along with many other new and remarkable objects, in the
forthcoming supplement to Pritchard’s valuable work on the
‘ Infusoria.’

Porodiscus elegans, n. sp., Grev.—Disc very convex, un-
armed, divided into compartments by pairs of the radiating
lines of very minute puncta, extending from the margin to
the centre. Diameter ‘0020’ to -0033". (Pl. IV, fig. 1.)

Barbadoes deposit, from Cambridge and other localities ;
C. Johnson, Esq., R.K.G.

This species is distinguished by the disc being divided into
numerous compartments, by pairs of radiating lines of puncta,
very distinctly seen under a moderately magnifying power,
and at the same time being quite destitute of spies. It is
the most frequent species, three or four valves sometimes
occurring in a single slide. The connecting zone is rarely
seen in situ.

Porodiscus major, n. sp., Grev.—Disc with a very large
pseudo-opening ; the radiating puncta very minute, irregular,
and interrupted for some distance round the opening, after-
wards becoming regular, with faint, equidistant rays, formed
by pairs of the longest lines. Diameter of pseudo-opening
0006”. (Fig. 2.)

Hab. Barbadoes deposit from Cambridge estate, in a slide
communicated by C. Johnson, Esq.

I have not seen an entire valve of this species, but from
what remains in the specimen before me it is probably not
less than -0040" or ‘0050" in diameter. The margin of the
pseudo-opening is somewhat crenate or plicate, in consequence
of the lines of puncta being somewhat thickened at their
termination. From its large size, it is easily seen that there
is no real perforation; and that it is simply concave, and
closed by a diaphragm. For a space round the pseudo-
opening equal to the diameter of the opening itself the
puncta are exceedingly irregular; many of the radiating

GREVILLE, on New Diatoms. 65

lines are interrupted, and here and there the puncta are
either altogether wanting or look as if they had been
shaken out of their places. At present it is impossible to
say whether this centrical irregularity is accidental or other-
wise.

Porodiscus conicus, n. sp., Grev.—Small; disc conical,
unarmed, with an obtusely truncate apex; radiating lines
of puncta extremely minute. Diameter -0014". (Fig. 3.)

Hab. Barbadoes deposit from Cambridge estate ; C. John-
son, Esq.; rare. noes

The smallest of the species hitherto discovered, and oc- -
curring not unfrequently in perfect frustules. The length of
the connecting zone is considerable, and that of the entire
frustule, when both valves are symmetrical, about :0040".
The valve is decidedly conical, but obtusely truncate at the
top when seen in profile. It hardly ever happens that the
valves are equal in the same specimen; indeed I do not think
that I have seen a single example perfectly symmetrical,
one valve being almost always considerably shorter than the
other. The length of the connecting zone gives the frustule
a cylindrical appearance.

Porodiscus nitidus, n. sp., Grev.—Dise convex, unarmed,
the longest lines of puncta single (not in pairs), alternating
with two or three series of shorter ones; puncta distinct, all
of them becoming much more minute towards the margin.
Diameter °0026”. (Fig. 4.)

Hab. Barbadoes deposit, from Cambridge estate; C. John-
son, Esq.

Dise much less crowded than in the three preceding species,
and the puncta larger and more distinct. A certain number
of the lines reach from the margin to the centre; a second
series very nearly so; a third are considerably shorter, and
the last extend but little beyond the margin. It is a scarce
species.

Porodiscus oblongus, n. sp., Grev.—Disc elliptical-ob-
long; pseudo-opening large. Long diameter about 0028”.
(Fig. 5.)

Hab. Barbadoes deposit.

A species by no means rare in some specimens of the
deposit which I investigated a few years ago, but it does not
seem to occur in those which have recently been so carefully
examined from Cambridge estate. The form alone is suffi-
cient to identify it. The pseudo-opening is very large, the
radiating lines of granules are less crowded, and the granules
themselves larger than in any of the preceding species.

66 GREVILLE, on New Diatoms.

HETERODICTYON, noy. gen., Grev.

Frustules free, disciform; disc with radiate or scattered
cellules or puncta in the middle portion, and a circle of large
intra-marginal cellules.

This genus is allied on the one hand to Coscinodiscus, on
the other to Brightwellia. From the former it differs in the
circle of very large cellules, from the latter in the absence
of the spiral arrangement of the central cellulation. Besides
this distinction, the circle of large cellules seems to be more
associated with the marginal structure than in Brightwellia,
at least such is very decidedly the case in one of our species.
In the other there is an approach towards the last-mentioned
genus, the circle being further removed from the margin.
Perhaps the best character will be found to consist (taken in
conjunction with the circle of large cellules) in the absence
of the beautiful curved or spiral cellulation which marks the
three known species of Brightwellia.

Heterodictyon Rylandsianum, nu. sp., Grev.—Dise with
minute radiating puncta, and a circle of very large, linear-
oblong, marginal cellules. Diameter -0050". (Fig. 6.)

Hab. Barbadoes deposit, from Cambridge estate, in a slide
communicated by C. Johnson, Esq.

An exquisitely beautiful disc, and so well marked as to
require no extended description. Viewed apart from the
circle of large cellules which occupy nearly a fifth part of the
radius, there is no character to distinguish it from Coscino-
discus, and the resemblance to various species of that genus
is rendered more striking by the presence of a little central
cluster of cellules considerably larger than the puncta which
radiate from them. The large cellules of the margin are
parallel with each other, somewhat arched at their inner ex-
tremity, and arranged in groups of three, the middle one
being the longest. A narrow band of puncta is situated
between the base of these cellules and the margin.

Heterodictyon splendidum, un. sp., Grev.—Dise small, the
central portion occupied with remotely scattered, large, round
cellules, and surrounded with a circle of large hexagonal
cellules, having an exterior border of coarse, moniliform striz.
Diameter -0023”. (Fig. 7.)

Hab. Barbadoes deposit, from Cambridge estate; C. John-
son, Esq.

A remarkable, ornamental species, and illustrative of the
generic name, as no fewer than three conspicuous structures

GREVILLE, on New Diatoms. 67

unite in its composition. The central and larger space has
round cellules, so remotely and irregularly disposed as to
render it unlike a diatomic structure. Then comes the cha-
racteristic circle of large, equal, hexagonal cellules, which
exhibit the singular peculiarity that the marginal angles of
the hexagons are not quite completed. Lastly, between the
large cellular circle and the margin the space (equal in
breadth to the diameter of the large cellules) is filled up with
radiating, robust, moniliform striz, which take the place of
the narrow marginal band of puncta seen in the preceding
species. It must be confessed that in general appearance the
two species differ exceedingly, and it is by no means im-
probable that the present one may be ultimately separated.

FENESTRELLA, nov. gen., Grev.

Frustules free, disciform; disc with a minute, radiant
cellulation, interrupted in the middle by linear bands, com-
posed of parallel lines of cellules, each band terminating in
a fiat ocellus.

This genus is composed for the reception of a solitary but
most curious diatom, the relations of which it is not easy to
define. The groundwork of the disc is very much that of
Coscinodiscus, being composed of radiating lines of cellules,
with a marginal row of puncta. But a couple of circular
ocelli, at little more than half the radius from the centre,
although not conspicuous, are sufficiently evident, and show
that we must look for affinities elsewhere. These ocelli are
not processes, but definite blank spaces in the cellulation, and
have therefore no connection with Eupodiscus or Aulacodiscus.
Another peculiarity is a broad, linear-oblong band passing
across the middle of the disc, and composed of about eight
rows of cellules; or perhaps it would be more correct to say
that two opposite sets of rows of cellules meet at their bases
in the centre, and at the other extremity converge as they
terminate in the occelli, with which they are evidently con-
nected. There is no umbilicus, the band of cellules intercept-
ing, as it were, the meeting of the radiating lines, the only
indication of the central point being a slight interruption in
the continuity of the cellules, not sufficiently definite to con-
stitute a character. The convergence of these lines of cellules
towards the ocelli seems to pot to some alliance with dw-
liscus, but, on the other hand, there is none between the
mastoid processes of that genus and the ocelli of the present
one.

68 GREVILLE, on New Diatoms.

Fenestrella Barbadensis, n. sp., Grev. (Fig. 8.)

Hab. Barbadoes deposit, from Cambridge estate, in a slide
communicated by C. Johnson, Esq.

The diameter of the disc is ‘0040’. Parallel lines lead-
ing to the ocelli, 8 in ‘001’. The most remarkable
feature in the disc, composed, as it is, of a radiating cellula-
tion, is the absence of a central point, there being neither
umbilicus nor centre of radiation, the band above described
lying like a bar across it.

CRASPEDOPORUS, noy. gen., Grey.

Frustules free, disciform ; disc divided into radiating seg-
ments, the alternate ones dilated towards the margin, and
bearing an intra-marginal ocellus or pseudo-opening.

In one species of this most curious genus the structure is
distincthy cellulate, but so irregularly as to bear no resem-
blance in this respect to Actinoptychus (Khr.) and its allies,
the walls of the cellules being thin and cobwebby. In the
other species the structure is more dense and opaque, and
scarcely any approach to cellulation can be perceived. There
are no septa, but the radiating segments or compartments
are defined by an undulation, or, perhaps, a slight fold,
the ocelliferous segments being very slightly raised above
the plane of the intervening spaces. The ocelli or pseudo-
openings are large and conspicuous, and appear to be concave
or foveate, with a somewhat prominent border, especially on
the side next the margin of the valve. In general character,
the genus would take its place among the Coscinodisci, but
the thickened and somewhat raised border of the ocelli
shows more affinity with the Hupodiscee.

Craspedoporus Ralfsianus, nu. sp., Grev.—Valve cellulate ;
ocelliferous compartments numerous, narrow and linear next
the central space, becoming spoon-shaped towards the margin ;
ocelli suborbicular. Diameter -0045”. (Fig. 9.)

Hab. Barbadoes earth, from Cambridge estate ; John Ralfs,
Esq. A fragment, in a slide communicated by C. Johnson,
Esq.

Structure an irregular network. Central space about a
fourth of the diameter of the disc, and somewhat more dense.
Ocelliferous rays eight, nearly lear for half their length,
then dilating into a spoon-like extremity, in which the
pseudo-opening is situated near the margin. The ocelli have
a distinct border, which is sometimes so much raised next
the margin as to cause it to resemble a little pocket. The

GREVILLE, on New Diatoms. 69

fragment in my own cabinet (half a disc) had, when perfect,
nine ocelliferous rays.

Craspedoporus Johnsonianus, n. sp., Grev.—Valve not visi-
bly cellulate, with five ocelliferous compartments; ocelli or
pseudo-openings large, transversely oval, close to the margin.
Diameter ‘0025’. (Fig. 10.)

Hab. Barbadoes deposit, from Cambridge estate ; C. John-
son, Esq.

In this species the compartments into which the disc is
divided are more equal, and it consequently bears some
general resemblance to <Actinoptychus (Ehr.). There is,
nevertheless, a great difference. In both species of our pre-
sent genus there is a sort of central nucleus, of considerable
size. No fine, decussating striation is perceptible; and the
whole structure is quite unlike the hexagonal cellulation of
Actinoptychus.

ACTINODISCUS, nov. gen., Grev.

Frustules free, disciform; valve granulose, with a central
nucleus and numerous broadly linear rays extending from
it to the margin.

This is distinguished from the last genus by the total ab-
sence of ocelli. The rays are not in the least degree wedge-
shaped, but are linear, about half the radius in length, and
resemble the spokes of a wheel. The structure is dense,
not showing any approach towards cellulation im any part.

Actinodiscus Barbadensis, n. sp., Grev. (Fig. 11.)

Hab. Barbadoes deposit, from Cambridge estate, in a slide
communicated by C. Johnson, Esq.

The most conspicuous feature in this disc are the numerous
rays, fifteen in number; they are slightly dilated at the
ends, and apparently somewhat thickened, but have not the
slightest indication of an opening. Diameter 0038".

AULACODISCUS.

Aulacodiscus inflatus, 1. sp., Grev.—Dise bullate beneath
the processes, the bullation causing a dark line of shadow
just within the margin; processes 4, submarginal, long,
cylindrical ; furrow defined by par allel lines of granules
reaching nearly to the centre, where the granules are arranged
irregularly round a somewhat quadrate blank space ; lines of
granules in the spaces between the inflations about 8 in ‘001”".
Diameter about 0035". (Fig. 12.)

70 GREVILLE, on New Diatoms.

Hab. Barbadoes deposit, from Cambridge estate; C. John-
son, Esq.

The section containing those species which have the pro-
cesses seated on an inflated portion of the dise is so limited
that there can be no hesitation in considering the one now
before us as new. It is more frequent than any other in the
particular sample of the deposit which has furnished so
many novelties. There are also at least three other Aula-
codisci about the same size with which it is associated, and
which are inflated beneath the processes. One of them is
the species next described. In another the inflations are
further removed from the margin, and are extended in an
oblong form nearer to the centre. In the third the inflations
are more or less rough with tubercles or apiculi, as in
A. Petersii, and the margin is besides distinguished by a
circle of gland-like tubercles.

Aulacodiscus mammosus, n. sp., Grey.—Dise very promi-
nently bullate beneath the processes, the bullations close to
the margin and forming elevated cones; processes long, cylin-
drical; furrows open, composed of two parallel rows of gra-
nules reaching the umbilical blank space. Diameter -0038",
(Fig. 13.)

Hab. Barbadoes deposit, from Cambridge estate ; C. John-
son, Esq.

This species may be known at once by the cone-like in-
flations, which are so elevated as to be completely out of
focus when any other part of the disc is examined; and they
rise so suddenly, and the sides are so steep, that it is impos-
- sible, in a vertical view, to see the structure. Having been
so fortunate as to discover a valve exhibiting a front view,
I am able to give the height of the bullation above the
surface of the disc, which is about ‘0010, and, including
the long cylindrical processes, ‘0012”! Indeed, they may
be not unaptly compared to thimbles. The ridges on
which the furrows are situated commence near the centre
with two parallel limes of granules, and gradually dilate, so
that, including the bullation (as viewed vertically), the whole
resembles in outline a child’s wooden battledore. On each
side of the ridge the granules are so arranged as to appear
like a fringe of diverging lines, while those on each side of
the bullations become widely radiating.

Aulacodiscus Kilkellyanus, un. sp., “Grev.—Dise with (3)
spherical, sub-marginal processes, and distant radiating lines
of minute granules, 7 or 8 in ‘001”, many of the lines not
reaching more than half way towards the centre; intra-mar-
ginal strize 31 in :001”. Diameter about 0040". (Fig. 14.)

GREVILLE, 0n New Diatoms. 71

Hab. Barbadoes deposit, from Cambridge estate ; C. John-
son, Esq.

A remarkably distinct and beautiful species, conspicuous at
first sight for the open character of the disc, arising from the
distance between the radiating lines, which, in regard to
length, are divided into several series, like the gills in an
Agaric. This is more or less the case in many of the species,
but here it attracts attention on account of the comparatively
small number of lines rendering the arrangement more visible.
The processes appear to the eye to extend as far as the mar-
gin. There is no bullation, and the connecting furrows are
so similar to the other interlinear spaces that they do not
form a prominent character.

I have great pleasure, in accordance with the wish of my
highly valued friend, Mr. Johnson, in bestowing upon this
exquisitely beautiful diatom the name of — Kilkelly, Esq.,
of Barbadoes, to whose kindness Mr. Johnson was indebted
for the material which has proved so rich in new genera and
species, and which has enabled us to extend so considerably
our knowledge of diatomic forms.

Aulacodiscus angulatus, n. sp., Grev.—Valve elevated in
the middle, and somewhat prismatic; the centre depressed,
with a blank umbilicus ; processes (5 or 6) without inflations,
submarginal; connecting furrows very narrow, on prominent
ridges. Diameter about -0040". (Fig. 15.)

Hab. Barbadoes deposit, from Cambridge estate ; C. John-
son, Esq.

The most characteristic feature in this species is the ele-
vated and somewhat angular form of the middle of the valve.
The centre is flattened or depressed, and surrounded by a
raised shoulder, from which the prominent furrow-bearing
ridges radiate to the processes. The prismatic form of the
dise will be best understood from the fact that when the
glass is adjusted for the shoulder and ridges the intermediate
compartments are quite out of focus. An additional angu-
larity is also imparted in consequence of the portion of the
raised shoulder which is left between the radiating ridges
being carried in a straight line between ridge and ridge, a
pentagonal or hexagonal effect (as the case may be) being
thus produced. The furrows are very narrow, the space being
often less than the diameter of the granules themselves, ex-
cept as they approach the processes. In the specimens which
I have examined, the processes seem to have been all broken
away, the roundish, blank spaces being quite flat.

Aulacodiscus spectabilis, n. sp., Grev.—Valve convex, with
the centre depressed, and a blank umbilicus ; processes (5)

72 GREVILLE, on New Diatoms.

without inflations, submarginal; furrows open, on slightly
convex ridges, regularly fringed on each side with short, gra-
nular lines. Diameter about 0050". (Fig. 16.)

Hab. Barbadoes deposit, from Cambridge estate ; C. John-
son, Esq.

Not prismatically elevated in the middle, as in the pre-
ceding species, but the centre is depressed, and the granules
irregularly disposed round the umbilicus, some of them, at
least occasionally, partially concentric. The connecting fur-
rows form a conspicuous feature, being twice as wide as the
diameter of the granules. From the two lines of granules
which define the furrows spring the fringe of short lines,
given off at right angles so regularly as to be pectinate, and
which increase in length near the processes and margin, like
the feathers on a bantam’s legs and feet.

Aulacodiscus pallidus, n. sp., Grev.—Valve pale, with nu-
merous (10) processes at some distance from the margin,
and radiating lines of minute puncta; connecting furrows de-
fined by two rows of puncta. Diameter -0035”. (Fig. 17.)

Hab. Barbadoes deposit, from Cambridge, estate in a slide
communicated by C. Johnson, Esq.

At first sight the present species appears to be very unlike
an Aulacodiscus, but the connecting furrows are sufficient to
establish its position. There is no umbilical vacancy ; the
radiating puncta commence at the very centre, and just before
reaching the circle of processes appear to sink down at an
obtuse angle to the margin, while the furrows are continued,
at a slight elevation, to the processes." The latter may have
been all broken off, as I can perceive merely the oval vacant
space, and a tubercle within it.

Aulacodiscus? paradoxus, nu. sp., Grev.—Valve divided by
radiating undulations into six compartments, filled with
decussating lines of distinct granules, each alternate com-
partment being in a higher plane than the rest, and pro-
vided with an intra-marginal, short process. Diameter 0040”.
(Fig. 18.)

Hab. Barbadoes deposit, from Cambridge estate, in slides
communicated by C. Johnson, Esq.

I have only seen two specimens of this most remarkable
diatom, but they are in so good a state as to render their
examination perfectly satisfactory. The general structure is
sufficiently characteristic of the genus, but in several points
of view the valve is anomalous. The equal division into six
compartments is more like Actinoptychus (Ehr.) and its allies,
and the resemblance is rendered more striking in consequence
of the alternate compartments lying in a different plane.

GREVILLE, 0n New Diatoms. 73

There is also something very unusual in the situation of the
processes. They are not placed at the termination of the
ridge-like folds which separate the compartments where we
should naturally look for them, but in the middle of each
compartment, next the margin; an arrangement which re-
minds us rather of the spine in Omphalopelta. Again, there
is no true connecting furrow. The usual law is a linear
channel, bounded on each side by a row of granules; or if
the channel or furrow be nearly obsolete, still the radiating
lines of granules run parallel with the obsolete furrow. There
is nothing like thisin A. ? paradoxus. The lines of granules,
which are beautifully arranged quincunx fashion, come down
obliquely from the ridge on each side, to meet in the middle
at an acute angle; and as the meeting of the two opposite
sets of lines is not exact, the end of one line often overlaps
the ends of another, and produces an irregularity which
attracts the eye, since it constitutes an obscure sort of line,
bearing, however, no resemblance to a furrow. The processes
themselves do not resemble those of the genus, being, as far
as I can make them out, mere oblong or linear-oblong
tubercles, in the middle of an elliptical blank space, and not
presenting the usual dilated base. In the centre of the valve
is a rather large umbilical space. This diatom will probably
form a distinct genus.

Evropiscus.

Eupodiscus punctulatus, n. sp., Grev.—Pale; disc slightly
convex, minutely and somewhat concentrically punctate ;
puncta smaller in the centre, then becoming equal through-
out; processes (4) marginal. Diameter -0032”. (Fig. 19.)

Hab. Barbadoes deposit, from Cambridge estate ; C. John-
son, Esq.

Clearly characterised by its minute, uniform punctation,
arranged somewhat in the manner of an engine-turned
pattern, there being no radiation in any part of the disc.
The four processes are rather small, circular, close to the
margin, and prominent when seen in profile,

Eupodiscus simplex, n. sp., Grev.—Dise slightly convex,
filled up with small, uniform, hexagonal cellules; processes
(2) large, circular, or broadly oval, at some distance from
the margin, within which is a row of very minute puncta.
Diameter about -0050". (Fig. 20.)

Hab. Barbadoes deposit, from Cambridge estate ; C. John-
son, Esq.

A most beautiful species, easily known by its regular net-
work of hexagonal cellules, which are about 7 in :001”. I

74 GREVILLE, on New Diatoms.

scarcely know what is the true form of the processes, as in
half the specimens I have seen they are not truly circular,
but tending to broadly oval.

AULISCUS.

Auliscus nebulosus, n. sp., Grey.—Valve circular (with 4
processes) ; no definite umbilicus ; radiating lines all uniform,
extremely fine; minute puncta, forming irregular clusters
beneath and between the processes. Diameter ‘0030’. (Fig.
21.)

Hab. Barbadoes deposit, from Cambridge estate ; C. John-
son, Esq., G. M. Browne, Esq. ; very rare.

Of this beautiful species various examples have occurred
to Mr. Johnson, Mr. Ralfs, and myself, but always with the
surface so abraded as to prevent description. Perfect speci-
mens have, however, been recently discovered. Nearly all
the frustules which have been seen present the singular
appearance of eight processes, the four of the subjacent valve
alternating with those of the upper, and being almost equally
conspicuous. In my figure I have represented the four
belonging tothe upper valve, in order to prevent confusion in
the engraving. As all the discs hitherto observed possess
this number, it is probably the normal one. The species
belongs to the group characterised by very fine and crowded
radiating lines ; but in the clusters of minute puncta, in the

neighbourhood of the processes, it is also allied to A. racemo-—

sus. It wants, however, the circle of marginal puncta. The
processes are circular, and large for the size of the disc.

Auliscus parvulus, n. sp., Grev.—Very small; valve circu-
lar, with 4 processes; structure obscure. Diameter ‘0015’.
(Fig. 22.)

Hab. Barbadoes deposit, from Cambridge estate, in slides,
communicated by C. Johnson, Esq.

I have been unable to make out any striation in the speci-
mens of this species which I have examined. It apparently
belongs to the same group as A. elaboratus and Johnsonianus,
having the same pale, semi-opaque, somewhat dense appear-
ance. I cannot refer it to any described species; and, m-
deed, it is so many degrees smaller than any one hitherto dis-
covered, that there is good reason to regard it as distinct. It
presents another example of valves with four processes.

Auliscus ambiguus, n. sp., Grev.—Valve broadly oval, the
whole surface filled up with a minute cellulation (no trace of
converging or radiating lines) ; cellules 11 or 12 in ‘001’.
Longest diameter ‘0022”. (Fig. 23.)

—_——

——_

GREVILLE, 0n New Diatoms. 75

Hab. Barbadoes deposit, from Cambridge estate, commu-
nicated by C. Johnson, Esq.

This is one of those anomalous forms which disturb the
natural habit of genera. In A. Ralfsianus we have a similar
instance, but in that case the indications of converging
lines could be perceived by an attentive observer in the
direction of the puncta within the meshes of the network.
Here, however, we have a very minute cellulation covering
the entire valve (with the exception of the processes), without
any indication of converging lines at all. At the same time
the diatom is evidently an Auliscus, the processes being un-
mistakable, and, as in all the other non-circular species, they
are placed, not in the exact line of the longest diameter, but
on each side of it. I have examined two specimens and the
fragment of a third, all of which are precisely alike.

TRICERATIUM.

Triceratium lineatum, n. sp., Grev.—Valve with a dense,
obscurely radiating structure, nearly straight sides, subacute
angles, and prominent pseudo-nodules; within each angle
three remote lines, sub-concentric with the angles. Distance
between the angles about ‘0040". (Fig. 24.)

Hab. Barbadoes deposit, from Cambridge estate; C. John-
son, Esq.

One of the most distinct species in the whole genus. The
remarkable lines within each angle include the greater part
of the surface. The structure is more or less opaque, ex-
hibiting an obscure radiation in the centre and an exceed-
ingly fine striation between the curved lines. The pseudo-
nodules are not large, but very conspicuous.

PEpontiA, nov. gen., Grev.

Valves sub-circular, conspicuously cellulate, suddenly con-
tracted, above and below, into a triangular apiculus ; cellules
round.

The definition of this genus must be regarded as provi-
sional until the front view of the frustules can be obtained.
Of the valve I have seen a very considerable number of speci-
mens, and in several instances the opposite valve partially
displaced, as shown in the figure, which shows that the con-
necting zone must be narrow. ‘The apiculus has sometimes
a distinct appearance of being furnished with a nodule or
short process, but I have not been able to satisfy myself on

76 GReEVILLE, on New Diatoms.

this point. This diatom is so exceedingly peculiar that, not-
withstanding the deficiency of the front view, and, conse-
quently, our ignorance of its precise place in the system, J
do not hesitate to make it known.

Peponia Barbadensis, n. sp., Grev. (Fig. 25.)

Hab. Barbadoes deposit, from Cambridge estate (not un-
frequent) ; C. Johnson, Esq.

Valve yellowish, more or less circular, the transverse dia-
meter being often the longest, suddenly contracted at the
opposite ends into a triangular, subacute apiculus. Whole
surface filled up with rounded cellules, largest in the middle.
In size the valves vary greatly, from ‘0020” to upwards of
0030" in diameter. Between the body of the disc and the
apiculus there is the appearance of a septum. The apiculus
itself is generally, but not always, destitute of cellules.
The individual figured is the finest I have seen.

THAUMATONEMA, nov. gen., Grev.

Frustules united into a filament; valves disciform, each
producing a central, forked process, which is articulated at
the apices with that of the opposite valve.

From the front-view position of the frustule it is difficult
to ascertain precisely the nature of the structure of the dis-
coid portion of the valve, but it appears to consist of radiating
lines of minute puncta. The genus, I presume, must be
placed among the Melosiree.

Thaumatonema Barbadense, n. sp., Grev. (Fig. 26.)

Hab. Barbadoes deposit, from Cambridge estate, in a slide
communicated by C, Johnson, Esq.

An extraordinary diatom, unlike anything previously de-
scribed. If the valves of Melosira West, instead of being
joined by their narrow, truncated ends, were each provided
with a central process widely forked, the apices of the forks
somewhat dilated and articulated with the forks of the oppo-
site valve, a tolerably accurate idea would be conveyed of
this singular production. Length of two valves, with pro-
cesses in situ, 0038". Breadth of valve, and also of the space
between the articulations of the forks, ‘0017’. Length of
process, including the fork, the one being about equal to the
other, ‘0013”". .

On the Nerves of the Cornea, and of their DistR1BuTioN
in the CorNEAL TissuE of Man and Antuats. By J. V.
Craccio, M.D., of Naples.

(Read May 13th, 1863.)
(Pl. VI and VII.)

Sryce Schlemm’s discovery of the nerves of the cornea up
to the present time nearly all observers who have investigated
the subject agree that these nerves, after dividing and sub-
dividing, terminate in a wide network, composed of non-
medullated or pale nerve-fibres. The ultimate arrangement
of this network has not yet, however, been fully pointed out,
neither has any one proved whether it exhibits the same
arrangement in different animals as in man. With the hope
of throwing some light upon a _ subject at present so
little known, I have made many observations on the cornea
of the sparrow, eel, frog, mouse, and man, and the conclusions
which I have arrived at will be detailed in the paper which
I have the honour to bring before the notice of the members
of this Society.

The great importance of the present inquiry, I imagine,
will be generally admitted. The cornea is endowed only
with common sensibility, so that when we have established
with certainty the manner in which the nerves terminate in
it, we may, with some reason, infer the mode of ending of
the nerves in the other parts possessing the same kind of
sensibility. By comparing, then, these results with those
hitherto obtained by observers, in reference to the ending of
motor nerves, the debated question about the terminal distri-
bution of these two kinds of nerves, perhaps, will be finally
settled. But this inquiry is as difficult as it is important.
Of the many difficulties which I have met with, I shall only
now allude to those which seem to me to be the greatest.

1. The first is, that the nerves of the cornea in all their
course continually change the plane and direction of their
distribution, so that in making very thin sections for micro-
scopical investigation, not only is the relative position of
nerves and the adjacent tissues altered, but those nerve-fibres
which we observe in the thin sections very often exhibit such
appearances that they are hardly recognised by the most ex-
perienced eye as nerve-fibres.

2. The second difficulty consists in this, that the optical
properties of the nerves and other elementary parts of the
cornea are such that, without the aid of some chemical

78 Craccio, on the Nerves of the Cornea.

agents, it is impossible for the nerves to be seen. But by
the use of chemical agents the natural aspect of the nerves
is always altered, and if we are not very careful in using
them, we may destroy the finest fibres.

3. The third difficulty arises from the peculiar structure
of the cornea itself, which contains a very large number of
corpuscles, with many anastomosing processes. This un-
doubtedly causes much difficulty in tracing the ultimate
nerve-fibres running through its lamellated structure; and
if we do not use much diligence in observing, we may mis-
take the processes of the cornea-corpuscles for the finest
nerve-fibres, and draw the erroneous conclusion that there
exists an intimate connexion between the nerve-fibres and the
cornea-corpuscles.

It seems to me that these three difficulties which I have
mentioned, if not totally, can at least in part be surmounted.
In fact, if we select for the microscopical investigation those
animals in which the cornea is not thick, we shall find that
the first difficulty decreases in proportion as the thickness of
the cornea which we have to examine diminishes. Hence
the cornea of small birds, of the frog, mouse, and so on, are
more suitable for investigation than that of man or the larger
animals. I have found by experience that in the sparrow’s
cornea the nerves can be easily seen and traced for a very
long distance, because in this little bird the distribution of
nerves is more simple than in the mouse and frog, and the
thickness of its cornea is such that by only dividing it trans-
versely we are enabled to examine it with high powers. We
cannot, In my opinion, completely overcome the second diffi-
culty in the present state of our knowledge; but the only
thing we can do is to moderate, in some way, the chemical
action of those agents which we are obliged to employ for
bringing out the nerves, which le hidden among the proper
fibrous tissue of the cornea. In such a case the best way is
to employ only a small quantity of the reagent, because, if
required, we can always add more; while, on the contrary,
we can never remedy the harm produced by a large quantity.
The third difficulty can only be avoided if we are careful in
observing. The processes of the cornea-corpuscles generally
exhibit such an appearance that they are with great difficulty
distinguished from the finest nerve-fibres. Like the nerve-
fibres, they become granular by the action of acetic acid.
How much this increases the difficulty it is hardly necessary
to say. In no other way, therefore, we can distinguish the
processes of the cornea-corpuscles from the finest nerve-fibres,
but by following both to their respective origins, viz., the

uu
:
L

Craccto, on the Nerves of the Cornea. 79

former to the cornea-corpuscles, and the latter to the branches,
from which they are derived. I say, candidly, that when IL
commenced this inguiry, I had fallen into the error of believ-
ing that, if not all, at least some of the finest nerve-fibres
distributed to the cornea, really terminated in its cor-
puscles; but a rigid and exact investigation has since
convinced me that I was greatly mistaken. I have often
succeeded in tracing beyond the cornea-corpuscles some
nerye-fibres which, at first, seemed to end in them. ‘The
truth is, that sometimes some of the finest nerve-fibres,
which could be followed as far as the cornea-corpuscles, could
not be traced further on, so that they appeared really to
terminate there. But I think this appearance depends on
the continuation of the fibre being destroyed either by the
pressure of the thin glass, or by the action of the chemical
agents which we are obliged to employ. Because if it were
not so, the above-mentioned appearance would be more fre-
quently observed.

After these brief remarks upon the great importance and
the difficulties of the present inquiry, I shall proceed to state
what my observations have shown with regard to the distri-
bution and termination of the nerves of the cornea; and I
shall divide, but only for the sake of a clear and methodic
arrangement, the whole subject into two parts. In the first
part the nerves, with all their peculiarities, will be considered ;
and in the second, the manner in which they end will be
described in detail.

I.—Or THE PLACE WHERE THE NERVES ENTER INTO THE
CORNEA—OF THEIR NUMBER AND SIZE.

The nerves of the cornea derived from the ciliary nerves
pass from the sclerotica into the laminated structure of
the cornea, rather nearer the posterior than the anterior
surface. They are seen at its margin in the form of several
fine trunks, which, as they pass in different directions from
their entrance, form with the border of the cornea various
angles. I have observed that, when the cornea of some
small animals, namely, frog, eel, mouse, and sparrow, is
transversely divided into two parts, at the microscopical ex-
amination, most of the fine trunks divided across their course
are found in the section corresponding to the posterior part
of the cornea, while the network formed by them is found in
the anterior part. The conclusion from this observation is,
that the nerves, in entering the cornea towards its posterior
surface, after dividing and subdividing, reach the anterior

VOL. XI. g

80 Craccio, on the Nerves of the Cornea.

surface, where they end in a very composite network or

plexus.

The number of the nerves of the cornea varies very much
in different animals. This number can be determined with
some certainty only in small animals, because in the larger
ones the cornea is so thick that in order to examine it with
high powers, it is necessary to make very thin sections, in
which we very often fail to find any nervous trunks, or not
more than one or two. In small animals, on the contrary,
the cornea is thin enough to be examined microscopically,
either entire, or only divided transversely into two parts.
According to my observations, in the cornea of the sparrow
there are thirty-one nerve-trunks; in that of the mouse
twenty-six, and in that of the frog about thirty. I say about
thirty, because, im a sixth part of the cornea of this animal,
I have seen nearly five trunks. Supposing, then, that in
each of the remaining parts were the same number, the total
sum will be as above. But this supposition is not quite cor-
rect, for in the cornea the nerve-trunks are not at equal dis-
tances from one another, so that in one part the number of
the nerve-trunks may be greater than in another part. In
the cornea of the frog, therefore, the nervous trunks may be
more or less than thirty.

Some observers have asserted that the nerves of the cornea
in man are from twenty-four to thirty-six; but every one
who considers the difference between twenty-four and thirty-
six, will at once see that this is only a mere assertion, and
nothing else. In man, as in other large animals, I believe
it .is very difficult to ascertain the precise number of the
nerves of the cornea. I must say that, in calculating the
nerve-trunks distributed to the cornea of the animals above
mentioned, I have not taken the slightest notice of those very
fine trunklets which, together with the large ones, enter the
cornea at various depths.

The corneal nerves also vary much in size. Not only is
there a great difference in the size of the various trunks in
the same animal, but between those of different animals
when compared the one with the other. From my observa-
tions, I am led to the conclusion that the nerves in the cornea
of the mouse are larger than those in the cornea of the eel,
frog, and sparrow.

The manner in which the nerves of the cornea branch.

It is generally admitted that the mode of distribution of
nerves to the cornea is effected by dichotomous division.

|
|

Craccio, on the Nerves of the Cornea. 81

Undoubtedly this is the general rule, nevertheless, I have
observed, although very rarely, in the cornea of the frog and
Sparrow, some large branches dividing into three or four
smaller ones. There are, however, in the mode of branching
of these nerves some points worthy of special note, which I
shall presently allude to.

Not all the nerve-trunks of the cornea begin to divide at
the same distance from its border. Some of them divide as
soon as they enter, while others do so after running for
some distance through its fibrous tissue. I have sometimes
seen two distinct trunks in the sclerotica converging more
and more as they approach towards the border of the cornea ;
but as soon as they arrive there they unite into a single trunk,
which enters the cornea and divides in the same manner
as the others. At other times I have observed a large trunk
running through the sclerotica like a single trunk; but as
soon as it reaches the margin of the cornea, it divides into
branches, which, as two distinct trunks, penetrate into the
cornea, and pass in different directions.

The division and subdivision of these trunks is generally
effected at angles more or less acute. It is seldom that we
observe a trunk or branch dividing at right angles. The
distance from one to the other division varies greatly. In
some cases, while from the first to the second division of a
trunk there is a great distance, from the second to the third
there is very little. As the nerves, however, approach their
ultimate distribution, the distance among the divisions be-
comes less and Jess. All the branches resulting from these
divisions are not of the same size. It sometimes happens
that we observe two nerve-trunks of various sizes entering
the cornea one close to the other, and while one divides into
two branches, the other, without dividing, unites with the
smaller branch, and the compound trunk thus formed runs
on. It is also not unfrequently observed that, from a trunk
before its regular division, a bundle of fibres separates at a
very acute angle, which, after a more or less circuitous course,
unites with one of the other branches of the same trunk, or
with that from another trunk.

The nuclei in connection with the nerves of the cornea.

Dr. Beale, from his numerous investigations upon the
peripheric distribution of nerves, has been led to the conclu-
sion that, in connection with all nerve-fibres, there are little
oval bodies, or nuclei, which form an integral part of each
separate fibre, and increase in number as the nerves approach

82 Craccio, on the Nerves of the Cornea.

their ultimate distribution. This general conclusion of Dr.
Beale cannot be accepted as regards the nerves of the cornea.
The nuclei, as I have observed, are very numerous in the
trunks and primary ‘branches of the nerves of the cornea,
but as the nerves reach their termination, these bodies gra-
dually decrease in number. ‘They are frequently seen in
connection with single nerve-fibres, but sometimes more than
one fibre is seen connected with a single nucleus. As to
the number and size of these nuclei, there is much variety.
I have found that in the nerves distributed to the cornea of
man and the mouse, the nuclei are comparatively more nume-
rous and broader than in the frog and sparrow.

Besides these nuclei connected with the nerve-fibres, I have
seen, especially in the frog, another kind of nuclei, which lie
on a more superficial plane than the former, and are spindle-
shaped and sometimes so bent on themselves as to exhibit
the form of the letter S. They are not arranged in the same
linear direction as the nerve-fibres, but incline to them ob-
liquely. I have been able to see these nuclei in the trunks
of the nerves and the largest branches; and I hold strongly
to the opinion that they are the special organs upon which
depends the growth and repair of that clear transparent
material in which the nerves at their peripheric distribution
are imbedded.

I cannot say from my own observations whether the other
nerves of common sensation have the same peculiar charac-
teristic as those of the cornea. There are, however, some
observations of Dr. Beale which satisfactorily clear up this
point. This able observer has investigated and figured ina
beautiful drawing the distribution of nerves in the mucous
membrane covering the human epiglottis. Every one who
attentively looks at this drawing will distinctly see branches
of nerve-fibres in connection with triangular as well as with
oval bodies. These bodies, however, in comparison with the
large number of the nerve-fibres, are very few, and the greater
part of the fibres represented in the drawing appear entirely
destitute of nuclei. This is not the proper place to discuss
whether the bodies alluded to are to be regarded as simple
nuclei, or as peculiar organs. I need only remark for the
present that the general appearance exhibited by the nerves,
which are distributed to the mucous membrane of the human
epiglottis, is, with some exceptions, the same as in the cornea.
Now if we conipare the before-mentioned drawing with those
given by the same observer of the termination of nerves in
the elementary fibres of striped muscles, we shall find a re-
markable difference between them. The motor nerve-fibres

Craccio, on the Nerves of the Cornea. 83

delineated in these drawings are seen largely nucleated. The
nuclei in connection with each individual fibre are often
equal to the fibre itself in width, and at short distances from
one another. Not one of those large oval or triangular
bodies often found in connection with the terminal branches
of the nerves of common sensation can be seen here. It
appears to me, therefore, that upon this progressive increase
of nuclei in motor nerves, as they approach their termination,
and on the remarkable diminution of them im sensitive
nerves, which, besides, are connected at their ultimate dis-
tribution with peculiar bodies, we can, with some degree of
reason, establish a fundamental distinction between the
terminal portions of motor and sensitive nerves. I cannot
flatter myself that this conclusion will be accepted as an
unquestionable fact by the generality of observers, because
more numerous and accurate observations are required for
establishing beyond any doubt its exactness. For the
present it is enough for me to have made an attempt to point
out some peculiarities which are found in motory and sensitive
nerves respectively at the periphery. I firmly believe that
when comparative investigations have been more advanced
than they are at present, we shall find something peculiar
not only in the termination of the nerves of motion and
common sensation, but also in that of every nerve of special
sensation.

The limiting investment of the nerves of the cornea.

The primitive fibres, of which the nerves of the cornea
are composed, as it may he easily observed, are in more or
less close apposition with one another. This depends upon
the nerve-fibres being imbedded in a transparent homogenous
substance, which forms not only a common covering to all
fibres composing each separate nerve, but also a special one
to each single fibre. The nerves in their ultimate ramifica-
tions are only separated from the adjacent parts by this
material. According to Dr. Beale, the presence of this
transparent substance is owing to the changes the nerves are
continually undergoing during life, and undoubtedly he has
brought forward a sufficient amount of evidence in favour of
this view. Notwithstanding, I feel inclined to consider the
above-mentioned material as a peculiar form of connective
tissue, produced by a special kind of nuclei. Of these nuclei
I have already spoken, and have stated the reasons why they
are to be regarded as different from the nuclei connected
with the nerye-fibres. I believe that this form of connective

84 Craccto, on the Nerves of the Cornea.

tissue has different degrees of firmness in the nerves of
different animals, and that in the same nerve its firmness is
gradually diminishing from the trunk to its terminal branches.
If this supposition is not allowed, the facts which we are
observing must remain either unaccounted for, or we must
admit that’ the nerves at their termination lose the common
investment, only retaining the special one to each separate
fibre. Although the latter supposition has many degrees of
probability in its favour, and explains very satisfactorily the
continual change of position which the nerve-fibres undergo,
as the trunks, dividing and subdividing, reach their ultimate
distribution; yet there are some facts which positively de-
monstrate that, in some animals, the finest nerve-branches
are provided with the same common covering as the trunks,
from which they originate. Thus I have observed that, in
the cornea of the sparrow, the individual nerve-fibres that
compose the trunks and all the branches imto which they
divide, scarcely undergo any change of position. In this
small bird the nerves of the cornea in the trunks, as well as
in all the branches, exhibit the general appearance of large
twigs, which, by dividing and subdividing, gradually diminish
in size. So great is the firmness of the connective tissue
which holds together the individual nerve-fibres, composing
the nerves distributed to the cornea of this bird.

Number, size, and relative position of the primitive nerve-
fibres composing the nerves of the cornea; their division
and nature.

The number of the primitive fibres which compose the
nerve-trunks of the cornea, is found to vary according to their
size. But sometimes we observe in animals of different kinds
nerve-trunks of the same size, containing various numbers of
primitive fibres. This depends upon the different diameters
of the nerve-fibres, as some of them are thicker than others.
According to my observations in the mouse, the primitive
nerve-fibres are larger than those of the frog and man; and
in the sparrow they are much finer.

Before the nerve-trunks of the cornea begin to branch, the
primitive fibres composing them undergo a very little change
of position, but as soon as their branching begins the change
of position takes place, and increases as the division of the
nerve-trunks goes further on. In different animals this
change of position does not occur to the same extent. Thus,
for instance, in the frog and eel the nerve-fibres change their
relative position very frequently and extensively, but less in

Craccio, on the Nerves of the Cornea. 85

the mouse. In the nerves distributed to the cornea of the
sparrow scarcely any change in the relative position of the
primitive nerve-fibres is observed. ‘The change alluded to is
effected in this manner :—A fibre running close by the side
of another is seen to leave it and unite with a new one, with
which, after proceeding for some distance, separates again
and passes with another fibre or with its first companion.

Some observers have asserted that primitive nerve-fibres
are seen dividing, although seldom, in the trunks of the
nerves of the cornea, but such division never occurs in the
network or plexus formed by them. This assertion is not
supported by actual observation. When we consider the
number of the primitive fibres contained in the trunks, and
compare it with the numerous fibres into which they re-
solve themselves, we must come to the conclusion either
that the fibres of which the nerve-trunks are composed divide
and subdivide freely, as the trunks themselves divide and sub-
divide; or that what appears in the trunks to be a primitive
fibre is not a single fibre, but a compound one. I have tried
many times to follow some of these primitive fibres as far as
I could, and I have always seen them gradually reduced into
finer and finer fibres. I feel quite convinced, therefore, that
the primitive fibres observed in the nerve-trunks of the cor-
nea are not single fibres, as is generally believed, but com-
pounded, of several finer fibres held together by that peculiar
kind of connective tissue already spoken of. Dr. Beale has
been led to conclusions of a similar kind from his observations
upon the nerves distributed to the mucous membrane which
covers the human epiglottis.

1t is well known that the opmion generally received as
regards the nature of these primitive nerve-fibres, is that the
nerves of the cornea “contain fine dark-bordered primitive
tubes only at the margin of the cornea, within a zone half a
line to one line in average breadth, while in their further
course they possess only non-medullated fibres, completely
clear and transparent” (Kolliker). In my own specimens
such distinction is not observed. All the nerves, from the
entrance into the cornea to their ultimate distribution, do not
appear to contain any fibre which could properly be called dark-
bordered, All the fibres exhibit the same appearance and
refract the light in the same way. I have, amongst many
others, a specimen in which all the nerve-fibres, from the
margin of the cornea to their termination, have been so acted
upon by acetic acid as to display a very remarkable granular
appearance. With the purpose of ascertaining the chemical
nature of these granules I have treated some specimens which

86 Craccio, on the Nerves of the Cornea.

presented such appearance with ether, and have found that
some of the granules were readily dissolved by the ether,
while others resisted its action. The natural conclusion from
this experiment is that the so-called non-medullated or pale
nerve-fibres consists of fatty matter in combination with a
protein compound. On being disintegrated by the action of
acetic acid, both assume the granular form. Nevertheless it
must be borne in mind that, although the pale nerve-fibres,
by the action of acetic acid, pass through the change I have
already mentioned, yet they never lose their outlines, which
only become paler and indistinct.

An alteration precisely resembling that which has been
described is also effected by acetic acid on the cornea-cor-
puscles and their branching processes ; and the granules thus
produced are acted upon by ether in the same way as those of
the pale nerve-fibres. This I mention incidentally, because
I am not sure whether it has been noted by those who have
purposely studied the subject. I believe that a comparative
study (histological as well as chemical) of the cornea-cor-
puscles would afford more positive information upon their
nature than we now possess. Careful observations have shown
that these corpuscles have not the same appearance and size
in man, cat, and mouse, as in the frog, eel, and sparrow.

I must not omit to say, finally, that the nerves distributed
to the cornea of different animals are not of the same degree
of firmness. I have found that in the sparrow, frog, mouse,
man, and fishes, the firmness of the nerve-fibres decreases in
the order in which I have mentioned the animals. It is not so
easy, therefore, to make out the nerves in the cornea of man
and fishes, because the nerve-fibres being extremely soft are
so altered by the chemical agents which we are obliged to
employ, that it is more difficult to trace them among the
other elements of the corneal tissue than in the other in-
stances.

Channels which contain the nerves running through the
corned.

This question, as it seems to me, must be considered from
two different points of view. If the term channels is here
taken in the meaning of grooves or spaces excavated through
the fibrous tissue of the cornea, where the nerves lie, the
existence of such channels cannot be doubted. But if, on
the contrary, the word is understood in the sense in which
it is generally used, viz., as signifying tubes with distinct and
-proper walls, I strongly hold that, in this meaning, such

Craccro, on the Nerves of the Cornea. 87

channels do not exist at all im the cornea. I have never suc-
ceeded in seeing one of these channels, and I am convinced
that the nerves distributed to the cornea are not separated
from its fibrous elements by any other means but by that
special transparent material in which they are imbedded.

id?

In the first part of this paper I have spoken of all
those peculiarities which are found in the nerves of the
cornea; I propose, in this second part, to explain the man-
ner in which they terminate, and also their relation to the
cornea-corpuscles.

I have studied this point with all possible attention, and
I can state positively that the nerves of the cornea do not
terminate in free extremities. I have often succeeded in
tracing some of the nerves from their entrance into the
cornea to their terminal distribution, and I have observed
the union of the ultimate branches one with the other. But,
if the nerves of the cornea do not end by free extremities, in
what manner are they arranged in their ultimate distribu-
tion? The results of many investigations which I have
made upon the cornea of several animals, have led me to con-
clude that the nerves of the cornea terminate in a network
or plexus. I attach a different meaning to each of these two
terms, which are generally employed almost synonymously.
I understand by the arrangement of nerves in a network,
when the different bands of fibres are not so interlaced with
each other as to prevent us from recognising their respective
origins ; and by the term plexus, when such an intermingling
of the bundles of nerve-fibres exists, that we cannot distin-
guish the point of their derivation.

Observation shows that sometimes the network seems to
result from the close apposition or coalescence of one branch
with another, without any visible interlacement of the pri-
mitive nerve-fibres which compose the uniting branches, and
at other times from the intermixture of the fibres of one
branch with those of another. Hence two varieties of net-
work ; the one, which may be called network by the coales-
cence of nerve-branches with one another, and the other net-
work by the intermixture of the nerve-fibres of one branch
with those of another. With regard to the plexus, as the
meshes produced by the inextricable union of the various
nerve-bundles may be either large or narrow, so two varieties
could also be formed, and called the one plexus with large,
and the other with narrow meshes.

88 Craccio, on the Nerves of the Cornea.

Having advanced these short considerations on the manner
in which the nerves of the cornea in their ultimate distribu-
tion are arranged, I pass on to say more particularly where I
have found these distinctions existing.

1. Network by the coalescence of nerve-branches with one
another.—I have observed this variety of network in the cornea
of the sparrow. The trunks of the nerves, which enter the
cornea of this little bird, are seen at different pomts from
- the corneal margin to divide and subdivide, and the immensely
numerous branches which result from these repeated divi-
sions are frequently observed to anastomose with each
other. When a branch is uniting with another no interlace-
ment of their fibres appears to take place; but they seem, so
to speak, to fuse into a single larger branch. The branches
generally unite themselves at angles more or less acute ;
sometimes, however, they appear to unite at regular right
angles ; and when such occurs, one of the branches forming
the angle sends out a fibre on each side of the point of junc-
tion parallel with the other branch. Thus it would appear
from such circumstances that the arrangement in the cornea
of the sparrow is the most simple and regular.

2. Network by the intermixture of the nerve-fibres of one
branch with those of another,—The second variety of network is
found in the cornea of the frog and fishes. I have previously
mentioned that, in the cornea of these animals, the different

primitive fibres which compose the branches spread out and

frequently change their relative position. Thence it happens
that, when one branch unites with another, a very percepti-
ble interlacement of their fibres takes place. I have often
followed some trunks to their furthest branches, and ob-
served that the disposition of these very fine branches is
the same as with the larger, and that the anastomoses among
them are of the same character as those between the main
branches, J think I may safely argue from the above state-
ments that the networks in the frog and fishes are more com-
plicated in their formation than that of the sparrow.

3. Plexus with wide meshes.—The nerves which are dis-
tributed to the cornea of the mouse terminate in this variety
of plexus. The ultimate branches of each trunk unite to-
gether in such a manner as to form meshes which have not
all the same dimensions, but are in immediate continuation
one with the other. The meshes generally assume an irre-

a

|

Craccro, on the Nerves of the Cornea, 89

gular, pentagonal, or quadrilateral form, but sometimes they
are seen exhibiting other shapes. The bundles of fibres,
from the intermingling of which the meshes are produced,
are of different sizes, and disposed in curved lines. Very
often, from various parts of the meshes, fibres more or less
fine are seen to arise, which cross the field of the meshes in dif-
ferent directions ; and after a tortuous course, and continually
change of plane, either unite with other fibres, which pro-
ceed from distant bundles, or with the bundles themselves.
These fibres, which, from their thinness, would lead us to
consider them as single, are never found in this state, but
are made up of at least two fibres, and generally more.

4, Plecus with narrow meshes.—From what I have ob-
served, I feel sure that the nerves distributed to the human
cornea terminate in a very extensive plexus with narrow
meshes. The plexus is not formed by single, separate nerve-
fibres, but by bundles, which are in direct continuation with
the smallest branches, into which the trunks, by repeated
division, are reduced. In some of my specimens these
branches may be seen crossing the corneal tissue in different
directions, and may be followed for a long distance, before
they are observed to divide into the bundles before mentioned.
As the fibres which compose the bundles are extremely
pale and transparent, and are also greatly softened and
changed very soon after death, considerable difficulty exists
in the investigation of this plexus, which can only be seen
in good specimens prepared in a particular way.

These different kinds of networks and plexuses, which have
been described, extend throughout the anterior part of the
cornea, and gradually cease towards the posterior portion.
It must be observed that the various bundles forming these
networks and plexuses are frequently changing the planes
and direction of their ramifications, so that each separate
bundle during the whole of its course comes into contact
with several other bundles. I have before stated that the
principal trunks of nerves, on entering the cornea, are very
near to its posterior surface, and pass in an oblique direction,
repeatedly dividing, and at length reach the anterior surface.
In this fact, which seems to me to admit of no further dis-
pute, is found the explanation why, in the whole space over
which the networks and plexuses extend, the different
branches which enter into their formation are of unequal size,
and the finest branches are found in that part of them which
lies immediately beneath the anterior elastica lamina of the
cornea,

90 Craccio, on the Nerves of the Cornea.

In connection with the nerve-branches or bundles which
compose both the networks and plexuses before mentioned,
are observed several small bodies, triangular, or quadrangular,
or even of an irregular shape. ‘These small bodies are not
all of the same size, and some of them appear of a uniform,
granular structure, whilst in others I have found nuclei im-
bedded in the granular matter. These nuclei are prominently
coloured by carmine, whereas the granular matter is not, or
only very slightly affected by this substance. From these
bodies bundles of fibres are seen to proceed in three, four, or
more directions, while some other fibres pass close by them
without being absolutely connected with the same. In the
first variety of networks these bodies are few in number, and
sometimes are found just at the point at which a branch is
met by another; and in this case they are of a quadrangular
form, and at others, at the point where a bundle of fibres
bifurcates, and then present a triangular shape. In the
second varicty the small bodies are more numerous, and may
exhibit an oval, triangular, or quite an irregular form, and
are found either amongst the fibres which compose the large
branches, or at the point of union of the bundles with each
other or where they divide. Again, in the first variety of
plexuses, the bodies alluded to are generally met with at the
angles of the different meshes forming the plexus, and are
usually either triangular or quadrangular. ‘They contain
granular matter, and sometimes a nucleus may distinctly be
seen at their centre or at one of the angles. As to the
second variety, I confess I have not succeeded in seeing any
of the bodies I had found in the first variety of plexuses. I
believe I have failed because the human corneze which I
could get for investigation were not so fresh as is requisite
for carrying out successfully such delicate researches. I say,
however, that in some specimens from man’s cornea I have
observed most distinctly very fine nerve-fibres connected with
certain small bodies exhibiting a triangular or quadrangular
form, but as the fibres ran for a long distance in straight
directions, I cannot help doubting their nervous nature.

Now here arises the question: What is the nature of the
bodies which have been described? Are they to be considered
as special organs connected with the terminal portions of the
nerves of common sensation? or are they not at all different
from the nuclei which, as I have said before, are observed to
be very numerous in connection with the mdividual fibres
composing the trunks and the largest branches of the nerves
of the cornea? It seems to me that Dr. Beale, who, so far
as I know, was the first to point out the existence of these

Craccto, on the Nerves of the Cornea. 91

bodies in the terminal branches of the nerves distributed to
the mucous membrane covering the human epiglottis, and
who spoke of them, without any distinction whatever, as
nuclei, could have thought them any way different from the
ordinary nuclei which are generally found in connection
with the nerve-fibres at their peripheral distribution. I
regret I cannot agree with Dr. Beale on this point, because
I find a remarkable difference between these bodies and the
common nuclei. In fact, as observation shows, the nuclei
connected with the nerve-fibres are always of an oval form,
and equal in breadth to the fibre itself. Each single fibre
contains several of them, separated from one another by
little intervals, and arranged i in linear series. They are seen
varying greatly in number, according as the nerves are
examined at an early period of development or in the adult
state. On the contrary, the small bodies which are con-
nected with the terminal branches of sensitive nerves are
often triangular, quadrangular, or may exhibit some other
form. As regards the fibres proceeding from them, these are
very fine, and the relation they bear to the small bodies
differs from that existing between the common nuclei and
the nerve-fibres. Their number is not observed to vary
according to the different periods of development of nerves,
and they only appear to exist in greater number and to be
more distinct in those animals in which there is reason to
believe that the cornea is more sensitive. Besides, we must
add, that the more the nerves approach the full development,
the more perfect and complete the structure of these bodies
appears to be. I think, therefore, that sufficient difference
exists between these two kinds of small bodies to enable us
to draw a marked distinction between them. Yet if we are
not allowed to consider them as special organs of the terminal
portion of the nerves of common sensation, it must still be
admitted that they have something similar to those peculiar
triangular nuclei which exist in connection with the nerves
of special sensation at their ultimate distribution.

It is not my intention to enter into any deep physiological
speculations with regard to the office of these special bodies,
and the nuclei which are observed in the nerves distributed
to the cornea. Yet I cannot forbear expressing my opinion
on this subject. I believe that the nuclei are the agents
which are concerned in the formation and repair of nerve-
fibres which are continually undergoing change during life ;
while, on the other hand, I hold that the above-named small
bodies take an active and important part in the phenomenon
of sensation, aud are the only organs by means of which the

92 Craccio, on the Nerves of the Cornea.

finest branches of sensitive nerves are brought into relation
with the tissues in which they ramify. The opinion I have
just expressed seems to me to be corroborated by this fact,
that the nerve-fibres which proceed from the ganglion-cells
are more or less nucleated. Now I ask, what is the office of
these nuclei which are seen in connection with the fibres near
their point of origin from the cells? It does not appear very
probable that they are concerned in the formation and repair
of the fibres while the cells are charged with a higher and
more important office. If such a conclusion be not ad-
mitted, the function of these nuclei must remain unexplained.

Relation of the terminal branches of nerves to the cornea-
corpuscles.

Scattered throughout the fibrous tissue of the cornea are
an immense number of bodies which Virchow, who studied
them carefully after their discovery by Toynbee, called cornea-
corpuscles. From each of these corpuscles arise several
branching processes, which freely anastomose with each
other so as to form an admirable network, which extends
over the whole so-called proper cornea. ‘These corpuscles
are intensely coloured by carmine, while their processes
remain or are very slightly coloured. Now, it must be ob-
served that the branches of the nerves which supply the
cornea during their course, are in close contact with the
cornea-corpuscles and their processes. I have often seen
very fine nerve-fibres passing close by some of these cor-
puscles, and as their external appearance is the same as that
of the processes, which are derived from them, it is difficult
to distinguish the former from the latter. It appears to me,
therefore, that between the nerve-fibres and the cornea-cor-
puscles there is no other relation but that of contiguity ;
because careful observations show that the nerve-fibres
always maintain their individuality and never lose them-
selves in another tissue.

I shall conclude by only adding a few words about the
preparations from whose careful examination are deduced all
the facts contained in this paper. All my specimens have
been prepared in the same way, and preserved as permanent
objects in glycerine. In fact, the same process has been
followed as that employed by Dr. Beale in his investigations
on many of the simple tissues of the body. Most of the
specimens have been examined by Dr. Beale, to whom I am
greatly indebted for the kind assistance and warm encourage-

Craccto, on the Nerves of the Cornea. 93

ment he has afforded me in the present undertaking, in which
I have spared neither time nor labour.

Some observers maintain that the sclerotica is entirely
destitute of nerves, but I do unhesitatingly affirm the con-
trary. I have distinctly seen some very fine bundles of
nerve-fibres distributed to this coat. These bundles, which
arise from the nerves destined to supply the cornea, separate
from them at different angles before they reach the corneal
margin, and after passing backwards ramify in the fibrous
tissue of the sclerotica, the bundles anastomosing with each
other. JI have a specimen from the mouse that evidently
proves this fact.

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TRANSACTIONS.

Of the Formation of the so-called INTERCELLULAR SUBSTANCE
of Cartitace, and of its relation to the so-called CEL1s ;
with OpsERvaTIons upon the Process of OsstricaTIoNn.
By Lronex S. Bzatz, M.B., F.R.S., Professor of Physio-
logy and of General and Morbid Anatomy i in King’s Col-
lege, London ; Physician to King’s College Hospital.

(Plates VIII and IX.)
(Read March 1st, 1863.) "

Ir is generally held that cartilage consists of cells, and a
‘connective’ or ‘intercellular’ substance or matrix. There
is, however, much difference of opinion as to whether the
cell-wall is a part of, or distinct from, the intercellular sub-
stance. Some observers maintain that, at least, im many
forms of cartilage, the cell-wall exists as a distinct structure.
Some hold, on the other hand, that the matrix itself corre-
sponds to the cell-wall, and others state that the matrix is in
part cell-wall and is in part composed of a cementing sub-
stance. There is the greatest difference of opinion as to the
relative importance of these two structures, cell and inter-
cellular substance, in the formation of the cartilage.

The cell-wall and matrix have been regarded in the light
of excretions from the cell. It has been maintained that the
cell exerts a direct influence upon the changes occurring
during the formation of the intercellular substance, and, on
the other hand, it has been considered to take part only in
the process of reproduction. Intercellular substance, gene-
rally, is believed to possess formative power, by virtue of
which (or, as Professor Huxley says, under the guidance of
the ‘ vis essentialis’) it becomes differentiated into the differ-
ent forms of tissue with which we are familiar.

Those who accept this view regard the cell-wall and inter-
cellular substance as of the highest importance, and the

‘nucleus’ as the less important anatomical element ; for this,
it is said, undergoes neither chemical nor morphological

VOL. XI. h

96 Dr. Beate, on the so-called

metamorphosis. Virchow considers that the nucleus is con-
cerned mainly in the maintenance and multiplication of living
parts; and while fulfilling its functions, he thinks that it
remains itself unchanged, and he says it is the other contents
of the cell, xot the membrane nor the nucleus, which give rise
to the phy ‘siological differences of tissues.

It seems to be a view gener ally entertained, that the inter-
cellular substance of cartilage results from changes occurring
in a plasma separated directly from the blood. Dr. Martyn,
of Bristol, has, however, endeavoured to prove that the
matrix of cartilage consists of the ‘old dilated and blended
capsules’ of the cells (‘Archives of Medicine,’ vol. 11, p. 110).
But Kolliker even ventures to assert that the fundamental
substance of cartilage, bone, and teeth, arises partly as a
secretion of the cells and partly from the blood independently
of them, and then goes on to say that—‘ The occurrence of
a solid, fundamental substance directly deposited from the
blood, shows that all the solid parts of the body are not, with-
out exception, formed from cells or m dependence upon them,
as Schwann was disposed to assume.’ Kolliker here, as in
many other instances, first makes an assertion, and then after-
wards employs it as if it were an ascertained fact. Before
such a statement can be used as an argument, it is obvious
that Kolliker must define precisely what part of the matrix
is formed independently of cells, but he has not advanced
any facts which indicate that the smallest portion arises from
the blood independently of the cells. There are, indeed, no
facts which prove that any form of intercellular substance
whatever is deposited directly from the blood.

The idea of this matrix being a cementing substance de-
posited between the cells, and uniting them, is very gener ally
entertained. According to this view, ‘the matter of the matrix
must be deposited around the cells, and the process of ‘ cell-
formation’? and ‘matrix formation’ must be perfectly dis-
tinct processes.

I now pass on to the special subject of my paper, and I
shall endeavour to show—

1. That the so-called intercellular substance of cartilage
and other tissues is never formed independently of cells, or,
more correctly, masses of living or germinal matter.

2. That the intercellular substance does not possess forma-
tive power, and that physical and chemical changes alone
take place in it.

3. That in all cases the masses of germinal matter are con-
a with the so-called intercellular substance, and that
the latter was once in the state of germinal matter.

;
|
5

Intercellular Substance of Cartilage. 07

4. That in the development and growth of these tissues,
the pabulum becomes (a) germinal matter; the germinal
matter becomes (4) the formed material (intercellular sub-
stance), which accumulates, and gradually undergoes conden-
sation.

I have endeavoured to show that at an early period of
development the elementary parts of all tissues consist of—
(1) matter in a living, active state; and (2) matter which
has lived, and which has ceased to exhibit vital or formative
power. The first I have called germinal matter, because it
alone is concerned in growth, development, and formation,
and gives origin to new elementary parts; and the second
has been called formed material, because it results from
changes which have occurred in the germinal matter. The
germinal matter passes gradually into the formed material,
so that, passing from without, inwards, we have (a) formed
material ; (b) imperfectly developed formed material, gradually
passing into (c) germinal matter; and in the nutrition
of an elementary part the inanimate pabulum first passes
through the formed material, comes into contact with and
is converted into (1) germinal matter. The oldest por-
tions of germinal matter undergo change, and become (2)
formed material. The formed material either accumulates
outside the germinal matter as ‘cell-contents,’ ‘cell-wall,”
‘intercellular substance,’ or becomes disintegrated and re-
solved into other compounds, which are removed in the form
of ‘secretions.’

If it could be shown that the intercellular substance of
cartilage is deposited from the blood mdependently of the
cells; or that ‘intercellular substance’ or ‘cell-walls’ are
ever formed mdependently of germinal matter; or that the
matter of which the ‘cell-wall’ consists 1s deposited layer wpon
layer, instead of layer within layer ; or that the germinal mat-
ter is not, at any period of development, in bodily con-
tinuity with the formed material; or that the germinal mat-
ter is capable of exerting an influence upon matter situated
at a distance from it, or that pabulum does not become ger-
minal matter, but is merely changed or converted into new
matter by some metabolic action exerted by the germinal mat-
ter, without coming into actual contact with it or becoming
a part of it; or that cell-wall or intercellular substance pos-
sesses the power of selecting certain substances from the
nutritive fluid, and converting these into matter lke itself;
nay, if it can grow in and form septa, as is described by
almost all observers to take place in cartilage—if but one of
these positions can be proved, my view must be greatly modi-

98 Dr. Beate, on the so-called

fied, if not entirely abandoned. So far, however, no observer
has brought forward facts opposed to it, although some have
expressed their dissent in general terms, which is not to be
wondered at.

Now, cartilage is probably the tissue which an opponent
would select as the one most likely to afford evidence against
me; and IJ propose, therefore, to discuss the minute structure
of this particular tissue, and shall endeavour to draw conclu-
sions as to the manner in which it is developed and grows.
The general structure of cartilage is represented in Pl. VIII,
fig. 1, from the temporal bone of an adult frog prior to ossi-
fication.

Structure of Embryonic Cartilage.

All cartilage, at an early period of development, consists of
masses of germinal matter imbedded in or surrounded with
a soft-formed material. The masses of germinal matter,
which are at first very close together, multiply by division.
(Figs. 1, 5.) Now, as development advances, the masses
of germinal matter become separated from each other by
gradually increasing distances, or, as I would say, the formed
material gradually accumulates between them as it continues
to be produced, but more and more slowly, upon the surface
of each mass. (Figs. 5, 6, 7, 8.)*

If the young cartilage be broken up, portions of the formed
material are seen to be continuous with the germinal matter
(fig. 2); and in specimens coloured with carmine we see, first,
the smooth and very finely granuiar and transparent ‘ matrix’
or ‘formed material’ colourless ; next, a layer faintly coloured;
and lastly, it is observed that the intensity of the colour in-
creases as the matter situated more or less centrally is ap-
proached. From this I argue that there is a gradual growth
and transformation proceeding from within outwards; and
as it is a fact that my colouring matter passes through all the
outer layers, and is deposited in greatest quantity in the cen-
tral part which is at the greatest distance from the solution,
it seems only reasonable to infer that pabulum takes the same
course during life. These points are shown in figs. 1 and 2.

But the development of cartilage can be studied in the
fully formed tissue as well asin the embryo, for up to a certain
period of life many of the cartilages are continually growing.
Indeed, if growth did not occur, the cartilage would diminish
in extent, because, as age advances, the. formed material

* Preparations illustrating the facts stated were passed round at the
meeting.

Intercellular Substance of Cartilage. 99

shrinks and undergoes condensation. Near the surface, in
many cartilages, a layer exists which could not be distin-
guished from embryonic cartilage, and here the changes
occurring during development may be readily studied.

Of the Formation of the ‘Cells within Cells.’

As growth continues in the higher forms of cartilage, the
masses of germinal matter already separated from each other
by a considerable thickness still contimue to divide and sub-
divide, but more and more slowly, and at the same time con-
densation still proceeds in the matrix already formed. There
are, therefore, collectionsof masses of germinal matter separated
from each other by thick layers of formed material, and there
are the individual masses constituting each collection separated
from each other by a thin layer of formed material. Each of
these may divide and be separated by a still thinner layer of
formed material. Thus are formed the ‘cells within cells.’
The septa do not grow in, but the hving germinal matter
simply divides, and its outer part undergoes conversion into
the formed material or matrix.

Of the Structure of a very simple form of Cartilage.

But in many cartilages of the frog the structure is not
complicated by the formation of these secondary and tertiary
formations (cells within cells). The cartilage in its fully
formed state consists merely of germinal matter, which passes
into imperfectly formed matrix, and this is continuous with
the fully formed cartilaginous tissue. (Figs. 2, 3,4.) Here
the continuity of structure can be most distinctly demon-
strated. If, however, the tissue be kept for a short time after
death, and more especially if it be placed in water, a clear
interval between the matrix and the so-called cell soon makes
its appearance, and we observe the characters, so often repre-
sented in figures, which have led most observers to infer the
existence of a cell-wall distinct and separate from the matrix.
If cartilage be kept for a longer period, the germinal matter,
and soft imperfectly developed formed material, break down
and become liquefied, and then the cartilage appears as a
matrix containing numerous vacuoles or spaces, an appearance
which has led to the view that cartilage and many other tis-
sues result from the ‘vacuolation’ of a plasma or matrix. But
there are no ‘vacuoles’ during life. These spaces were occupied
by the living active matter, which was alone concerned in the
formation and growth of the cartilage-tissue (matrix).

100 Dr. Brae, on the so-called

Of the Formation of the Matriz.

In the fresh cartilage of the frog the actual conversion of
the germinal matter into formed material may be studied.
In the preparation passed round (Prep. 4), magnified 700 dia-
meters, numerous oval or spherical masses of a granular ap-
pearance will be noticed, but amongst them many of a half-
moon shape may be observed, and others varying very much
in shape, and with so ragged and irregular an outline that no
one would be disposed to call them cells, or would maintain
that they possessed a cell-wall. (Figs. 2,3, 4, 5, 6,7,8.) At
the edge of the specimen, where it is exceedingly thin, some of
these angular masses, composed of granular matter, with the
central part deeply coloured with carmine (nucleus), can be
seen to shade wninterruptedly into the matrix. The granular,
ragged edges gradually pass into, and are continuous with
the “clear, transparent matrix. Not only so, but in some of
the oval masses, the formation of the clear, transparent matrix
1s seen to commence as a separate point in the granular matter
itself, as well as to proceed upon its surface. In other parts
of the specimen nothing but what would be termed the
nucleus remains. It seems to be imbedded in the matrix of
the cartilage, so that the whole of the outer part of the ‘cell’
has been transformed into this structure (matrix, intercellular
substance), and the change has proceeded until of the ger-
minal matter only a very small portion remained unchanged.
This would soon die, and almost entirely disappear. A small
space occupied by a few granules would remain in the sub-
stance of the cartilage, and this is all that would remain to
mark the position ofa cartilage-cell.

If I have interpreted these phenomena correctly, the history
of the life of cartilage and allied structures is very simple, and
easily understood. Masses of germinal matter appropriate
pabulum, and having thereby increased in size, divide and
subdivide, while those portions which are oldest and at the
outer part of each mass gradually cease to manifest their
active powers, and become resolved into soft-formed material,
which gradually accumulates and undergoes condensation.
The formation of the matrix proceeds more and more slowly
as the tissue advances in age, because the impediment offered
to the access of pabulum to the germinal matter must become
greater as the formed material around it increases in amount
and undergoes condensation.

It seems to me, therefore, that the vital changes occurring

Intercellular Substance of Cartilage. 101

in this and other tissues are restricted to the granular struc-
tureless substance 1 have termed germinal matter. This
alone can communicate to inanimate pabulum new and pecu-
liar properties and powers. No cell-wall, no matrix or inter-
cellular substance, no formed matters, as fat, starch, bile,
and the like, are ever produced unless germinal matter be
present. Without it a tissue may be changed, but it cannot
change or alter by virtue of its own powers; it is a lifeless
tissue that may be acted upon, but it is no longer a living
tissue which can change, conyert, or alter inanimate matter.
All tissues and all elementary parts consist of germinal matter
and formed material, and all formed material was once ger-
minal matter, and the germinal matter itself was once pabu-
lum. But pabulum could never have become germinal
matter unless pre-existing germinal matter had been present
to communicate to it its wonderful powers. The germinal
matter does not secrete the formed material, but becomes
resolved into it. The properties and composition of tissues
and animal fluids depend upon the relations of the elements
which enter into the composition of the germinal matter at
the time while these are gradually passing from the living to
the formed and lifeless state. Do not the elements assume
these fixed and definite relations to each other in conse-
quence of being influenced by a power, the nature of which
we cannot understand, but which is very properly termed
vital ?

When the formed material has been produced, it may be
the seat of physical and chemical changes. Of the nature of
these changes there can be no doubt, as they may be imitated
artificially ; but the formed material itself, as, for example,
the matrix of cartilage, cannot be produced artificially, nor
can it be produced from any substance in the blood. Its
formation is due to changes occurring in the matter when it
was in a living state.

I think I am justified in the conclusion that physical and
chemical, but not vital, changes occur in the matter of which
the fully developed formed material is constituted, while vital
changes take place in the germinal matter alone.* I would
say that the matrix of cartilage is not living, but the germi-
nal matter embedded in it is living, and the matrix itself was
once in the condition or state of living germinal matter. The
living matter is continuous with the matter that has lived.

* * An attempt to show that every living structure consists of matter
which is the seat of vital actions, and matter in which physical and chemical
changes alone take place.” —Bnritisu Assocrarion, 1862.

102 Dr. Beater, on the so-called

Mr. Rainey’s Cbservations on the Process of Ossification.

Mr. Rainey has shown how globules of calcareous mat-
ter deposited in a viscid matrix * evadually coalesce, and at
length assume somewhat the appearance presented by tis-
sues during the process of calcification. This observer goes
so far as to attribute the entire formation, not only of such
tissues as bone, teeth, shell, &c., but soft tissues (as, for
example, the crystalline lens), to physical and chemical
changes alone.

Now, no one has yet produced artificially a tissue that
could be mistaken for bone or dentine, nor has the slightest
approach ever been made towards the production of any soft
tissue that exhibits any special anatomical characters. Nor
has a particle of anything having the chemical composition
and physical characters of the matrix of cartilage or any form
of fibrous tissue ever been formed by artificial process. It
is, therefore, somewhat premature to advance such a generali-
zation as this, and I shall endeavour to show that the con-
clusions are not justified even as regards bone.

I regret to be compelled here to bring forward evidence
against Mr. Rainey’s conclusions; but as his statements are
most positive, and have been accepted by some writers as
evidence in favour of certain views, according to which the
formation of tissues generally is ascribed to physical processes,
as, for example, the attraction towards each other of mole-
cules by gravitation, unfortunately the only course left is to
give to conclusions resulting from observations which have
been conclusively proved to ‘be erroneous, the most distinct
and positive contradiction. Mr. Rainey says that the pro-
duction of bone takes place independently of cells or cell-
germs, and that when cartilage ossifies, the globules and
rings ‘of calcareous matter deposited in the matrix have no
definite relation to the cartilage-cells. Now, I submit a
specimen of the cartilage of the temporal bone of the frog
(Prep. 5) to the examination of the members of the Micro-
scopical Society. Mr. Rainey’s drawings, illustrating the
process of ossification, as it occurs according to him, have
been copied in figs. 9 and 10. He does not represent
one single nucleus in either drawing.* I cannot but
believe that when the specimens from which these drawings
have been copied were part of the living frog, nuclei were
present in great number. In the first a nucleus must have
existed in every space left blank; Mr. Kainey exhibits ten

* © On the Formation of Shells, &e.’

Intercellular Substance of Cartilage. 103

spaces, and there must have been at least ten distinct nuclei
or masses of living germinal matter. There is a nucleus or
mass of living germinal matter in every single case in, or
about the centre of the ring of calcareous particles. The
caleareous matter is always first deposited around and at a
distance from the germinal matter, in fact, in the very part
of the formed material which was first produced, and is, there-
fore, at the time of ossification, the oldest. I pass round a
specimen where one or more masses of germinal matter may
be seen with the ring of calcareous particles around them.
(Prep. 6, Pl. IX, fig. 14.) Now, as long as these masses
of germinal matter live in the normal condition, so long the
deposition of calcareous matter proceeds in a direction from
without inwards, or, as the fact would be generally stated,
the lacuna becomes smaller as the tissue grows older. In
every lacuna, even of fully formed living bone, a nucleus or
mass of germinal matter exists. (Figs. 11, 12,18.) If the
lacuna is a real space, filled only with air or fluid, the bone
is dead, and the lacuna could not become smaller.

Bone, therefore, cannot be formed independently of living
or germinal matter.

The formation of the matriv of bone depends upon the
changes taking place in germinal matter, and these changes
must, at least, at present be referred to a force, power, or
influence, the nature of which we do not understand—vital
power. The matrix having been formed, the precipitation of
calcareous matter takes place. ‘This is merely due to a
chemical change, the reaction of the oldest part of the matrix
becoming alkaline; but it would seem that the currents flow-
ing to and from the gradually diminishing mass of germinal
matter determine the position in which the precipitation
takes place, and so long as these masses are alive, the con-
version of the outer part of each into matrix, and the deposi-
tion of calcareous matter in the matrix already formed, goes
on in one definite direction from without inwards; so that in
all cases the matrix exists for some time before it becomes
impregnated with calcareous matter, the precipitation com-
mencing in the oldest part of the matrix, and proceeding in
the same direction as the formation of matrix itself—that is,
from without inwards. When this mass of living matter
dies these changes cease, and the corresponding portion of
bone-tissue is dead. If, on the other hand, one of these
nuclei or masses of living matter be too freely supplied with
pabulum, it rapidly increases, divides, and subdivides. The
tissue already formed around it becomes softened, disin-
tegrated, and appropriated, and a soft mass composed of

VOL. XI. e

many separate spherical masses of living matter results. A
space may thus be scooped out in the compact tissue of bone,
and the process may go on until what is termed an abscess
results. Very rapid growth is associated with the formation
of a soft, spongy, and short-lived tissue; very slow growth
with the production of a very hard and lasting structure.
But im all cases the active changes are dependent upon the
existence of living matter, that is, matter in which certain
phenomena can be observed or proved to occur, which can-
not, in the present state of science, be explained by physics or
chemistry, and which never do occur except in matter derived

104 Dr. Braxe, on Intercellular Substance of Cartilage. |
from a living being. |

INDEX TO TRANSACTIONS.

VOLUME XI.

A.

Actinodiscus, v.. g., Grev., 69.

ms Barbadensis, n. sp., 69.
Amphiprora, 20.

oblonga, n. sp., 20.

Aulacodiscus, 69.

5 angulatus, 69.

ss en n. sp., Grev.,

69,

_ Kilkellyanus, nu. sp., 70.
5 mammosus, N. SP., 70.
3 pallidus, n. sp., 72.
paradoxus, n. sp. 72.
Auliseus, R. K. Greville, monograph
of the genus, 36.
» definition of, 42.
ambiguus, n. sp., Grev., 74.
» Americanus, Khr., 52.
3, c@latus, Bail., 44.
» cylindricus, Ebr., 52.
elaboratus, 0. sp., ’ Ralls, 51.
» elegans, 0. Sp., Grev., 45.
gigas, Khr., 52.
ra Johnsonianas, u. sp., Grev.,

Macreanus, 0. sp., Grev.,
51.

» mirabilis, n. sp., Grev., 47.

» nebulosus, n. sp., Grev., 74.

» ovalis, Arn., 47.

» parvulus, n. sp., Grev., 74.

» LPeruvianus, Grev., 50.

» polystigma, Khr., 52.

» pruinosus, Bail., 48.

» punctatus, Bail., 49.

», racemosus, n. sp., Ralfs, 46.

» radiatus, Bail.?, 48.

» reticulatus,n. sp., Grev., 46.

», seulptus, Ralfs, 43.

B.

Beale, Dr., on the formation of inter-
cellular substance of cartilage, 95.

C.
Campylodiscus, 13.

= crebrecostatus, 0. Sp.,
Grev., 14.

a ornatus, 0. S8p., Grev.,
13.

i Robertsianus, n. sp.y
Grev., 14

is Wallichianus, n. sp.,
Grey., 13.

Cartilage, on the formation of inter-
cellular substance of, by Dr. Beale,
95.

Cells, formation of, 99.

Ciaccio, J. V., on the nerves of the
cornea, and of their distribution
in the corneal tissue of man and
animals, 77.

Cornea, J. V. Ciaccio on the nerves
of the, 77,

Craspedoporus, n, g., Grev., 68.

- Johnsonianus, N. Spy
Grev., 69.

5) Ralfsianus, iy.) fS)Ob
Grev., 68.
Di;

Diatoms, J. A. Tulk on the cleaning
and preparing of, 4.

R. K. Greville, descriptions
of new and rare, Series
VIII, 13.

Series IX, 63,

22

> ”

E.

Eupodiseus, 73.

punctulatlus, n. sp., Grev.,
ps
73.

simplex, 2. sp., Grev., 73.

»
»
F.
Farrants, R. J., president’s address,
aie n. sp., Grev., 67.

a Barbadensis, i.
Grev., 68.

Sp-5

Formation of intercellular substance |

of cartilage, 95.
G.

Greville, R. K., a monograph of the
genus Auliscus, 36.

>

and rare diatoms, Series VIII,

13.
AX; 63.

be) >

Heterodictyon, n. g., Grev., 66.
Rylandsianum, n. sp.,
Grev., 66.
* splendidum,
Grev., 66.

39

n. Sp.;

Es

Licmophora, ¥. C. 8. Roper on the
genus, 53.
i definition of, 57.
se flabellata, Ag., 57.
splendida, Grev., 59.

ce)
M.

Maddox, R.L., on the photographic
delineation of microscopic objects,

Martin, Benjamin, afew more words
on, by J. Williams, 1.

Microscopical Society, annual meet- |

ing of the, 23.
‘3 if auditor’s re-
port, 25.
>> 3)
dress, 26.

descriptions of new |

president’s ad- |

INDEX TO TRANSACTIONS.

N.
Javieula, 15.
» ? Cistella, n. spa iGrerm

19.
» dohnsoniana, un. sp., Grev.,
ie ,
» Lewisiana, un. sp., Grev.,
Tb.
» ‘uxuriosa, n. sp. Grev.,
» notabilis, n. sp., Grev.,
18.
Nerves of the cornea, J. V. Ciaccio
on the, 77. :
O.

Ossification, observations on the pro-
cess of, by Dr. Beale, 95
¥, process of, 102.

PB

Peponia, n. gen., Grev., 75.
» Barbadensis, vn. sp., 76.
Photographic delineation of micro-
scopic objects, R. L. Maddox on
the, 9.
Plagiogramma Robertsianum, nu. sp.
Grev., 13.
Porodiscus, n. g., Grev., 63.
. elegans, nu. sp., 64.
a conicus, N. Sp., 65.
i M07, W. SP., 65.
Bs nitidus, n. sp., 65.
5 oblongus, n. sp., 65.

R.

Roper, F. C.S., on the genus Licmo-
phora, Agardh, 53.

iy

Thaumatonema, n. g., Grev., 76.
5 Larbadense, n. sp.,76.
Triceratium, 75.
fs lineatum, n. sp., 75.
Tulk, J. A., on cleaning and prepar-
ing diatoms, 4.

W.

Williams, John, a few words more

on Benjamin Martin, 1.

TRANSACTIONS OF MICROSCOPICAL SOCIETY.

DESCRIPTION OF PLATE I,

Illustrating Dr. Greville’s paper on New Diatoms.
Series VIII.

Fig.
1.—Plagiogramma Robertsianum, front view.
2.— eS - side view.
3.—Campylodiscus ornatus.
4,— 3 Wallichianus.
5.— = Robertsianus.
6.— 55 crebrecostatus.
7.—Navicula Lewisiana.
8— ,, Johnsoniana.
9— ,, notabilis.
1,U— ,, luxuriosa.
12.— ,, ? Cistella, front view.
1g |) ey 8 side view.

15.—Amphiprora oblonga.

All the figures are x 400 diameters.

CORRIGENDUM IN SERIES VII.

The walls of the cellules in Yriceratiwm Davyanum are unfortunately ren-
dered much too thick by the engraver. he figure is, in other respects,
faithfully executed.

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TRANSACTIONS OF MICROSCOPICAL SOCIETY.

DESCRIPTION OF PLATES II & III,

Illustrating Dr. Greville’s Monograph of the genus
Auliscus.

Fig.

1—3.—Auliscus sculptus.

4—7.— 4, celatus.

c= 5, elegans.

9— 4, racemosus.
10.— ,, ~ reticulatus.
ll— ,, mirabilis.
12.— ,, ovalis.

13.— ,, pruinosus.
14.— 4, radiatus.
15,16.— ,, punctatus.
17.— ,, Peruvianus.
18.— ,, Macreanus.
19.— ,, elaboratus.
20.— ,, Johnsonianus.
21— ,, Ralfsianus.
22— ,, n.sp.? from Japan. Very imperfectly repre-

sented by the engraver.

All the figures are x 400 diameters.

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TRANSACTIONS OF MICROSCOPICAL SOCIETY.

DESCRIPTION OF PLATES IV & V,

Illustrating Dr. Greville’s paper on New Diatoms,
Series IX.

Fig.
1.—Porodiscus elegans.
2.— = major.
3.— Fs conicus.
4,—— 3, nitidus,
5.— 3 ovalis.

6.—Heterodictyon Rylandsianum.
7.— - splendidum.
8.—Fenestrella Barbudensis.
9.—Craspedoporus Ralfsianus.
10.— 3 Johnsonianus.
11.—Aecetinodiscus Barbadensis.
12.—Aulacodiscus inflatus.

13.— 5 MAMMOSUS.
14,— 33 Kilkellyanus.
1b6.— Pe angulatus.
16.— “a spectabilis.
17.— Bs pallidus.
18.— » £ paradoxus.
19.—Liupodiscus punclulatus.
20.— fa simplex.
21.—Auliscus nebulosus.
22:— 4, parvulus.
23.— ,, ambiguus.

24.—Triceratium lineatum.
25.—Peponia Barbadensis.
26.—Thaumatonema Barbadense.

All the figures are x 400 diameters.

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TRANSACTIONS OF MICROSCOPICAL SOCIETY.

DESCRIPTION OF PLATES VI & VII,

Illustrating Dr. Ciaccio’s paper on the Nerves of the Cornea,
and of their Distribution in the Corneal Tissue of Man
and Animals.

ig.

= Ose of the largest nerve-trunks from the cornea of the sparrow, show-
ing the manner in which the nerves branch, the nuclei connected
with the primitive nerve-fibres, and the relative position of the
latter in the trunks as well as in the branches. x 150.

2.—Shows the manner in which the bundles of nerve-fibres are arranged in
the formation of the network in the cornea of the sparrow. Two
triangular bodies are also seen in connection with these bundles.
x 700.

3.—One of the quadrangular bodies found in connection with the nerves
distributed to the cornea of the sparrow. Bundles of nerve-fibres
are observed to arise from it in four different directions. Some of
the fibres, in passing from one bundle to another, flank one of the
‘sides of the small body, while others seem to proceed directly
from it. A nucleus and granular matter are also seen in the part
within. x 750.

4.—From the cornea of the sparrow. A. Small, triangular body, with
nucleus aud granular matter, connected with bundles of nerve-
fibres. B. A very small bundle of fibres, which, on meeting

. another bundle, nearly at a right angle to it, divides into two finer
ones, which run in opposite directions, parallel with the other
bundle. x 350.

5.—A rather large nerve-trunk, just at its entrance into the corneal tissue.
The fibres, of which it is made up, are seen to be nucleated, but
they have not the slightest appearance characteristic of dark-bor-
dered fibres. On the contrary, the fibres bear a great resemblance
to the so-called gray or gelatinous fibres of the sympathetic. From
the cornea of theeel. x 250.

6.—Very small bundles of nerve-fibres forming networks. From the
cornea of the ecl. x 350,

7.~One of the branches resulting from the fourth division of a large nerve-
trunk from the cornea of the frog. The course and continual change
of the relative position of the nerve-fibres is well shown. More-
over, in the point where the branch undergoes division, is seen a
fine fibre, which seemed to be a single fibre, but really divides into
two finer ones, which go in opposite directions. ‘This fact is very
frequently observed in the distribution of nerves to the cornea of
the frog. No nuclei are observed in connection with the fibres
forming the branch, x 350.

PLATES VI & VIL (continued). :
Fig.

§—a ands. Two ultimate branches of two different nerve-trunks, from
the cornea of the frog, showing very distinctly the precise manner
in which the one branch anastomoses with the other. The anas-
tomoses are effected by the mutual change of the fibres. x 350.

9.—From the cornea of the frog. Bundles of nerve-fibres, forming
networks. Connected with them may be seen a triangular body,
from which fibres proceed in different directions. Some fibres of
the bundles pass close to this body without any intimate connec-
tion with it. The triangular body contains granular matter, which
appears to have collected in two places, assuming the appearance
of two dark spots. x 350.

10.—Triangular body, from which fibres spring in three different directions.
From the cornea of thefrog. x 350.

11.—Network of pale nerve-fibres, and network of the branches of the
cornea-corpuscles, from the cornea of the frog. These two kinds
of networks lie on different planes, aud the relation between them
is well shown. x 350.

12.—Shows the course, size, and relative position of the primitive nerve-
fibres in the branches of the nerves distributed to the cornea of the
mouse. X 350.

13.—Nervous plexus in the cornea of the mouse. The general arrangement
of the bundles of nerve-fibres in the formation of the plexus, and
the special bodies connected with them, are well seen. x 250.

14.—One of those special bodies which are seen in connection with the
nervous plexus of the cornea of the mouse. Besides a nucleus, it
contains granular matter. Bundles of fibres proceed from it in
three different directions. 350.

15.—Another body of the same kind, in which the nucleus has undergone
division. From the cornea of the mouse. x 350.

16.—From the cornea of man. Small nerve-branch, which divides into two
smaller ones; and from the pressure to which the thin section of
the cornea has been subjected, the nerve-fibres of one branch ap-
pear-separated from one another. x 350.

17.—Shows the manner in which the fine bundles of nerve-fibres are
arranged in the formation of the plexus existing in the human
cornea. X 850.

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After Mr. Rainey.

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TRANSACTIONS OF MICROSCOPICAL SOCIETY.

DESCRIPTION OF PLATE VIII,

To illustrate Dr. Beale’s observations on the Formation of
the so-called Intercellular Substance of Cartilage. (See
p. 90.)

Fig. 1—Section of cartilage from the temporal bone of the common frog.
The so-called “cell” is seen to consist of granular matter, in which smali
globules and a nucleus are embedded. Owing to change occurring after the
removal of the cartilage, a slight interval appears to exist between the outer
part of the granular matter and the matrix, but in the living state there is
no such interval. The nucleus and the granular matter around constitute
the author’s “ germinal matter.’ The oil-globules deposited in it correspond
to secondary deposits. The matrix between the masses of germinal matter
constitute the author’s “formed material.” Two of the masses of germinal
matter are undergoing subdivision. The septa are not produced by the
growing-in of the matrix, but the outermost part of the masses of germinal
matter is converted into the matrix.

Fig. 2.— Germinal matter” and surrounding formed material—costal car-
tilage—of a kitten at birth. The germinal matter exhibits zones, which are
coloured with carmine, and exhibit different degrees of intensity as we pass
from the outer one, which is faintly coloured, to the spot in the centre, which
is intensely coloured. It is clear that these zones are all composed of material
of the same general characters, so that it would be very unreasonable to call
the outer zone “ cell-contents,” the next “nucleus,” the next “nucleolus,”
and the spot in the centre “nucleolulus.” The outermost zone is struc-
turally continuous with the matrix, and is gradually being converted into
matrix. The matter of which all these zones are composed is “ germinal or
living matter.’ The matrix around is formed and lifeless, but was once
* germinal matter.”

Figs. 3 and 4.—Cartilage from the frog, showing the germinal matter
shading into and becoming gradually converted into “ matrix” or formed
material.

Figs. 5, 6, 7, and 8, represent sections of the cartilage of the ribs taken
from corresponding spots. Kaitten.—Fig. 5, at birth; fig. 6, at six weeks
old; fig. 7, young but nearly full-grown cat; fig. 8, adult cat. These
drawings show the gradual separation of the masses of germinal matter from
each other as the matrix increases in the intervals between them, and the
gradual increase in size of the masses until the tissue attains its adult
condition.

Figs. 9 and 10.—Drawings copied from Mr. Rainey’s work illustrating
his views upon the mode of formation of lacune. He states that no nucleus
or cell exists in any of the spaces represented in fig. 9, and that the calea-
reous particles are deposited in the matrix independently of the “cells” of
the cartilage. No “nuclei” or “cells” (masses of germinal matter) are re-
presented in either of these drawings, but the author maintains that when
the sections were fresh several such bodies must have existed.

TRANSACTIONS OF MICROSCOPICAL SOCIETY.

DESCRIPTION OF PLATE IX,

To illustrate Dr. Beale’s views upon the Formation of Bone
(‘ Transactions,’ p. 103), the changes occurring in “ Pro-
toplasm” (‘ Mic. Journ.,’ p..260), and the Structure of
the so-called “‘ Unipolar Nerve-cells’” from the Sympa-
thetic Ganglia of the Frog (‘ Mic. Journ.,’ p. 304).

Fig. 11.—Thin section of the frontal bone of the frog, showing the for-
mation of four lacune.

Fig. 12.—T wo lacune in a further stage of formation. The “canaliculi”’
commence at the intervals between the particles of calcareous matter depo-
sited in matrix of the cartilage.

Fig. 13.—Two recently formed lacune from the frontal bone of the frog.

Fig. 14.—A diagram showing the mass of germinal matter with calcareous
particles deposited in the matrix around it. The author considers that
masses of germinal matter existed in each of the spaces left in Mr. Rainey’s
figure (Plate VIII, fig. 9).

Fig. 15 —Mucus-corpuscle from the mucus of the throat, showing the
different forms it assumed within a minute. The nuclei are seen in the
centre of the parent mass. Portions of this have moved away some dis-
tance, and two are detached. These would grow and form new mucus-
corpuscles. Nuclei might arise in the portions detached. The movements
observed seem to be independent of the nucleus. The nature of these
movements has not yet been explained, but Dr. Beale calls them ‘‘ vital”
movements. (See ‘ Mic. Journ.,’ vol. iii, N.S., p. 260.)

Fig. 16.—A so-called “ unipolar” nerve-cell, with, 1st, a s¢raight, and 2nd,
a spiral, fibre emanating from it. The fibres continuous with these are seen to
pursue opposite directions. ‘The straight fibre is continuous with the central
part of the material, of which the body of the ‘‘cell” is composed, and the
spiral fibre with the peripheral part of the same. Both fibres are nucleated,
and a large nucleus and nucleolus are seen in the upper part of the cell.
The specimen from which this drawing was taken was coloured with car-
mine. ‘The nucleolus was most intensely coloured, then the matter around
this (nucleus). The matter around the nucleus was paler, and that portion
at the lower part of the cell which is gradually undergoing conversion into
the “spiral fibre” was not coloured at all. The nerve-fibres were not
coloured, but all the nuclei embedded in these fibres were darkly coloured.
(See ‘ Mic. Journ.,’ vol. iii, N. §., p. 304.)

EG Ast oy

TRANS. MICR, SOC., VOL. XI., N.S., PE 1X

x 1700.

Fig. 16.

Of an Inch ee 7 ()l),

Tou
SCALE.
of an Inch — x 1700.

10,000

L, 8, B., ad nat.

QUARTERLY JOURNAL

OF

MICROSCOPICAL SCIENCE:

EDITED BY

EDWIN LANKESTER, M.D., F.R.S., F.L.S.,

AND

GEORGE BUSK, F.R.C.S.E., F.R.S., Sxc. L.8S.

VOLUME III.—New Series.

With Allustrations on Wood and Stone, —

LONDON:
JOHN CHURCHILL AND SONS, NEW BURLINGTON STREET.
1863.

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ORIGINAL COMMUNICATIONS.

On the DeveLorpMEN’ of StrrpeD Muscutar Frisre in Man,
Mamaia, and Brrvs. By J. Locxnart Cxarxe, F.R.S.

(Continued from page 231, vol. ii.)
On the Development of Muscular Fibre in Man.

In man the development of striped muscular fibre is on
the same plan as in birds and mammalia, but presents some
points of difference that deserve consideration. In its early
stage one does not observe those striking forms that appear
in the chick between the sixth and seventh days of incuba-
tion (Pl. XI, fig. 9), and in the sheep or ox at a correspond-
ing period. From the fourth to the fifth week of utero-
gestation is about the earliest period at which this tissue can
be distinguished with certainty from some others. In a fetus
of three fourths of an inch in length it forms a gelatinous
mass, consisting, as in the other cases described, of fibres
and nuclei imbedded in a semifluid, granular blastema.
Pl. I, fig. 18 represents fibres from a fcetus three fourths
of an inch in length; and fig. 19 both fibres and free
nuclei from another foetus, of one inch in length. In the
formation of these fibres, as in similar cases already de-
scribed, granular processes of condensed blastema extend
from the sides or from around the nuclei; and along the
surface of these a new substance forms, until they become
partially or completely invested. At first the investing
substance appears only on one side, in the form generally of
a plain band or fibre (see fig. 18 a), but subsequently is seen
also on the other. Sometimes, however, it is deposited in
the shape of distinct, longitudinal fibrille, until the surface is
completely covered (fig. 18 4) ; and sometimes these fibrillz
are at once or soon after divided into particles, which, when
close together and on the same level, appear as transverse
strie (fig. 18d). Seen under a power of 420 diameters,
these two rows of particles had the appearance of short, trans-
verse lines. On one side of them are the remains of the
granular layer of blastema, ready to be converted into

VOL. II],—NEW SER. A

2 CLARKE, ON STRIPED MUSCULAR FIBRE.

another fibrilla or row of particles. But even when the sur-
face of the fibre is perfectly plain, with the exception of the
two lateral borders, it may be resolved into fibrilla by the
influence of certain reagents, particularly chromic acid.

The diameter of the same fibre varies at different parts of
its course, and the nuclei it contains are located at variable
distances from each other. Sometimes, however, three or
four are heaped closely together, one overlapping the other ;
and sometimes two are in contact at their edges, having just
undergone the process of division. The fibres arrange them-
selves side by side, with the nuclear enlargements of one a
little above or below those of another, so that their respective
curvatures admit of their lying in close contact. PI. I, fig. 19 d
represents three fibres disposed in this way, but intentionally
separated a short distance from each other. Sometimes they
may be seen to increase in diameter or in the number of
fibrille by the adhesion of fresh nuclei, from which new
granular processes of blastema extend along their edges
(fig. 20 a, 6). Each of their lateral borders constitutes one
fibrilla or more; but, except under the influence of chromic
acid or some other reagent, it is only occasionally that the
fibrillee are resolved into particles or granules, which are in
some cases exceedingly fine (see fig. 19 a).

The muscular tissue of the heart in the same feetus differed
in some respects from that of the trunk. The free nuclei
were more densely crowded together, but the granular blas-
tema was less abundant. All these bodies gave off processes,
which, in many instances, were mere fibres, but in others
they were broad at their attachment to one side or end of
the nucleus, from which they tapered off into fibres, so as to
present a funnel-shaped appearance (see fig. 21 a).* During
the first formation of the muscular fibres the nuclei, with their
processes, were disposed side by side, as represented in fig.
216. When formed, they were, in general, more uniformly
granular than those of the trunk, more varied in shape, and
irregular in breadth, and gave off branches by which they
were connected in a kind of plexus or anastomosis. In some
cases they were joined together by broad expansions of con-
densed blastema (something like the webb in a frog’s foot),
in which much finer branches might be frequently seen in

* From their appearance there is reason for believing that these funnel-
shaped bodies are rudimentary nerve-cells in the substance of the heart ; for
they bear a striking resemblance to the rudimentary cells which I found in
the intervertebral ganglia of the foetus (see ‘Phil. Trans.’ for the present
year, 2ud part). Some of the fusiform bodies belong to the tendinous tissue,
and are of stronger outline than the others.

CLARKE, ON STRIPED MUSCULAR FIBRE. 3

process of formation. Fig. 21 ¢ represents different kinds of
these fibres. In the bundles which they form they lie in
such close apposition that they appear to be almost cemented
together. One of these is represented at fig. 2le. At its
lower part the fibres have become separated. At the sides
of such a bundle it was not uncommon to find oval nuclei
with processes which divide into branches, as shown in the
figure. Sometimes several nuclei appeared to be joined to-
gether by a condensation of the intervening blastema, in
which at the same time a kind of plexus of fibres, of very
small but variable diameter, became developed (fig. 21g). In
the heart the fibrille were much more frequently resolved
into particles or sarcous elements, and therefore the appear-
ances of transverse strie were much more common than in
the trunk.

In foetuses of one and a half or two inches in length the mus-
cular fibres of the trunk, which were first developed, had in-
creased considerably in diameter ; but many smaller ones were
either formed or in process of formation. Fig. 22 represents
several fibres in different states of development, from an arm
of a human fcetus about two inches in length. Their increase
in diameter depends, in some places, partly on a certain in-
crease in the size of the nuclei which they contain, but chiefly
on the deposition of new layers of the substance or the fibrille
by which they are invested, and which, therefore, extend the
breadth of the original borders. In the majority of instances
these new layers are deposited nearly equally round the axis,
but in many others they are added—at least for a variable
length—more thickly on one side, as shown at a, fig. 22; so
that from this cause, as well as from the size and relative
distance from each other of the nuclei, the same fibre may
vary in diameter at different parts of its course. It is flatter
also in some parts, and gradually assumes a more cylindrical
shape and uniform structure throughout its entire thickness.
Numerous nuclei lie on its surface, along which granular
processes may be frequently seen to extend from one to the
other, as the foundation of new fibrille (see fig. 226). In all
the larger fibres, and in most of those of intermediate size,
the striz are beautifully marked, but have often a different
aspect in different fibres and in different parts of the same
fibre. On each side of the axis there is commonly observed
a very remarkable border of transverse striz, corresponding
to the plain lateral borders, and indicating the depth of the
fibrillation. Fig. 22y is an exact representation of a large
and strongly marked fibre from the same foetus. Its striated
border, under a sufficient magnifying power, was easily re-
solved into several rows of sarcous particles, like those re-

4, CLARKE, ON STRIPED MUSCULAR FIBRE.

presented at a, 0, fig. 20, in which, particularly, in a, if we
suppose a number of other fibrillee of the same kind to be
deposited round the nucleus a’ and its granular prolongations,
we should have a general resemblance to the fibre now under
consideration, in which it was easy to see, by changing the
focus, that the whole of its upper surface consisted of fibril
similar to those at its sides. When the granular axis has
disappeared, and the fibre throughout is composed of fibrillee,
and is therefore of uniform structure, the lateral bands, as
bands, of course, disappear; while the nuclei, in many in-
stances, reach the surface, in consequence of the unequal
deposition of material around them. In other cases, how-
ever, the nucléi have seemed to disappear by breaking up
into granules; but I am not sure that this is a natural histo-
logical change. In the embryo of the fowl, when the fibres are
changing from the condition represented at a, fig. 12, to that at
a, fig. 13 (Pl. XI)—that is, when the axis is disappearing, and
the fibre is becoming a compact bundle of fibrillee—the nuclei
seemed as if they were escaping to the surface between the
fibrille, as it were, by pressure, for many of them were partly
between and partly without the fibrille. I have not wit-
nessed the same appearances in mammalia, nor have I seen
the same reed-like structure of the fibres as is represented at
a, fig. 12, where the nuclei seem as if they were compressed
by the lateral bands stretched over them at intervals.

Up to the time of birth nothing of importance remains to
be observed. Fig. 23, Pl. I, represents three muscular fibres
from the leg of a human foetus of three and a half months;
one of them is left blank.

Such are the results of my own observations on the deve-
lopment of striated muscular fibre. Let us now consider
how far they agree with the theories and observations of pre-
vious inquirers.

It is well known that, according to Schwann, every mus-
cular fibre is at first developed from round nuclear cells,
which arrange themselves in linear series and coalesce at
their points of contact. The septa by which they are sepa-
rated then become absorbed, so that there results a hollow
cylinder,—the secondary cell of muscle, within which the
nuclei of the original cells are contained, generally lying
near together on its wall.*

In 1849-50 Lebert published some investigations on the
development of the same tissue in vertebrate animals,t+
opposing at the same time the theory of Schwann. Speak-

* ‘Microscopical Researches,’ &c., p. 141.
+ ‘Aunales des Sciences naturelles.’

CLARKE, ON STRIPED MUSCULAR FIBRE. 5

ing of the origin of the muscular cylinders, he says—
« J’avoue que la théorie cellulaire ne me rend pas bien
compte de leur premiére formation, et je n’ai pas pu con-
firmir leur mode de développement par alignement et fusion
de globules, mode indiqué par plusieurs physiologistes dis-
tingués.”* According to him, the first traces of the mus-
cular fibres make their appearance as fusiform, somewhat
oval, cylindrical, or irregular corpuscles or cells, which he
calls the myogenic bodies, and in which certain indications
of longitudinal striz are already observable; (‘‘ corpuscules
fusiformes, ovoides ou irréguliers ;’” “corps ou cellules myo-
géniques ;” “ espéces de longues cellules irreguliérs’”). He
confesses, however, that he was unable, by ‘direct observa-
tions, to determine the mode of origin of these bodies—
* dans loiseau, comme dans les autres vertébrés, la premiére
origine des cylindres musculaires ne peut pas encore étre
précisée par observation directe.”+ It seemed to him that
they were formed by a coalescence of all sorts of pieces, and
that the nuclei within them were only accidentally inclosed.{
It is evident that the “corps ou cellules myogéniques” of
Lebert correspond to the bodies which I have described and
represented as appearing in the chick between the sixth and
seventh day of incubation (see Pl. XI, fig. 9, c, d,e, f); but of
their mode of origin, as already shown, he was unacquainted.
Neither does he make any mention of the smaller fibres which
are formed at an earlier period, as I have already described.
In 1854 a paper, by Mr. Savory, of London, “ On the
Development of Striated Muscular Fibre in Mammalia,”
was read before the Royal Society, and in 1855 was pub-
lished in Part II of the ‘ Phil. Transactions.’ The results of
these investigations are completely at variance with the cell
theory of Schwann. The following is a brief statement of
the principal facts connected with the plan of development.
The first stage consists of the aggregation and adhesion of
the free cytoblasts or nuclei into clusters, and their invest-
ment by blastema to form elongated masses, which are irre-
gularly cylindrical or somewhat flattened. The nuclei thus
aggregated next fall into a single row, while the surrounding
substance at the same time grows more transparent, and is
arranged in the form of two bands, which border the fibre,
and increase in thickness by the addition of fresh blastema to
their external surface. ‘The fibres next begin to lengthen,
while their nuclei part from each other, and as the distances
* © Annal. des Sciences nat.,’ 1849, p. 352.
+ Ibid.
} Ibid., p. 377.

6. CLARKE, ON STRIPED MUSCULAR FIBRE.

between the latter increase the bands which separated them
fall in and coalesce, so that the diameters of the fibres
decrease. Soon after the nuclei have separated some of
them begin to decay by breaking up into irregular clusters of
granules, which themselves soon disappear. At this period
the strize first become visible within the margin of the fibre,
and then pass gradually towards the centre. The fibres now
begin to increase in size by means of the surrounding cyto-
blasts. These become attached to their exterior, and invested
by blastema, which generally forms a continuous layer be-
tween them. The nuclei subsequently sink into the sub-
stance of the fibre, and an ill-defined elevation, which soon
disappears, is all that remains.

Now, while this account and that which I have given as the
result of my own investigations differ from each other in
many particular points, they still very nearly coincide in
regard to the general principle or plan upon which the fibres
originate in the blastema. In the first stage of their forma-
tion, however, the nuclei are far from being always aggre-
gated in clusters, or even in contact with each other in linear
series, as may be seen in birds, mammalia, and especially in
man, in whom such an arrangement never occurs (figs. 4,
5, 14, and 18); and even when they are in contact or overlay
each other their adhesion always takes place by means of a
certain quantity of blastema, as at c¢, figs. 5, 6, and 14,
When they are at some distance from each other, the blas-
tema which cements them in a larger or smaller quantity is
more or less enclosed as an axis by the condensed substance
of the lateral bands, and contributes to the extension of these
bands or to the formation of separate fibrille around the rest
of the fibre, which, however, increases in diameter by the
deposition of fresh material on its surface (fig. 4 a, 6, ¢;
fig. 5 a, b, d.) In many instances, particularly in the
younger fibres, the nuclei are crowded together in close con-
tact, as represented by Savory, and sometimes they overlap
each other, as represented at ¢, fig. 5. When several of them
are compressed closely together they frequently seem as if
they were undergoing a process of division, and such a pro-
cess does actually take place in many instances within the
fibres, where the nuclei frequently occur in pairs or in rows
of three or four.

My observations on the first stage of development of mus-
cular fibre in the human foetus, with many of the drawings, were
made at the beginning of the present year (1861). Those in
the chick I made in the following June and July; and while
occupied with the same subject in mammalia during the

CLARKE, ON STRIPED MUSCULAR FIBRE. 7

month of October, my attention was directed to a recent
paper on the development of striated muscular fibre by
Deiters, of Bonn.* This author’s observations were made on
the tissue formed during regeneration of the tail of the tad-
pole. The conclusions at which he arrives are as follows:

1. Striated muscular fibre results from the transforma-
tion of a structure belonging to the class of connective
tissues.

2. This transformation proceeds directly from the con-
nective-tissue-cells, which, however, preserve their spindle
and stellate shapes. .

3. The essential nature of the process consists in this—
that the cells deposit the striated substance on their outer
cell-wall, so that it possesses the relation of an intercellular
substance.

4. This substance shows itself at first in the form of a
simple, long, smooth, and frequently transversely striated
band or border of condensed material (Verdickungssaum),
which corresponds to our fibrilla, and increases by the con-
tinual deposition of new layers on its outside.

5. The deposition takes place mostly on one side, but may
occur on other sides.

6. During this process the cells multiply by a considerable
increase in the number of the nuclei. At the same time
the striated border increases in length, and may extend very
far beyond the cell.

7. The cells do not lie immediately behind one another,
but either side by side or obliquely behind each other,
somewhat in the fashion of tiles.

8. The formative cells are connected with the connective-
tissue-cells of the tendons.

9. The sarcolemma is the last product of the developed
primitive bundles; it is not cell-membrane.

From some of these statements it is obvious that, as
regards the manner in which the muscular fibres first make
their appearance in the blastema, there is a general coinci-
dence of this author’s views with those put forth by Savory,
as well as with my own. The chief points of difference are
the following :—Ist. That although, according to Deiters,
the muscular fibres are not formed directly by the coalesced
substance of nucleated cells, as maintained by Schwann and
others, yet that nucleated cells are the real agents in their
development. 2nd. That these “formative cells’ are not

* ‘Beitrag zur Histologie der quergestreiften Muskeln,’ von Dr. Otto
Deiters. Reichert’s u, Du Bois-Reymond’s ‘ Archiv,’ Heft iii und iy,

8 CLARKE, ON STRIPED MUSCULAR FIBRE.

ultimately inclosed by the striated substance to which they
give origin.

With respect to the first of these statements, the question
to be decided is, whether these formative bodies are to be
regarded as true nucleated celis. In the regenerate tissue of
the tadpole, according to Deiters, they are real cells, possess-
ing distinct envelopes. Now, although in this particular
case I am not prepared to offer any opmion from direct
observation, since the season had already passed for making
the necessary examination before the publication of the
Deiters’ paper, yet I think I may safely assert that im
man, mammalia, and birds, the granular substance surround-
ing the nuclei, and concerned in the development of the
muscular fibres, have no envelope or cell-wall in the proper
sense of the word, and that these bodies are not entitled to
be considered as nucleated cells.* It is true, as I have already
shown, that the granular substance sometimes assumes the
form of a fusiform cell; but, if the process of development
be examined in very young embryos, the tapering or conical
prolongations of the nucleus may be observed in different
stages of formation, and to consist frequently, at first, of
delicate streaks of the finely granular blastema. But it
very commonly happens, as I have also shown, that the
intervening blastema cements the nuclei together, without
forming a separate mass around each. In other instances, as
represented at e, fig. 11, inthe chick, and at m, fig. 14 (Pl. XI),
in the pig, a fibre originates in the blastema, between series
of nuclei, at some distance asunder, which are each con-
nected with the fibre by a more or less globular, oval, or
fusiform mass. Fig. 14, like the others, is an exact repre-
sentation of a fibre from the dorsal muscles of a foetal pig of
not quite an inch in length, The granular blastema on the
left border of the middle nucleus had not yet actually
assumed the appearance of a fibre. The free edges of these
delicate and variously shaped masses of blastema are at first
frequently uneven, ragged, or, at least, not sharply defined,
and contrast strongly with the very distinct and well-defined
wall of the nucleus itself. But when a fine fibre or lateral
band has formed along each side of one of the masses
surrounding the nucleus, and has joined its fellow at both
ends (as at the lower part of m, fig. 14; the upper part
of e, fig. 11, and elsewhere), this investing substance has

* Tt is necessary to state that an abstract of my present communication
was received by the Royal Society of London, on November 21, 1861; read
January 16, 1862; and published in No. 48, vol. xi, of the ‘ Proceedings of
the Royal Society.’

CLARKE, ON STRIPED MUSCULAR FIBRE. 9

frequently the appearance of a cell-wall, so that the body
might be taken for a true nucleated cell, giving origin to a
process or fibre. Such would be the case at fand g, fig. 14,
if the lateral band were a little finer, and were joined at
each end of the mass by another from the opposite side. I
have examined such a multitude of specimens from embryos
of all ages, with so much care, that I can scarcely see how
any unbiassed and candid inquirer, who has devoted the
same attention to the subject, can arrive at any other conclu-
sion than the one I have just drawn.

In the opinion of Deiters, the muscular fibre and striated
mass is to be considered in the light of an intercellular sub-
stance, secreted by the so-called nucleated cells. Whether it
be a product of secretion or not, I leave out of the question ;
but supposing these bodies to be true nucleated cells, with cell-
walls, it is quite certain that their separate existence, as such,
is far from being a necessary condition for the development
(secretion) of the muscular fibres; for by the descriptions
and figures of Dieters himself, it is shown that several of
these cells frequently coalesce to form either a continuous
band or tube,—in which the nuclei are disposed in linear
series,—or an irregular mass, in which they lie without any
order, so that in these cases the process of secretion would
be carried on, not by separate cells, but by tubes, bands, or
irregular masses formed by the coalescence of cells. However,
there is little doubt that the muscular substance is the result
of some process carried on by the nuclei themselves. Now, ac-
cording to my own opportunities of observation, the organic
muscular-fibre-cell is developed on the same plan as the
striated fibre in its first stage, viz., by the formation of sar-
cous substance around a nucleus encrusted with blastema ;
so that the latter kind of fibre, instead of being the product of
a nucleated cell, would appear to be itself a kind of cell-
formation, which at first finds its prototype in the organic
muscular-fibre-cell, and in which the investing sarcous sub-
stance represents the cell-wall.

10

On the GenpraL Anatomy, HistoLtocy, and Puysio.oey of
Limax maximus (Moquin-Tandon). By Henry Lawson,
M.D., Professor of Physiology in Queen’s College,
Birmingham,

Ir has often occurred to my mind that the objects by
which we are almost invariably surrounded are not unfre-
quently those with whose characters and history we are least
acquainted. How many are there who, though on terms of
intimacy with the utmost minutiz of some arabesque, or
specimen of medieval ornamentation, can accurately depict
from memory alone the pattern of a well-known carpet or
the design of a drawing-room’s tapestry? If so common-
place a comparison be not inadequate to the subject, I beg to
offer it as one of the circumstances which instigated the re-
searches, upon which the results stated in the following pages
have been based.

The variety of L. maximus selected for dissection has been
in most instances the dark one, with occasional examinations
of the mottled specimens ; the chief morphological distinc-
tion between the two, being the possession by the latter of a
distinct shell, the material of which in the former is usually
found in a condition of disintegration, mingled with the
mucous exudation of the sac in which it is contamed. We
find, according to the philosophic investigations of Prof.
Huxley,* that the slug, like other pulmonata, develops in the
embryonic state, an abdomen or mass of tissue anterior to the
anal aperture, in this way causing the intestine to bend, with
its concavity facing the nervous region of the body, and hence
it comes under the category of molluscs, exhibiting a “ neural
flexure” of the archetype of this naturalist.t The arrange-
ment of the organs included im the economy of gasteropodous
creatures is generally stated to partake of irregularities, to
be devoid of co-ordination, and to be asymmetrical. I cannot
say that I have been forcibly impressed by the truth of these
dogmas, for to me, a very decided symmetry is apparent, and
that too, in many instances, of the bilateral type. Thus, in
the nervous, the circulatory, and the special sense systems,

* © On the Morphology of the Cephalous Mollusca, as illustrated in the
Anatomy of certain Heteropoda and Pteropoda collected during the Voyage
of H.M.S. ‘Rattlesnake’ By T. H. Huxley, F.R.S.” ‘Philosophical -
Transactions,’ 1853.

t+ Some difficulty is at first experienced in endeavouring to realise this
change, but the author’s explanation (vide note, p. 51, of memoir referred
to) renders the matter most explicit.

LAWSON, ON LIMAX MAXIMUS. 11

we find the constituent organs equally divided between the
two sides of the body, and there are two salivary glands and
two principal divisions of the liver, one of each lying on either
side of the median line. The lungs we may also, to some
extent, distribute with reference to a central plane; and, finally,
there remain but the generative and digestive apparatuses,
which, though seemingly aberrant, we are not warranted in
concluding to be asymmetrical till better acquainted with their
phases of development. In a rude way we may look on this
animal as a tough, elongated pouch, containing viscera, and
having attached to its dorsal surface, on its anterior third, a
convex and in some measure pyramidal cap, which is com-
posed of the so-called mantle; this, in vertical section, is
dome-shaped, and is a perfectly closed cavity, in which is
placed the loose mass of calcareous particles of the shell ;
below, it is limited by a delicate, transparent membrane, which
lies upon the heart and pericardial gland, and appears by a
process of splitting to pass beneath these latter also, in this
manner completely separating them from the great visceral
chamber subjacent (see Pl. II). I propose to treat of the
anatomy of Limax after the following scheme:

1. Tegumentary system. 5. Circulatory system.

2. Muscular system. 6. Nervous system.

3. Digestive system. 7. Special sense and glandsystem.
4, Respiratory system. 8. Reproductive system.

Integument.—The skin system is of the musculo-cutaneous
type, and may be said to consist of three coats, an outer or
dermoid, a middle or muscular, and an internal or fibro-vas-
cular, and calcareous. The first resolves itself into two layers,
a more external stratum, which is transparent, and, so far as I
could observe, structureless, and in some instances detachable,
and within this a bed of fusiform endoplasts, imbedded in a clear
matrix, and which assume the fibrous appearance of connec-
tive tissue as they approach the next coat, from which they
are inseparable. The muscular or central lamina is also com-
posed of two layers of fibres, the most external being longi-
tudinal, and those within them transverse, yet the line of
distinction cannot be clearly drawn, for as you advance
inwards you find the outer fibres gradually losing the longi-
tudinal and by assuming an oblique position, in this way
passing almost insensibly into the truly transverse ones; the
fibres, at best, are indistinct, and are composed of elongate
endoplasts. The inner coat consists of meshes of connec-
tive tissue, tunneled for the conveyance of the venous blood,
and impregnated with round, granular particles of carbonate

12 LAWSON, ON LIMAX MAXIMUS.

of lime, which give that portion lining the visceral chamber
a pure, white, lustrous aspect. I have not entered into the
shell question in these pages, because the shell in its mature
form is more or less structureless, and its homologies can only
be arrived at by an appeal to development, the study of
which in this animal I have not devoted sufficient atten-
tion to.*

Muscular System.—The muscles in this animal are not
numerous, as, indeed, they are not in any mollusk, and may
be conveniently grouped under two heads—those blended
with the integument, and those distinct. The former I have
already described. The isolated muscles are very few in
number, and embrace those of the tentacula, and the retractors
of the head. In both cases they are flattened bands, of a
glistening, semi-transparent appearance, and are made up of
long, fusiform endoplasts, with dark nuclei, and surrounded by
a clear periplast. The retractor of the head is along, tough, flat
band, which arises from the integument of the right side,
about the middle of the antero-posterior plane, and, passing
beneath the viscera reaches the nervous collar of the gullet;
here it comes through the circlet of nerves and beneath the
cesophagus, and on approaching the head bifurcates, the
two filaments thus produced being inserted into the musculo-
fibrous tissue of the head, with which they become continuous.
The tentacular are much more complex in mode of arrange-
ment, and are three in number for each side of the body.
These three are united in such a manner as to give rise to a
more or less perfect equilateral triangle, whose base lies in
the longitudinal plane, with the apex pointing laterally and a
little upwards; the posterior extremity of the base is con-
tinuous with the dense skin of the foot, to which it is attached,
and the anterior side is prolonged and blended with the tissue
of the foot in the median line and just below the mouth.
From the apex of the triangle springs the superior tentacle,
and from the muscle constituting the base arises the inferior
one; hence, if the basal cord contracts, the superior tentacle
will be drawn in; if the posterior side of the triangle is
shortened, the inferior tentacle will be brought in; and should
the anterior band be stimulated, it will tend more or less by
its contraction, to place both tentacula in a position to allow
of eversion by the usual means. A glance at the semi-
schematic figure on Pl. II will suffice to make these remarks
intelligible.

* For an admirable memoir on this subject, consult “ Beitrage zur Ent-
wickelungsgeschichte der Land-Gasteropoden,” by Carl Gegenbaur, in

Siebold und Kolliker’s ‘ Zeitschrift,’ &c., for 1852.

LAWSON, ON LIMAX MAXIMUS. 13

The Digestive System, with the appendages which appertain
to it, forms the bulk of the slug’s viscera, and in treating of
it we have to speak of the following parts :—head, salivary
glands, gullet or pro-stomach, stomach, liver, and intestine.
The head is the most anterior portion of the body, and when
deprived of the tentacula and integument which cover it
appears as a solid, glistening, white structure, of a more or
less spherical form, viewed from above, in profile seeming
oval, the large end behind, and having, projecting from its
posterior inferior border, a small, whitish, semi-transparent
papilla. On its two sides, above, are seen the superior ten-
tacles, and beside and beneath, various branches from the
cephalic or supra-cesophageal ganglia; moreover, the two
most anterior ganglionic masses are strongly united to its
external lateral surfaces, and their branches wind around it
as before described. It is about + inch long in an antero-
posterior direction, and measures + inch transversely. In-
teriorly it is hollow, has in front an aperture—the mouth
—and receives at the most superior border of its pos-
terior surface the commencement of the gullet; its cavity
resolves itself distinctly imto two—the upper or true
mouth, and the lower or pharynx—which must be described
separately.

The mouth lies superiorly, and has its position indicated
by the conception of a right line uniting oral orifice and
gullet, and which is horizontal; the outer opening is provided
below with a fleshy lip (a modification of the general integu-
ment), which is partially divided by vertical slips into squarish
segments, and plays the part of an inferior jaw. Above, the
lip is absent, its place being taken by a very distinct and
perfect maxilla. This is a horny or chitinous structure,
about + inch wide and + inch long, which is soldered to the
palate; it is of a brownish colour, and of a somewhat tri-
angular outline, the base in front notched, and bent down-
wards at right angles to the rest, thus performing the
office of teeth; the apex pointing to the cesophagus, and the
whole non-dental surface constituting, as it were, a second
palate ; behind, and close to its junction with the gullet, are
seated the openings of the salivary glands.

The pharynx or inferior cavity is a kind of pocket or diver-
ticulum, which I can compare only to an inverted and bi-
sected hollow cone, flat behind and angular in front; it is
lined with a roughened membrane, and has, pointing from
it downwards and backwards into the visceral cavity, the
papillary process above alluded to, which organ can, by an
eversion, be brought forwards so as to lie obliquely in the

14 LAWSON, ON LIMAX MAXIMUS.

pharyngeal sac. The roughened membrane with which the
pharynx and tongue (for so the papillary organ must be
termed) are covered, when seen under the microscope, is a
very pretty object. It is covered by a multitude of closely
set spines of a calcareous nature, arranged in linear order, side
by side, the lines being placed one behind the other; each
spine consists of a central portion or body, which is elliptical,
and an exquisitely slender curved hooklet springing from this
latter; the poits of the hooklets all project backwards, and
the spines are placed one behind the other, and not alternately,
with an exceedingly small, rounded process rising from the
membrane between every pair. The functions of the head
are two, those of prehension and mastication, deglutition
being achieved through the contractions of the gullet. Now,
the first, as I take it, is performed by the jaw and lips, which,
grasping the leaf or other portion of vegetable matter, bring
it within reach of the pharynx ; arrived here, it is acted on
by the salivary fluid which has been thrown into the pha-
ryngeal bag, then by a series of compound movements of the
tongue it is submitted to a rasping process between the
hooklets of this latter and those of the pharynx, and eventu-
ally, having been reduced to a state of very fine division, it
is tilted backwards by the tongue, and being now within the
grasp of the cesophagus is gradually carried onward to the
stomach. The head is principally composed of connective
tissue, but about the oral orifice on the inferior border, a con-
siderable band of nucleated, unstriped fibres may be observed ;
a few fibres of a similar description are mingled with the
layers of connective web, and the tongue [beneath the spinous
coat] is almost entirely muscular.

The salivary glands are two in number, extremely delicate
in texture,.and of a pale-white colour ; they lie on either side
of the esophagus, in the respiratory region, being covered by
the heart and pericardial gland, and resting in part upon the
great supra-cesophageal ganglia ; they are bound to the gullet
by numerous arterial branches common to both, and are
flattened and leaf-like in appearance. Hach gland has a
length of = inch, from side to side measures about | inch, and
pours its secretion into the mouth by a long and narrow duct,
which passes anteriorly from the gland, beneath the great
ganglia, to the orifice of the gullet immediately above the
pharynx, and in which I, less fortunate than Miller, have
not detected ciliated epithelium. In general structure these
glands are loose, and are made up of a number of minute
lobules, arranged in clusters upon the terminal ramifications
of the ducts. Microscopically, each lobule is of an oval shape,

LAWSON, ON LIMAX MAXIMUS. 15

filled with transparent fluid, and contains, floating in this
latter, many well-marked circular endoplasts, with nuclei
in their interiors, and has attached to its inner edge a deli-
cate twig from the excretory duct (Pl. II, fig. 3).

The gullet is a canal, at first narrow as it leaves the mouth,
but having passed the nervous collar it widens so as to re-
semble a funnel, and its walls become more dense and mus-
cular; it is usually of a dark-brown colour, this being for the
most part owing to a quantity of bile, which it nearly always
contains, and which renders it not unlikely that much of the
true digestive process is gone through here. Like the other
division of the alimentary canal, the cesophagus exhibits the
tendency to curve spirally in its passage from head to
stomach, and though prior to its passage through the second
nervous circle it is horizontally situate in the median lime,
yet, between this and the stomachal sac, it turns to the left
and downwards, and again bending to the right in the central
axis and, equidistant from the head and caudal extreme of
body, it terminates in the stomach. It is related above to
the heart, pericardial gland, lung-sac, nervous masses, ante-
rior lobe of liver, and large and small intestines, the rectum
just passing over it between the head and ganglionic centre ;
it rests upon the foot (having the pedal gland below it) and
inferior nervous masses ; is bounded on the right by the ante-
rior portion of the reproductive organs, on the left by a fold
of the large intestine, and on both sides by the tentacula
and their muscular apparatus. It is little more than two
inches in length, has a calibre of + inch at the cardiac orifice
of the stomach, and measures diametrically ~; inch as it
leaves the mouth. Histologically, the cesophagus is identical
with the other divisions of the alimentary canal except the
stomach, and therefore the sketch of its microscopic anatomy
will suffice for all, except the latter. Two coats enter into
its composition, a fibro-muscular and pseudo-mucous, neither
of which, however, can be detached without injury to the
other. The first, most external, or visceral layer, when ex-
amined under a low power, presents to the eye a collection of
muscular and connective tissue fibres, nerves, and blood-
vessels, mingled heterogeneously together; but if the larger
branches of the latter be carefully teased out, and a small
section submitted to a much higher power, it is then seen
that the outer coating is composed of two distinct strata of
nucleated, non-striated, muscular fibres, crossing each other
pretty nearly at right angles, and, blending with them
and pursuing an undulatory course, a few fibres of the
elastic connective tissue (fig. 4). The muscular fibres are
absent in some localities, thus leaving small rectangular

16 LAWSON, ON LIMAX MAXIMUS.

spaces between the strata. The second lamina is with diffi-
culty prepared for examination ; it is perfectly transparent,
and, so far as I could observe, entirely devoid of epithelium,
ciliated and non-ciliated, and perfectly structureless, seeming
to be a kind of protective glazing, thrown out over the exter-
nal coat.

The stomach is an oval-shaped bag, of a dark-brown colour,
into one end of which open together, the gullet and intestine,
so that these latter appear almost continuous, and the stomach
itself looks as though it were a diverticulum (fig. 1). It
is placed in the centre of the antero-posterior plane, inclin-
ing a little to the left; to its dextral end are attached the
gullet and intestines, its sinistral extreme being free; it is
supported by the foot and oviduct, has the ovary behind, the
two bile-ducts in front, and the liver on either side and on
its superior edges. Above, it is in relation to the inner surface
of the integument only, and therefore it is one of the struc-
tures seen on removing the dorsal covering. It is about + inch
long, ;2; inch deep, and + inch wide. As in the gullet, so
here, we have two separate laminee—the outer or muscular,
the inner or mucous. The external coat is made up of three
rather well-marked, muscular layers—circular, longitudinal,
and oblique—which present the same appearance as those of
the cesophagus, with this exception, that, whilst the nuclei in
the fibres of the latter were short, in those of the stomach
they are large, distinct, and fusiform; the imner layer is
nothing more than a bed of oblong endoplasts, resting upon
the outer; a zone of indifferent tissue, or a protomorphic line
(to use Prof, FIuxley’s expression), being interposed.*

The intestine is a tube, musculo-membranous in character,
as wide as the gullet for about one third of its length, but
gradually diminishing in diameter as it approaches the anus ;
from this peculiarity, that portion of the gut which is nearest
the stomachal cavity must be termed the larger, and the
remaining division of the canal the smaller intestine. Except
toward the anal aperture, it is of a dark, brownish-green
colour, which is due in some measure to the vegetable and
biliary contents. In its entirety it averages a length of seven
inches, is of equal capacity with the gullet as it leaves the
stomach, and measures not more than ~; inch at the anal
orifice. It is better, in treating of its relations, to assume
that it is a single tube, and in this way avoid the difficulty of
drawing the exact line between the greater and lesser gut.
The intestine, then, leaving the pyloric end of the stomach,
travels obliquely, forwards and upwards, beneath the liver, and

* T have not seen the spinous coat, so often alluded to in popular treatises
ou microscopic anatomy.

LAWSON, ON LIMAX MAXIMUS. Bey

above the cesophagus, where it is covered by the integument
only, to the right lateral respiratory region ; arrived here, it
makes a sudden turn, and passes beneath the gullet to the
left; next it curves slightly upwards and then downwards—still
being upon the left—and descends again, coursing beneath the
cesophagus and toward the right side; it now ascends, and,
going to the left above the gullet and below the liver, it is
lost sight of ; continuing its course upon the left, it approaches
the stomach, its convexity reclining against this organ. At
this point, by a perfect sigmoid flexure, it encloses a portion
of the liver (being still, however, beneath the upper part of
this latter), winds to the right across the cesophagus, and, pass-
ing under one of its own folds, and, finally, beneath the heart
and pericardial gland and above the gullet, it terminates in
the anus at the superior angle of the pulmonic orifice, being
here retained in situ by the united muscles of the retractor
capitis, which are looped around the gut. The anus is closed
by a circular band of elastic tissue, which encircles this tube
at its junction with the integument.

The liver is by far the largest and most complete gland in
the economy of this animal, aud when separated from the
other organs with which it is connected, appears as two
separate structures, exhibiting what we should not have been
led to expect, similarity of size and form; these are of a
dark-brown colour, and have their under surfaces crowded
with exquisite white, arterial ramifications. The liver shows
the general tendency to assume a twining arrangement, for
we find it adapting itself to the various folds of the intestine,
aud so embracing the latter, that, a separation of the two
involves some delicate dissection. Each lateral division is
conjoined to the stomachal end of the cesophagus by its wide
and easily distinguished hepatic duct; that of the left side
pouring its secretion into the gullet about 4 inch anterior
to that of the right. Each is of an irregular oblong shape,
bearing some likeness in outline to a lanceolate, acute leaf,
with notched edges, and consists of numerous large and
small lobes, bound loosely together by a web-like connective
tissue, and attached to branches of the principal duct; it
measures about 2 inches in length, and at its widest part
is more than + inch in breadth, but in some specimens
which I examined the liver did not exceed 1 inch in length,
and was proportionally narrow. Every lobe may be divided
into a number of component lobules, and each of the latter
comprises seven or ten still smaller structures of an uneven
polyhedral type, within whose walls may be observed nume-
rous endoplasts, some of them large, with yellow or lght-

VOL, IlI.—NEW SER. B

18 LAWSON, ON LIMAX MAXIMUS.

brown contents, others small, without nuclei, and also a con-
siderable amount of loosely floating granular particles. The
duct, on entering one of the lobules, divides into several
branches, which surround the many-sided compartments,
and become eventually indistinguishable from the fibrous
septa; but never have I detected a communication between
duct and theca, the two portions of the organ being as sepa-
rate as they are in the human liver, according to the view of
a recent investigator.* Had there been any distinct con-
nection, it could not have remained unobserved, since it is
easily perceived when it does exist, as in the salivary gland.
The bile is a dark-brown liquid, with a faintly unpleasant
odour and a nauseous sweetish taste, which is poured in large
quantity into the gullet when the animal has been without
food for some days. Under the microscope it seems a trans-
parent fluid, suspending many clusters of brown granules,
and nucleated and non-nucleated endoplasts.

General remarks.—Lebert, in a communication to Miiller’s
‘Archives’ for 1846, has given many figures of the head,
tongue, and spinous membrane of Limax, but in some in-
stances, I conceive, he has not accurately depicted the struc-
ture and form of these organs. The palate, judging from
his sketch, seems but a mere slip proceeding from the central
portion of the jaw, which is not the case, the whole
palate and jaw forming, when flattened out, a complete
triangle, two of whose sides are slightly concave outwards.
Again, he has certainly mistaken the arrangement of the
processes attached to the lingual membrane, inasmuch as he
has placed them in alternate rows, and has omitted the inter-
vening mammillary elevations. The head, also, I fancy, is too
much prolonged. Finally, his representation of the muscular
fibre I cannot reconcile to anything I have perceived. It
might, at first sight, seem difficult to put faith in Mr. H.
Jones’s views of the liver’s functions, the conditions under
which the hepatic circulation is carried on here being differ-
ent from those we meet among vertebrata, but this apparent
difficulty disappears when we know that if the special secre-
tion were thrown out into the visceral cavity, it would at once
be taken up by the veins.

Respiratory System.—The function of respiration is carried
on by means of atmospheric ‘air introduced into a special
cavity, containing uumerous blood-vessels upon its surface,

* “On the Structure, Development, and Function of the Liver.” By
C. Handfield Jones, M.D., F.R.S. ‘Philosophical Transactions,’ 1853.

ee Oe ee

LAWSON, ON LIMAX MAXIMUS. 19

and this cavity is termed the lung. The respiratory organ
is usually described as being a ring surrounding the heart ;
this, however, is not correct; it is a double sac, one pocket
of which is situate on the right, and the other on the
left side, having two channels of communication, by means
of which the air is conveyed to every portion of the vascular
surface. 'These pouches are placed in the thoracic region of
the body (fig. 5), and are constituted externally of the general
integument, and within of a delicate fibrous membrane,
which also serves to define their limits; their upper borders
are bounded by the inferior surface of the shell, and below
they are separated from the viscera by a septal fold of their
inner membrane, which also forms a posterior partition be-
tween the lung and abdomen; anteriorly they are closed in
by the same structure, and internally they are related to the
heart and pericardial gland, which are placed between the
two sacs. The connecting channels cross the body, one in
front of the pericardial gland and heart, and the other im-
mediately behind them. The air is admitted through an
orifice of an elliptical or doubly cuneate form, which is upon
the right side near the middle lateral line, and at about
+ inch from the right upper tentacle. The great veins which
convey the blood to the lung are two in number, one for
each of the pockets, in the external walls of which they are
grooved, being merely, as it were, ploughed channels in the
integument, which have been covered in by fibrous membrane.
Each sends off several branches from its upper and lower
edge, which respectively pass upwards and downwards,
curving in their course, with their concavities facing each
other, and terminate in the border of the pericardial gland.
In the outer portion the vessels are, as I mentioned above,
but passages in the integument (which here, from the particles
of carbonate of lime imbedded in it, is white, as in the other
regions of the body), but internally they lie between two
transparent layers of membrane, and from this circumstance
are easily observed in their passage to the pericardial gland.
Each division or sac of the lung measures about + inch
in length, and is a little more than a + inch from above
downwards. The width is variable, depending, as it
does, upon the condition of the body as to contraction or
elongation. The course of the blood through the pulmonary
vessels is more properly described under the head of—

Circulatory System.—The course of the blood, in its passage
through the bodies of molluscs, has long been misunderstood.
Heretofore it has been thought that a perfect circulation ex-

20 LAWSON, ON LIMAX MAXIMUS.

isted, that is to say, a complete series of channels, by which
the nutrient fluid was conveyed from the propelling organ to
the various regions of the body, and returned to the heart.
Milne Edwards* has done much to correct the errors of the
earlier investigators; but as his observations do not extend
to Limax, and since the latter genus and that of Helix, the
course of whose circulation has been traced, are so widely
distinct anatomically, the mode in which the blood is car-
ried to and from the heart and pulmonary organs of the slug,
has not as yet been distinctly explained. I have most care-
fully pursued the examination of this subject, occasionally
with the assistance of injections prepared with new milk, and
the result has been the adoption of the following view. The
blood, having been expelled from the heart, travels through
the short aorta and its two divisions, in this way reaching the
head, reproductive organs, intestinal sanal, and liver, and,
having arrived at the terminal ramifications of the arterial
vessels, is poured through their open extremities into the ab-
dominal and sub-thoracic cavities, thus bathing the external
parietes of the viscera; these cavities are continuous, and
clothed without by the general integument, in whose walls
the various channels are tunneled. Now, the veins begin as
minute apertures,t which admit the blood hitherto contained
in the visceral chamber, allowing it to pass into their smaller
branches ; from these it then flows into the larger vessels,
and is finally transmitted by the great pulmonary vein of
each side, to the respiratory sacs. It is here that difficulty
has been invariably experienced, in tracing the channels by
.which the blood travels to the heart, some contending that a
portion flowed to the so-called kidney, whilst the remainder
was brought on to the heart by a large pulmonary vessel ;
others that the blood was here poured into a sinus or lacuna.
Both these ideas I conceive to be erroneous, the more so as
I have been unable, after the closest scrutiny, to detect any
single pulmonary vessel which might of itself convey the
blood to the heart; and besides that, the relations and cha-
racter of the quasi kidney have been most certainly misin-
terpreted. The circulation in this locality is most complete
and peculiar, and can be seen with more or less distinctness
by removing the mantle, and membrane of the shell-sac.
When this has been done, it will be observed that the blood
travels in the direction I have endeavoured to indicate
diagramatically (fig. 6), viz., having been poured by the

* © Ayn. des Sci. nat.,’ viii, 1847.

t+ The merit of this discovery is, I believe, due to Cuvier; vide for
Aplysia, ‘Ann. du Mus. d’histoire nat.,’ ii, p. 299.

LAWSON, ON LIMAX MAXIMUS. 21

great pulmonary vein of either side into the numerous lesser
ramifications of the lung-membrane, and been in this way
fully exposed to the atmospheric air, it flows in two principal
directions, according as it has passed from the upper or lower
borders of the great lateral veins. That which has been sent
upwards travels in obedience to the limits of the pulmonary
sac, first superiorly, then horizontally, and finally inferiorly,
till it gains the external edge of the pericardial gland; and
eonversely, that which left the under surface of the vein
courses first inferiorly, then horizontally, and eventually as-
cends, till it arrives at the same position as the rest. Here,
then, we find all the blood which has traversed the respiratory
reticulation at one period or other of its career, and from
this it passes internally, through the pericardial gland, in a
perfectly centripetal manner, till it has reached its inner
border; this latter expands, and constitutes, by a double,
sector-like fold of membrane,—whose arc is confluent with the
anterior division of the gland, and the junction of whose sides
is intimately attached to the heart,—a capacious sinus. Into
this expansion the blood is next introduced, flowing readily
into it at its immediate union with the gland, and being con-
veyed from the posterior internal border of the latter by a
canal partly circular, whose concave edge lies against the
heart, whose convexity is continuous with the gland, and
whose two orifices open into the lacunal cavity referred to.
From the sinus the blood is transmitted to the heart by an
aperture of communication between the former and the base
of the latter. Finally, by the contractions of the heart it is
propelled onwards through the aorta and its divisions (regur-
gitation into the sinus being prevented by a small fold of
membrane acting as a valve) to the different systems of organs,
and so on, as before. The heart is a thin muscular bag, of a
somewhat triangular or pyriform description, and of a faintly
marked flesh-like colour; it is placed in the thoracic region,
being surrounded by the pericardial gland, bounded below
by the fibrous membrane separating the heart-chamber from
the visceral sac, and above by the floor-tissue of the shell-
bag; it lies obliquely, its apex pointing backwards and to the
right, and its base in the opposite direction. It measures a
4+ inch in length, and + inch or thereabouts in width. It
is wrong to describe the heart as being composed of an
auricle and ventricle; it is a simple bag, having but one
cavity, and not presenting any division, either by constric-
tion or otherwise. It is almost wholly formed of non-
striated muscular bands, interlaced in the most complex
manner, and freely united to each other at their extremities.

22 LAWSON, ON LIMAX MAXIMUS.

The fibres, if they may be so termed, are filled with long,
spindle-shaped endoplasts, containing clear nuclei. Examined
under a low power, a very interesting arrangement is observed
in connection with the contractile structure. A number of
muscular cords are seen upon the internal surface of the heart,
which are thus disposed :—they pass from two centres, which
are situate about the middle of the lateral surfaces, in a radi-
ate manner, being continuous at their extremities with the
ordinary fibres ; and in this way they form two stellate eleva-
tions, much resembling the muscular cords in mammalian
hearts, and probably serving a similar purpose. The true
auricular chamber is the sinus to which I have already
alluded, but it is not contractile. The heart gives about twenty
pulsations in the minute, each contraction being succeeded by
a dilatation, and then an interval of repose following; during
the period of rest the sector-like expansion is gradually fill-
ing and becoming convex; on the moment of the heart’s
dilatation, by the tendency to vacuum occasioned, it is emptied
of its contents, and then, contraction ensuing, the blood is
rapidly driven through the arteries. The arterial system
consists in the aorta, with its branches and their numerous
divisions. The aorta arises from the apex of the heart, and
on attaining a length of + inch it divides into two branches,
measuring each =}; inch in diameter, which continue together
for a distance of 1 inch till they reach the intestinal fold ; then,
both having crossed the gut, one branch becomes recurrent, and,
passing beneath the intestine,runs downwards and forwards pa-
rallel with the rectum and beneath the generative organs, heart,
and pericardial gland, and becomes lost in supplying the gullet
and organs of the head. The posterior branch passes backwards
towards the stomach, and in this course gives off about twenty
branches to the intestine and liver, the intestinal branches
being given away distinctly, and passing over the latter organ
to their destination. These vessels divide and subdivide ex-
tensively, and form the most exquisite ramifications upon the
alimentary canal, with which they contrast very markedly,
being themselves of a pure white colour, whilst the intestine,
from its vegetable contents, is green. Arrived at the stomach,
the main artery bifurcates, one branch passing backwards to
supply the ovary and caudal lobe of the liver, the second being
sent to the stomach and left division of hepatic gland, upon
the inferior surface of whose lobes the most beautiful arbo-
rescent ramifications may be observed. I am not disposed to
coincide with the view of Erdl,* that a capillary network
exists—

* ‘De Helicis algire,’? Bruxelles,

LAWSON, ON LIMAX MAXIMUS. 23

Istly. Because it is not discoverable.

2ndly. Because the rootlets of the veins terminate by aper-
tures.

8rdly. Because the whole of the viscera in the posterior part
of the body are completely unattached below to the venous
integument; and as the principal arterial supply is to the
inferior surfaces, had there been any intervening series of
vessels, the integument and viscera would be adherent to each
other in this locality. The arteries are composed of nucleated
muscular fibres, having buried in them clusters of calcareous
granules, which give the snow-white colour to those vessels.
I cannot say I have been enabled to confirm the truth of
Von Siebold’s assertion, that the arterial extremities are
formed of calcareous particles alone, the organic tissue being
completely absent ; for in every specimen I examined, where
it was possible to arrive at any clear decision, I most dis-
tinctly observed, mingled with the lime-granules, long, nu-
cleated endoplasts. The veins, as I before stated, are merely
channels ploughed in the musculo-fibrous tissue of the skin,
covered on their inner surface by a fold of transparent mem-
brane; the great lateral vein of either side begins near the
caudal extremity of the body, and travels forward horizontally
to the lung-sac, at a distance of about + inch from the median
sulcus of the foot. It increases in calibre as it approaches
the lung, and on its journey receives several branches from the
upper and lower divisions of the integument.*

The pericardial gland or kidney, as it has been styled, is,
in my opinion, no more an urine gland than is the heart or
liver; nor, indeed, can I see any just reason why it has
received this appellation; for I conceive the assertion of
Jacobson,+ that it contains uric acid, is of no weight whatever,
seeing that it is based upon the idea that murexide is pro-
duced when the dried kidney has been subjected to the action
of nitric acid and ammonia. Undoubtedly these reagents give
rise to a reddish stain (which I fancy does not need the am-
monia to its production), but it is equally true that a portion
of the liver, when placed under similar conditions, will give
apparently the same results. Moreover, the statement that
this gland possesses an excretory duct is entirely without
foundation, and I can only account for its origin, by sup-
posing that in emaciated individuals the rectum has been
mistaken for a duct leading to the respiratory orifice. Not-
withstanding the most patient and persevering endeavours

* For the development and characters of the blood, see the admirable memoir

of Mr. Wharton Jones (‘ Phil. Trans.,’ 1846), to which nothing can be added,
+ Meckel’s ‘ Archives,’ vi, p. 370, 1820,

24. LAWSON, ON LIMAX MAXIMUS.

to discover something which might be construed into a duct,
I have failed signally to detect anything of the kind. This
gland constitutes a sort of collar surrounding the heart,
is bordered externally by the lung, and within by the semi-
circular canal and sector-like sinus; it is of a dark, reddish-
brown colour, and measures from side to side (including
heart and sinus), more than + inch. It is made up of a great
number of lamellz, placed against each other like those
of a fish gill, and viewed under the microscope, each of them
is seen to be composed of numerous irregular vacuoles, con-
taining within them solid, round, non-transparent, incom-
pressible nuclei. Between the lamellz many blood-vessels
may be observed travelling from the lung to the heart-
sinus, and giving off several branches, which, passing between
the vacuoles, anastomose frequently. The pericardium
embraces this organ and the heart in its folds, forming on
the one hand, the floor of the shell-sac, and on the other
the roof of the thoracic gut-chamber, and, being perfectly
transparent, admits of our observing most satisfactorily the
movements of the heart and sinus (fig. 5). I do not appre-
ciate the necessity for assuming that there is any kidney
in the economy of Limax; nor, if I did, should I therefore
conclude, that this gland was its representative simply
because one of the compounds discoverable in the urine of
man, was found, or said to have been found, here also; for,
pursuing the same line of argument, had not the kidney of
man been discovered, its being known that urea is found in
the sudoriparous secretion, would constitute a valid reason for
asserting that the human kidney was located in the skin. From
the descriptions of some of the earlier anatomists an im-
mense deal of confusion has resulted, owing to the kidney
being, according to one or other, termed the muciparous
gland, organ of the purple, &c., and these being, in turn, con-
founded with portions of the reproductive apparatus.

The Nervous System is composed of four separate gan-
glionic masses, two superior and two inferior, which, by con-
necting cords, constitute three distinct rmgs. The first ring
lies upon, the second surrounds, and the third is placed im-
mediately beneath, the gullet, and springs, as it were, from
the second. The two latter are by far the most distinct,
and from the circumstances of their size and contiguity have
been generally supposed to embrace the entire nervous
system. The anterior ganglia are two in number, exceed-
ingly minute, measuring about =; inch in length, and
situate on either sideof the enlarged oval organ or head,

a eee

LAWSON, ON LIMAX MAXIMUS. 25

being at the superior and posterior border of this structure ;
they are of a dumb-bell shape, slightly curved, their concave
edges embracing the convexity of the head; they are of a
whitish-yellow colour, but do not contain as muck. calca-
reous matter as the ganglia of the posterior divisions ; they
are attached to each other by their posterior expan-
sions, through the medium of a strong, nervous filament,
4 inch in length. From their anterior extremities eight
nerves pass off, four on each side, to supply the various
portions of the gustatory and linguze-prehensile apparatus ;
finally, from each posterior extreme, a minute, lingual twig is
seen passing to the superior surface of the gullet, and two long
internuncial branches, which take their course backwards,
on the upper surface of the cesophagus, for a distance of
about 2 inch, and terminate in the second circle. This
is formed of two irregular, oblong pieces (one lying on
the gullet, and the other beneath it), and a connecting
nerve, which passes vertically downwards on each side,
and which, though apparently a single flattened structure, is
actually composed of two riband-like nerves, from which
no branches are given. The upper ganglion-mass is slightly
concave, both anteriorly and posteriorly, but more so behind
than in front; it is composed of two ganglia, which have
become completely amalgamated, and which are indicated
by a transparent colourless spot at each extreme. That the
ganglia are not merely contiguous, I have satisfied myself,
and, from my own repeated observations, must give unquali-
fied denial to the assertion of Von Siebold,* that the gan-
glia, though fused into one in Murex and others, are not
so in Limax. This nerve-mass is easily seen on removing
the heart, intestine, and reproductive organs, and is the more
readily perceived on account of its snowy whiteness, which I
imagine is due to the presence in large quantity of calcareous
granules, for when the structure has been for some time im-
mersed in acetic acid the colour is lost, and the mass becomes
transparent. From the translucent and crescentic ends of
this supra-cesophageal mass, four pairs of nerves arise; of
these, the first pair passes to the superior tentacles, supplying
these organs with filaments, and transmitting a branch to the
eye, which is the true’ optic nerve ;+ the second pair is
also distributed after many divisions to the inferior tentacula
and lips; the third pair runs downwards and forwards, and,

* See ‘ Vergleichenden Anatomie,’ Burnet’s translation, note 9, p. 235.

+ Johannes Miiller (* Ann. des Sci. nat.,’ xxii, 1831) maintains this view
also, which, so far as I can see, is the correct one. It is strange, however,
that Siebold contends for the distinctness, from its origin, of the optic nerve.

26 LAWSON, ON LIMAX MAXIMUS.

after a slight degree of ramification, is lost in the tissue and
muscles of the lower tentacles; the fourth and most posterior
pair passes forwards, and, being lost upon the mouth and
adjacent structures, deserves the name of buccal. The third
ring we now arrive at. It is about as wide as the second
(which measures transversely somewhat more than + inch) ;
indeed, its upper ganglionic mass is nothing more than the
inferior expansion of the latter (fig. 8). Its superior com-
ponent is oblong, iregular, and not very symmetrical,
slightly convex anteriorly and concave behind, with its
noduliform extremities pointing forwards; it is united
directly by fusion to the lower mass. The latter is com-
posed of three ganglia, soldered to each other in an arciform
manner, the concavity directed upwards. The two portions
of this ring are so closely related, that, to the naked eye the
existence of an intervening space is barely perceptible. It is
from this congeries of ganglionic centres that the different
viscera and the great pedal muscles receive their nervous
filaments, which, though numerous at the periphery, are
referable to five primal pairs, and an azygos central branch
proceeding to the posterior surface of the head. The first,
passing from the superior extremities of the mass, supplies
the heart, part of the gullet, stomach, and the lungs. The
divisions of this pair are peculiar, for many of the threads,
after separation, again unite, thus forming a very rudimentary
plexus. The second, third, and fourth pairs all origmate in
the lateral portions of the ring, and terminate in the walls of
the intestine, the reproductive organs, and the liver. The
fifth pair is the most inferior, and arises from the inferior and
internal border of the external walls of the ring, leaving a
central and included space, from which vo nerves start. The
nerves comprised in this couple are “ the great pedal ;” they
direct their course backward on either side of the great cen-
tral gland (?), and beneath all the viscera, and after having
transmitted three or four branches to the musculo-connective
tissue of the foot, terminate at a distance of 2 inches from
their origin, in that portion of the pedal organ just beneath
the ovary, and last lobe of liver.

Histology of Nervous System, and general remarks thereon.
—The nerves viewed under the microscope present rather the
aspect of connective tissue than the tubular appearance
characteristic of vertebrate nervous fibres, the outer edge of
each individual nerve seeming denser and to have undergone
more decided differentiation than the imner portion. On
entering the ganglion the nerve splits up into a considerable

LAWSON, ON LIMAX MAXIMUS. 27

number of delicate threads, which become lost between the
endoplasts of the ganglion itself. On no occasion have I been
enabled to discover the division of the ganglion into compart-
ments, as described by Von Siebold. I have carefully pre-
pared sections with the assistance of Valentin’s knife, and
have subjected these slices to the action of the compressorium,
and in both cases the same appearance was presented to the
eye, Viz., an opaque periplast, consisting of fatty matter and
calcareous particles (as evidenced by transparence ensuing on
immersion in a mixture of acetic acid and ether), imbedding
numerous large, and readily perceivable endoplasts of the fol-
lowing kinds :

A, With an outer wall, granular contents, and a well-
defined nucleus and nucleolus.

B. With two outer walls, the substance between the two
clear and non-granular; the interior filled with a granular
material, a nucleus, and two or three well-marked nucleoli
(fig. 7).

Both varieties were of an irregularly elliptical outline,
large and small, but never pedunculated. From KEhren-
berg’s observations on Arion, I had expected to find tailed
globules in Limax, but they have no existence. Anderson’s*
woodcut is calculated to mislead, because he has not given
the proper number of nerves arising from either the superior,
or inferior ganglia, and, besides, he has faller’ into error in
representing two pairs ‘of filaments as united to the bands
connecting the supra- and infra-cesophageal centres ; and one
would suppose from his engraving, that the pharyngeal
nervous masses had no direct connection with the others. It
might be objected to the foregoing account, that, I have taken
no cognizance of the splanchnic series as a special system ;
but I would reply, that on this subject I hold the opinions or
M. Claude Bernardy+ to be in the main correct.

Sense System.—Organs of Hearing.—lIt is stated in most
works on the anatomy of molluscs that these organs are
represented bya pair of transparent, membranous saccules,
containing either siliceous or calcareous particles termed
otolites, and placed upon the inferior nervous masses. I
frankly confess that I have never succeeded in finding them
present in Limax. I have taken great pains to detect them,
but in vain, and although naturally anxious to discover some

* “Cyclopedia of Anatomy and Physiology ;’ ;’ Article “ Nervous System ;”
Division ‘‘ Comparative Anatomy.

+ ‘Med. Times and Gazette,’ vol. for 1861; and ‘Journ. de Physiologie,’

28 LAWSON, ON LIMAX MAXIMUS.

apparatus which I could set down to their credit, up to this
time my efforts have been unsuccessful. From this cireum-
stance I am led to suspect that in this creature no auditory
mechanism really exists, and this suspicion is somewhat
strengthened by the fact, that, the so-called ear-vesicles are
said to be among the first detectable organs in the embryo,
which I should not suppose probable as regards an appendi-
cular mechanism or sense-capsule. ‘Tio speak more plainly,
if we were informed, that, in the embryonic life of a verte-
brated animal, the most well-marked system was the auditory,
should we not be inclined to fear there was some blunder in
either the statement or the observation? And, besides, if
the otolitic capsules be locatedupon the lower nervous centres,
as is asserted, and thus virtually buried in the viscera, how
are the sonorous impressions to be received from without ?
Surely, this would not be an advantageous arrangement of
parts, nor in obedience to the simplest laws of acoustics.
For the only method by which a vibration could be conducted
to the receiving vesicle would be through the mouth and
cesophagus, so that the familiar expression “ swallow” should
not be at all inapplicable.

Organ of Touch—Some state that the tactile sense is
resident in the inferior tentacula, these bemg, according to
the same authorities, provided with bulbous enlargements
similar to those of the upper ones. Respective of their func-
tion I can offer no comment, but I cannot just now endorse
the opinion that nervous expansions exist here ; an enlarge-
ment of some kind is occasionally observed, but I am not
prepared to admit its nervous character. Moquin-Tandon*
attributes to these tentacles the sense of smell.

Tuste.—This faculty, I am disposed to thin/, resides in the
rugose integument forming the lateral boundary of the mouth ;
this portion of the labial organs is supplied on each side with
a branch of the inferior tentacular nerve, and here a peculiar
and interesting nervous arrangement may be observed. The
branch, on reaching the tegumentary fold alluded to, widens
as it approaches its extremity, and terminates in a pectinate
expansion, which is imbedded in the delicate skin of the lip ;
this comb-shaped structure results from the division of the
final portion of the filament for about + inch distance into
a series of minute twigs, which pass off on either side, and
become lost in the neighbouring tissue.

* ‘Vistoire naturelle des Mollusques terrestres et fluviatiles,’ tome i.

LAWSON, ON LIMAX MAXIMUS. 29

Organ of Vision—The eyes are two in number, and are
situated, one at the extremity of each superior tentacle, and
are recognisable as a pair of black spots within the membranes
by which they are surrounded. By delicate manipulation
the eye, together with the tentacular and optic nerve, may be
separated from the surrounding darkly stained connective
tissue, and then is seen the origin of the nerve of sense from
the extremity of the tentacular branch. The latter, just
before it terminates in the end of the tentacle, expands mto
five or six short, thick, and unequal divisions, thus exhibiting
a palmate end, the fingers being arranged in such a position
as would be assumed by those of the human hand, when
grasping a large ball, and from the centre of the palm, so
constituted, a very fine nervous thread travels to the eyeball,
the intervening distance being exceedingly short. This at-
tenuate nerve having reached the eye, apparently enters the
posterior part of the sphere, but, so far as I could observe, it
becomes blended with the membrane of the ball, which is a
connective-tissue structure, and after the choroidal pigment
has been completely removed, the two tissues, those of the
optic nerve and sclerotic, appear, not only continuous, but
identical in structure, and this peculiarity, although at first
sight anomalous, is at once appreciable by an appeal to in-
vestigations, of my friend, Prof. Beale,* into the structure and
homologies of connective tissue. Indeed, I very much doubt
that any structure resembling a retina, has ever been observed
in pulmonates, and this idea is borne out by the fact that,
Von Siebold, in speaking of the organs of vision generally,
among cephalopora, writes, “The internal surface of the
choroid is covered by a whitish pellicle, which is undoubtedly
the retina ;” adding afterwards, “ Kthn affirms that he has
seen this white pellicle in Paludina,” as if he hesitated to
accept the onus probandi himself. I confess I am sceptical
as to its existence, having never observed the faintest trace of
it myself. The sclerotic membrane forms a more or less
spherical sac, which is quite transparent at a point opposite
the apparent penetration of the nerve; internally this sac is
lined with exceedingly fine, black, granular pigment, which, so
far as I could observe, is not enclosed in cells, but is bedded
in the inner wall of the sclerotic, and for the most part is
disposed in regular lines, long and short alternately, which
assume the horizontal position. The eyeball owes its globu-
lar form to being filled with a thick, tenacious, perfectly
transparent, vitreous humour ; this is very well observed by

* See ‘Quart. Journ. of Micros. Science’ for Oct., 1861; ‘ Med.-Chir.
Review,’ Oct., 1862; ‘ Archives of Medicine ;’ &c.

30 LAWSON, ON LIMAX MAXIMUS.

exerting compression on the sac, when, a portion of the wall
being ruptured, the contained gelatinous matter is gradually
forced out in a worm-like manner, or exactly as is the semi-
fluid oil colour from the leaden tube of an artist. The cornea
is at once perceived, and on two or three occasions I have
teased from it a small, solid, transparent, pointed, elliptical
body, which I dare say serves the function of crytalline lens,
but I do not think this is easily or often detected. The
integument is attached to the eyeball in front, but I cannot
imagine it passes over it, else I should suppose there was a
second cornea, unless, indeed, it were termed conjunctiva.
Yet Siebold states that the integument passes over the eye-
ball as a thin, transparent lamella. Siebold also asserts that
in no case can ganglionic globules be seen in the expansion
of the so-called optic nerve, but why, I cannot think, it being
a matter of the greatest ease to discern the very well-marked
elliptical endoplasts, with their nuclei and granules.

The pedal gland consists of a central canal closed behind,
open in front, traversing the internal portion of the tissue
of the foot, from the posterior extremity of the creature to the
integument immediately beneath the mouth, and having
attached to its lateral borders clusters of endoplasts, which
simulate the structure of follicles. Between these clusters
numerous blood-vessels lie, and therefore, did we suppose a
water-vascular system to exist, we might conceive of the
aqueous fluid being through this channel introduced into the
blood. Various functions have been assigned to this organ,
among which not the least seemingly absurd is that of smell,
which Leidy* has set down to it.

Reproductive System.—The organs which collectively make
up this system are, as we might anticipate, akin to those
represented in the genus Helix. They are those of the two
sexes combined ; that set which is characteristic of either sex
being morphologically complete in every individual, and not,
as Steenstrupt would have us believe, the non-abortive
moiety of a complex apparatus, which exhibits a complete
bilateral symmetry. For perspicuity, the parts comprising
this machinery may be thus classified, as in the case of
Helix:

1. Female. 3. Androgynous.
2. Male. 4, Appendicular.

* Silliman’s ‘American Journal of Science,’ 1847; and ‘Ann. Nat.
Hist.,’ xx, 1847.

+ ‘Untersoegelser over Hermaphroditismus Tilvaerelse i Naturen,’
1845, p. 76.

LAWSON, ON LIMAX MAXIMUS. SE

The female portion, as with Helix, comprises the ovary,
oviduct, albumen-gland, uterus, and vagina. The ovary, un-
like that of the snail,* is not a mere flattened expansion,
almost inseparably united to the lobules of the liver; but is
a thick, imperfectly egg-shaped, oblong gland, of a purplish-
brown colour, divided coarsely into three or four lobes, and
these again into innumerable lobules, which project in every
direction, being more loosely bound together than in Helix.
It is situate beneath the final and posterior lobe of the liver,
and immediately behind the stomach; it is bounded below
by the musculo-cutaneous structure of the foot, upon which
it lies almost freely, being merely attached to the inferior
portions of the liver by loose filaments of connective tissue.
It is 3 inch long, 1 inch wide, and + inch thick, but in the
unimpregnated condition it is diminished in bulk by about
one third of the whole. Viewed under a medium power, the
lobules appear as small cavities, of an irregular, spherical
shape, which seems due to compression, these being
filled with a transparent fluid and numerous endoplasts con-
taining granules; to each group of five or six lobules a slight
branch of the oviduct is adherent, but it cannot be traced
to any individual lobule, appearing, as it were, to become
continuous with the connective tissue which serves to unite
them in bundles.

In the anatomy of this organ I have been more than ever
convinced of the error of H. Miiller’s views, for if any second
vesicle existed within the ovarian lobule, I could not have
failed to detect it; but nothing bearing the faintest resem-
blance to an included saccule could be discovered; nor have
I detected the presence of zoosperms, although I have oc-
casionally seen them in small numbers within the ovarian
follicles of the snail. The ovary is provided with a tolerably
large blood-vessel, one of the main branches of the superior
division of the aorta, and the chief peculiarity of the cir-
culation is this :—the arterial vessel, having sent several
branches to the gland, passes from it, and is distributed to
the posterior lobe of the liver. At the middle of the anterior
inferior border of the egg-gland enters the oviduct, a deli-
cate conduit, cylindrically tubular throughout, a little convo-
luted anteriorly, and containing no second canal, which is
very slightly larger at its anterior than at its ovarian extremity,
and is of a pearly-white colour. It is situate between ovary
and uterus, being placed at first beneath the liver and
stomach, but afterwards, assuming a superior position, lies

* “The Generative System of Helix aspersa,” by the author. ‘ Quart.
Journ. of Micros, Science’ for Oct., 1861,

32 LAWSON, ON LIMAX MAXIMUS.

between the pro-stomach and the duodenal bend of intestine,
the ovarian artery running beside it, and, finally, about the
middle of the body, it becomes confluent with the posterior
portion of the uterus. It measures about 21 inches in length,
and in width =}, inch behind and =; inch in front.
The albumen-gland resembles that of the snail; it is, how-
ever, less compact, and more linguaform than boat-shaped,
and is usually of a yellowish-white aspect both externally
and within; it is continuous anteriorly with the uterus, and
it is not easy to draw a decided line of demarcation between
the two, the albumen-gland seeming but a solid continuation
of the uterus, on which, moreover, it is folded back, (when in
its normal position) and retained by almost gossamer folds of
connective tissue. It les with the uterus beneath the liver,
and inferior to, and to the right of, the various folds of
intestine. In the impregnated individual it attains a length
of 1 inch, and a breadth of 1 of an inch at its widest
portion, for it tapers gradually in the posterior direction.
Owing to the existence of several transverse divisions,
it is resolved into many segments or lobules, each of which
assumes a rudely indicated wedge-shape, and is adherent
internally along the inferior mesial line [to a slender branchiet
of the oviduct, which traverses the gland from end to end.
Microscopically, the anatomy is similar to that of Helix—an
enormous assemblage of albumen-globules and fibres. I
have never noticed any distinction, as regards opacity,
between the component lobules of this gland, but on two
occasions I have found it entirely absent. The uterus may
be regarded as the tubular prolongation of the albumen-
gland, which has just received the termination of the egg-
duct. It is a vessel of considerable calibre, and of a pure,
translucently white colour; it is thrown into about a hundred
transverse folds, which give it, to an extraordinary observer,
the semblance of as many little pockets lying side by side
on a string, and which may be due to a shortening (rela-
tively) of one side of the tube, thus giving rise to a corrugated
or plicated appearance on the other, by forcing it into a
series of puckers. It is located between the white-of-egg-
gland and the vagina, to which its anterior end is con-
joined, and makes two or three serpentine windings in its
passage from behind forwards ; it is accompanied by a medium-
sized artery, and has upon its (as it seems) shortened
border, the testicular follicles, firmly adherent. It is placed
in the purely abdominal region, and beneath the liver,
gullet, and folds of the alimentary canal, lying more or less
to the right side of the body, and retained in situ by various

LAWSON, ON LIMAX MAXIMUS. 33:

ligamentous filaments of connective tissue. When separated
from its attachments, it is a little more than 21 inches
in length; whilst in calibre, at its widest point, and even
when undistended by ova, it reaches } inch in fully developed
specimens. Structurally, it possesses all the features of in-
elastic connective tissue, with a few nucleated fibres, which
have the aspect of involuntary muscle. It is contracted
anteriorly and infundibuliform, and is continued as a strong,
straight, white duct, about + inch long and +: inch wide,
which I term the vagina, and this, in its turn, opens
into an expansion of the cloaca, for which I would propose the
name of egg-sac, and of which I shall speak presently. The
male section of the generative organs includes the testis,
with the vas deferens and penis, which latter are virtually
one and the same organ. The sperm-forming gland is
a simple and prolonged structure, being constituted of
a repetition of similar parts, each of which follows the
follicular type; it is commonly of a whitish-yellow colour,
and from this circumstance may at once be distinguished
from the uterus, which otherwise, to a careless observer,
might seem to be part and parcel of it. Beimg strongly united
to the shortened border of the uterus, it has the same rela-
tions and position as that vessel, and is of the same length,
but in breadth is not more than ~,; inch at its widest
part. It consists of a narrow duct—cecal at its posterior
extremity, which lies against the albumen-gland, and free
in front, where it is continued as vas deferens—to one side*
of which is attached a collection of follicles, which secrete
the sperm, and pour their contents into the common ex-
cretory duct. Each follicle is of an ovato-lanceolate out-
line, the apex pointing outwards, and from its surface nu-
merous papillary elevations rise, which I fancy are lesser fol-
licles, thus giving to the whole gland a higher position as re-
gards organization than that of Helix ; indeed, it is remarkable
that two animals so very closely related zoologically should
exhibit such well-defined differences in the minute structure
of their glandular mechanisms. Here, however, as in the
snail, I observed, on compressing a portion of a follicle, very
many squamose, oval endoplasts, occasionally nucleated; the
testicular duct leaves the uterus as this passes into the vagina,
and is now called the vas deferens. This channel, I should
think, has been incorrectly designated ; for although in other
molluses it is easy to trace the point of union between it and

* This affords a marked contrast with the same organ in Helix, in which
a double row of follicles is found (vide ‘Dub. Quart. Journ. of Science,’
April, 1861).

VOL. III.—NEW SER. c

34 LAWSON, ON LIMAX MAXIMUS.

the penis, yet in Limax the one is so completely the prolonga-
tion of the other, that, it is impossible to indicate either the
commencement of penis or the termination of vas deferens ;
hence this tube may be looked on as the penis. It is of a
transparently white colour, a little wider in front than be-
hind, and takes its course from the testicle posteriorly, to the
generative outlet, in the following manner. It first curves
outwards and to the left, and then, turning in the opposite
direction, approaches the right side of the body, passmg over
the uterus and beneath the rectum; here, placed in the right
lateral region, and covered by the membrane of the lung, it
travels anteriorly as far as the cloaca, when, bending at an
acute angle, again below the rectum, it insinuates itself be-
tween the ovary and duct of the spermatheca, posterior to
the latter, and, finally, after lying beneath the aorta and
above the egg-sac, it opens by a rounded aperture into the
cloaca. The androgynous division involves the sperm-
sac and its duct. The former is a spherical expansion of the
latter, with an exceedingly thin, transparent, easily ruptured
coat, upon the outer surface of which several arterial twigs
ramify, producing, by the contrast between their white
branches and the transparent groundwork, a very beautiful
appearance. I cannot think how Treviranus* could have
supposed that this vesicle was a urinary organ, for it has
not the slightest connection with the so-called kidney, and,
on the other hand, is decidedly attached to the generative

outlet by its duct. It is situate on the left of the uterus, by

whose anterior fold it is embraced, has the gullet below it,
and is covered by the right anterior lobe of the liver. In the
unimpregnated animal it is empty, wrinkled, and triangular
shaped, with a length of ;°, and a breadth of + an inch;
but subsequent to coition it is distended with semen (which,
contrary to the assertion of Von Siebold, is not at this period
fully developed), assumes the globular form, and has a
diameter a little over 2% inch. Its microscopic structure
is that of connective tissue, simulating here and there a fibril-
lated constitution, which disappears under the influence of
caustic potash, and having a few of the nucleated endoplasts
of non-striated muscle. It empties its contents imto the
cloaca, through the duct of the spermatheca. This is a strong
and short canal, uniting the sac and outlet. Starting from
the former, it travels to the right beneath the aorta and
uterus, and, curving across the penis, with the egg-sac to its
left, it communicates with the cloaca by a circular open-
ing, just beside the penis and at its dextral border. It is
* © Zeitschrift fiir Physiologie,’ i.

rs:

LAWSON, ON LIMAX MAXIMUS. 35

about + inch long, and somewhat more than ;4; inch in dia-
meter.

The appendicular series embraces the egg-sac and cloacal
glands. The first is a conical, papillary extension of the
hinder portion of the outlet, its apex towards the left and
front, and its base in the opposite direction. Interiorly, it 1s
hollow, and receives at its greatest diameter the orifice of the
vagina, which projects into it something in the manner of
“‘prolapsus ani.” I do not know that any function has been
ascribed to this cavity, and in the absence of any other office,
and from the fact that, during the deposition of ova each egg
remains within it for some time, I would suggest that it may
serve to place the ovum in a position to receive the attach-
ment of the peculiar threads which connect the deposited ova.
It measures 2 inch or thereabouts in length, and has a thick-
ness varying between 1+ and 1 inch, and is composed of
muscular and connective bands intermingled.

The cloacal glands, so far as I am aware, have not been
heretofore described, yet they are numerous and interesting,
and deserve notice, because in Limax the multifid vesicles of
the Helicide do not appear; and, therefore, it is likely that,
be their function what it may, it is here performed by these
cloacal organs. They present in their entirety to the naked
eye a purplish-brown, tripy, pilose aspect, and surround
closely the internal or abdominal surface of the cloaca, from
its anterior extremity to the egg-sac; their ducts pierce the
cloacal walls, and may be seen externally (on the inner or
non-abdominal side) as a cluster of minute apertures. If a
thin, carefully prepared section be made, with Valentin’s knife,
the following structures are observed. An immense quantity
of dark follicles, lying in indifferent tissue, and recalling at
first sight the Meibomian glandules of the eyelid; each
follicle is compound, being composed of a central stem or
channel, which, as it passes towards the outer surface, sends off
three or more lateral branches, and to the end of each of these
a dark, spherical, grape-like vesicle is united, which, when
ruptured by compression, shows its contents to be a liquid
matter containing endoplasts and granules (fig. 2). The
common generative outlet I have not yet described, for as
it belongs to no section in particular, it could not have
been referred to till the other regions were disposed of.
Divested of its glandular appendages, it is a very simple tube,
about + inch long, and as wide also when distended; into its
posterior part open the penis and the sperm-sac-duct; it is
attached to the egg-sac behind, and in front, where it forms
the generative aperture—which is closed by an elastic band—

36 LAWSON, ON LIMAX MAXIMUS.

is lost in the general integument. It is upon the right side,
about midway between the pulmonic orifice and night upper
tentacle, and in a plane about | inch lower.

The eggs of this creature are deposited during the months
of August and September, usually under large stones, but
seldom in the earth; they are about twenty in number,
collected together by means of glutinous threads which adhere
to them. The egg is spherical, of an opaque white, measures
about + inchin diameter, and consists of two coats, a quantity
of albumen, and the yelk-mass. The outer coat, and that
in which the opacity is observed, appears glistening and
granular under the microscope when viewed by reflected
light ; when isolated, it is found to be exceedingly tough, and
to be composed of some material having a fibrillated structure
apparently, and bearing in its substance particles of carbonate
of lime, for, when acted on by weak acetic acid, an effer-
vescence results, and the opacity vanishes. The fibres of
which it seems made up are not real, but due possibly to the
wrinkling to which the membrane is exposed in submitting
it to examination ; at all events, when a portion of it has, by
careful manipulation, been flattened out, and allowed to remain
for some time in a solution of caustic potash, the fibrillation
disappears, anda clear, structureless membrane remains. The
inner coat is transparent, but presents the falsely fibred aspect
of the outer one. The yelk is a yellowish mass, presenting
the usual granular aspect, and built up of rounded endoplasts
oil-globules, and coloured granules.

. General remarks.—In contrasting the reproductive appa-
ratus of Limax with that of Helix, as concerns position, form,
and structure, we find that, while occupying the same place
as that of Helix with relation to the viscera among which it
lies, it presents many characters, morphologically and histo-
logically, which were not observed in that of the latter genus.
We miss here the dart-sac, multifid vesicles, flagellum,
and spermatheca-cecum, which are so fully developed in
Helix. The first has no representative ; the cloacal glands
may be a substitute for the second; and since it is probable
that the third and fourth are mutual adaptations—the one
owing its development to the requirements of the other—it
follows that the non-development of the one is consequent
upon the teleological absence of the other. Here, too we‘
observe no cloacal valves, aud from this it is probable that
the function which in a former memoir I attributed to these
organs is not the incorrect one. It is not a little surprising
that Moquin-Tandon, who has given a rude engraving of a

Rim pusye PR LDR ICS Er ge gs

LAWSON, ON LIMAX MAXIMUS. 37

portion of the reproductive apparatus, should have overlooked
the glandular character of the outlet, and not less so that he
should have represented the egg-sac as being of acrescentic
form, and termed it the “ horned appendage.” Moreover, I
can with difficulty imagine that he has ever seen the spermatic
particles, for he figures these latter (as though he had been
looking at tadpoles or, more probably, at pictures of human
semen), with gigantic spherical heads, whereas, actually, they
only exhibit an approach, and a very faint one, to a capital
extremity, in the form of a little spiral coil. The testicular
and uterine divisions of the genital system are supplied witb
blood by a lateral vessel, which passes from the vaginal end
to the albumen-gland, lying upon the border of the uterus,
and transmitting branches to this structure and to the testis.
With regard to the distinctness of the latter organ, I may
state that its excretory duct is not the semi-canal which
Prevost* took it for; I have, after a little manipulation, suc-
ceeded in isolating completely its lower or anterior end,
together with its continuation, the penis. The retractor
muscle of the intromittent tube is often absent, but when
present is a simple band, arising from the integument above
the foot.

It is almost impossible to describe the anatomical peculi-
arities of a creature so highly organized as that of Limax,
with the accuracy, and perspicuity which are desirable ; hence,
doubtless, in the foregoing very general account there may,
of course, be errors, not only in observation, but in induction.
These—should they exist—it is hoped, may soon be pointed
out, by others more skilled in the examination of molluscan
organisms than the author, who can only add, in conclusion,
that his sole object in the communication of these researches,
has been the advancement of biologic science, by an effort
to elucidate what seemed to him, a subject left too long in
obscurity.

* © Ann. des Sciences nat.,’ xxx.

33

Note on Dr. Watuicn’s Microscopic “ Jaw.”
By G. Buss, F.R.S.

In the October number of the ‘ Annals of Natural History’
(p. 804) is described and figured an organism contained in a
muddy deposit dredged up at St. Helena, and regarded at
that time by its discoverer, Dr. Wallich, as the lower jaw of
a vertebrate animal, although, as he confesses, he had not
then submitted it to any detailed examination.

The minute size, however, and general characters of the
specimen, when it was exhibited at the meeting of the British
Association at Cambridge, led many at once to doubt the
propriety of this determination. Opinions, nevertheless, ap-
pear to have been very widely divided as to the real nature
of the object. Ina subsequent notice respecting it, in the
December number of the same journal (p. 441), Dr. Wallich,
in retracting his former opinion, as having been too hastily
formed, states that the specimen had been pronounced by
different observers to be—the mandible of a fish—a portion of
the lingual ribbon of a Mitra—the claw of a minute crusta-
cean—part of the manducatory apparatus of Notommata or
an allied species,—and lastly, a valve of the pedicellaria of some
species of Echinus, in which last view he is himself now in-
clined to agree.

As it would appear, therefore, that there must be some-
thing peculiar in a structure about which such diversity of
views can be entertained; and as Dr. Wallich, in his latter
communication, has cited me as the author of the last opi-
nion in the above list, it may perhaps be interesting to some,
that the grounds upon which it is formed should be stated.

As none of the drawings hitherto given of the organism
afford anything like a correct notion of its real appearance,
I have had the accompanying figures prepared by an artist,
wholly, I believe, unaware of the nature of the disputes about
it, and whose representation, therefore, may be regarded as
uninfluenced by any preconceived opinion.

Of the various opposed views above enumerated, it appears
to me, and will perhaps also appear to most others, that
the only ones requiring serious consideration are that advo-
cated by myself and that so ingeniously supported by Mr. C.
Spence Bate, in the December number of the ‘Annals of
Natural History’ (p. 440). That gentleman, whose opinion
in such a matter, if he had had an opportunity of inspecting
the specimen itself, would, of course, carry the very greatest

BUSK, ON DR. WALLICH’S MICROSCOPIC “ JAW.” 39

weight, suggests that the so-termed “jaw” may be the dac-
tylosor moveable claw of a minute crustacean (Phrosina).
But, with all due allowance for the circumstance that this

‘ : s+
Vip ‘
A Mi

WON my,
=~ = hy

opinion appears to have been based only upon the inspection
of the original very faulty figure given by Dr. Wallich, it
seems to me that, even with this allowance, an insuperable
objection to Mr. Spence Bate’s view would arise from the fact
that the ‘‘ second row of marginal armature” is really placed
as if it were the second ramus of an actual jaw, and not, as
he erroneously interprets or appears to interpret the figure
(‘Ann. Nat. Hist., x, p. 304), in the same line or plane, but
above the first row, as I understand him to mean.

There can be no doubt, as he or any one would see on a
glance at the specimen itself, that the two serrated margins
are placed one behind the other, as the alveolar borders of a
jaw would be. This being the case, it is needless, I should
fancy, any longer to entertain the question of the object being
the claw of a crustacean, in which the serrations or denticles,
if there be any, are always placed in a single median row.

But having negatived this view, upon what grounds is the
thing to be regarded as the valve of a pedicellaria? This
may be explained in a few words, and will, I hope, be found
to be satisfactorily elucidated by the adjoimed figures. Of
these, fig. 1 represents the ‘‘jaw” as it is exhibited in Dr.
Wallich’s preparation, in which the object is unfortunately
a good deal obscured by foreign matter. Fig. 2 is the side view
of a valve of the pedicellaria of Echinus lividus, of which some

40 BUSK, ON DR. WALLICH’S MICROSCOPIC “ JAW.”

mounted specimens have been kindly furnished by Dr. Wallich,
whilst fig. 3 shows the corresponding part of the pedicellaria
of a species of Amphidotus, as I am informed by Mr. R.
Beck, to whom I am indebted for the illustration. The figures
of several other pedicellarian valves might have been added,
all differing more or less inter se, though agreeing in essential
structure; but I have thought the above examples would be
sufficient for the present purpose. I would remark, however,
in passing, that a full account and accurate figures of the va-
rieties which exist in the pedicellarie of various Echinide
and Asteride, would afford a subject for a very useful and
interesting paper, and might assist, perhaps, very considerably,
in the discrimination of species or genera in those families.

In those cases that I have examined, and probably in all,
the pedicellariz of the Echinide consist of three valves, arti-
culated apparently in a complex manner to each other, and
furnished with appropriate processes for the attachment of
the muscles by which they are moved. It is not my intention,
nor, in fact, im my power, to describe fully the mechanism of
these organs, but simply here to point out in a few words the
essential points regarding them, so far as they throw lght
upon the structure of the “ jaw.”

Each valve consists of a spoon-shaped distal portion, at the
base of which is a strong, curved, arched process, like a door-
knocker, and on either side of the same part an irregular pro-
cess or condyle, by which the valve appears to be connected by
a ligamentous tissue with those next toit. Viewed on the inner
or concave side, the valve will be seen to be strengthened by
a prominent median ridge or kelson, from which a ridge passes
off obliquely forward on each side, nearly to the edge of the
spoon-shaped portion. This kelson posteriorly or towards
the base of the valve, rises into a strong, bluntly-toothed pro-
cess, generally, I believe, connected to the sides of the base,
or to the external condyles above mentioned, by a slender
caleareous areh. To this rough eminence of the kelson I
conceive the occlusor muscles or muscle to be attached, whilst
the dilators are doubtless imserted in the door-knocker
appendage below. The anterior part of the kelson some-
times also supports one or more sharp denticles,* but
in some cases, as for instance, I think, in Echinus sphera,

* [had entirely overlooked the median tooth in the “jaw,” and was
quite unaware of the occurrence of any in that situation, in other Pedicel-
larize, until it was pointed out to me by my friend Mr. R. Beck, to whose
quick sight and ready assistance I am much indebted on the present as I
have been on other occasions. 4

iets —

HENDRY, ON THE NERVE-CELLS IN THE OX. 41

this median armature is wanting in the “spoon,” whose

edges also in that species are armed, not with sharp denti-
cles as in all other instances I have as yet seen, but with
blunter transverse ridges—presenting, in fact, pretty nearly
the same difference that exists between the dentition of
Mustelus levis, and that of other dog-fish. The only other
essential point to which I need refer, is the serration or den-
tition, as it might well be termed, on the edges of the valve.
This armature usually consists of a series of very fine teeth,
extending from the hinder end of the border throughout its
whole length, except at the point where it may be interrupted,
as appears usually to be the case, by one or more considerably
larger denticles on each side, or at the apex. Besides this, the
margin may be either straight, as in Amphidotus and Echinus
sphera and the “jaw,” or scalloped as in Kchinus lividus.
And doubtless numerous other variations will be met with.

Now, upon inspection of the figures, it will be seen that all
these parts, except the hinder door-knocker process, which is
wanting in every specimen, being easily detached from the rest
of the valve, are exhibited in the “jaw.” The letters in each
figure are applied to the corresponding parts.

a. The serrated margin.
6. The larger denticles.

c. The median ridge or kelson, with a large denticle in front.
d. The lateral condyles.

On the Nerve-Cetts of the Spinat Corp in the Ox.
By W. Henpry, Surgeon (Hull).

Tue careful and patient manipulation required in order to
display and mount the nerve-cedls of the cord has undoubtedly
tended to retard any general knowledge of these most singular
and interesting bodies, whose structure and relations have
hitherto remained in comparative obscurity. They are nume-
rous and well-defined corpuscles, exeeedingly variable in size
and form, and furnished with conspicuous circular nuclei and
nucleoli, of a yellowish colour, and usually presenting towards
one or other extremity a pigmentary matter of a peculiar
kind. They are also furnished with one or more processes,

42 HENDRY, ON THE NERVE-CELLS IN THE OX.

and hence have been designated, wnipolar, bipolar, or roulti-
polar cells. The processes in question are described as anas-
tomosing filaments, or as branches connecting one cell with
another, or as continuous with the peripheral nerve-fibres.
In some cases, again, they appear to have free terminations im
the surrounding tissues. But these are questions upon which
all observers are not satisfactorily agreed; nor is this a matter
of surprise when we consider the extremely minute portions
subjected to microscopical examination, the necessary pre-
liminary preparation required, and the unavoidable disturb-
ance of parts, all tending to interfere with if not wholly to
destroy the normal arrangement of such delicate structures.
Nevertheless, keen research, multiplied observations, and
careful description of what is seen, may eventually lead to a
more perfect knowledge of the distribution of those parts
wherein at present some ambiguity may exist.

It is no easy matter, under most circumstances, correctly to
determine the question of the attachments of the processes
just referred to, some lying above and others below the cells,
whilst others, again, abruptly terminate short of, or apparently
extend beyond them ; some of these appearances seeming to
be produced by the rough usage employed to bring the objects
properly into view. And in many instances in which we
might feel inclined to believe in the union or continuity of
the processes with nerve-filaments, or with other processes of
the same kind, the employment of higher magnifying powers
(1 inch) will in some cases resolve these connecting filaments
into capillaries, which are so distributed and so completely
encircle the cells, that but for the characteristic nuclei in the
walls of the capillary vessels, very incorrect inferences might
be entertained as to their true nature. From careful and re-
peated observation, however, my own conviction is, that
anastomoses do exist between one cell and another, and that
the processes do likewise become connected or continuous
with nerve-fibres, and that free terminations are also to be
met with, although it is not improbable that the latter may
be produced in consequence of the manipulation to which the
parts are subjected.

The nucleated vessels I have observed in the spinal cord of
the ox, in close apposition with the nerve-cells, have a
diameter of +-,,th, =-+,;th, and ;,,,th of an inch, whilst
the nuclei in their walls are about =,,"" in length, and
are of a roundish or oval shape, with a breadth of -2,,°", or
equal in some cases to that of the vessel itself. Vessels un-
doubtedly exist below and above these measurements, but the
extremes are not now sought for. The nerve-filamer’

HENDRY, ON THE NERVE-CELLS IN THE OX. 43

present a more homogeneous structure, and, asa further dis-
tinction, the blood-vessels may frequently be traced in con-
nection with others containing altered blood-corpuscles, their
nature being thus placed beyond all doubt.

My present object is not so much to enter fully into the
histology of the cord as to endeavour to awaken new interest
in the subject, and to offer certain suggestions with respect
to manipulation, by which the investigation may be rendered
more easy and satisfactory.

I would, in the first place, recommend the experimenter to
obtain a foot or two in length of the cord of the ox, to cut
this up into pieces two or three inches long, and then to
place these in a wide-mouthed quart stoppered bottle contain-
ing a solution of chromic acid, of a moderate yellow colour.
Other portions may be preserved in spirits of wine. After a
few days the investigation may be commenced, it being by no
means necessary to wait for some months, as is usually stated
to be requisite, before sections can be made. These should
be made with a sharp razor, with which the larger portions
are to be cut into lengths of about 1 inch. On the surfaces
thus exposed, the arrangement of parts in the interior of the
cord will be seen. Its substance consists of a white external
and a gray or cineritious internal substance, disposed in the
form of two crescentic masses, one on either side and placed
back to back, united by a transverse band or commissure.
Of the horns, or cornua as they are termed, of each crescent,
the anterior are short and thick, whilst the posterior are
longer, slenderer, and more divergent. Besides this, the cord
will now be seen to be partially divided into two halves by an
anterior and posterior median fissure, the former not so deep
but wider than the latter, and both occupied by a vaseular
membrane or tissue.

It will be found convenient to have the following articles
and reagents at hand, and in readiness for immediate use.

One or two pair of surgeon’s forceps, several common
sewing needles, a razor, several glass slides, box of round,
thin, glass covers, three or four watch-glasses, one or two wine-
glasses, two or three glass rods, blotting-paper in slips of
one inch square, one or two cloths, basin of water for clean-
me slides, &c., lancet or two, and a pair of sharp scissors—

so—

1. A solution of moderately dilute caustic soda, in a watch-
glass.

2. Dilute acetic acid, in a wine-glass.

3, Water, in a wine-glass.

4, Creosote and naphtha solution, in watch-glass.

44 HENDRY, ON THE NERVE-CELLS IN THE OX.

5. Microscope, with one inch objective in focus, and
illuminated to examine progress.

Then take up one of the smaller sections of the cord, and
with a pair of forceps lay hold of a small portion in or about
the transverse commissure, or in one of the cornua, as being
the parts which promise the most successful yield. This
fragment may then be immersed for a few moments in the
solution of caustic soda, and then transferred to the acetic
acid, to neutralize the soda, and render the tissue somewhat
clearer. After a minute or two transfer it to the vessel of
water to remove the acid, &c., and then place it in the
creosote or preservative solution. All this is but the work
of a few minutes, and with a careful avoidance of a too pro-
longed destructive immersion in the soda-solution, a number
of a similar smal] particles of the cineritious substance may
thus be passed through the successive stages, before they are
placed in the preservative solution preparatory to micro-
scopical examination.

Any of the little portions so prepared may now be taken
up with the forceps, and placed upon a glass slide, and
broken up in more minute particles (size of pins’ heads),
which are again to be teased-out with needles as finely as
possible, aided by a drop of the solution. These particles
should then be so arranged that, upon moderate pressure,
they shall not run together, it being desirable that they
should be mounted and examined separately. The fluid
may now be withdrawn by blotting-paper, and the remainder
of the slide wiped dry; a drop of the solution is then to be
placed in the middle, and the thin glass cover, previously
breathed upon, applied by means of the forceps, all air-
bubbles being carefully excluded. Moderate pressure is
applied with the points of the forceps, and the surplus fluid
absorbed at the edges; the slide being every now and then
placed under the microscope to examine progress, until the
appearances are rendered as distinct as they can be. The
cover is now, probably, slightly adherent, and a due supply
of solution being inclosed, the whole is to be cleansed and
dried without disturbing the object, and, at the end of a few
minutes, the slide may be tranferred to the turning-plate,
and finished off with a border of varnish.

I have various slides in my possession prepared in this
manner, which have kept for several weeks. Their ultimate
durability I know not, but the measures adopted have served
for my own investigations, as well as for the exhibition to
others of a class of objects, which I should conceive to be

2 CO TN ty oF era airlines

STRETHILL WRIGHT, ON BRITISH ZOOPHYTES. Ad

thus as readily and perfectly illustrated as by any other pro-
ceeding hitherto promulgated.

Measurement of the cells—The utmost variety exists in
the magnitude and form of these bodies ; they are usually de-
scribed as globular in man, and Carpenter assigns them a
diameter of from ;,,th to =1,th of an inch.

Kolliker gives a diameter of from ‘05’ to 06" for the larger
variety, which, being reduced to fractional parts of the Eng-
lish inch, shows a range of from ,1,th to +4,th of an inch.
My own measures of the cells in the ox, which, though for
the most part are of a peculiar elongated form, are some of
them more globular, average—

In length, from 1th to -;1,th of an inch.
In breadth Py 4th eee!

OME LCOS ee eee te
Mieco, ti 5, =e, 5.

Kolliker gives to the age in man a diameter of 0:0015’”
to ‘008’, or from 7,5 to +,},,th of an rss inch, a to
the nucleolus one of 0-0005’" to -003”” eth
of an English inch.

In th of an inch square, or the ;1,th part of a square
inch, I have counted forty-nine large, elongated cells ; whence
it may be estimated that there are between three and four
hundred thousand nerve-cells in a cubic inch of the cineri-
tious substance in the ‘spinal cord of the ox. How vast,
therefore, must be their number computed throughout the
entire length of the cord; how complex their relations, and
how marvellous their functions, whether we regard them as
active centres of growth and reparation, or the source them-
selves of nervous power.

547 9

OsBsERVATIONS ov British Zooruytes. By T. SrrerHiLye
Wraieut, M.D., F.R.C.P. Edin.

1. On Reproduction in quorea vitrina. Communicated to
the Royal Physical Society of Edinburgh, November 27th,
Gare (Pl. LV).

In vol. i of Agassiz’s ‘Natural History of the United
States’ the following passage occurs:—“<As to the Alquo-
readze, I have no doubt that they are genuine Hydroids, though
I have not been able to trace with certainty the origin of the

46 STRETHILL WRIGHT, ON BRITISH ZOOPHYTES.

£quorea of our coast to any true hydroid. But the structure
of AZquorea in its adult Medusa state is so strictly homolo-
gous to that of all the naked-eyed Meduse, that even if it
were ascertained that it undergoes a direct metamorphosis
from the egg to the perfect Medusa, I would not hesitate to
consider it as a member of the order of Hydroids, since it has
simple, radiating, aquiferous tubes, a circular canal, and mar-
ginal tentacles closely connected with it, and provided with
minute pigment-spots at the base.’? Agassiz was doubtless
correct, and he might also have predicted that it belonged to
the genus Campanularia or Laomedea, as it corresponded with
the Medusoids of those genera in the presence of otoliths,
while the Medusoids of the Tubularian hydroids hitherto ob-
served, are destitute of those appendages. In the begin-
ning of this month (November) Mr. Fulton sent me two living
specimens of Afquorea vitrina (Pl. IV), one about three inches
in diameter, the other about six inches and a half. The number
of lips of the latter was about forty, the radiating canals, each
having a long, double ovisac, about eighty, and the marginal
tentacles, by estimation, four hundred. On examining the
ovaries, I found that the eggs were hatched, and the young,
in the form of almost invisible planulz, were issuing from the
ovisacs. These were gently extracted with a glass syringe,
an instrument so useful to those who practise the obstetric
art amongst the Hydroidz, and were placed about three weeks
ago in glass tanks of clean sea-water prepared for their re-
ception. Many thousands of larve were placed in the tanks,
and of those about a score have been developed into Cam-
panularian polyps; about a hundred are still progressing to
that end, and the rest have disappeared. It was with no little
impatience and anxiety that I saw the planula during a fort-
night fix itself to the glass, spread itself out into a short
thread, secrete its scleroderm, put forth its polyp-bud—this
last slowly swelling day by day, until at last it opened, and a
polyp appeared, furnished with twelve alternating tentacles,
joined together for about one third of their length by a web,
the polyp enclosed in a cell terminating in many acuminate
segments. It is now about six years ago that I was watching,
in like manner, the slow evolution of a bud from a Campanu-
larian zoophyte, the Laomedea acuminata of Alder, the bud
opened, and a bright-green Medusoid issued forth, having
four lips and two tentacles.* The hydroid phase of A/quorea
vitrina is, as far as I can determine, identical with that of
L. acuminata in shape; but is so excessively small—quite

* «Edin. New Phil. Mag,’ vol. vii, N. 8., p. 110.

ae es

STRETHILL WRIGHT, ON BRITISH ZOOPHYTES. 47

invisible to the naked eye—that we must wait for further
development before we can determine their identity. Ge-
genbaur has proved that the Medusoid of Velella acquires a
further number of canals and tentacles ; and I have elsewhere
recorded the successive changes which occur in the Medusoids
of several species of Atractylis. It is also certain that such
increase in the number of elements (canals, lips, tentacles,
and otoliths) does occur in AZquorea vitrina, for the smaller
specimens have always a less number than the larger. Mean-
time the question as to the larval state of quorea vitrina is
settled. This, the largest of all the naked-eyed Medusas, is

the reproductive phase of one of the smallest of all the Hy-
droidze.

2. Reproduction of Atractylis arenosa, Alder. (P1. 1V). Com-
municated to the Royal Physical Society of Edinburgh,
February 26th, 1862.

This zoophyte was described by Mr. Alder at the last meet-
ing of this society. In September last I found a large female
specimen at Largo, and was fortunate enough to have an op-
portunity of studying its anatomy and reproduction. The
polyp-stems are, as Mr. Alder has shown, funnel-shaped and
expanding at the top. From them the milk-white polyps
issue, each furnished with an alternating row of long tenta-
cles. The scleroderm, or corallum, is covered by a thick layer
of colletoderm, which is continued over the body of the polyp,
and which, when the polyp retires within its tube, fills up the
top of the tube by its cushiony folds, so that the polyp is
completely hidden, and the funnel appears, as it were, closed
by a valve. The colletoderm in my specimen was coated and
impregnated with mud. Mr. Alder’s specimen was covered
with grains of fine sand. I was at first inclined to believe
that this zoophyte was merely a variety of Atractylis repens,
which, with its Medusoids, I have already described to the
society; but after it had been in captivity a few days, I found
that it was beginning to put forth ovisacs, one on opposite
sides of the polyp-stems (PI. IV, fig. 7).

The mode of reproduction in this zoophyte is unique
amongst the Tubulariadz, though I have noticed and de-
seribed it in the Sertularias and Campanularias.

The female generative sac of Afractylis arenosa resembles
that of Hydractinia; it is a simple sac, formed of ectoderm,
or the outer layer of the ccenosarc, enclosing a similar sac of
endoderm, the “ placenta,’ the whole being covered by a
‘ayer of scleroderm and colletoderm. Between the placenta
and the ectoderm a large number of ova are developed, each

48 STRETHILL WRIGHT, ON BRITISH ZOOPHYTES.

showing a germinal vesicle and spot (fig. 8). When the ova
are sufficiently advanced for extrusion from the generative
cavity, the investments of the sac are ruptured, the sac as-
sumes a long, cylindrical form (fig. 9), and a most laborious
process of parturition commences. With each pain the ecto-
derm of the sac contracts laterally, like the bell of a Medusa,
and at the same time the placenta (fig. 9 c) is dilated by fluid
pumped into it from the somatic cavity of the zoophyte, so
that the ova, which are floating in a milky fluid, are forced
against the summit of the generative sac. Meanwhile, another
process has been going on—the external surface of the sum-
mit of the sac has been secreting a thick cap of gelatinous
colline (fig. 9d), which is to form a nidus for the further de-
velopment of the ova. The contractions become still more
violent, until the ova are confined in a mass at the dilated
upper part of the sac; this last is ruptured, and they are then
forced into the gelatinous cap, which still remains attached to
the summit of the empty generative sac (fig. 10d). The ova
now undergo imperfect fissure, and are developed into planulz
within their nest, from which they at last escape, and, after
swimming in the water, doubtless become fixed and converted
into polyps.

Atractylis arenosa, although it gives off an immense num-
ber of young, is one of the rarest zoophytes on our coast,
probably on account of the low viability of its planule. While
Sertularia pumila, one of the commonest species, the young
of which are likewise developed in a similar gelatinous nest,
will quickly line the vessel in which it is kept with forests of
young zoophytes, not a single planula of Atractylis arenosa,
of the immense number that were given off by my specimen,
ever attained the polyp stage.

We have in this zoophyte the reappearance amongst the
Tubulariade of a mode of gelatinous nidification which ob-
tains in various orders of the animal kingdom—in the Pro-
tozoa, the Mollusca, the Annelidz, the Insecta, and even
amongst the Vertebrata, as in the common frog. We may
ask, how is it that the ova of Hydractinia and Coryne are
discharged into the water to float about without any protec-
tion, while those of Atractylis arenosa, the Sertularias and
Laomedeas, require such various provisions for their further
development? But we do not find anything in the physiology
of these zoophytes to answer the question.

3. Alractylis miniata, T. 8S. W. (New species.) Communi-
cated to the Roy. Phys. Soc., February 26th, 1862.

Polypary yellow, dendritic, branches given off at an acute

STRETHILL WRIGHT, ON BRITISH ZOOPHYTES. A9

angle from the stem, crooked, wrinkled, but not ringed.
Polyp with eight alternate tentacles, buccal cavity
silvery, endodermal lining of stomach bright red-lead
coloured. Reproduction not observed.

This .zoophyte was found on stones at Largo, in little
gnarled, shrubby trees, about an inch high, exposed at the
lowest tides. The bright-yellow colour of the polypary at
once strikes the eye, which is also arrested by the gaudy
colour of the minute polyps. These appear to be marked by
two broad internal patches; one, corresponding to the buccal
cavity, of a dense silvery white; the other to the cavity of
the stomach, of a brilliant reddish orange. I have also found
very minute specimens of this species at Granton.

4, Laomedea decipiens, T.S.W. (New species.) Commu-
nicated to the Roy. Phys. Soc., February 26th, 1862.

Polypary minute; stem filiform flexuose, with from one
to five branches, each bearing a cell; the stem is an-
nulated with about five rings above the origin of each
branch ; the branches are annulated throughout ; cells
widening rapidly towards the top, with even, double
rims. Polyp with about sixteen tentacles and trum-
pet-shaped proboscis.

This pretty little Laomedea resembles much the Laomedea
neglecta of Alder, except that the margin of the cell is even,
and has the appearance of being double for about half its
length from the rim, though, from the extreme delicacy of
the cell, this character is only made out with difficulty. The
reproduction of this zoophyte resembles exactly that I have
described in Laomedea lacerata,* except that each gelatinous
nest of A. decipiens contains only three ova, while that of
L. lacerata contains six or eight.

5. Clava nodosa, T.S. W. (New species.) Communicated to
the Roy. Phys. Soc., March. 26th, 1862.

“Polypary creeping. Scleroderm membranous. Polyps
single, small, aurora-coloured, each springing from
small knot of convoluted tubes.”

This zoophyte was found on the fronds of Delesseria
sanguinea at Queensferry and Largo. The very delicate
threads of the polypary creep over the fronds of the
seaweed, and at intervals twine themselves into a convo-
luted knot of membranous tubes, from which a single
polyp arises. This species occurs only at low-tide mark,

* «Tidin. New Phil. Mag.,’ N. S., vol. ix.
VOL. III.—NEW SER. D

50 STRETHILL WRIGHT, ON BRITISH ZOOPHYTES.

while C. repens, for which it may be mistaken, is found in
shallow rock-pools.

6. Acharadria larynx, T.S.W. (New genus and species.
Pl. V, figs. 7, 8.) Communicated to the Roy. Phys.
Soc., March 26th, 1862.

“ Polypary branched, spirally twisted. Polyps pale orange,
with two rows of tentacles. The lower row from 4 to
12, the upper row from 2 to 8 capitate.”

On stones carrying Caryophyllia Smithii, received from
Ilfracombe. This little Tubularian was about a quarter of
an inch high, with three polyps, and resembled in habit
Tubularia larynx. It bears the same relation to Vorticlava
that Tubularia larynx does to Corymorpha.

7. Vorticlava Proteus, T.S.W. (New species. Pl. V.)
Communicated to the Roy. Phys. Soc., May 7th, 1862.

Scleroderm absent. Colletoderm covering body of polyp.
Upper row of tentacles capitate 5; lower row 9.
Several specimens of this zoophyte were found in the
“Fluke Hole,” Firth of Forth. The body of the polyp is
exceedingly extensible. At one time a mere button at-
tached to the stone on which it dwells; at another it trans-
forms itself into the various shapes shown in the accom-

panying figures. A hard covering to the body would neces- —

sarily prevent or impede these motions. The scleroderm,
therefore, is absent, and the whole body of the polyp is
covered with a layer of transparent “ colline,” which extends
from the foot, where it forms a thick mass, to a ridge which
runs beneath the insertion of the lower rim of tentacles.
The zoophyte has the power of changing its place.

8. Trichydra pudica, T.S.W. (Pl. VI.) Communicated to
the Roy. Phys. Soc., May 7th, 1862.

This Hydroid, which I have already described tothe Society,*
was found recently covering a small shell from the ‘“ Fluke
Hole.’ As its mode of reproduction had never been observed,
I placed it in a small vessel of carefully examined sea-water,
and exposed it to light, a mode of treatment which often
induces the Hydroide to assume their Medusoid phase.
After some time, two small Medusoids were found in the
water, but I was unable, by the most careful examination, to
detect their mode of development, as no ‘ gonophores ” ap-
peared on any part of the ccenosare. The connection of these
Medusoids with Trichydra is yet open to doubt, although I

* © Kdin, New Phil, Mag.,’ N, 8, vol. vi, p. 108,

,
°

STRETHILL WRIGHT, ON BRITISH ZOOPHYTES. 51

am convinced that no other zoophyte occurred on the shell,
or in the water in which it was placed.

Medusoid of Trichydra pudica?—Umbrella mitre-shaped,
covered with minute thread-cells. Sub-umbrella with four
lateral canals, destitute of ovaries or sperm-sacs. Peduncle
short, cylindrical, four cleft at the mouth. Tentacles four,
short, with two or four intervening tubercles. Oolites
absent. Eye-specks absent.

9. On the Development of Pycnogon-Larve within the Polyps
of Hydractinia echinata. Communicated to the Roy.
Phys. Soc., May 7th, 1862.

In a communication made by Professor Allman to the
British Association in 1859, entitled, ‘On a remarkable
form of Parasitism among the Pycnogonide,’ the author de-
scribed the occurrence of certain vesicles on the branches of
the Coryne exima, which, although possessing a strong re-
semblance to the reproductive sacs of the zoophyte, and
formed of all the proper tissues of the ccenosare and its
coverings, were distinguished from those organs by each
enclosing a single living Pycnogon, which, in the smaller
vesicles, was embryonic, while in the larger it presented an
advanced stage of development. A similar observation was
made by Mr. G. Hodge (‘ Ann. and Mag. N. Hist.,’ ser. 3,
vol. ix), who considered that the sacs were modified or stunted
branches of the Coryne, the development of which had been
arrested by the presence of the enclosed Pycnogon. On read-
ing the papers of these gentlemen I remembered that I had,
some time before, been much puzzled by the discovery of
armless Pyenogons resembling Mr. Hodge’s figure (pl. iv,
fig. 10, op. cit.) in several altered polyps of a specimen of
Hydractinia. In this case two or three were found in each
polyp, which had assumed the form of a dilated and trans-
parent sac, crowned by its usual tentacles. The polyps ap-
peared to be bloated and overgrown under the use of their
Pyenogon diet. Mr. Hodge’s paper at once set me on the
look-out for another specimen of Hydractinia tenanted by
Pycnogons, and this I at last obtained by the kindness of my
friend, Dr. Wilson, Demonstrator of Anatomy at the Univer-
sity of Edinburgh. In this, one of the polyps contained
three larve of a pale-yellow colour, which appeared, as far
as could be seen without injuring the polyp, to be destitute
ot legs. When first observed, the polyp was furnished with
its proper complement of tentacles; but as the development
of the Pyenogons proceeded, the tentacles were absorbed, and
the polyp became a long sac, pointed at its upper extremity,

52 STRETHILL WRIGHT, ON THE EOLID#.

and fitting closely on the larvee, which appeared to be im-
bedded in the longitudinal folds of the highly developed
endoderm. Mr. Hodge supposes that the larve, at a very
early stage, are swallowed by ordinary alimentary polyps
of the Coryne, and carried through the tubes of the cceno-
sare until they arrive at a part which is about to become a
polyp, which thereupon has its destination altered. And
T think there can be little doubt that his surmise is correct,
as in Coryne the Pycnogon sacs, in all stages of development,
are not only destitute of tentacles, but are, according to
Professor Allman, covered by a layer of the chitinous poly-
pary or scleroderm. Such a mode of nidification, however,
could not take place in Hydractinia, the ccenosarcal tubes
of which are of exceedingly small calibre. Accordingly we
find that the Pycnogon sacs in this zoophyte are formed, not
by the arrest or change in development of an immature polyp,
but by the degeneration of a tentacled polyp previously per-
fect.

Perhaps I ought to mention here that globular sacs are
occasionally found in place of the polyps in Coryne glanduiosa,
Dalyell. These are destitute of scleroderm, and lined with
a very dense brown endoderm, arranged in somewhat reticu-
lated folds. As far as I observed, they were empty, and, by
constantly undergoing alternate processes of dilatation and
contraction, appeared to influence the circulation of the
zoophyte. Itis possible that minute Pycnogons may have
existed in these sacs.

On the Urnticatine Fitaments of the Hou.
By T. Srretuitit Wrieut, M.D.

In the second volume, new series, of this Journal, p. 274,
is contained a translation of a paper, by Dr. Bergh, “ Ou the
existence of Urticating Filaments in the Mollusca.” As
neither Dr. Bergh nor his translators appear to be aware that
anything has been written on these bodies in Great Britain
since the observations of Messrs. Hancock and Embleton
were published, I am induced to lay before the readers of this
Journal an abstract of a paper read by me to the Royal
Physical Society of Edinburgh, on the 22nd of December,
1858, and published in their ‘ Proceedings,’ containing obser-
vations “On the Cnide or Thread-cells of the Eolide,”
which I have since confirmed by repeated experiments.

STRETHILL WRIGHT, ON THE EOLIDZ. 53

“Dr. Strethill Wright, after describing the anatomy of the
respiratory, digestive, and hepatic organs in the LHolide,
stated that in his memoir on Hydractinia echinata, read
before the society, November 26th, 1856, he had written—
Hydractinia is infested by a small species of Holis (Kolis
nana), which peels off the polypary with its rasp-like tongue,
and devours it—possessed, | suppose, of some potent magic,
which renders all the formidable armament of its prey of no
avail. Now, each of the dorsal papille of the Eolide contains
at its extremity a small ovate vesicle, communicating, through
the biliary sac, withthe digestive system, and opening externally
by a minute aperture at the end of the papill. This vesicle is
found crowded with compact masses of thread-cells, which masses
in Kolis nana, consist of aggregations of small and large thread-
cells, identical in size and shape with those of Hydractinia—
on which this Eolis preys—not contained in capsules, but
cemented together by mucus. When we consider that each
of the vesicles is in indirect communication with the stomach,
I thmk we may, without presumption, suggest that the
masses of thread-cells found in Holis nana are quasi fecal
collections of the thread-cells of Hydractinia, which, protected
by their strong coats, have escaped the digestive process. In
corroboration of this view, I may mention that the Holis
papillosa, as figured in the work of Alder and Hancock, have
a perfect resemblance to those found in the Actinias, which
last animals furnish an Abyssinian repast to these carnivorous
mollusea.’ Dr. Wright afterwards found that, as to the
above idea, he had been anticipated by his friend, Mr. Gosse,
who, in his ‘Tenby,’ after noticing the existence of the
thread-cells in the papillz, remarked—“ The inquiry I suggest
would be, how far the presence of thread-cells might be
connected with the diet of the mollusc? And whether,
seeing the forms of the missile threads vary in different genera
of zoophytes, the forms of the corresponding organs in the
papillz of the Eolides would vary if the latter were fed ex-
clusively first on one and then on another genus of the former.”
He afterwards found that Mr. Huxley had also doubted, pre-
viously to Mr. Gosse and himself, whether the thread-cells of
the Holidze were not adventitious. Here were three inde-
pendent observers to whom the idea had suggested itself:
Mr. Huxley had first hinted it; Mr. Gosse suggested it and
how it might be found to be true; Dr. Strethill Wright also
had suggested it, and given two instances in corroboration of
his opinion, and then he proceeded to detail observations
which would, he hoped, entitle it to be enrolled as a proved
fact in the records of science. Ist. A specimen of Eolis nana

54 STRETHILL WRIGHT, ON THE EOLID.

was brought home from Morison’s Haven, on a shell covered
with Hydractinia, taken from a rock-pool, in which was a
profuse growth of Campanularia Johnstoni. The papille of
this Eolis contained the two kinds of thread-cells which are
found on Hydractinia, together with the large thread-cells
which occur within the reproductive capsules of C. Johnstoni.
2nd. An Eolis coronata was taken at Queensferry, on a
massive specimen of Coryne eximia, which was very
abundant there. The thread-cells of C. extmia were very
distinctive, being very large, oval, and containing a four-
barbed dart. The thread-cells of the Eolis and Coryne were
carefully compared together, and were found to be identical.
3rd. Dr. M‘Bain and Dr. Wright found an Eolis Drummondit
on a fine specimen of Tubularia indivisa. They first carefully
examined the thread-cells of the Tubularia, and found four
kinds, two (large and small) of a nearly globular shape, each
containing a four-barbed dart, and two (large and small) of
an almond shape, the larger one containing a thread fur-
nished with a lengthened brush of recurved barbs. They
then examined the papille of the Eolis, and found the ovate
sacs filled with an indiscriminate mixture of all the four kinds
of thread-cells found on 7ubularia indivisa. 4th. Dr. M‘Bain
and Dr. Wright found a specimen of Kolis Landsburgit on
Eudendrium rameum. Eudendrium rameum was furnished, as
to the bodies of its polyps, with very large, bean-shaped thread-
cells, in which an unbarbed style could be detected, while the
tentacles of the polyps were covered with exceedingly minute
cells. They compared the thread-cells of the Eudendrium
with those found in the sac of Eolis, and found both kinds
identical. Lastly, Dr. Wright had kept the specimen of
Eolis Drummondii above mentioned fasting for a long time,
and then introduced it to a large specimen of Coryne
eximia fresh from the sea. The next morning every polyp
of the zoophyte had vanished, and the ovate sacs of the Eolis
were packed with the distinctive thread-cells of the Coryne,
mixed with a few thread-cells of J. indivisa, the remains of
its former feast. He also found the thread-cells of C. ex-
imia in the alimentary canal. It was at one time supposed
that thread-cells, or Cnidze as Mr. Gosse had named them,
were only to be found in the Hydroid and Helianthoid polyps
and the Medusz ; Professor Allman afterwards discovered them
in a species of Loxodes, a protozoan animalcule; and Dr.
Wright had the good fortune to find them on the tentacles of
an Annelid, Spio seticornis, and also on the tentacles of
Cydippe, one of the Ctenophora. Since then he had observed
them on the very minute tentacles of Alcinée, another of the

STRETHILL WRIGHT, ON THE EOLID. 55

Ctenophora. In all these classes of animals thread-cells
were developed within the ectodermal coat of the animal,
and in many, such as in 7’. indivisa, each within a distinct
and very apparent sac, and not in connection with the diges-
tive system.* The type of structure, moreover, of the thread-
cell in the Protozoon, the Hydro-mednsa, the Annelid, and
the Ctenophore, was essentially different for each class; and
this fact alone would lead an observer to doubt as to the
origin of the thread-cells of Eolis, which so exactly resembled
those of the Hydro-medusz in their structure. Nevertheless
it was certainly a very strange fact, for a fact the author
firmly believed it to be, that one animal should be furnished
with apparatus for storing up and voluntarily ejecting organic
bodies derived from the tissues of another animal devoured
by it, and that these should still retain their distinctive
functions unimpaired; and he stated that his friend, Mr. Alder,
one of the highest authorities on the Nudibranchi, still
hesitated to assent to the doctrine sought to be proved by the
present communication, on the ground of its extreme im-
probability. He should therefore feel obliged to any of the
members of the society or others who would lend their aid
to the confirmation or disproof thereof.

* This remark only applies to the Hydroids and their medusoids amongst
the zoophytes. In the Actinia, Lucernarian Meduse, and Lucernaria,
thread-cells are found in connection with processes of the endoderm, related

to the reproductive apparatus.

TRANSLATION.

On the DeveLopmMENt of ECHINORHYNCHUS.
By Prof. Rup. Leucxarr.

(From the ‘ Gottingen Nachrichten,’ No. 22, October 22nd, 1862.)*

The Echinorhynchi, or Acanthocephali, constitute a group
of entozoa with respect to whose development and _life-
history we are confessedly at present wholly ignorant.

The observations of Von Siebold and of Dujardin have, itis
true, shown that the ova of these worms contain an embryo
wholly unlike its parents; but how, or under what circum-
stances, this embryo is developed into the perfect animal, in
the absence of direct experiments, we have been left, up to the
present time, merely to surmise. Most observers, and in
particular Van Beneden and G. Wagener, have been dis-
posed to assign to the Hchinorhynchi, a simple metamor-
phosis hardly, perhaps, more remarkable than that which has
been shown to take place in some of the Nematoidea. The
latter helminthologist goes so far even as to believe that the
organization of the perfect animal may be discerned in the
embryo. The hook-apparatus at the anterior end of the body
of the embryo would in this view be comparable to the pro-
boscis of the perfect worm, and a pair of strap-shaped organs
in the interior (which exist, it should be said, only in one
species) have been assumed to represent the so-called
** lemnisci.””

In order to put these views to the test, I resolved, in the
course of the last summer, to institute a series of experiments
with the ova of Echinorhynchus Proteus, a species which
abounds in our river fish, and particularly in those of the
Perch tribe.

In the common Gammarus Pulex of our ponds and brooks,
I had already noticed, on several occasions, Echinorhynchi

* The interesting paper of which we here give a translation constitutes
the third of a series of ‘ Wxperimental Researches in Helminthology’ insti-
tuted by its distinguished author.

LEUCKART, ON DEVELOPMENT OF ECHINORHYNCHUS. 57

with the neck retracted, and having the sexual organs unde-
veloped. From all appearance these were waiting to be
transferred to the intestine of a higher animal, and from the
construction of their proboscis the suspicion was awakened
that they might be derived from Echinorhynchus Proteus.
Induced by these circumstances I selected Gammarus Pulew
as the subject of my researches. Having placed abundance
of these crustaceans in a vessel of water, I introduced into it
the ova afforded from six or eight female Echinorhynchi, and
in the course of a few days had the satisfaction of detecting
not only numerous ova in the intestinal canal of the Gammari,
but also of seeing that the embyros had quitted the egg-shell,
and had made their way through the walls of the intestine
into the visceral cavity, whence they had wandered in various
directions into the appendages, and had begun to grow. In
a short time J was thus convinced, that i Gammarus pulex
I had discovered the true intermediate supporter of the
entozoon.

The ova of Echinorhynchus Proteus, in form and structure,
resemble those of the allied species. They are of a fusiform
shape, and surrounded with two membranes, an external,
of a more albuminous nature, and an infernal, chitinous.
When the eggs have reached the intestine, the outer of
these membranes is lost, being m fact digested, whilst the
inner envelope remains until ruptured by the embryo, usually
in the middle.

The embryo when it quits the egg measures 0:056 mm. in
length, and 0°014 mm. in thickness. The hinder extremity
is attenuated and pointed, the anterior truncated obliquely
towards the ventral aspect. The surface thus formed, and which
may be termed the vertex, supports a bilateral apparatus of
spines. I counted five (rarely six) spines, which are inserted,
at a certain distance on each side of the median line, in an ex-
panded arch; so that the central spine, which is also the longest
of all (0°002 mm.), occupies the highest position. Neither
root nor claw can be distinguished in these spines. They
present the appearance of straight ridges closely applied to
the cuticle, and project only at the extremity in the form of
ablunt point. Between the two halves of this apparatus of
spines may be seen, close to the median line, on each side,
also another short chitinous elevation or ridge, which consti-
tutes with the above described spines, a more or less perfect
right angle. G. Wagener regards these ridges as a pair of
lips, between which is placed a slit-like pone, but in. reality
they are merely thickenings of the cuticle, which afford a firm
point of insertion for the contractile substance of the embryo.

58 LEUCKART, ON DEVELOPMENT OF ECHINORHYNCHUS.

That this is really the case is shown most completely when
ai opportunity is afforded of observing the mode in which
the embryo performs its boring movements. In this
manceuvre the terminal surface with its two ridges is intro-
verted, or rather its two sides are folded towards each other,
and brought into contact throughout their entire length, the
points of the spines being thus disposed in a line on either
side, from which position, in a few seconds, by a simultaneous
opening out of the folded surface they are moved to the right
and left in a downward, or, if the expression be preferred, in
a backward direction.

The parenchyma of the body is colourless and transparent.
But at the same time there may be distinguished in it a
firmer peripheral layer immediately covered by the cuticle,
and which below the terminal surface forms a knob-lke
projection (regarded by Wagener as a “sac,”—perhaps a
stomach?), and a more fluid medullary substance of a fine
granular consistence. That the peripheral layer, notwith-
standing its apparent homogeneousness, is contractile, is
proved beyond doubt by the movements of the terminal disc.
Moreover, the motions of the embryo are not confined exclu-
sively to the act of boring. The body may occasionally be
seen to contract both longitudinally and transversely. It
may be seen also now and then to bend itself in various
directions; and in transparent specimens of Gammarus this
mobility is manifested in the circumstance that the young
parasites are constantly changing their place in the interior of
their host, slowly progressing sometimes among the viscera,
sometimes among the muscles, and migrating from the visceral
cavity into, and even penetrating, perhaps, to the extremity
of the appendages, whence they return to their original site.

The only distinct structure perceptible in the interior of
the embryo is a comparatively large (0°014 mm.) oval-shaped,
granular mass, which occupies nearly the whole of the central
part of the body, and is occasionally lodged in what has the
appearance of a vacuolar space. Von Siebold, who has already
recognised this granular mass as a constant organ in the
Echinorhynchus-embryo, explains it hypothetically as being
a remnant of the vitellus. Although at a subsequent period
this body exhibits a distinctly cellular structure, it appears
at this time to be a mere agglomeration of granules, charac-
terised by their considerable size and strong refractive power.
Similar granules are also found isolated here and there in
other situations in the interior of the embryo, imbedded in
fact in the softer internal substance, together with which,
during the contractions of the peripheral layer, they may not

a

.

LEUCKART, ON DEVELOPMENT OF ECHINORHYNCHUS. 59

unfrequently be seen to be propelled in different directions.
The granular mass, moreover, itself lies free in the interior
of this substance, and without any connection with the peri-
pheral layer of parenchyma, as may be readily proved not
only from the circumstance that it may be easily squeezed
out of the embryo, but in a more direct manner from the
fact that it is seen to change its place on the occurrence of
any powerful peristaltic movement.

During the first fourteen days after the commencement of
its migration, the morphological development of the embryo
undergoes no change. It merely increases in size, and this
so rapidly that at the end of this period some individuals are
met with measuring in length 0-6 and 0°7 mm., and having a
transverse diameter of 0:15 mm. The embryo during all this
time retains the spines at the anterior extremity, but the
form of this extremity is so far changed that the dorsal sur-
face above the vertex projects in the form of a transparent
hemispherical eminence, which forms with the neutral sur-
face an angle of about 100°, whose apex is constituted by
the meeting of the two parallel longitudinal ridges above
described. It is clear that the presence of these ridges
interferes, to a certain extent, with the equable expansion of
the anterior end of the body, and it is to this circumstance
that is due the peculiarity of comformation of the anterior
part of the head. The spines, like the ridges, retain their
former proportions and respective position. They are placed
close to the longitudinal ridges on the sides of the cephalic
surface, which bythis time has become raised into two rounded
eminences. At this stage I have never observed any true
boring movements, although the forepart of the body is still
occasionally retracted. It would seem, nevertheless, as if the
spines were still of some use in the locomotion of the embryo,
affording it, as they do, the means of affixing itself.

In consequence of this change of form of the anterior end
of the body, the embryo has now acquired a more regular
fusiform shape, which becomes more manifest when it has
been rendered rigid and motionless by the endosmotic absorp-
tion of water.

But the growth of the embryo is not limited merely to the
outer body. The nuclear granular mass in the interior has
also considerably increased in size (in embryos of 0°7 mm. long
to 0°09 mm.). Whilst at the same time it has lost its original
granular aspect. Instead of the granules, pale cells are now seen
measuring from 0°007 to 0°02 mm. in size, and continually
multiplying. These cells constitute a compressed, almost
spherical ball, with a well-defined outline. The surrounding

60 LEUCKART, ON DEVELOPMENT OF ECHINORHYNCHUS.

parenchyma, as at an earlier period, consists of a fine granular
substance, of nearly fluid consistence, out of which, moreover,
on prolonged contact with water, numerous clear drops
about 0°38 mm. in diameter exude, which at first present a
perfectly homogeneous aspect, but, subsequently, m conse-
quence of their undergoing a sort of coagulation, exhibit a
regular nucleus of considerable size (0°016 mm.), and strongly
refractive power. That these bodies, notwithstanding their
celleform structure, are not a normal constituent of the
embryonal body, is clearly manifest from the circumstance
that they may be seen gradually forming during the exami-
nation, and disappearing as soon as the object is floated in a
thin solution of albumen—a proceeding which it is advisable
to adopt upon other grounds as well.

The peripheral layer of contractile substance still retains
its former condition, except that, of course, it has increased
in thickness, and become more sharply defined on its inner
surface. Its greatest thickness is still, as before, towards the
anterior end of the body, although the knob-like projection
has in the meanwhile disappeared.

After the embryo has attained the dimensions just stated
without any other essential change, it begins, in the course
of the third week, to exhibit a most wonderful metamor-
phosis. The nucleus, which up to this time has been constituted
of a simple, small aggregation of cells, now increases rapidly
in size, and at the same time elongates, and becomes trans-
formed by a definite grouping of its elements into a complex
organism, in which, after a short time, may indubitably
be recognised the features of a young Echinorhynchus.
During this process, however, the body of the embryo
remains unchanged, except that it is slightly larger (up to
0:09 mm.), and presents, in the cortical layer, yellow granules
constantly increasing in number, and which necessarily offer
no slight obstacle to the further study of the processes
going on in the interior.

The embryo of Echinorhynchus, therefore, stands in the
same relation to the future worm that the Pluteus does to
the Echinoderm or the Pilidium to Nemertes. As in those
cases, so in Echinorhynchus, the ultimate animal arises in the
interior of the primordial body, by a process which presents
so close an analogy with the production of an embryo, and,
consequently, with the act of generation, that one feels inclined
at once to identify it with such an act, and, consequently,
to regard the Hchinorhynchus as exhibiting, instead of
a metamorphosis, an alternation of generations in its mode of
development.

LEUCKART, ON DEVELOPMENT OF ECHINORHYNCHUS. 61

Without going into minute particulars with respect to the
transformation of the cellular mass in the Echinorhynchus,
still a few words may be said regarding the most important
points concerned in this metamorphosis.

As before remarked, this process commences in a defined
and regular grouping of the cells which had previously been
united into a simple ball. Next, it may be seen that the
anterior end of the ball becomes defined from the rest, or
rather, that in consequence of a clearing up in its interior,
it is transformed into an almost lenticular vesicle, whose
outer wall is constituted of a thin layer of cells, and is
usually distinguished by a number of yellow granules. Sub-
sequent observation will show that this transparent vesicle is
the rudiment of the cavity of the proboscis. Behind this part
will be seen an oval mass of cells of considerable size, extending
backwards in the axis of the body to about the middle of its
length, and in its posterior half enclosing a smaller, though
still a considerably sized cellular body. This body ‘is the
future ganglion, whilst its envelope represents the future pro-
boscis-sheath. At the hinder end, again, of this part are
attached, also in the axis of the body, several small collec-
tions of cells, which are sometimes crowded together, some-
times arranged one behind the other, in a longitudinal series,
and which, together with the terminal portion of the nucleus,
go to constitute the sexual apparatus together with the so-
termed suspensory ligament. ‘The lateral walls of the middle
portion of the body, bounded in front by the cavity of the pro-
boscis, and behind by the terminal portion of the repro-
ductive organs, and which, at first, are of very considerable
thickness, are destined to form the future muscular tunic or
sac of the Echinorhynchus. At this time no trace of visceral
cavity is perceptible.

The next changes in the young Echinorhynchus consist in
its continued and rapid growth in length to twice or thrice
its original dimensions, without any increase in its transverse
diameter. The growth is limited almost entirely, however,
to the middle section of the body, or that which is sur-
rounded by the lateral walls, and the form of this part con-
sequently becomes more and more cylindrical as the growth
proceeds. At the same time the walls of this part become
thinner; whilst the inclosed organs, the proboscis-sheath,
and the sexual organs appended to the so-termed “ ligament,”
notwithstanding all the stretching, retain their original
plump form almost unchanged. ‘The most remarkable
alteration is the lengthening of the cavity of the proboscis,
which continues to extend backwards deeper and deeper into

62 LEUCKART, ON DEVELOPMENT OF ECHINORHYNCHUS.

the proboscis-sheath, in consequence of which it gradually
acquires a club-shape.

When the young worm has reached the length of from
0:4 to 0'-45mm., or about half that of its parent, a space
becomes perceptible between the integument and the viscera,
and which represents the commencement of the visceral
cavity. This space is widest and most distinct in the annular
segment between the sheath of the proboscis and the ligament.
And in this situation may now be perceived in their proper
places on either side, a pair of short and thick retractor
muscles, extending in a straight line from the end of the
proboscis-sheath to the contiguous wall of the body. And

about this time, I thimk, may be observed the first traces”

of certain differences in the position and form of the internal
sexual organs, which may be taken, I conceive, to indicate
a sexual difference.

Up to this stage the anterior and posterior half of the body
have continued to grow pretty nearly in an equal ratio. But
now the growth of the latter begins more and more to pre-
ponderate. The points of insertion of the retractor muscles
recede further and further backwards, and the suspensory liga-
ment, which at first could hardly be distinguished as an inde-
pendent structure among the crowded parts constituting the
sexual apparatus, becomes more and more evidently the sup-
porter of those organs. In its uppermost part, two oval
swellings may be perceived in it, which partially overlap each
other, and represeut the first rudiments of the male and
female reproductive glands, as the case may be. Some way
behind these is a short, cylindrical portion, surrounding the
lower end of the ligament like a sort of sheath. In the
female this is the first rudiment of the so-termed uterine-bell or
tube. Inthe male, in which from the first it has a somewhat
different aspect, it becomes afterwards the vas deferens and
vesicula seminalis. Posteriorly this median organ terminates
in an almost spherical end, at this time nearly completely en-
veloped by the muscular wall of the body ; and which, in the
male, becomes more and more evidently recognisable as the
rudiment of the bell-shaped penis, whilst in the female it is
transformed into the vagina, whose upper end is not de-
veloped into the elongated, so-termed “ uterus,’ until after-
wards, as the time of sexual maturity approaches.

The preponderating growth, both in length and thickness, of
the posterior half of the body continues to be more and
more manifest, so that the anterior segment, with the pro-
boscis-sheath, and proboscis-cavity, which now reaches as far
as the ganglion (but little increased in size), acquires more

aignte take — apne

p>

LEUCKART, ON DEVELOPMENT OF ECHINORHYNCHUS. 63

and more the aspect of a cervical appendage to the proper
body.

In the meanwhile, the worm has gradually become so large
as almost completely to fill the interior of the embryo. But
notwithstanding this, the latter has undergone no change,
except in the continued multiplication of the yellow granules
beneath the contractile cortical layer, and the appearance
of vesicular cells (0°007 mm.) in that layer. It contracts
and stretches itself as be‘ore, and is in continued motion
within its host. Its movements, however, appear on the whole
to be less effective than they were, owimg to its free move-
ments being interfered with by the worm in its interior.

Having traced the young Echinorhynchus up to this stage
of development, I expected every moment to witness its
liberation from the original embryo. But I was again
astounded to find that this liberation never took place. The
embryonic body, with its cortical layer and yellow granules, is
persistent during the whole of life, and gradually becomes closely
attached to the worm, which is developed from the metamor-
phosis of the nucleus in the manner above described. It is
transformed, in fact, into the tunics external to the muscular
sac, and which from their thickness and granular texture, as
well as from the existence in them ofa distinct vascular system,
as has been long known, constitute one of the most striking
characters of the Acanthocephali.

Properly speaking, however, it is not actually the whole
embryonal body which is transformed into this tunic. The
original cuticle, together with the spines, is thrown off, as
soon as the Echinorhynchus occupies the whole interior of
the embryo. But this shedding of the cuticle is in any
case of but little importance, and scarcely to be com-
pared to the mode in which Nemertes slips out of its
Pilidium.

It should, moreover, be remarked, that I have not directly
observed the shedding of the embryo-cuticle, and only
conclude that it takes place from the circumstance that
Echinorhynchi of about 1 mm. in length no longer present
the embryonic form of head, and are not furnished with
spines. The primary embryonic body, which at first might
be regarded as, to a certain extent, an independent animal,
after the loss of the original euticle accommodates itself
more and more accurately to the form of the Echinorhynchus.
And this is the more remarkable when it is considered that
the growth of the latter from this time proceeds at a very
rapid pace.

As at an earlier period in the inclosed worm, so now in

»

64 LEUCKART, ON DEVELOPMENT OF ECHINORHYNCHUS,

the entire body may be distinguished a somewhat ventricose
oval trunk, contaming the reproductive organs, whose sexual
differences are now very manifest, suspended by the ligament,
and a much contracted cylindrical neck, inclosing and almost
entirely occupied by the proboscis-sheath with its contents.
In worms of a large size, even at this stage, the extremity of
the neck, which corresponds to the anterior vesicular expan-
sion, or proboscidian vesicle before described, but which at
this time has become much contracted, and transformed into
a slender muscular apparatus (m. retractor proboscidis), is
prolonged in the form of a distinct though sma!l capitulum.
The anterior border of the proboscis-sheath is inserted into
the neck of this capitulum, in which, notwithstanding the
absence of the hooklets, even now the future proboscis can-
not fail to be recognised.

As growth continues, however, the connection between the
muscular sac and the enveloping body becomes closer and
closer. At first there exists between them a continuous
interspace filled with the remains of the fluid parenchyma,
which is so abundant in the embryo, and this parenchyma,
with its yellow granules, may be seen to be propelled in
any direction, in obedience to the contractions of the body,
but, by degrees, this movement becomes limited to certain
spots, and confined more and more to narrow passages. In
other words, the muscular membrane and external layer con-
tinue to grow more and more together, m consequence of
which the original space is transformed into a system of inter-
communicating canals.

* I must also mention that the motions of the worm, after
the shedding of the embryonic cuticle, become not only
weaker and more limited in extent, but also gradually assume
a different character. In place of the earlier creeping or
crawling movement, will now be remarked nothing but still
slower oscillatory motions in the extremities of the body,
and move or less extensive constrictions, limited for the most
part to the trunk, and dependent, doubtless, upon the action
of the newly-formed muscular walls, although their histo-
logical development has at this period made but little pro-
gress.

When the worm, by continued growth, especially of the
genital organs, has acquired a length of about 4 mm., the
appearance of the hooklets marks its entrance into the last
stage of development. The hooklets arise first on the summit
of the head, but it is very remarkable that they do not spring
from the outer cuticular tunic, but from the inner membrane,
which might be regarded as the limitary layer of the original

~

LEUCKART, ON DEVELOPMENT OF ECHINORHYNCBUS. 65

proboscis-cavity. They are developed from a special layer of
cells which originate in the subcuticular granular layer, and
which is especially related to the inner tunic of the head. Before
the hooklets, which first make their appearance, are fully
formed, the formation of the rest begins, so that the entire
proboscis is soon completely armed. But as soon as this
armature is completed the proboscis is retracted, the retrac-
tion commencing by the introversion at first of the vertex
into the neck, and afterwards when the introversion by the
continued growth of the body extends beyond this part, into
the proper cavity of the body. Thus it is only at a later
period that that peculiar conformation is assumed which has
been so often remarked in the Echinorhynchi, frequently met
with in an encysted condition in the flesh and intestines of
fish, and what has been compared with the conditions pre-
sented in the Cysticerci. The form of the Echinorhynchi is
at first rather slender, and almost fusiform. It would seem to
require some time to assume the rounded shape.

When the introversion of the neck begins will be observed
for the first time the commencement of the so-termed
“‘lemnisci,”’? which are at first short and contracted. With
respect to the origin and relations of these organs to the peri-
pheral vascular system, I am at present unable to make any
positive statement. Nor have I as yet investigated the
changes undergone by these entozoa after they have reached
the intestine of their ultimate host ; but this investigation
shall be undertaken on the first opportunity. Considering
the relatively high development of the young parasites, these
changes, it may be presumed, will be found to be but simple,
and probably passed through in the course of a few days,
whilst the metamorphosis of the embryo, up to the formation
of the Echinorhynchus, occupies, on the whole, about six
weeks.

In conclusion, I would, moreover, remark that the parasitism
of the young Echinorhynchi is not unfrequently fatal to their
entertainer. This is particularly the case in those instances
in which the parasites are numerous—in some I have seen
fifty or sixty,—and in the later stages of their development.
In the young state, these entozoa, notwithstanding the free-
dom with which they exert their boring powers, are but little
injurious.

Giessen ; Aug. 28th, 1862.

VOL. IIT.—NEW SER. E

REVIEWS.

On the Germination, Development, and Fructification of the
Higher Cryptogamia, and on the Fructification of the
Conifere. By Dr. WitHEeLm Horrmeister. ‘Translated
by Frepertck Currey, M.A., Sec.L.8. London: printed
and published for the Ray Society, by Robert Hardwicke.

Waeruer or not Linneus intended by the term Crypto-
gamia to express a doubt about the sexuality of flowerless
plants which one day might be cleared up, there is no doubt
that many of the earlier observers suspected that the same
conditions of reproduction existed in the lower as well as the
higher plants. It was not, however, till the remarkable dis-
coveries of Suminski with regard to the fructification of ferns,
and the demonstration, not only of the existence, but of the
function of sperm-cells and germ-cells in these cryptogams,
that general attention was drawn to the subject. <A host of
observers have come upon the field, and we are now almost
in a position to lay it down as a law, that throughout the
whole vegetable kingdom there is going on a reproductive
process, involving the union of two dissimilar cells—a germ-
cell and a sperm-cell. In the lower cryptogamia there are
many cases in which this has not been demonstrated; but in
the higher cryptogamia it has been done for the whole series.
Science is largely indebted to the labours of Dr. Hoffmeister
for this result; and he has not only laboured as an original
observer, but has collected together, with an industry and
pains-taking diligence which is altogether German, all that
has been done by others on the subject. His first published
work on this subject was produced at Leipzig, in 1847. Since
that period, however, much has been done, and Dr. Hoff-
meister, in the ‘Transactions’ of the Royal Academy of
Saxony, and in the ‘ Regensberg Flora,’ has added much ori-
ginal matter to his first observations. In 1852, the Ray So-
ciety had brought before it a proposition for the translation
of Hoffmeister’s work. This was, however, not entertained
at the time, as a London publisher advertised a translation of
the same. This translation, however, never saw the light ;
and in 1859 Mr. F. Currey, who was himself well acquainted
with the subject, undertook to correspond with Dr. Hoff-
meister on the subject of a translation of his labours on

CURREY, ON THE HIGHER CRYPTOGAMIA. 67

Cryptogamic Botany, and the result has been the production
of this work. It should therefore be understocd, that this
present volume is not a translation of Dr. Hoffmeister’s ori-
ginal work, nor a new edition of it, but a new work. It is,
indeed, founded on the author’s first work, but not only have
the papers before alluded to been added, but the author has
contributed also a large quantity of new matter, and revised
the whole work, so that it is really a complete record of all
that is known at present. This is not only the case with the
letter-press, but also with the plates. The work is illustrated
with no fewer than sixty fine plates, all of which have been
prepared for this work by the author, and engraved by Mr.
Tuffen West.

It would be impossible for us here even to give a sketch of
the grand series of observations of which this work is the ex-
ponent. Each group of plants belonging to the higher
cryptogamia is subjected to a searching investigation, some-
times by Dr. Hoffmeister, and sometimes by French, but more
frequently by German observers. We wish we could say that
we sometimes find the name of an English observer, but the
higher cryptogamia is not the field of English triumphs. Dr.
Hoffmeister commences with the structure of Anthoceros,
and passes on to the leafless and leafy Jungermannie. To
these succeed the Marchantiacez, the mosses and ferns.
Equisetacee with Pilularia, Marsilea Salvinia, Isoetes, and
Selaginelia, are the groups which lead to the Coniferz, stand-
ing on the outside of the cryptogamic group. We may spare
ourselves any further review of the work by presenting the
author’s own summary of his labours:

The comparison of the development of the mosses and liverworts on
the one hand, with that of the ferns, Equisetacee, Rhizocarpex, and
Lycopodiacez on the other, discloses the most complete uniformity between
the fruit-form:tion on the one hand and the embryo-formation on the
other. The structure of the archegonium of the mosses—the organ
within which the fruit-rudiment is formed—is exactly similar to that of
the archegonium of the vascular cryptogams, the latter being that part of
the prothallium in the interior of which the embryo of the frond-bearing
plant originates. In both the large groups of the higher cryptogams
there is a cell which originates freely in the larger central cell of the
archegonium, by the repeated division of which (free) cell, the fruit of
the moss and the frond-bearing plant of the fern are produced. In both,
the divisions of this cell are suppressed and the archegonium miscarries,

unless, at the time of the opening of the top of the latter, spermatozoa
find their way to it.

Mosses and ferns therefore exhibit remarkable instances of a regular
alternation of two generations very different in their organization. The
first generation—that from the spore—is destined to produce the different
sexual organs, by the co-operation of which the multiplication of the pri-
mary mother-cell of the second generation, which exists in the central
cell of the female organ, is brought about, By this multiplication a cellu-

68 CURREY, ON THE HIGHER CRYPTOGAMIA.

lar body is produced which in the mosses forms the rudiment of the fruit;.
and in the vascular eryptogams, the embryo. The object of the second.
generation is to form numerous free reproductive cells—the spores—by
the germination of which the first generation is reproduced. The leafy
plant in the mosses answers therefore to the prothallium of the vascular
cryptogams ; the fruit in the mosses answers to the fern in the common
sense of the word, with its fronds and sporangia. The pro-embryo, that
is to say the confervoid process produced by the germinating spore of
most of the mosses and many of the liverworts, cannot be looked upon as
a special generation any more than the similar organ (the suspensor) in
phenogams. It isto be remembered that when new individuals are produced
from single cells of the leaf of a moss, and also during the development
of the gemmz of many mosses, the formation of the rudiment of the
first leafy axis is preceded by the formation of a similar confervoid pro-
embryo. ‘This holds good as well in the mosses* as in those liverworts
which possess a pro-embryo. When new individuals are formed from
the fragment of a leaf of Lophocolea heterophylla or of Radula compla-
nata, the cell of the surface of the leaf which becomes the mother-cell of
the new plant produces in the former of the above-named plants a single
or double row of cells, and in the latter a cellular surface. In each case
the body produced is exactly similar to the pro-embryo which originates
from the germinating spore in both species.

The vegetative life of the mosses is confined exclusively to the first,
and the fructification to the second generation. The leafy stem alone
sends forth roots: the spore-forming generation draws its nourishment
from the first generation, The life of the fruit is usually much shorter
than that of the leaf-bearing plant. In the vascular cryptogams this
State of circumstances is reversed. It is true that the prothallia send out
capillary roots: this is always the case in the Polypodiacez and Equise-
tacee, and frequently in the Rhizocarpez and Selaginella, But the pro-
thallium lives a much shorter time than the leaf-bearing plant, which
latter, in most cases, does not produce fruit for several years. The con-
trast, however, is not so marked as it appears at first sight. The appa-
rently unlimited life of the leaf-bearing moss depends merely upon con-
tinual renovation. Phenomena of a similar kind are met with in the
sprouting prothallia of Polypodiaces: and Equisetacee. In the lowest
liverworts (Anthoceros and Pellia) the structure of the fertile shoots
is less complicated, and their duration little longer, than that of the
fruit. On the other hand the ramification of the prothallium of the
Equisetacez is very variable; its life is not of shorter duration than that
of an individual shoot.

It isa circumstance worthy of notice that in the second or spore-form-
ing generation of mosses and ferns, complicated thickenings of the cell-
walls usually occur (witness the teeth of the peristome in mosses, the
capsule-wall and the elaters in liverworts, and the vessels in ferns), whilst
in the first generation these thickenings are rare and exceptional.

An unprejudiced consideration of the subject will show that the sepa-
ration into two groups only of the plants comprising the mosses on the
one hand, and the liverworts (Jungermannieew, Marchantiex, Anthoce-
rotez, and Riccieew) on the other, is not natural. There is no marked
feature by which these two groups can be distinguished. It is true that
a pro-embryo like that in the mosses is wanting in most of the genera of
liverworts, especially in all the leafless ones. Many leafy Jungerman-
niew, however, especially the true Jungermanniz, exhibit the phenomenon

* W. P. Schimper’s excellent work, ‘Recherches sur les mousses,’
renders it unnecessary for me to cite examples.

n CURREY, ON THE HIGHER CRYPTOGAMIA. 69
of the conversion of the germinating spore into a single row of cells, one
of which cells, by repeated divisions in all three directions of space, be-
comes the rudiment of the leafy axis. ‘This phenomenon is as well
marked as in any of the mosses. The outward form of the antheridia
and archegonia in the two groups differs very slightly. The first stages
of development of the fruit-rudiment of the mosses on the one hand and
the Jungermanniz on the other, are, it is true, very different. In the
former the longitudinal growth is caused by the continually repeated
division of a single conical apical cell of the organ, by means of septa
inclined alternately in two directions; in the latter this growth is caused
by the repeated division by horizontal septa, of four cells constituting the
upper end of the fruit-rudiment. But the normal mode of cell-multipli-
cation in: the fruit-rudiment of the Marchantiee (including the Tar-
gioniez), and of the Ricciex, coincides exactly with that of the mosses.
Lastly, Anthoceros exhibits a form of cell-multiplication of the endo-
gonium which is the same as that of the punctum vegetationis of the ends
of the axes of a great number (probably the majority) of phenogams.
The septa produced in the one apical cell of the organ, are inclined in
regular succession towards the four points of the compass. The presence
or absence of a columella, or of elaters in the ripe fruit, are points of no
characteristic value; Anthoceros has the columella, but this genus and
the Ricciez have no elaters. Radula in the Jungermanniez has a vagi-
nula, and so has Anthoceros.

Upon instituting a closer comparison between the mode of develop-
ment of different forms, four types soon become conspicuous, around
which all the phenomena hitherto sufliciently investigated may be con-
veniently arranged. We thus arrive at the following equivalent groups,
which are not however equally rich in the number of genera and forms.

1. Mosses according to the ordinary limits of the family, including the
Sphagnacee.

2. Jungermanniex; in which the leafy ones are connected with the
leafless ones by a succession of intermediate stages.

3. Marchantiex, Targioniex, and Ricciee; all intimately connected
with one another by the similarity of the earliest conditions of the fruit,
as well as by many vegetative phenomena,*

4. Anthocerotes.

The mode in which the second generation originates from the first is
much more various in the vascular cryptogams than in the others. All
ferns however agree in the fact that the first axis of their embryo has only
a very limited longitudinal development; it is an axis of the second order
which breaks through the prothallium and becomes the principal axis ;
and they all agree further in this, that the end of the axis of the first
order never forms the root. All vascular cryptogams are without main
roots; they have only adventitious ones.

In more than one respect the formation of the embryo of the Conifer
is intermediate between the higher crytogams and the phenogams. Like
the primary mother-cell of the spores of the Rhizocarpee and Sellaginella
the embryo-sac is one of the axile cells of the shoot, which in the one case
becomes converted into the sporangium, in the other into the ovule. In
the Conifers also the embryo-sac soon becomes free from any mechanical
connexion with the surrounding cellular tissue. ‘The filling of the
embryo-sac by the endosperm may be compared with the production of

* As, for instance, the precisely similar succession of the shoots; the
separation of the tissue of the shoots into an upper layer with intercellu-
lar cavities, and a lower layer without cavities; the occurrence of pecu-
liar thickenings upon the inner wall of the capillary roots, &c.

70 CURREY, ON THE HIGHER CRYPTOGAMIA.

the prothallium of the Rhizocarpee and Selaginelle. The structure of
the corpuscula bears the most striking resemblance to that of the arche-
gonia of the Salviniz, and still more of the Selaginelle. Irrespective of
the different mode of impregnation—which in the Rhizocarpee and Sela-
ginellz takes place by free spermatozoa, and in the Conifere by a pollen-
tube, in the interior of which spermatozoa are probably formed—the
transformation of the germinal vesicle into the primary mother-cell of the
new plant in the Conifer and the vascular cryptogams, only differs in
the fact, that in the latter there is usually one single germinal vesicle
only, whilst in the former there are very numerous germinal vesicles, of
which, normally, one only is impregnated. The embryo-sac of the Coni-
ferze may be looked upon asa spore remaining enclosed in its sporangium ;
the prothallium which it forms does not come to the light. In order to
reach the archegonia of this prothallium the impregnative matter must
make itself a passage through the tissue of the sporangium.

Moreover, the development of the pollen of the Coniferz, when dis-
persed, varies in a marked manner from that of phenogams, and exhibits
vital phenomena similar to those met with in the microspores of Pilularia,
Salvinia, and Isoetes. The extinction of its sexual function (the protru-
sion of the pollen-tube) is preceded by a cell-formation in its interior, of
which no instance is to be found amongst monocotyledons and dico-
tyledons.

Two of the phenomena which have led me to compare the embryo-sac
of the Coniferz with the large spores of the higher cryptogams, is common
to the embryo-sac of phznogams, viz., the origin of the ovule from an
axile cell, and the want of connexion with the adjoining cellular tissue.
This is very remarkable in the Rhinanthacee on account of the indepen-
dent growth of the embryo-sac. The Conifere are closely allied to the
phznogams in the fact that their pollen-grains develope tubes.

The phznogams therefore form the upper terminal link of a series, the
members of which are the Conifer and Cycadez, the vascular crypto-
gams, the Muscinez, and the Characeez. These members exhibit a con-
tinually more extensive and more independent vegetative existence in
proportion to the gradually descending rank of the generation preceding
impregnation, which generation is developed from reproductive cells cast
off from the organism itself. The closing members of this series, the
Characez, pass through their entire vegetative development in this gene-
ration, whilst the vital phenomena of the generation which follows
impregnation are limited to the filling with oil and starch of the newly-
formed cell in the central cell of the fruit-branch or archegonium. The
development of the latter generation in the Muscinee is far more impor-
tant, although in some instances, as for example in Riccia, it is very
limited in comparison with the first generation, that, namely, which pre-
cedes impregnation.* This state of things is reversed in the Ferns, the
Equiseta, and the Ophioglossee. From the Characez up to these orders,
there is an uncertainty in the different species as to the sexual function
of the reproductive cells which are cast off from the organism itself, viz.,

* Anthoceros—which in the development of the second generation
stands very low in the scale—exhibits a remarkable analogy with the
Characew, in the fact that, as in the latter, the formation of its antheridia
commences by the growing out of the cells of the wall of an intercellular
cavity. The well-known red globules of Chara are manifestly states of
antheridia. Cavities communicating with one another are formed round
the middle point of the hitherto solid globular mass of cells, within which
cavities the antheridia—or cellular threads in whose joints the vesicles
which produce the spermatozoa are formed—become developed.

~~ weete”

CURREY, ON THE HIGHER CRYPTQGAMIA. 71

the spores. In these orders species nearly allied to one another are
partly monecious and partly dicecious. Certain species amongst the
Char, Muscine, the Ferns, and the Equiseta,* produce both kinds of
sexual organs, archegonia and antheridia, upon the same individual of
the generation preceding impregnation: the latter are always produced
before the former. In other Characeze, Muscinex, and Equiseta, the
male and female sexual organs are distributed upon different individuals
—a separation which is very complete in certain species of mosses, and
not in others. The spores from which, in the Characee, Muscinex, and
Equiseta, dizcious prothallia are developed, exhibit no indication of the
sex of the individual to be produced from them. But there is often a
marked difference in the complete form between the male and female
individuals: the former are much smaller than the latter; they are
dwarfish. Extreme instances of this are to found, amongst mosses, in
Dicranum undulatum and Hypnum lutescens. In the Equiseta also the
male prothallia are always smaller than the females.

Lastly, the reproductive cells of the Rhizocarpee, Isoetes, and Selagi-
nella exhibit, according to their sex, the most remarkable differences in
their mode of development, size, and form, so long as they continue in
vital connexion with the organism belonging to the generation following
impregnation. In the Coniferee the reproductive cells differ in their
origin and formation but little from those of phenogams; they differ
only in the nature of the vegetative growth subsequent to their formation
—which growth in the Conifer is in a high degree independent—in the
formation of the row of cells in the interior of the pollen-grain, as well as
in the formation of the endosperm, and of the corpuscula in the interior
of the embryo-sac.

There are so many essential points of agreement between the Conifer
and the phznogams, that it is more to the point to get rid of the marked
differences in their respective processes of embryo-formation, than to
indicate in what they agree. One of these differences is the cell-forma-
tion inside the pollen-grain, but the principal one is the development of
the endosperm and of the corpuscula, a process exactly analogous to the
formation of the prothallia and archegonia of the vascular cryptogams,
and which is entirely wanting in the phenogams. ‘The whole series of
developmental processes which occur in the Conifers between the filling
of the embryo-sac with the cellular tissue of the endosperm and the pro-
duction of the germinal vesicles in the corpuscula, is entirely passed over
in the phenogams. Here the germinal vesicles are formed immediately
in the embryo-sac. In the phenogams there is no vital phenomenon
analogous to the development of the prothallia and of the endosperm of
gymnosperns, just as in the cryptogams and the Coniferz there is no ana-
logue to the endosperm-formation which takes place in so many pheenogams
after the arrival of the impregnating organ at the embryo-sac. The
breaking up of the pro-embryo of the Conifers into a number of inde-
pendent suspensors is a phenomenon of the most peculiar kind, to which
nothing amongst the vascular plants bears any resemblance,f and to
which the division of the spore (i. e., the mother-cell of the oospores) of

%* The greater number of the Chare and Muscinex, a few only of the
Equiseta, and all the known forms of Ferns and Ophioglossea.

y The formation of the pro-embryo of Loranthus Europeus out of four
longitudinal rows of cells may be looked upon as a slight indication of
this. One only of these cells, the terminal cell, becomes transformed
into an embryonic globule, (Hoffmeister, in‘ Abh. Kon, Sachs. Ges, d.
Wiss.,’ vi, 543.)

72 CARPENTER, ON THE MICROSCOPE.

Fucus into several cells capable of impregnation and development* is
hardly analogous, inasmuch as with the latter process the impregnation
of the free spore commences and forthwith terminates.

The Microscope and its Revelations. By Witutam B.
Carpenter, M.D. Third Edition. London: Churchill.

Tus work, which has now reached its third edition, needs
no commendation from us. It is undoubtedly the best ma-
nual on the use of the microscope in the English language.
Nevertheless, this edition contains a large mass of new matter
which claims our recognition. The classification of the Dia-
tomaceze has been remodelled in accordance with the views of
Mr. Ralfs, and the account of that group has been consider-
ably extended. The account of the Rhizopoda has been alto-
gether rewritten, and that of the Infusoria has been aug-
mented by a summary of Balbiani’s recent researches on their
sexual reproduction. As might be expected from the extent
of the author’s own researches on Foraminifera, the chapter
on these organisms has been rewritten and greatly extended.
Mr. Salter’s researches on the teeth of Echinus, and those of
Mr. Houghton on the parasitic habits of the larva of Anodon,
have been embodied with the author’s more recent views of the
structure of the shell in the chapter devoted to the Mollusca.
Additions have been made also to the account of the forms of
Annelida, and the description of the structure of the shells
of the Crustacea have been considerably modified. In the
section devoted to Insects, Dr. Hicks’ researches upon their
eyes, and Mr. Beck’s upon the Podura scale have been de-
scribed. Amongst the new accounts of structure among the
vertebrate animals, are those of Mr. Whitney on the circula-
tion in the Tadpole. Mr. Rainey’s important researches in
** Molecular Coalescence” are also noticed in this edition. The
work is still further improved by the addition of ten separate
plates, and twenty woodcuts. ‘Two of the plates, represent-
ing chiefly the circular forms of Diatomacez, are on steel,
and form frontispieces to the work. It gives us much pleasure
to recognise, in so large a quantity of the new matter which
Dr. Carpenter has introduced into the present edition of his
work, the results of researches which the ‘ Quarterly Journal
of Microscopical Science’ has been the means of introducing
to public notice. We feel that the study of this work will be
one of the best incentives to the student of the microscope to
pursue his investigations in a spirit which will enable him to
become a contributor to our pages, and a future helper of
Dr. Carpenter in the subsequent editions of his work.

* Thuret, ‘ Ann. d, Se. Nat.,’ iv Sér., 1854, p, 273.

NOTES AND CORRESPONDENCE.

Note respecting Parasites found in the Blood of the edible
Turtle—In Vol. i, N. 8., of this Journal, p. 40, is an
account by Mr. Canton, of some fusiform ova, found by him
adhering to the eyes of the edible turtle. Similar organisms
have since been noticed by Dr. Leared, in the blood from the
heart of the same animal, in two instances. In one of these
latter cases, examined in August, 1860, the heart also con-
tained numerous minute fluke-worms, which were pronounced
by Dr. Cobbold to belong to an undescribed species of
Distoma, and named D. constrictum, from its’ peculiar form.
Whether the minute oviform bodies noticed by Mr. Canton,
and these Distomata stand in any relation to each other is yet
to be made out, and is an interesting subject for enquiry.
Dr. Leared’s account of the Distomata and oviform bodies
will be found in vol. xiii. of the ‘ Transactions’ of the Patho.
logical Society, p. 271.

On the Terms used in the description of Diatoms.—Dr. G.
Fresenius, in the ‘Senckenb. Proc.’ vol. iv., p. 68, describes
and figures four species of Navicula, one beimg new. Pinnu-
laria Silesiaca, Bleisch, and Amphora selina, W. Smith. In
his introductory remarks he proposes the adoption of the
terms, “frons” and “ latus,” to express what English ob-
servers call the “front view ” and “ side view.” (‘N. Hist.
Rey.,’ vol. ii., No. 8, p. 481.)

On the occurrence of Parasitic Sacs on Crustacea and some
Insect-Larve.— Lieberktithn (Mull. ‘ Arch.,” 1856, p. 494) and
Schenk (‘ Verh. der Phys.-Med. Gesells, in Wiirzburg, 1858)
have described certain organisms parasitic upon the gills of
the larve of Phryganea, Asellus aquaticus, and Gammarus
pulex. ‘These organisms have been since examined by Pro-
fessor Cienkowski, who considers them to be forms of a uni-

74: MEMORANDA.

cellular plant, to which, from the amzeboid character of its
zoospores and its parasitic habit, he has given the name of
Amebidium parasiticum. Cienkowski found the plant on
Phryganea and Gammarus pulex, and also very plentifully on
the larve of gnats. It is tubular or sac-shaped, unicellular
and variable in form; the largest plants were 0°5 mm. long
by 0:001 mm. broad; the smallest 0°015mm. long. In the
spring they produce in their interior spindle- or sac-shaped
bodies, which escape through the cell-wall of the mother
plant, being sometimes projected by the elastic contraction
of that cell-wall. Pear-shaped zoospores are afterwards
formed, which, when free, exhibit amzboid expansions and
contractions, but are distinguishable from Ameba diffluens,
which they much resemble, by the absence of a contractile
cavity. These zoospores eventually become motionless, and
at once produce spindle-shaped bodies (young ameebidia) in
their interior, or they become transformed into resting spores,
which, after a time, also produce young ameebidia. The author
concludes that amebidium is a plant belongmg to the lower
Algz or Fungi. He then proceeds to describe a very singu-
lar growth, as to which he was long in doubt whether it be-
longed to or was parasitic upon amzbidium. He describes
the stages of development of this growth, which is attached
to the sides of the amebidium, and, when perfect, consists of
a large obovate or pear-shaped cell, crowned with moniliform
rows of cells like the head of an Aspergillus. He concludes
that it is a fungus, but of doubtful affinity, and calls it Basi-
diolum fimbriatum. (‘ Nat. Hist. Rev.,’ vol. 11, No. 8, p. 477.)

Note on a simple Mounting for any Microscopie Objects.—
Few microscopists use black japan as a mounting without
having their objects occasionally spoiled by the running in
of the cement. Having suffered, like my neighbours, from this
difficulty, I have sought to obviate it by the use of various
other methods of mounting, which should combine speed,
ease, and certainty in their performance. One of these ap-
pears so far promising in utility, that I am induced to draw
attention to it. It is performed as follows :

Little pieces of kid leather, wash-leather, or blotting-paper,
about one inch square, have circular holes punched in the
middle, the hole being somewhat smaller than the thin glass
cover which is subsequently to be used.

The object having been prepared and placed upon the glass
slip, or on the cover, if more desirable, one of the pieces of
leather is brushed over with “liquid glue” (a thickish varnish
made of shellac and naphtha). When covered on both sides

il Ur ees

MEMORANDA. 75

with this cement, it is placed upon the glass slip, the cover
put over it, and gently pressed down, to insure close contact
withont squeezing the cement out of the leather. It may
then be put away. The cement soon dries, and at any sub-
sequent time the superfluous leather may be cut away close
round the edges of the thin glass cover.

Care should be taken that the leather or paper is soft, and
free from elasticity, so that it may lie flat upon the glass;
also that it has enough cement to imsure adhesion, and not
so much as to spread over the object when the cover is placed
upon it. The consistency of the cement also requires atten-
tion ; it should be just so fluid that it is readily absorbed by
blotting-paper.

So far, I have found it combine the advantages of speed,
ease, certainty, and cheapness, requiring no special appliances
in its performance,—the liquid glue, bottle and brush being in
constant use for other purposes, where cement or a yellow
varnish is required, and the punch being the same that is
used for cutting out labels, &c. The little squares of leather
for thick objects, and of paper for thin objects, are all that
it is necessary to keep specially for this purpose.—B. 8.
Proctor, 11, Grey Street, Newcastle-on-Lyne.

Plan for finding the Focal Length of Objectives.—If you
think the followmg communication worth insertion, per-
haps you will find it a place in the ‘Journal’ It is a
modification of Professor Thury’s plan for finding the
focal length of microscopic objectives. It was suggested
by reading Captain Mitchell’s paper in the October
number of the ‘ Journal,’ and may be of use to those who,
like myself, wish to know the true focal length of their objec-
tives, but have not a positive eyepiece micrometer. The differ-
ence from the professor’s plan consists in using the eye-lens of
the negative eyepiece only, the micrometer being placed, as
usual, exactly in its focus. I send you a table of the results on
my own objectives, also the magnifying power as given by the
camera and my longest eyepiece, to prove the correctness of the
method by comparison with the magnifying power obtained by
multiplying the power of the objective by that of the eyepiece,
the results being as coincident as unavoidable errors will allow.
To arrive at this, I have, however, been obliged to differ from
Captain Mitchell in considering the power of the objective to
be the exact number that one of the stage covers of the eye-
piece micrometer, and not with the addition of one, as in his
method. Any one following out this plan will find that, as
the power of the eyepiece must be the same with every ob-

76 MEMORANDA. e

jective at the same distances, it is impossible to make the
results with that addition agree, particularly with the lower
powers, where the proportion of one to the whole is so much
greater, and where all errors are as a minimum.

It is necessary to have the same distance from the stage
micrometer to the focus of the eye-lens im measuring the
magnifying power with the camera, as between the two mi-
crometers in measuring the power of the objective ; ten inches,
when possible, being most convenient. The adjustment of
the objective to be always at the same place.

Table of objectives.—Distances of micrometers divided by
the number of eyepiece micrometer equal to one of stage plus
one.—F'ocal length—Magnifying power by multiplying num-
ber by 5 (power of eyepiece).—Also magnifying power by
camera at ten inches, with longest eyepiece—The adjustment
ring in a line.

Magnifying
Focal length. No. x 5. power by
camera.
a D— 10-in.
tal Sf - A412 . 406:
No. + 1 = 83°5
4 D— 10
le | OL Pee 351.0) ; 256°
No. L— 52-2
+ D— 10
— = ‘390 ey : 123°
No. + 1 = 25°6
i D— 10

—_- = 93 ; AG 7 Dias 48°
No. + 1=10°75
2 D— 11
sin aOe : 23°50 . 23°7

No. -f1l= 5:7

I also enclose a method of finding the angular aperture by
daylight. If it has not been published, and is worth inser-
tion, perhaps you will find room for it also. It appears to
me to have the advantage of being able to see clearly the ex-
treme limits of distinct definition of the objective, although it
is difficult to use with some objectives of low power, which do
not give a sharp edge to the field of view. The method is
by using the objective as a diminishing telescope, the eye-
glass to be a common pocket or watchmaker’s eye-lens, of
two or three inches focal length, so placed behind the objec-
tive as to show distinctly a rule or a wall a few inches or more

MEMORANDA. rw

before it. The field of view will be the base of an angle,
which appears equal to the angular aperture. To measure
this angle, place the central point of the straight edge a gra-
duated semicircle, exactly under the edge of the lowest com-
bination of the objective, the convexity being towards the rule
or wall. The number of degrees included between two lines
drawn from that point to the extreme limits of the field of
view, will be the measure of this angle.

The following table is, lst, by this method ; 2nd, after Mr.
Pritchard, as described by Dr. Lardner; and, 3rd, as given
by the maker. The adjustment ring in a line. I think that
by the second method you by no means get the full angle with
the two and one-inch.

Table of Angular Aperture of Objectives.

Ist. 2nd. ord.
2h 128° 126° 125°
4 108° 105° 106°
el 58° 57° 60°
1 22° 16° Dox
2 16° 10° 15°

Ricuarp Nicuors, M.R.C.S.

St. HeELEN’s, JERSEY.

Micro-Stereographs.—In ‘ Quart. Journal of Micro. Science,’
No. 3, for April, 1853, Professor Riddell gives the first an-
nouncement of a binocular microscope, and mentions its ap-
plicability for obtaining “ match drawings” with the camera
lucida, to be viewed with the stereoscope; and again, in
No. 5, p. 24, for the same year, he says, “ If the same object
be drawn as seen, through each ocular respectively, a differ-
ence between the two drawings is perceptible, similar to that
between match stereoscopic pictures; so that if these two
drawings be viewed each with the appropriate eye, the natural
relief of the object is reproduced.”

In ‘Trans.’ of the Micro. Society (‘ Quart. Journal of
Micro. Science’), No. 10, Jan., 1855, pp. 5, 6, in a paper on
“Microscopic Photography,” I described a method of obtain-
ing micro-stereograms without shifting the object, simply by
obscuring the alternate halves of the object-glass, by means
of a sliding stop. I had before this abandoned the use of the
camera, and given the preference to the image obtained
through the shutter of a dark room, by means of a Heliostat ;
in fact, using the ordinary microscope as a solar one. ‘This,
besides other reasons, gives the very important one of allow-
ing the light to be adjusted while the sensitive plate is in

78 MEMORANDA.

place (in an open frame) the instant before the impression is
taken. With the arrangements employed, I may state it to
be the most luxurious mode of taking photographs that I
have practised—bath, developers, plates, &c., all being close
to hand, so that there is no occasion to stir one step from
your position. A pane of yellow glass is let into the shutter,
above the microscope, to furnish light for manipulation. Also,
during these experiments, I found that a pair of pictures,
each taken with a right and left-handed illumination alone,
was sufficient to bring an object up into relief in the stereo-
scope, particularly when objectives of large aperture were
employed. As micro-photography and stereography are again
the subject of attention, I allude to these circumstances, be-
cause they have either been lost sight of or revived as new
facts. —F. H. Wenuam.

Gn the seat of the Colouring Matter in Flowers.— M. F.
Hildebrand’s observations* on the forms under which various
colouring matters are found in flowers, and their distribution
in the tissue of the several organs, warrant the following
general conclusions :—(1) That the colour of flowers is in con-
stant connection with the cell contents, never with the walls
of cells. (2) Blue, violet, rose, and (if there be no yellow in the
flower) deep red, are due, with little exception, to a cell-fiuid
of corresponding colour. (3) Yellow, orange, and green, are
usually associated with solid granular or vesicular substances
in the cells. (4) Brown or gray, and, in many cases, bright
red and orange (apparently uniform to the unaided eye) are
found to be compounded of other colours, as yellow, green, or
orange, with violet, or green and red; bright red and orange
in like manner of blue-red with yellow or orange. (5) Black,
excepting in the Bean, is due to a very deeply-coloured cell-
fluid. (6) All the cells of an organ are rarely uniformly
coloured. (7) The colour usually resides in one or in a few
of the outer layers of cells. (8) The coloured cells are but
exceptionally covered by a layer of uncoloured ones. (9)
Combinations of colour are occasioned by diversely-coloured
matters in the same or in adjacent cells (‘ Nat. Hist. Reyv.,’
vol. ii, No. 8, p. 438).

Kelner’s Orthoscopic Eyepiece.x—Permit me to direct the
attention of your readers to the new form of eyepiece lately
brought out by Ross, ‘ Kelner’s Orthoscopic.’? The advantages
which it possesses over the old Huyghenian eyepiece are

* Contained in Pringsheim’s ‘ Jahrb.,’ iii, p. 50.

MEMORANDA. 79

a very much larger field, with more light, and yet without
any sacrifice of defining quality. In using the lower powers
of the microscope, it is often of much importance to have the
whole of a large object in view, such as a section of coal, or
wood, or a section of Echinus spine, &c., this the new eyepiece
accomplishes most satisfactorily, and with a beautiful flat
field. For more minute objects, when these consist of great
diversity of forms, such as shells of Polycistina, or spicula of
Gorgonia, or sponges, it is equally good, or better. These
objects, shown by a one inch glass, and under the dark
ground illumination, and viewed with the “C” Kelner’s
eyepiece, have thrown all to whom I have shown the sights
into extacies; the almost illimitable view and the vast
variety of objects strike the beholder with wonder; and the
change that is effected when the old form of eyepiece is sub-
stituted, is very strikingly in favour of the new. It is also
equally useful with the higher powers. Many of the larger
and finest forms of Diatomaceze cannot be all seen when
shown by the highest powers, and a deep eyepiece of the old
form ; but, with the “ Kelner,’ you may magnify an “ Arach-
noidiscus,”’ until it appears like a dinner-plate in size, and
yet be able to see the whole of the object. In conclusion, I
may say that nearly all the microscopists to whom I have
shown it have expressed their approval ofits merits by procur-
ing it for themselves.—Josreru Davison, Newcastle-on-Tyne.

PROCEEDINGS OF SOCIETIES.

MicroscopicaL Socrrty, October 8th, 1862.

R. J. Farranvs, Esq., President, in the Chair.

The following paper was read:—‘‘On the Cleaning and Pre-
paring of Diatoms,”’ by J. A. Tulk, Esq.

November 12th, 1862.
R. J. Fannants, Esq., President, in the Chair.

Rev. Wm. Tyler, W. F. Graham, Esq., George Tyler, Esq., and
Conrad Wm. Finzel, Esq., were balloted for, and duly elected mem-
bers of the Society.

The following papers were read :—“On the Photographie De-
lineation of Microscopic Objects,’ by Dr. Maddox.

“On Acari produced in a Nitrate Bath,” by the same.

December 10th, 1862.
R. J. Farnrants, Esq., President, in the Chair.

‘Henry Davis, Esq., Wm. Revill, Esq., and Jno. T. Murray, Esq.,
were balloted for, and duly elected members of the Society.

A paper by Dr. Greville, ‘“On some New Species of Diatomaceze,’”’
was read.

Lirerany AND PutLtosopHiIcaL Socrety, MANCHESTER.

Microscorican SECTION.

October 20th, 1862.

Professor WILLIAMSON, F.R.S., President of the Section,
in the Chair.

Mr. George Venables Vernon, F.R.A.S., was elected a member of
the Section.

Mrs. Bury, of Croft Lodge, Ambleside, presented, through Pro-
fessor Williamson, a series of twelve photographic plates, with
seventy-two figures of Polycistins from drawings by that lady ;
also seventeen mounted slides of Barbadoes earth.

PROCEEDINGS OF SOCIETIES. 81

Mr. Horatio J. Frembly, of Gibraltar, presented, through Mr.
H. A. Hurst, thirty-four slides of tongues of mollusca, collected and
mounted by himself. An elaborate report upon their scientific
classification was read by Dr. Thomas Alcock.

Mr. H. A. Hurst presented a collection of tongues of mollusca,
from Bengal, made by him during his residence in India. They
have been placed in the hands of Dr. Alcock, who has kindly under-
taken to examine and report thereupon.

Captain J. C. Gales, of the ship “ Quito,’’ presented soundings
taken off the coast of Chili and the Falkland Islands ; two speci-
mens of anchor mud, from the Falkland Islands; and some of the
Fucus natans from the Sargossa Sea, with specimens of its inhabi-
tants, dried in the sun. Captain Curling, of the P. and O.S8.S.
“China,” presented four soundings from the coasts of Malabar,
Yemen, Malacca, &c. ; Captain Vickers, of the ‘‘ Rosina Claypole,”
anchor mud from Port Royal and Black River, Jamaica, and a
sounding taken off the south coast of Ireland; and Captain Samuel
Flood, of the ship “ Pantoleon,’’ anchor mud from Sumatra and
Malacca. Two deep Atlantic soundings in 1730 and 2220 fathoms,
were also thankfully acknowledged.

Mr. Thomas Heelis presented many interesting specimens, col-
lected during his late voyage, amongst which may be named two
soundings from the Agulhas Bank, two specimens of Hoogly mud,
seales of flying fish, and gulf weed, with minute crustacea and
other animals preserved in spirits.

Mr, Joseph Sidebotham presented to every member of the Section
a photographed finder for high powers, in case inscribed with the
member’s name.

Mr. John Dale presented a quantity of desiccated balsam dissolved
in chloroform, to be divided amongst the members.

Mr. A. G. Latham presented a mounted spiracle of a mole cricket
from Africa, and pointed out the difference from that found in this
country.

Mr. E. W. Binney presented a copy of his paper “On some
Fossil Plants showing structure, from the Lower Coal Measures of
Lancashire.”

A letter was read from Mr. Thomas D. Toase, of Jamaica, with
reference to the animalcule previously described.

Mr. Brothers exhibited some fine specimens of Stephanoceros.

Mr. Parry exhibited some photographs of magnified sections of
wood.

Mr. W. H. Heys exhibited the peculiar oil glands on the leaf of
the Procranthera violacea; stellate hairs on the calyx of the
Deutzia scabra, which differ from those on the leaves by having a
greater number of rays and a central disc; spines of the Loasa
coccinea ; and two kinds of spangles upon oak leaves from
Beddgelert.

Dr. William Roberts exhibited a mounted specimen of crystals
of Cystin.

VOL. III.—NEW SER. i F

82 PROCEEDINGS OF SOCIETIES.

November 17th, 1862.
J. G. Lynpz, F.G.S., M. Inst. C.E., in the Chair.

Captain Randall, late of the barque “ Brazil,’ forwarded eight
soundings taken on the north coast of the Brazils.

Mr. Thos. Heelis presented a specimen of the Echeneis Remora,
or sucking fish.

Mr. Parry presented a number of cells and rings in cardboard ;
they were very smooth, and sharply cut, without the bur usually
produced by punching out cells. Mr. Parry explained that he had
cut them in the lathe twenty or thirty together, the outside cuttings
only presenting an appreciable bur.

Dr. Roberts called attention to the aid that might be received in
the examination of the structure of animal and vegetable tissue by
the use of colouring materials. Magenta is peculiarly adapted for
this purpose, in consequence of its solubility i in simple water and its
inert chemical character. The nuclear structures of animal cells
are deeply tinted by magenta, and by its use the nuclei of the pale
blood-corpuscles, of pus-globules, of the renal and hepatic cells, of
cancerous growths, and of all epithelial structures are brought out
in great beauty, tinted of a bright carbuncle red. The ved blood-
disks are tinted of a faint rose-colour and a darker red speck, not
hitherto noticed, is to be observed on the periphery of the corpuscle ;
it undergoes some changes when treated with tannin, and, subse-
quently, with caustic potash ; but this point is still under investi-
gation.

Dr. Roberts exhibited mounted specimens to illustrate his views.

’ Mr. John Leigh, M.R.C.S., exhibited a case of microscopical dis-
secting instruments, by Wood, of Manchester, which were highly
approved of for completeness and finish.

Mr. Thos. H. Nevill exhibited, with dark ground illumination,
some fine specimens of Conochilus Volvoz.

ORIGINAL COMMUNICATIONS.

On our Present Knowiepce of the GrecarInip#, with
Descrietions or THREE New Specizs belonging to that
class. By E. Ray Lanxester.

In Vol. I. of this Journal (1853), p. 211, an abstract ap-
peared of some observations made by Kolliker and others
on the Gregarinidz, a group of animals of very simple struc-
ture, met with in the intestine and other parts of many in-
sects and annelids, the nature of which was then, and is
still, a matter of considerable interest to naturalists. Others
have worked at the subject since that time, but little has
been published in England relating to these parasites, nor
are they generally known to microscopic observers in this
country. It may, therefore, be advantageous to give in a
condensed form what is known of their structure and de-
velopment, adding a list of species and a few original obser-
vations.

In 1837, Léon Dufour* described a group of microscopic
organisms, which he discovered in the interior of several
species of insects, under the name of Gregarina, “‘ qu’exprime
Vhabitude qu’ont ces Entozoaires de vivre par troupeaux.”
He had before remarked upon their occurrence,t but with-
out fully describing or naming them. Here he describes
them as possessing a mouth and composed of two membranes,
the internal one enclosing a clear fluid. Later researches
have shown Dufour’s description to be partially erroneous.
The Gregarine vary considerably in form, being, in most
cases, more or less ovate. In those found in insects and
crustacea the body is unequally divided by internal septa
into two segments, which have been called respectively the
anterior and posterior sacs. In some species three such
divisions have been observed. Other forms met with in
Annellida have no internal septa, but are unilocular. In

* «Ann. des Sci. Nat.,’ tome vii, 1837, p. 10.
+ Ibid., tome viii, lre ’séries, xiii.
VOL. 11I,—NEW SER, G

$4. E. RAY LANKESTER, ON GREGARINIDA.

some a sort of process projects from one end of the body,
frequently provided with a circle of reflexed hooklets, which
in the bilocular Gregarine is attached to the anterior sac.
There is no appearance whatever of a mouth in these animals,
and they appear to live by a process of absorption through
the membranous envelope. Lach sac contains in its interior
a mass of granules varying in quantity, which by reflected
light appear whitish and semi-opaque, but when viewed with
transmitted light are seen to be transparent, and of a yellow
colour. In the posterior sac a clear and well-defined vesicle
is situated, which sometimes contains granules and a nucleus.
The membrane of which the sacs are formed is transparent
and contractile. In some species the existence of a second
tunic within the posterior sac has been ascertained.

Dufour described six species of these parasites, all of
which were bilocular.

Dr. Hammerschmidt, in the ‘Tsis von Oken,’ 1838, followed
up Dufour’s observations, and named several new species,
which he placed in four different genera—Clepsidrina, Rhiz-
inia, Pyxinia, and Bullulina. There was, however, no ground
for such a division, his genera being based upon the most
trivial characters.

Dr.C.Th.v. Siebold also, in the ‘Neueste Schriften,’ Dantzig,
1829, described new species of Gregarinz, which are given in
the list below.

In 1845, Kolliker* described several unilocular forms of
Gregarinz, from the intestines of various Annelida. Between
the publication of this first paper of Kolliker and_ his
second, three German authors wrote, viz., J. Henle, in
Miiller’s ‘ Archiv,’ 1845, who described, for the first time, a
species of Gregarina from the earthworm; A. von Frant-
zius (‘Observationes quedam de Gregarinis,’ Berolini, 1846),
who, with Henle, questions the correctness of Kolliker’s
assertion, that the Gregarine are unicellular animals; and
thirdly, Dr. F. Stein, in Miiller’s ‘ Archiv,’ 1848, described
various new species of Gregarine, and divided them into
three families, of which mention will be made further on.
Kolliker then published his second paper in the first volume of
Siebold and Kolliker’s ‘Zeitschrift.’ He enumerates thirty-
five species of Gregarinz, and enters at some length into
their structure and affinities. The conclusions which he
arrived at have before been quoted in these pages; it will
be, therefore, only necessary to give them here briefly. Ist.
The Gregarine are animals. 2ndly. They consist indubitably

* ‘Zeitschrift fiir wissenschaftliche Botanik,’ von M. T. Schleiden und
C. Nageli, 2tes Heft, 1845.

E. RAY LANKESTER, ON GREGARINIDZ. 85

of a single cell; their membrane corresponds to a cell-mem-
brane; their contents to cell-contents; their vesicle to a
nucleus; the granule or granules within it to a simple or
broken up nucleolus. 3rdly. The Gregarine, which are con-
stricted at the middle, also correspond most probably with a
single cell of a peculiar kind. 4thly. There is no reason what-
ever for supposing that the Gregarine are not perfect animals.
These four assertions have been questioned by various authors
since that time. C. Bruch, in ‘Sieb. and KOll.,’ vol. 1, p.
110, opposed the last-mentioned assertion of Kolliker, and
was inclined to regard the Gregarine as Filariz in a quiescent
state. Dr. F. Leydig, in Miiller’s ‘ Archiv’ for 1851, brought
forward what was apparently very strong evidence in favour
of Bruch’s theory, having seen the successive development
of a simple quiescent Gregarina into an active vermiform
creature, which he considered as a nematode. Kolliker,
however, replied to this that he regarded the form de-
scribed by Leydig as an Infusorium allied to Opalina or
Proteus. It appears from the researches of M. Claparéde
and others, within the last few years, that some of the uni-
locular forms of Gregarine do present very curious, elongated,
and active forms, which from their movements and general
appearance might be mistaken for nematodes. Dr. Joseph
Leidy has in the ‘ Transactions of the Philadelphia Soeiety,’*
denied the fact that the Gregarine are unicellular animals,
upon the following grounds. In the examinations of some
new species of Gregarinz which he has described, and also
in the Gregarina Blattarum of Siebold, he discovered that
the membrane enclosing the granular mass of the posterior
sac was double. He observes, “‘ Within the parietal tunic of
the posterior sac is a second membrane, which is transparent,
colourless, and marked by a most beautiful set of exceedingly
regular parallel longitudinal lines, which in G. Juli. mar-
ginati measure the ,,!,,rd of an inch apart; in G. Blatte
orientalis the =;)5,th of an inch; and in G. Passali
cornuti the = ',,,th of an inch. This tunic has entirely
escaped the notice of all previous observers, and I can account
for the circumstance in no other way than by supposing it
has arisen from the inferiority of the microscope made by
European continental artists. The lines or markings are
easily observed without any other than the ordinary arrange-
ments for light by + of an inch, but better the +1, of an inch,
focal power of the instrument of Messrs. Powell and Lealand.
Of course, if the existence of this second tunic be confirmed,
and I have seen it too frequently and plainly to think I have
* «Trans. of Phil. Society,’ 1853.

86 E. RAY LANKESTER, ON GREGARINID&.

been deceived, the idea of the Gregarina being a simple
organic cell is at once exploded.”

I have carefully examined the Gregarina Blattarum with
Powell’s 1, and Smith and Beck’s +, and have been able thus
far to confirm Dr. Leidy’s observations. In the intestine of
the Blatia orientalis I met with the Gregarine in some
numbers, presenting to the unassisted eye the appearance of
semi-transparent whitish globules; when placed under the
microscope and subjected to slight pressure the sacs appeared,
containing but few granules, most having escaped through
the rupture of the membrane. This was seen to be double,
consisting of a transparent external tunic, through which the
striz on the internal coat were distinctly seen (fig. 20). This
internal striped tunic appears not to extend to the an-
terior or cephalic sac, which is entirely without structure,
and formed only by the external membrane.

The contents of the sacs were minute, ovoid granules,
transparent, and presenting, en masse, a slightly yellowish
colour. The anterior sac generally contains a less number of
these granules ; it is not contractile, as the posterior sac, and
is more easily ruptured. This latter fact may be attributed
to the absence of the striated tunic. In fig. 13, the striated
appearance of the inner tunic is represented, the lines are
nearly the =,5);,,th of an inch apart. Figs. 9, 10, 11, are
various forms of the Gregarina Blattarum which I have met
with. In fig. 18, the nucleus is drawn as it appears when
extruded from the posterior sac. Occasionally there are two
such bodies lodged in the granular mass. The partition
which divides the anterior from the posterior sac is structure-
less, and is probably an inversion of the external membrane.
All communication between the anterior and posterior sacs is
cut off by this membrane.

In the ‘ Mémoires de Académie Royale de Bruxelles’ for
the year 1854, an elaborate and beautiful paper, by M.
Lieberkiihn, copiously illustrated, appeared, describing his re-
searches on the Gregarine of the earthworm. The author does
not express any very decided opinion upon the two questions
which have been discussed by Leidy and Bruch; but devotes
the principal part of his memoir to the development and re-
production of the Gregarine. He, however, mentions that
he has seen longitudinal striations on the membrane of some
forms, and figures them, but is uncertain as to whether
they are structural, or due only to contraction. With regard
to the development of Gregarine into filaria-like worms,
which Bruch, who made his observations chiefly on the Gre-
gerina Lumbrici, thought probable, M. Lieberkitihn says but

E. RAY LANKESTER, ON GREGARINIDE. 87

little, but, nevertheless, has proved beyond doubt that the
nematodes of the earthworm are developed from eggs, whence
they emerge, not as Gregarie, but as true nematodes.
The transformation of two Gregarine, after a process of en-
cystation, into navicula-like bodies, has already been described
by Bruch; but Lieberkthn has more fully illustrated the
changes which go on, and has endeavoured to trace the
existence of the Pseudo-navicule after they have been expelled
from the cyst. In the perivisceral cavity of the earthworm
he found Jarge numbers of small corpuscles, exhibiting
Ameeba-like movements and likewise Pseudo-navicule, con-
taining granules, formed from encysted Gregarine. He
imagines that these latter bodies burst, and that their con-
tained granules develope into the Ameebiform bodies which
subsequently become Gregarine. In the same year* M.
Lieberkiihn published another paper, describing his further
researches among the psorosperms of fish, in which he adopts
the same view, that the Amcebiform corpuscles of the blood
of fish are Gregarine. Few physiologists will feel disposed to
agree with M. Lieberkiihn, in considering these bodies as
parasites. Dr. Williams, of Swansea,t has described a great
variety of forms, from Mollusca, Crustacea, and Annelida,
remarking that they are characteristic of the fluids of inverte-
brata. M. Milne Edwards, in his ‘ Legon sur Physiologie,’
speaking of the white corpuscles of the blood, makes the
following remarks upon Lieberkiihn’s proposition :— Enfin
M. Lieberkiihn qui vient de faire une étude attentive de ces
corps, croit méme de voir les considérer comme étant des ani-
malcules parasites et les assimiler aux Amibes, petits infusoires
dont Vintestin de divers animaux est parfois infesté; mais les
arguments en faveur de cet opinion ne me paraissent pas assez
solides, pourque dans |’état de la science, on puisse l’adopter ;
et lors méme que quelques uns de ces corps seraient réellement
de la nature des animaux sarcodaires,il ne faudrait pas conclure
que tous les corpuscles incolores et granules du sang sont des
parasites, car il parait evident, comme nous le verrons par
suite, que ce sont en générale, bien réellement des produits
de Vorganisme” (pp. 73, 74, vol. i). Also further on, in
speaking of these “ corpuscles de plasme”’ in invertebrata, he
adds, “Ce phénoméne remarquable a été fort bien observé par
M.Wharton Jones, aussi que par M. Williams, et par quelques
autres physiologistes * * * * et il est si frequent ici
que je ne saurais l’attribuer 4 l’existence d’Amibes parasites
comme le fait M. Lieberkiihn” (p. 103, vol. i). The
* Miiller’s ‘ Archiv,’ 1854.
T ‘Proc. Royal Soc.,’ 1852.

88 E. RAY LANKESTER, ON GREGARINIDA.

Ameebiform bodies, then, described by Lieberkiithn cannot be
considered as the young stage of the Gregarina. It is possible,
however, as M. Milne Edwards has observed, that some of
these bodies, which are hardly distinguishable from the
true plasmic corpuscles, are developed from the Pseudo-na-
vicule. I have made careful examination of more than a
hundred worms for the purpose of studying these questions,
but have succeeded in arriving at no other conclusion than
that certain forms of these corpuscles may be the products of
encysted Gregarine. The Gregarina Lumbrici (fig. 25) is one
of those forms which are unilocular, and are met with most
frequently among Annelids. It consists of a transparent
contractile sac (which has not hitherto been demonstrated to
be formed by more than a single membrane), enclosing the
characteristic granules and vesicle. The vesicle is not always
very distinct, and is sometimes altogether absent ; occasion-
ally it contains no granules, sometimes several, one of which
is generally nucleated (figs. 25, 26). The average length
is z4>th of an inch. Many varieties are met with in the
Lumbricus, but there appears to be no reason for considering
them as distinct species. In figs. 26,27, a rather uncommon
form is drawn. It is much smaller than that drawn in fig. 25,
measuring from z}5th to 45th of an inch in length, and is
provided with a number of motionless filaments; there are
few granules in the interior, but one of them is always nucle-
ated. Another form (fig. 28), which I have only met with
twice, contains the vesicle and granules, and is further sur-
rounded by a number of conical bodies which seem to
form a sort of envelope enclosing it. Lieberkthn, who has
seen both these forms, calls them ‘‘ Gregarines velues,” and
has observed them in the act of casting off this remark-
able covering. Frequently in the examination of the testis
of the Lumbricus, two Gregarine of the larger, well-developed
form may be seen enclosed in a transparent cyst, varying in
size from the 7;4,th to z4doth of an inch in diameter
(fig. .21). Occasionally a single individual appears in this
condition. In some of these cysts a number of nucleated
cells may be seen developing from the enclosed Gregarine,
which gradually become fused together and broken up, until
the entire mass is converted into these nucleated bodies, which
are then evident in different stages of development,
(figs. 22, 23), assuming the form of a double cone, like that
presented by some species of Diatomaceze, whence their name
Pseudo-navicule. At length the cyst contains nothing but
Pseudo-navicule, sometimes enclosing granules, which
gradually disappear (fig. 24). Finally the cyst bursts.

E. RAY LANKESTER, ON GREGARINIDZ. 89

This fact was denied by Stein,* who affirmed that the cysts
burst only upon being subjected to the action of water.
Lieberkiihn has, however, proved this statement to be
erroneous, having kept cysts taken from Lumbricus in
water for the space of five days, without any apparent change
taking place in their form or size. I have frequently seen
agglomerations of the Pseudo-navicule evidently in the same
position as they were when contained in the cyst, which had
itself entirely disappeared, probably by decomposition. On
escaping from the cyst, the Pseudo-navicule contain no gra-
nules (fig. 32); but the gelatinous fluid which they enclose
appears to concentrate itself, and give rise to certain minute
bodies, which, collecting towards the centre, form a nucleus-
like mass. A change then comes upon the form of the Pseudo-
navicula (figs. 29—31); it loses its symmetry, and becomes
faced’; the external membrane becomes atrophied (fig. 31),

‘commence a s ’atrophier,” and assumes an irregular shape.
j have not been able to trace the changes which these curious
bodies undergo any further. M. Lieberkiihn, as remarked
above, considers that the granules which they enclose are
liberated, and become the Amcelea-like bodies found in the
perivisceral fluid. In a note at the end of his memoir,
M. Lieberkiihn modifies his views with regard to the nature
of the corpuscles, and allows that they may, perhaps, be
analogous to those found in the perivisceral fluid of the
naiads; but still maintains that, at any rate, some of these
bodies are young Gregarina, an opinion in which my own
observations lead me to concur.

I have made repeated examinations of the Gregarina Blat-
tarum, in the hope that facts might be gained thence which
would throw additional light on the subject. Encystation
seems to take place much more rarely among the bilocular
forms of Gregarina than in the unilocular species found in the
earthworm and other Annelids. In fig. 17, a cyst is represented
enclosing two of the Gregarina Blattarum ; this is the only
instance of the kind which I have met with in the Blatta.
Stein figures certain bodies from the Blatta orientalis, which
he calls the Pseudo-navicule of G. Blattarum. I have not
met with these forms in my examination of the species.
The blood-corpuscles of the insect itself have an appearance
very similar to that which Stein figures. In fig. 14 are
represented three very minute forms, which are not un-
common in the ne of Blatta. They measure re-
spectively the +15,th,’ +/,,th, and ;,,th of an inch in
length, and, perhaps, may be the young of the Gregarina.

* Miiller’s ‘ Archiv,’ 1845.

90 E. RAY LANKESTER, ON GREGARINIDA.

The smallest of them is merely a cell containing granules
and a nucleus. In the second a septum is seen dividing the
cell into two halves. The third form has all the appearance
of a true Gregarina in a very young stage. Leidy has seen
such bodies in the intestine of Julus.

M. Ed. Claparéde, in his ‘ Recherches Anatomiques
sur les Annelides, Turbellaries,’ &c., describes several new
forms of Gregarina from three species of Annelida. The
most interesting of these is from the intestine of Capitella
capitata, It is unilocular, contains granules and a vesicle,
and has the form of an anchor; its length is ‘35 mm.
This species appears to have been seen by Leuckart, who -
named it G. sagittata.* In the intestine of a Phyllodoce,
M. Claparéde frequently met with a species of Gregarina,
striated longitudinally, somewhat fusiform in shape, and very
active; its length was ‘41mm. Some of these organisms
contained Pseudo-navicule ; other smaller forms were abun-
dant, which were not striated—probably the young of the
preceding. In the intestine of Pachydrillus semifuscus
another species was found; very minute, containing gra-
nules and a vesicle: its average length was ‘OS5mm. M.
Claparéde does not name these last two species, but in the
catalogue below I have given them specific names, in order to
complete the list.

In the intestine of Serpula contortuplicata I have met with
a species of Gregarina in some numbers (figs. 4—7). In its
general form it approaches the species described by M. Cla-
parede from the intestine of Phyllodoce; it is striated longi-
tudinally, contains a vesicle and very minute granules. The
average length is ,1,th inch; its movements are slow but con~
stant; in some specimens there was an anterior prolongation
of the sac-membrane, which, however, was not persistent. I
have given the specific name ‘‘ Serpule” to this species, as I
believe it has not before been described.

In the intestine of Aphrodite aculeata J have found an
elongated, fusiform Gregarina, of large size (figs. 1—3), con-
taining numerous granules and a clear vesicle. It measured
2; inch in length, and was provided with an elongated ap-
pendage one third the length of the body, the extremity of
which was involuted and terminated by a circular protube-
rance. This is the only unilocular form of Gregarina which
at present has been found provided with a proboscis; it is
interesting, too, inasmuch as the existence of two membranes
composing the sac is evident. The external one envelopes
the whole animal, and forms the involutions at the extremity

* Wiegman’s ‘ Archiv,’ 1861, Bericht, &., for 1859.

E. RAY LANKESTER, ON GREGARINID&. 91

of the proboscis (fig. 2 a). Within this the second membrane
ean be plainly observed, enclosing the granular mass, and
extending within the proboscidiform appendage, but not in-
voluted as is the external membrane (fig. 2 6). In some va-
rieties this second tunic is still more evident, being contracted
within the external membrane, and exhibiting striations
(fig. 3). In the list appended to this paper, I have named
this species after the annelid which it inhabits.

In various species of Sabella, I have met with many uni-
locular Gregarinide of an elongated form, measuring from
oath to —2,,th of an inch in length (fig. 15,16). This species,
which I propose to call Monocystis Sabelle, differs considerably
from that found in Serpulee, being much longer in proportion
to its breadth, and attenuated at one extremity. There are
but few granules in the sac, and very indistinct striations on
the surface ; a well-defined vesicle, generally without any con-
tents, is always present. The species of Sabella I examined
were S. alveolata, (Amphitrite) bombyx, inpendiculum ; but the
Gregarinze appear to belong to one species, and present no
difference in structure or form.

On account of the great mutability of form which is cha-
racteristic of the Gregarinz, the attempt to divide them into
families, genera, and even species, is attended with consider-
able difficulty. In 1838,* Dr. Hammerschmidt placed certain
new forms of Gregarina in four genera, Clepsidrina, Rhizinia,
Pyxinia, and Bullulina, scarcely assigning his reasons for so
doing. Kdlliker did not make any division of the species he
described, but left them all im Dufour’s genus Gregarina. In
1845, Dr. F. Stem, believing Hammerschmidt’s genera to be
entirely unsatisfactory, proposed the following classification
of the species then known, dividing them into three families
and seven genera, thus :

Family. Monocystidez ; unilocular Gregarine.
Genus. Monocystis ; animals living singly.
Genus. Zygocystis ; animals living in pairs.
Family. Gregarinariz ; body divided into two portions by
a septum.
Genus. Sporadina; single animals, without an ap-
pendage to the head.
Genus. Stylorhynchus; single animals, with a probo-
scidiform appendage to the head.
Genus. Actinocephalus; single animals, with an ap-
pendage to the head, furnished with hooks.

* ‘Isis von Oken, 18388, p. 356.

92 E. RAY LANKESTER, ON GREGARINID&.

Genus. Gregarina; two animals frequently hanging
together.
Family. Didymophyidez ; body divided into three parts by
two septa.
Genus. Didymophyes ; characters of the family.

Of this classification Professor Greene* remarks—“ This,
however, is an arbitrary division, and if not erroneous, is
certainly premature.’ Certain of the genera proposed by
Stein are, without doubt, objectionable; thus, the genus
Zygocistis is based upon a habit of the species, namely, that
of adhering together, which is only occasional, and is com-
mon to all Gregarinz when about to become encysted. The
fact of certain Gregarinee being provided with anterior ap-
pendages is not sufficient to constitute a genus, inasmuch as
certain species which usually present the characters of the
genus Sporadina have occasionally been found with a well-
developed appendix to the cephalic sac. Similar objections
may be raised against the genera Actinocephalus and Gre-
garina. Dr. C. M. Diesing, in his ‘ Systema Helminthum,’t
has given a complete list of species known at that time, with
descriptions of some new species from Crustacea, and has
supplemented this by a further catalogue of species m the
‘ Sitzungsberichte der Academie der W issenschaften,? 1859.
The existence of a double membr ane, and its peculiar modifi-
cation into a prehensile or absorbent organ, certainly does ap-
pear to raise certain Gregarinz above the Protozoa; their true
position in the scale of nature is by no means yet satisfactorily
decided. He places the Gregarinidee among the Helmintha rhyn-
godea, considering the proboscidiform appendage with which
some Gregarine are furnished, as a suctorial apparatus. He
enumerates seventy-five species, but many of these require fur-
ther investigation before they can be admitted as distinct from
other forms with which they are associated. Dr. A. Schmidt,
in ‘ Abhandl. d. Senkenberg’schen Gesellschaft,’ i, 1854, has
described several varieties of Gregarinz from the earthworm.
Schultze, Cirsted, and others have described species of Gre-
garine ; reference to their works will be found in the biblio-
graphy at the end of this paper. In the following list of
species I have modified Stein’s classification, and suppressed
some of the species which appear to be mere varieties. I have
also given the names under which the species were originally
described, Diesing having attempted to alter them consider-

* © Manual of the Protozoa,’ p. 51.
T Leidy, loc. cit.
¢ Vol. ii, p. 6, &., Vindobone, 1851.

a

E. RAY LANKESTER, ON GREGARINID. 93

ably, without assigning any justification of such a procedure.
There appears to be no reasonable ground for objecting to
the separation of the unilocular forms from the rest of the
Gregarine. In addition to the absence of any septa dividing
them into distinct chambers, they differ so much from the
other Gregarinze in their general form and habit, that there
is, it will be allowed, sufficient pretext for placing them pro-
visionally in a distinct genus.

Ruyneopes Hetmintua. Diesing.

Protozoa symphyta, Stein.

Animals composed of a double membrane, enclosing minute
granules and a vesicle; frequently provided with a prehensile
or suctorial (?) appendage.

Genus, Monocystis, Stein. Unilocular.

Syn. Gregarina, Kolliker, Diesing, &c.
Zygocystis in part, Stein.

1. M. Lumbrici, Henle and Lieberkitihn. Lumbricus.

Syn. Zygocystis cometa, Stein.
Monocystis agilis, Stein.

* cristata, Schmidt.
zs magna, Schmidt.
e nematoides, Schmidt.

Pe porrecta, Schmidt.
Lumbrici olidi, Schmidt.
Gregari ina Lumbrici, Bruch.

2. M. Sipunculi, Kolliker. Sipunculus.
Syn. Zygocystis Sipunculi, Stein.

Holothurie, Schneider. Holothuria.
Senuridis, Koll. Sznuris.

ss

Syn. Zygocystis Senuridis, Stein.

. Enchytrei, Koll. Enchytreeus.

. Spionis, Koll. Spio.

. Terebelle, Koll. Terebella.

. Nemertis, Koll. Nemertis.

. Planarie, Schultze. Planaria.

. Pachydrilli, Claparéde. Pachydrillus.
. M. Phyllodoce, Claparéde. Phyllodoce.
12. M. pellucida, Koll. Nereis.

Syn. Greg. Nereidis, Leidy.

SSSSS8SSS

13. M. Serpule, Lankester. Serpula.

94

E. RAY LANKESTER, ON GREGARINID.

. M. Aphrodite, Lankester. Aphrodite.

. M. sagittata, Leuckart. Capitella.

. M. Clavelline, Koll. Clavellina.

. M. Sepie, Lieberkiihn. Sepia.

. M. Euazris, Menge. Euaxis.

. M. putanea (7), Lachmann. Gammarus.
. M. Sabelle, Lankester. Sabella.

Grecarina, Dufour, Bilocular.

Syn. Clepsidrina, Rhizinia, Pyzxinia, Bullulina, Hammer-

schmidt.

Sporadina, Actinocephalus, Stylorhynchus, Didymophyes,

Stein.
. curvata, Hammerschmidt. Cetonia.
. clavata, Koll. Ephemera.
Syn. Zygocystis Ephemera, V. Frantzius.
. Dytiscorum, V. Frant. Dytiscus.
. Reduvii, Stem. Reduvius.
. Jul, V. Frantz. Tulus.
Syn. G. Juli pusilli, Leidy.
G. Juli marginati, Leidy.
G. larvata, Diesing.
. Scolopendre, Koll. Scolopendra.
. ovata, Dufour. Gryllus, &e.

RMRRW AHN

. soror, Dufour. Phymata.
ovata, Dufour. Gryllus, Forficula.
. hyalocephala, Dufour. Tridactylus.
. oblonga, Dufour. Gryllus.
. Amare, Hammerschmidt. Amara.
tenuis, Hamm. Allecula.
Tipule, Hamm. Tipula.
elongata, V. Frantz. Crypticus.
Mystacidarum, V. Frantz. Mystacida.
Polydesmi, Leidy. Polydesmus.
Passali, Leidy. Passalus.
Achete, Leidy. Acheta.

Syn. G. oviceps, Diesing.
Scarabei, Leidy. Scarabzeus.
Melolonthe, Leidy. Melolontha.
. Psocorum, V. Siebold. Psocus.
. Blattarum, V. Siebold. Blatta.
Syn. G. Blatte, Leidy.

. caudata, V. Siebold. Sciara.
. Locuste, Leidy. Locusta.

Syv. G. fimbriata, Diesing.

AA ARAN RAARRARARRARARAARRA

. spherulosa, Dufour. Aidipoda and Gryllotalpa.

E. RAY LANKESTER, ON GREGARINIDE. 95

27. G. conica, Dufour. Coleoptera and Gryllus.
28. G. rubecula, Hammerschmidt. Dermestes.
29. G. acus, Stein. Carabus.

30. G.oligacantha, V. Siebold. Agrion.

Syn. G. Sieboldii, Koll.

31. G. Lucani, Stein. Lucanus.
Syy. G. obesa, Diesing.

32. G. longicollis, Stein. . Blaps.
Syn. G. Mortisage, Diesing.

33. G. Heerii, Koll. Phryganea.

Syn. S/ylorhynchus octacanthus, Frantz.
G. Frantziusiana, Diesing.

34. G. polymorpha, Hammerschmidt. Tenebrio.

Syy. Stylorhynchus ovalis, Stein.
G. cuneata, Stein.
35. G. Phallusie, Koll. Phallusia.
36. G. Balani, Koll. Balanus.
37. G. longissima, v. Siebold. Gammarus.
Syn. (?) G. diffluens, Diesing.
G. milliaria, Diesing.
(Actinocephalus) Stein.
G. putanea, Leuckatt.
G. Gammari, V. Siebold.
(Didymophyes), Stein.
38. G. conformis, Diesing. Cancer.
39. G. premorsa, Diesing. Platycarcinus.
40. G. paradoxa, Stem. Geotrupes.
Syn. G. echinorhynchus, Diesing.
Echinorhynchus, Stein.
41. G. brevirostris, Koll. Hydrophilus.
42. G. gigantea, Stein. Oryctes.

BiBLioGRAPHY.

Bruch, C. . . . .Siebold and Kolliker’s Zeitschrift, vol.
i, p. 110.

Claparede, Ed. . . Recherchés Anatomiques sur les Anné-
lides, Turbellariés, Opalines, et Gré-
garines. Bailliére, 1861.

Diesing, Dr. C. M. .1. Systema Helminthum, vol. ii, pp.
6—18, 552.

2. Sitzungsberichte der Kaiserlichen

Academie der Wissenchaften. Wien,
1859, p. 719.

96 E. RAY LANKESTER, ON GREGARINID.

Dufour, Leon. . .1. Annales des Sciences Naturelles,
tom. vill (Ist séries), tom. xii (Ist
séries), tom. vii (2nd séries).

2. Recherchés Anatomiques et Physio-
liques sur les Hemiptres, pl. ui, fig.
206.

Frantzius, Dr. A.von. 1. Observationes queedam de Gregarinis.
Berolini, 1846.

2. Wiegman’s Archiv, 1848, p. 188.

Hammerschmidt, Dr. Oken’s Isis, 1838, p. 351.

Hipple G30 . Miller’s Archiv, 1845, p. 369.

MRICS. iso . Virchow’s Archiv, vol. xvi, p. 188.

Kélliker, Dr. A. . 1. Schleiden und Nageli’s Zeitschrift
fiir wissensch. Botanik, vol. ii.
Zurich, 1845.

2. Siebold und Kolliker’s Zeitschrift fiir
wiss. Zoologie, vol. 1, 1848, p. 1.

Lachmann. . . .Verhandlung des naturh. Vereins der
pr. Rheinlande, vol. xvi, p. 33.

Leidy, Dr.T. . .1. Journal Acad. Philadelphia, 2 ser.
ii, 144.

2. Proc. Acad. Phil., viii (1856), p. 144.

Leuckart, Dr. Rud.. Wiegman’s Archiv, 1861, p. 263.

Leydig, Dr. F. . .Miiller’s Archiv, 1851, p. 221; also m
Quart. Journ. Mic. Soe. Lond., 1853,
p- 206.

Lieberkiihn, N. . «1. Miiller’s Archiv, 1854, p. 103.

2. Mémoires de l Acad. Roy. de Brux-

elles, 1854, p. 1.

Menge. . : . Wiegman’ s Archiv, Neha p- 82.

Cirsted und Referent —

Ramdohr . . . .Abhandlung iiber die Verdaungswerk-
gange der Insecten, 194, pl. XXil,
9, 10 (Greg. Reduvit).

Schmidt, Dr. Ad. .Abhandlung d. Senkenberg’schen Ge-
sellch., 1, p. 168, 1854.

Schneider . . . . Miiller’s Archiv, 1858, p. 325.

Siebold, Dr.C.Th.von. Neueste Schriften, Danzig, 1839, p. 58.

Stein, Dr. F.. . «1. Miller’s Archiv, 1848, p. 182.

2. Von Carus. Icon. Zootom., pl. 1.

Schulize . . . . Beitrage zur Naturg. d. Turbellarian,
Abth: aga lk? p. 70.

Reference may also be made to Greene’s ‘ Manual of Proto-
zoa, p. 51; ‘ Carpenter’s Microscope’ (2nd edition), p. 464 ;
Pritchard’s ‘ Infusoria’ (last edition), p. 262; Micrographical
Dictionary, article, “ Gregarina.”

a

97

On the Anatomy of Nerve-ripres and Cris, and the
Uutimate Distripution of Nerve-ripres. Three De-
monstrations delivered by Professor Lionrn 8S. Beats,
M.B., F.R.S., at King’s College, on January 16th, 23rd,
and 30th, 1863. Abstract and Remarks by G. V. Craccto,
M.D., of Naples.

Proressor Beate has been giving, in connection with his
course of Physiology at King’s College, several demonstra-
tions ‘On the Practical Use of the Microscope, and the
Structure of the Simple Tissues of the Human Body’ In
each lecture eleven microscopical specimens magnified from 20
to 700 diameters, and illustrative of the subject of the lecture,
have been passed round a class of nearly one hundred students
and medical gentlemen, and many most difficult points
relating to this very important branch of study have been
demonstrated and studiously discussed. We propose to give
a short account of the specimens illustrating three of the
most interesting of these demonstrations on the structure of
nerves and ganglia, and on the origin and termination of
nerve-fibres. Although we believe that many of the readers
of the ‘ Microscopical Journal’ are well acquainted with Dr.
Beale’s researches on the general anatomy of tissues, and
his views upon structure and growth, it seems to us to be
necessary, before proceeding to the description of the speci-
mens, to give a brief sketch of his views on the hystology of
the nervous system, which have resulted from other observa-~
tions made during the last three years.

Dr. Beale holds strongly to the opimion that the nerves,
in every case, are continuous in the nervous centres, with
the substance of the nerve or ganglion-cells, and, at the
periphery, with other small masses of germinal matter, com-
monly termed nuclei. He maintains that there are no true
ends to be demonstrated, and that nerves never shade off into
or become continuous with other tissues. Although often in
very close relation with the elements of other textures, the
nervous still exists as a distinct tissue. The nuclei or cor-
puscles above referred to are found in connection with all
nerves at their peripheral distribution. They are generally
oval, although they may sometimes exhibit the triangular or
other form, and they always constitute an essential part of
the nerves. Their number varies greatly, not only in the
nerves, which are distributed to the different parts of the

98 DR. BEALE, ON NERVE-FIBRES AND TISSUES.

same animal, but also in the nerves distributed to similar
parts in different animals. Besides, the nuclei are found
more numerously in the nerves at an early period of develop-
ment than in the fully developed nerves. For imstance, the
nerves distributed to the leg muscles of the frog contain
fewer nuclei than those which are distributed to the muscles
of the eye, tongue, or heart of the same animal. Again,
the nuclei contained in the nerves distributed to the
thigh muscles are far more numerous in mammalia, espe-
cially in the mouse, than in the frog. The general conclusion
which may be drawn from these facts is, that the nuclei con-
nected with the nerve-fibres at the periphery are the special
organs upon which depend the growth and multiplication of
the fibres, and most probably, through their influence, the
nerves are brought into relation with ‘the different tissues of
the body. It may be also inferred that, when a tissue is
supplied with numerous nuclei, its importance as a structure
or apparatus concerned in nervous action must be very great.

As Dr. Beale, by a careful examination of a great many
specimens, has never been able to find an end to the nerve-
fibres, either at their peripheric distribution or at their im-
plantation into nervous centres, he is strongly of the opinion
that the fibres proceeding from a central nerve-cell return to
the same cell, after a course more or less circuitous and
tortuous. They may be connected during their course with
other cells and fibres, but the circuit which they form is
considered by Dr. Beale to be complete ; so that every
nerve or ganglion-cell with the fibres which proceed from it
establishes and forms a nervous circuit. This circuit, however,
is not independent, but always in relation with the circuits
formed by the other cells. According to this view, it is
very probable that all nervous phenomena, either of motion
or sensation, are associated with the setting free of electric
or of some other current allied to it, and its conduction to
distant parts above the fibres. Chemical and _ physical
changes which take place in the germinal matter of the
nerve or ganglion-cells at the centre or periphery lead to the
production of the currents. The supposed currents must
always originate in, and start from, the germinal matter
alone ;—the nerve-fibres being, as agreed by all observers,
mere conducting fibres.

Dr. Beale’s views on the anatomy of nerve-structures and
organs and their action are opposed to the conclusions of
most of the German observers. And if their statements
respecting the existence of a polar or unipolar cells, and the
free termination of nerves, could have been proved true, Dr.

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4
.
‘

DR. BEALE, ON NERVE-FIBRES AND CELILS. 99

Beale’s views would not be tenable. But, Dr. Beale states,
that after very numerous observations upon the ganglia of
man and animals, especially those of the frogs, he is com-
pelled to conclude that neither apolar nor unipolar cells exist
anywhere, and that nerves never terminate in free ends in any
tissues.

All nerve or ganglion-cells are bipolar or multipolar. The
existence of cells with only one fibre is very doubtful, even in
the case of very young cells, for what seems to be only a single
fibre under a power of 250 or 300 diameters, is found to be
composed of two or more fibres when the highest powers are
used. Dr. Beale, in many cases in which, at the first ap-
pearance, the ganglion-cells seemed to be without any fibre
whatever, has been able to show several springing from
different parts of them. He has also demonstrated that the
so-called Remak’s fibres are true nerve-fibres ; and in affirm-
ing this he differs from most observers in the present day ;
for it is generally held that this kind of fibre is nothing else
than a modified form of connective tissue, an extension of
which is supposed to form the capsule of the ganglion-cell.
These fibres, as is shown in his specimens, contain a great
number of nuclei, and are continuous with the outer part of
the germinal matter of the ganglion-cell.

With regard to the termination of the nerves in voluntary
muscles, and especially in those of the mouse, Dr. Beale has
given the results of his investigations in a very valuable paper
read before the Royal Society in June, 1860. The conclu-
sions which he arrived at are as follows :

1st. That every elementary fibre of the striped musle of the
mouse is more or less abundantly supplied with nerves.

2nd. That the nerves terminate in a network outside the
sarcolemma.

3rd. That the nerve-fibres which form this network are
pale fibres abundantly nucleated. They cross the muscular
fibre at short intervals in every part, and often at right angles.

4th. That these pale fibre are directly continuous with the
dark-bordered fibres.

Since the publication of Dr. Beale’s paper, Kiihne and
Kolliker have studied the subject, and the conclusions which
they have. arrived at are quite inconsistent with those of
Dr. Beale.

Kiihne states that he has observed the thin breast muscle
of the frog, and found that the pale nerve-fibre, at one point,
penetrates the muscular fibre, and divides beneath the sarco-
lemma into two or more fine fibres, which terminate in peculiar
oval bodies, considered by him as special organs. He further

VOL, I1I,.—NEW SER, H

100 DR. BEALE, ON NERVE-FIBRES AND CELLS.

says that, in the muscles of the leg of Hydrophilus piceus, the
axis cylinder, after passing through the sarcolemma, is lost
amongst granular matter, but is probably connected with the
rows of granules, or nuclei, which extend throughout the
length of each elementary muscular fibre. Through these
nuclei it comes into close relation with the sarcous substance
of the fibre.

Kolliker, on the other hand, after examining the same
muscle of the breast of the frog, has arrived at a different
conclusion. He quite failed to see the special oval bodies as
described by Kiihne, but saw the nuclei connected with the
fibres ; and he states that the nerve-fibres never pass through
the sarcolemma, but always lie outside it. So, far, therefore,
he agrees with Dr. Beale, but differs from him in asserting
that the nerves end in free extremities.

It was indispensably requisite for Dr. Beale, after these
statements of Kiihne and Kolliker, to study this same muscle.
The results of his observations were given in a memoir read
before the Royal Society on June 19th, 1862. According
to his observations the ultimate arrangement of the nerves
in the pectoral and other muscles of the frog is fundamentally
the same as that in the muscles of the mouse, the only dif-
ference being that the nerves in the frog are thinner, firmer,
and much less numerous than in the mouse. They form a
network outside the sarcolemma, the meshes of which are
very wide. The various nerve-fibres of this network are very
fine, and the nuclei are much less numerous than those of
the mouse; they are directly continuous with the dark-
bordered fibres, and result from their division and subdivision ;
but there are also to be traced some very fine fibres derived
from fine fibres ramifying in the sheath of the dark-bordered
fibres which have not previously been described by any ob-
server. He was also enabled to follow the fibres much
further from the point where Kihne and Kolliker make
them to end; the former in the special oval bodies, and the
latter in free extremities. It may also be added that the
finest nerve-fibres seen by him in the breast-muscle of the
frog are often not more than one third of the width of the
pale fibres of Kiihne beneath the sarcolemma; and even
these fine fibres are not single, but consist of at least two
fibres. By a careful examination of the ultimate distri-
bution of the nerves to the muscles of the leg of Hydrophilus
piceus, he came to the conclusion that the rows of nuclei
described and figured by Kiihne as belonging to the nerve-
fibres, are the proper nuclei of the muscular fibre itself. In
this insect, as is shown by a transverse section of the mus-

DR. BEALE, ON: NERVE-FIBRES AND CELLS. 101

cular fibre, the nuclei are seated in the substance of the con-
tractile substance. The nerve-fibres do not penetrate through
the sarcolemma, but always lie on the surface, where they
divide and subdivide, forming networks of very fine fibres,
many of which (although much finer than the fibres delineated
by Kine in his drawings) can be traced over several ele-
mentary muscular-fibres. It is most unsatisfactory, and, at the
same time, surprising to find that these three authorities in
microscopical anatomy have: been led by studying the same
object to conclusions so incompatible with each other. This,
however, occurs not unfrequently in all investigations of
natural things, and we believe that it arises from two causes.
The first, that the minds of individuals are differently consti-
tuted, so that when two observers investigate one object
they do not view it in the same manner; the second, that
the same object prepared in various ways exhibits under
microscopical examination different appearances. To the
latter, rather than to the former cause, we are inclined to
ascribe the different conclusions arrived at in the present
instance; and we believe that had the observers examined
one object always under the same conditions we should
not have to complain of so many terrible discrepancics
which at present complicate histology. It is of great im-
portance in microscopical investigations to prepare the object
in such a way, that while we are endeavouring to find out
the structure and render the appearances distinct, so as to
demonstrate them to others, we should preserve, as far as
possible, their natural appearances. With regard to the ex-
amination of the ultimate arrangement of nerves in different
parts of the body, we think that Dr. Beale’s method of pre-
paring is one of the best, for it alters, as little as possible,
the delicate structure of nerves at their termination. We
have had many opportunities of using this method, and
always with great success. We, therefore, highly reeommend
it to those who are engaged in this kind of research; and
it should be borne in mind that in preparing all the tissues
of vertebrate animals, Dr. Beale employs the same method.
Not only so, but the appearances described by him in many
of the lower plants and animals, were observed in specimens
prepared by the same general plan.

We shall now proceed to describe briefly the principal and
most interesting specimens which were sent round during
the lectures. Every specimen has been carefully examined by
us, and we feel convinced that the description given is sup-
ported by irrefragable facts.

Prep. 1.—Bundle of pale, gray, or gelatinous fibres with

102 DR. BEALE, ON NERVE-FIBRES AND CELLS.

ganglion-cells, from the pericardium of the ox. Each ganglion-
cell is seen to be connected with several fibres. The bundle
does not contain any nerve-fibre with the white substance of
Schwann. The specimen shows evidently that the so-called
Remak’s fibres are true nerve-fibres, and the structure, which
has been described as the connective tissue capsule of the
ganglion-cell, consists only of true nerve-fibres. If we
accept the opinion entertained by some German observers,
that Remak’s fibres are nothing but fibres of connective
tissue, we are compelled to admit that there are ganglion-
cells imbedded in connective tissue with no connection what-
ever with nerve-fibres. In which case the physiological sig-
nificance of these cells would be inexplicable. x 215.

Prep. 2.—Large ganglion with several cells form the cord of
the leech. Some of the cells are larger than others. Bundles
of fibres are seen proceeding from the ganglion in six different
directions. Some fibres, which spring from its upper and
lower part, are observed in connection with those which arise
from the sides. Some other fibres pass downwards through
the ganglion without beg connected with it. The ganglion
is seen to be composed of several parcels of cells which are
connected together by strands of fibres. The connections
between the different cells are very numerous. x 215.

Prep. 3 and 4.—Are two beautiful specimens which plainly
show the origin of two fibres from the so-called unipolar
ganglion-cells from the frog. The finest of the nucleated
fibres is seen passing spirally round the other. This arrange-
ment has not been previously described. Dr. Beale is en-
gaged upon a memoir on this subject. x 215, 500.

Prep. 5.—Shows several ganglion-cells, each of which is
connected with a dark-bordered fibre. The second very fine
fibre is not visible in this specimen. From the posterior root
of spinal nerves of a frog. x 1380.

Prep. 6.—Very large ganglion from the posterior root of
spinal nerves of the mouse. The nerve-fibres of the anterior
and posterior root pass through the ganglion and mix
together. Every cell is seen to be connected with many
fibres which pass off in different directions. x 40.

Prep. 7.—Two ganglion-cells with nerve-fibres from the
superior cervical ganglion of the sympathetic of man. The
nerve-fibres connected with these ganglion-cells are seen
largely supplied with nuclei. x 215.

Prep. 8.—A very small ganglion from the tongue of a
mouse. It appears to be composed of about twelve cells.
Nucleated nerve-fibres proceed from the ganglion in four
different directions. x 700.

DR. BEALE, ON NERVE-FIBRES AND CELLS. 103

Prep. 9.—Shows bundles of nerve-fibres connected with
ganglion-cells near the origin of the aorta. From man. x 130.

Prep. 10.—Large ganglion-cells, from each of which two
fibres proceed, with bundles of nerve-fibres near the iliac
artery of a frog. Some fibres are seen passing over the
artery. x 130.

Prep. 11.—TIliac artery, with nerves and ganglion-cells in
its outer coat. From the frog. Some very fine nerve-fibres
are seen ramifying in the muscular coat of the artery. 215.

Prep. 12.—This beautiful specimen shows arteries, pigment-
cells, nerves, and ganglia near the kidney. The different
nerve-fibres arising from the ganglion-cells are seen to con-
tain numerous nuclei. x 215.

Prep. 13.—Some nerve-fibres from the pig’s snout, show-
ing individual tubular nerve-fibres, separated from their
neurilemma. Some fibres much finer than others. The
medullary sheath of the nerve-fibres is clearly visible. x 40.

Prep. 14.—Some other individual nerve-fibres from the
same animal. The specimen most distinctly demonstrates
the white substance, the axis cylinder, and the nuclei of the
primitive nerve-fibres. Some of the nuclei, which at first
seem to belong to the so-called tubular membrane, after a
more accurate examination, are undoubtedly proved to be the
proper nuclei of fine nerve-fibres ramifying in the sheath.
x 130.

Prep. 15.—A bundle of very fine nerve-fibres imbedded in
connective tissue of frog. x 130.

Prep. 16.—Is a section through a large nerve of pig’s
snout, and demonstrates that nerve-trunks are made up of
several bundles of nerve-fibres joined together by connective
tissue; the nerve-fibres forming a bundle, and the various
bundles also are of different sizes. The neurilemma and the
capillary vessels for the nutrition of the nerve are distinctly
seen in this specimen. x 40.

Prep. 17.—Median nerve of a foetus at the sixth month.
Capillaries injected with carmine solution. Numerous nuclei
are seen in connection with the dark-bordered fibres, and
many vessels also, running over and amongst the connective
tissue of the nerve. This specimen proves that the nuclei
and vessels are more numerous in nerve-tissue during the
development than when the development has been completed,
as is the case in all tissues of all animals. x 215.

Prep. 18.—Bundles of very fine dark-bordered fibres from
the submucous tissue of the palate of a frog. The bundles,
after dividing and subdividing, form a network, the fibres of
which are compound, and are themselves composed of nume-

104. DR. BEALE, ON NERVE-FIBRES AND CELLS.

rous very fine fibres. Vessels injected with Prussian blue.
x 215.

Prep. 19.—Shows the manner in which the dark-bordered
nerve-fibres branch on the surface of the elementary fibres of
muscles. Some fibres are seen dividing dichotomously, and
others into three or four branches. x 215.

Prep. 20.—A Pacinian corpuscle from the mesentery of a
cat, showing the pale nerve-fibre at the centre. x 130.

Prep. 21.—Small piece of the skin of a frog, showing some
large bundles of nerve-fibres ramifying upon its under sur-
face. x 130.

Prep. 22.—Shows a small artery with bundles of nerve-
fibres in the skin of the frog. The network formed by the
different bundles is clearly seen. x 215.

Prep. 23.—Skin of the mouse, showing hair-bulbs, sebaceous
glands, connective-tissue-corpuscles, and nerve-fibres. The
coarse nervous network, and the fine network around the
hair-bulbs are plainly demonstrated. x 215.

Prep. 24.—Shows nerve-fibres and capillaries, with their
nuclei distributed to the peritoneum of the frog. The net-
work formed by the different bundles of nerve-fibres is dis-
tinctly seen. x 130.

Prep. 25.—Another specimen from the peritoneum of the
frog, showing a bundle of fine nerve-fibres, with one dark-
bordered fibre, which divides. The dark-bordered fibre is
observed continuing onward as a bundle of very fine fibres.
Here are no separate pale fibres. Capillaries injected blue.
x 215.

Prep. 26.—Shows the ultimate distribution of the nerves
to the cornea of the frog. Not one dark-bordered fibre can
be observed. The nerves, after dividmg and subdividing,
form a network of very fine fibres. The relation of the nerve-
fibres to the cornea-corpuscles is clearly shown. The nerve-
fibres always maintain their individuality at the periphery,
and never lose themselvesin the corneal-corpuscles or any other
tissue. x 215.

Prep. 27._Shows several bundles of very fine, pale fibres,
distributed to the bladder of the frog. The bundles are seen
repeatedly dividing, and at last forming a network which lies
on different planes. Bundles of muscular fibre-cells are also
observed interlacing with one another. Some of the nuclei
of the muscular fibre-cells exhibit a triangular form, and the
contractile tissue passes off in three directions. x 550.

Prep. 28.—Another specimen from the bladder of the frog,
showing the termination of the dark-bordered nerve-fibres
in very fine fibres, which form a network which ramifies

ie 4

DR. BEALE, ON NERVE-FIBRES AND CELLS. 105

in every part of the mucous membrane, and amongst the
bundles of the muscular fibre-cells. x 700.

Prep. 29.—Ultimate distribution of the nerves to the
muscles of the leg of Hydrophilus piceus. In the specimen
some very fine bundles of nerve-fibres are observed crossing
in different ways the muscular fibres, and passing from one
fibre to others. The nerve-fibres of each bundle frequently
join together, and form a very fine network over the sarco-
lemma. No connection can be demonstrated between the
rows of nuclei in the contractile tissue and the nerve-fibres.
The direction of the rows of nuclei is parallel to that of mus-
cular fibres, while the nerve-fibres cross the muscular fibres
either obliquely or transversely. It is beyond all doubt that
the rows of nuclei delineated by Kiihne, and stated by him
to be connected with the terminal nerve-fibres, are nothing
but the nuclei of the muscular fibre itself, which are imbedded
in the contractile substance, and which take part in its for-
mation. x 700.

Prep. 30.—Muscular fibres from the human heart. The
nuclei, surrounded by granular matter, are seen in the centre
of the fibres. The mode of growth of muscular fibre from the
centre to the circumference is clearly demonstrated. Nerve-
fibres and vessels, with their nuclei, may be also observed.
We must recall to mind that in insects many muscles have
central nuclei. x 130.

Prep. 31.—Shows the ultimate distribution of nerves to
the cutaneous breast muscle of the frog. Several fine bundles
of nerve-fibres are seen passing in different directions over
the muscular fibres, and forming, after dividing and subdi-
viding, a network with large meshes. Some of the muscular
fibres, being in a state of contraction, prove conclusively that
the nerve-fibres do not pass through the sarcolemma. Not
one of the oval bodies described by Kiihne as the peculiar
organs in which every nerve-fibre ends beneath the sarco-
lemma can be seen. Only some nuclei are seen in connection
with the nerve-fibre of the network. The termination of the
nerve-fibres in free extremities, as has been stated by Kolliker,
is also not observed. We must, however, say that some very
fine nerve-fibres, after having been traced over the muscular
fibres for a great distance, are at last lost sight of; but these
may be followed for much greater distance from the dark-
bordered fibre than the point at which Kdlliker’s fibres ter-
minate. x 700.

106

On the Anatomy of the Nervous System in the LumsBrRicus
TERRESTRIS. By James Rorig, M.D.

Ur to avery recent date, anatomists have generally re-
garded the nervous system of the Insecta, Mollusca, and
Annulosa, as consisting of a structure essentially different in
its microscopical characters from that of man and the higher
mammalia generally. The nerve centres of these animals,
for instance, have usually been considered as composed of
unipolar cells, from which minute fibres arise and pass di-
rectly to the muscles and organs supplied. That such an
arrangement is the correct one has, however, now been called
in question, not only on anatomical but also on physiological
grounds ; for if we admit that these nerve-cells are unipolar,
then we must also admit that each cell is a separate nerve
centre having no connection or relation withits neighbouring
cells. This view, while opposed to all analogy, will be shown
by the following notes to be equally opposed to correct obser-
yation. It is not, however, to be wondered at, that such a
view should have been so generally received. On examining
the nervous system, particularly of the Insecta, the appear-
ance of unipolar cells is often presented, and it is only by very
careful management of the light that a correct knowledge of
the arrangement of the nerve-cells and nerve-fibres can be
arrived at. In the present paper I propose to consider the
anatomy of the nervous system of the common earth worm,
(lumbricus terrestris,) because it presents to our view a
nervous system of a very simple form, and especially because
on account of its small size and transparency the different
ganglia can be examined entire without our being obliged to
have recourse to sections.

General anatomy.—In the Lumbricus terrestris, the nervous
system may be considered as consisting of two parts, a supra-
cesophageal portion and a ventral or infra-cesophageal portion.

The former or supra-cesophageal portion consistsof two small
spheroidal ganglia, situated immediately over the mouth of the
animal, and connected together by ashort commissure. From
each of these ganglia a band of nerve-fibres pass downwards on
either side of the esophagus, and become attached to the first
of the ventral or infra-cesophageal chain. The only nerve given
off from this portionof thenervous system, is “a simple nervous
filament,” which, according to Brandt, “is continued from
the cesophageal ganglion along the dorsal aspect of the
alimentary canal,” and which is by Owen considtred to be

RORIE, ON LUMBRICUS TERRESTRIS. 107

the analogue of the great sympathetic and nervous vagus in
the higher forms of animal life. We will, however, again
refer to this question afterwards.

The infra-cesophageal or ventral portion of the nervous
system consists of a number of ganglia so closely connected,
that the appearance presented by this chain of gangha is
rather that of a flat knotted riband. The ganglia in this
chain correspond in number with the number of rings of
which the body of the animal is composed. They differ some-
what in size, becoming gradually smaller as we approach the
caudal extremity. The first of this chain of ganglia is conse-
quently the largest, and is triangular in shape. From each
of the ventral ganglia, two nerves pass off, one from either
side to supply the muscles, &c.

Microscopic anatomy.—On examining the nervous system
of the lumbricus terrestis microscopically, with a carefully
adjusted light and power of about 300 diameters, I found
that the ganglia above described presented each a slightly
different appearance and arrangement of the nerve-cells and
nerve-fibres. It will suffice, however, to arrange them under
three heads :—

1. Arrangement of the nerve-cells and nerve-fibres in the
ventral ganglia generally.

2. Their arrangement in the first or sub-cesophageal gan-
glion ; and

3. The microscopical anatomy of the supra-cesophageal
ganglia. -

1. Arrangement of the nerve-cells and fibres in the ventral
ganglia generally. On examining the fifth or sixth anglion
of the ventral chains, I found it present the followig appear-
ance :—my description of which, the accompanying sketch
(Pl. VIII, fig. 1), may assist in rendering more intelligible.
The nerve-cells were all multipolar, those towards the sides
of the ganglion being quadripolar, while those in the centre
frequently gave off five, or even six branches. They were dis-
tinctly nucleated, very transparent, and possessing but little
pigmentary deposit. The branches or nerve-fibres passing
off from the lateral or quadripolar cells had the following
arrangement: one passed inwards, and became continuous
with one of the branches given off by the central multipolar
cells; a second fibre passes upwards, and a third down-
wards or backwards, in the direction of the neighbouring
ganglia; while the fourth is given off along the branch of
distribution. In some of the ganglia a few fibres appeared
to pass through the ganglion towards the branches of dis-
tribution, without having any connection with the nerve-

108 RORIE, ON LUMBRICUS TERRESTRIS.

cells of that ganglion. This circumstance may account, in
some measure, for the gradually tapering appearance of the
whole chain.

2. Arrangement of the nerve-fibres and nerve-cells in the
first or sub-cesophageal ganglion. This ganglion, as I have
already stated, differs from the ventral ganglia generally in
being of a triangular rather than of a quadrilateral form.
It also differs in the nerve-cells not being so uniform in
their arrangement. The quadripolar cells appear to be in a
greater measure mixed up with those giving off more branches.
As in the other ganglia, so here also some fibres may be
seen passing through the ganglion without being connected
with its nerve-cells. A sketch of some of the cells and
fibres of this ganglion is given at fig. 2.

3. This microscopical anatomy of the supra-cesophageal
ganglia (fig. 3). The minute anatomy of this portion of the
nervous system differs to a considerable extent from that of
the other ganglia. Each ganglion, or to speak more correctly,
each hemisphere presents the appearance of being composed of
two layers of nervous matter, differing from each other not
only in colour, but also in microscopical character. The outer
layer is of a reddish-grey colour, contains a considerable
amount of pigmentary matters, and appears to be composed
of spheroidal apolar cells, between which may be seen more
or less granular matter. The inner layer, on the other hand,
contains but little pigment, is transparent, and composed
for the most part of multipolar cells. From these cells
branches may be traced as follows :—From the outer cells
fibres pass to form the ribbon-lke collar surrounding the
cesophagus, while, from the inner cells, fibres may be traced
passing between the two hemispheres, thus forming a distinct
commissure. Both classes of cells communicate freely
with each other by means of other fibres; and, in addition,
a few fibres are given off, which become lost in the granular
matter of the outer layer. In fig. 3, a nerve is seen arising
immediately from the cells of the transparent layer, and is,
in all probability, the nerve referred to by Brandt.

With regard to the manner in which the nerves terminate
at their periphery little is known. On the walls of the di-
gestive organs of many Insecta they may be seen dividing
and subdividing until they become lost to view, when exa-
mined with a power of 450 diameters.

Fig. 4 represents the appearance presented by one of the
ganglia of the mussel (Mytilus), from which a few fibres may
be seen, terminating in cells situated apparently in connection
with a few fibres of the adductor muscle ; but whether or not

WYMAN, ON THE FORMATION OF INFUSORIA. 109

these last-mentioned cells have any definite relation to the
muscular structure, I have as yet been unable to determine.

Having thus described the anatomy, general and micro-
scopical, of the nervous system of the Lumbricus, a question
very naturally arises—to what portion of the nervous system
in man and the higher mammalia is the above type of nervous
system analogous? The supra-cesophageal ganglia, both from
their position and structure, are evidently the analogues of
the cerebral hemispheres, but the ventral chain is not so easily
disposed of. Some anatomists regard it as being analogous
to the spinal cord, while others consider it as belonging to
the sympathetic system. It would be foreign, however, to the
present paper for me to enter at length into this question. I
may here, however, state my opinion, and reserve my reasons
for holding such an opinion for a future communication.

The supra-cesophageal ganglia I am inclined to regard as
analogous to the cerebrum of man and the higher mammalia
in a very rudimentary state, and with the spinal cord unde-
veloped. The ventral chain of ganglia I regard as belonging
to the sympathetic system; the lateral quadrepolar cells
beig the analogues of the lateral ganglia in man; the cen-
tral multipolar cells representing the central plexuses in the
human subject. The flat, ribbon-like collar surrounding the
cesophagus I believe to be the vagus nerve largely developed.
Viewing the supra-cesophageal ganglia as an undeveloped cere-
bro-spinal system, and the ventral chain as a well-developed
sympathetic system, and comparing these two portions of the
nervous apparatus as we ascend in the scale of animal life,
it will be found, as a rule, that as the cerebro-spinal system
increases in size and development, the ventral or sympathetic
system decreases in proportion.

Experiments on the Formation of Inrusorta in BorLep
Sotutions of Oreantc Marrer, enclosed in hermetically
sealed vessels, and supplied with pure air. By Jerrrizs
Wrman, M.D., Hersey Professor of Anatomy in Harvard
College.

(From ‘Silliman’s Journal.)

PastreuR in his admirable researches on fermentation has
brought forward experimental evidence to show that this
process depends upon the presence of minute organisms in
the fermenting fluid, and that the source of all such organisms

110 WYMAN, ON THE FORMATION OF INFUSORIA.

is the atmosphere. In support of this opinion he asserts, that
when a fluid containing organic matter in solution is put into
a flask and “ boiled two or three minutes,” and supplied only
with air which has been filtered by passing through a tube
heated to redness, and the flask is then hermetically sealed,
no fermentation takes place, no organisms are formed, and
that the contents remain indefinitely without change. But if
the same solution is exposed to the air in its ordinary condi-
tion it becomes filled with various living forms. Out of a
large number of experiments prepared in the manner above
described, he has not known one to give a different result
from that mentioned.* He further states that if the neck of
the flask is drawn out into a very slender curved tube of
several inches in length, the contents boiled, and then allowed
to cool without the end of the tube bemg closed, so that the
air enters at the ordinary temperature, and has free access to
the interior of the flask, even then no fermentation takes
place, and no organisms appear. His explanation of this is,
that the air which enters first, meets with the hot steam, and
the spores or organisms contained in it are killed, while those
which enter the tube later move more slowly, and are depo-
sited on the moist walls of it, without entermg the body of
the flask.+

In most of the experiments given below, the results have
been quite different, and living organisms have made their
appearance in some instances where even greater precautions
were taken than those mentioned by Pasteur. In order that
the reader may understand what precautions were taken, we
shall first describe the manner in which the experiments were
performed.

(1.) In some instances (as in Experiments | to 5, 7 to 11,
13 to 15, 29 and 30 inclusive) they were prepared as im fig. 1.
The materials of the infusion were put into a flask, and a
cork a, through which was passed a glass tube, drawn to a
neck at 6, was pushed deeply into the mouth of it. The space

* “ Paffirme avec la plus parfaite vérité que jamais il ne m’est arrivée
d’avoir une seule expérience disposée comme je viens de le dire, qui m’ait
donné un seul resultat douteux.”—Avznales des Sciences Naturelles, t. xvi,
iv™ serie, 1861, p. 33.

+ “Il semble que lair ordinaire rentrant avec force dans les premiers
moments doit arriver tout brut dans le ballon. Cela est vrais, mais il
rencontre un liquide encore voisin de la temperature d’ebullition. La rentrée
de l’air se fait en suite avec plus de lenteur et, lorsque le liquide est assez re-
froidé pour ne plus pouvoir enlever aux germes leur vitalité, la rentrée de
Pair est assez ralenti pour qu’il abandonne dans les courbures humides du col
toutes les poussieres capables d’agir sur les infusions, et d’y determiner des
productions organisées.”—Azn. des Sc. Nat., 1861, t. xvi, p. 60. ;

WYMAN, ON THE FORMATION OF INFUSORIA. If!

above the cork was filled with an adhesive cement d, composed
of resin, wax, and varnish. The glass tube was bent at a right

angle, and inserted into an iron tube e, and cemented there
with plaster of paris c. The iron tube was filled with wires f,
leaving only very narrow passage ways between them.*

(2.) Others (as in Exps. 6, 12, 16 to 24, and 21 to 23 inclu-
sive), were prepared as in fig. 2, in which the joining at a, fig.
1, is avoided, and the iron tube is cemented directly into the
mouth of the flask, the neck of which is drawn out at 4, to
render the sealing of it easy; otherwise, the conditions are the
same as in fig. l.

(3.) In other experiments (as in Exps. 24 to 28, and 24 to
28 inclusive), the flask, fig. 3, was sealed at the ordinary
temperature of the room, and submerged during the period of
the experiment in boiling water. This was the method fol-
lowed by Needham and Spallanzani, and has the merit of
eliminating all suspicions of error which might be supposed to
arise from some imperfections in the joinings.

Tn the first and second methods, the solution in the flask is
boiled, and at the same time the iron tube filled with wires is
heated to redness. While the contents are boiling, the steam
formed, expels the air from the flask; when the boiling has
continued long enough, the heat is withdrawn from beneath
the flask, and, as the steam condenses, the air again enters
through the iron tube, the red heat of which is kept up, so
that all organisms contained in the air are burned. In both
methods the flask is allowed to cool very slowly in order that
the entering air may be as long as possible in passing through
the iron tubes, and thus the destruction of its organic matter

-* An advantage in preparing the experiment in this way is, that the same
flask may be used many times,

112 WYMAN, ON THE FORMATION OF INFUSORIA.

ensured. When cold, the flasks are sealed at 0, figs. 1 and 2,
with the blowpipe.

In experiments 29 and 30, a glass tube filled with asbestos
and platinum sponge was used instead of the iron tube filled
with wires.

The time during which the infusions were boiled varied, as
will be seen by the records, from fifteen minutes to two
hours, and the amount of infusion used from one twentieth
to one thirtieth of the whole capacity of the flask, the object
being to have the materials exposed to as large a quantity of
air as possible.

In the account which follows, especial mention is made, in
most instances, of the time of the formation of the “ film.”
This is always the first indication which can be had, without
opening the flasks, that minute organisms are developed; it
is in fact made up entirely of them, as has been proved by
repeated examinations with the microscope. It may first be
detected in small patches, but soon covers the entire surface,
and if the flask is gently moved so as to cause the infusion
to change its position, the film adheres to the glass and is
left by the liquid. In a few of the experiments no such film
was formed.

After the flasks were prepared, they were suspended from
the walls of a sitting room near the ceiling, where they were
exposed to a temperature of between 70° and 80° Fahr.
throughout the day and nearly the same during the night.

Experiment 1.* (1)+ Feb. 3rd, 1862. <A few grains each
of sugar, gelatine and fine cut hay were introduced into a
flask of 500 c.c. capacity, 20 c.c. of water were added, and
the whole thoroughly boiled. A film formed on the surface
of the fluid on the eighth day, the flask was opened on the
ninth, and found to contain large numbers of Bacteriums.

Exp. 2. (1) Feb. 3rd. This was prepared in the same way
as the preceding, excepting that pepper was added to the solu-
tion. The flask was opened on the twenty-ninth day and
Bacteriums were found in great numbers.

Exp. 3. (1) Feb. 4th. A few grains of cheese, sugar and
gelatine were dissolved in 17 c.c. of water, filtered and boiled
in a flask of 500 c.c. capacity. A film formed on the nine-
teenth day, the flask was opened on the thirty-sixth, and
found to contain Bacteriums.

Exp. 4. (1) Feb. 4th. Twelve cubic centimetres of a solu-

* Tn the first seven experiments the time which the contents were boiled
is not stated, but it was in no instances less than fifteen minutes.

+ Tue figures in brackets following the number of the experiment indicate
which of the three modes of preparing the experiment was made use of.

WYMAN, ON THE FORMATION OF INFUSORIA. 113

tion like the preceding, with the addition of a small quantity
of pepper was boiled in a flask of 250 c.c. capacity. It was
opened on the twentieth day, but no living organisms were
found.

Exp. 5. (1) Feb. 5th. A solution of sugar, gelatine, and
cheese was boiled and filtered, and again boiled in the flask,
which was opened on the twenty-ninth day, and no organisms
detected.

Exp. 6. (2) Feb. 10th. A solution of gelatine and sugar to
which was added a few drops of urine and milk, were put
into a bolt-head, the tube of which had been drawn to a neck,
and after boiling, was hermetically sealed. The flask was
opened on the thirteenth day, and found to contain yeast
plants and some very slender filaments which appeared to be
of a vegetable nature.

Exp. 7. (1) Feb. 10th. Twenty cubic centimetres of a
solution like the preceding was boiled in a flask of 875 c.c.
capacity. A film formed on the eleventh day, and on the
thirtieth the flask was opened, and found to contain Vibrios
and Bacteriums.

Exp. 8. (1) Feb. 25th. A solution of sugar and gelatine
to which fragments of green leaves and flesh were added, was
boiled one hour and forty minutes. The flask was opened on
the fifteenth day, no organisms were found.

Exp. 9. (1) Feb. 25th. The same as the preceding, with-
out the addition of the flesh; this solution was boiled forty
minutes and opened on the third day; no organisms were
found.

Exp. 10. (1) March 6th. Three flasks, a, 5, c, were pre-
pared in the same way, each containing a solution of sugar
and gelatine to which was added a few drops of urine and
some fragments of muscle ; a and c were boiled thirty minutes
and 6 one hour. Air was supplied to a and d through a heated
tube and to c at the temperature of the room. A film formed
in a on the eleventh, and in ¢ on the twelfth day, and at a
later period in 6, They were all opened a few days after-
ward, and found to contain Bacteriums, Vibrios and ferment
cells.

Exp. 1]. (1) March 12th. An ounce of meat was sus-
pended in a flask of 850 c.c. capacity, with about 40 c.c. of
water in it. This was boiled twenty minutes, during which
time the meat was exposed to the steam in the flask. The
juice which dropped from the meat was coagulated in the
water beneath, and the meat itself was thoroughly cooked ;
on the second day the meat was covered with a gelatinous
exudation, and on the third a film was formed on the surface

114 WYMAN, ON THE FORMATION OF INFUSORIA.

of the water. The flask was opened on the fifth day, and
found to contain Vibrios, Bacteriums, and a few ferment cells.
The gelatinous exudation on the surface of the meat also
contained the same organisms, and appeared to be wholly
made up of them.

Exp. 12. (2) March 13th. The juice of an ounce of beef,
to which was added 10 c.c. of urine and 40 c.c. of water was
boiled twenty minutes in a bolt-head and hermetically sealed.
A film formed on the fourth, and the flask was opened on the
eleventh day, when there was a distinct rush of air outwards.
Large numbers of Bacteriums were found, also small spheri-
cal bodies with ciliary motions and oval bodies like Kolpoda,
containing what appeared to be Bacteriums; one of these
Kolpoda-like bodies moved with cilia.

Exp. 13. (1) March 15th. An ounce of beef was suspended
over water in a flask of 500 c.c. capacity and boiled twenty-
five minutes. The same changes took place as in the pre-
ceding experiment. The exudation appeared on the surface
of the meat, and the film on the water on the second day ;
on the fourth day the meat fell to pieces; the flask was
opened on the ninth day; Bacteriums were found in large
numbers, and there was a slight odour of putrefaction.

Exp. 14. (1) March 17th. Juice of beef and a few shreds
of beef were boiled in a flask of 300 c¢.c. capacity for twenty
seconds. A film was formed on the second day, and the flask
was opened on the eleventh day. Bacteriums existed in
abundance. ;

Exp. 15. (1) March 19th. Fifty cubic centimetres of beef
were boiled forty minutes in a flask of 800 c.c. capacity.
The film began to form on the second day, and the flask was
opened on the 24th. The film had disappeared, the fluid had
a nauseous odour, and the Bacteriums were diffused through
the whole mass instead of being mostly confined to the sur-
face as in the preceding experiments.

Expts. 16, 17, 18, 19. (2) March 20th. Were made with
juice of beef and water in flasks of 550 c.c. capacity ; 16 was
boiled fifteen minutes, the film formed on the second day, and
the flask was opened on the ninth. Vibrios were found in
abundance, of different lengths, some of them moving with
great rapidity. 17 was boiled thirty minutes, the film was
formed on the third, and the flask was opened on the ninth
day. Vibrios were found in great numbers, some of them
bending and extending themselves rapidly. Some minute
spherical bodies were also seen, having the kind of motion
which results from vibrating cilia, though none of these were
detected. Exp. 18 was boiled fifteen minutes, the fluid having

WYMAN, ON THE FORMATION OF INFUSORIA, 115

been previously filtered; the film formed on the third, and
the flask was opened on the eighth day ; the organisms found
were the same as in 17. Exp. 12 was boiled one hour, the
film formed on the second, and the flask was opened on the
twenty-fourth day. The infusion had a slightly putrid odour,
and contained Vibrios and Bacteriums.

Exp. 20. (2) March 22nd. The flask and the contents of
it were the same as in the experiments just described. The
solution was boiled fifteen minutes, the film formed on the
fifth, and the flask was opened on the thirty-first day. The
fluid had become of a dark reddish-brown colour, the film
had disappeared, and some of the shreds of the coagulated
albumen had become nearly black. Bacteriums were found
in large numbers, and the darker shreds seemed to be made
up of them.

Exp. 21. (2) March 27th. Beef juice was boiled forty
minutes, the flask was opened on the twenty-fifth day, and
found to contain Bacteriums.

Exp. 22. (2) April 2nd. Beef-juice and fragments of beef
were boiled fifteen minutes, and the air was introduced through
a much smaller tube. Bacteriums were found on the twentieth
day.

ig 23. (2) April 5th. Was prepared in the same way as
the preceding experiment. The film formed on the sixth day,
and the flask was opened on the seventeenth. The sealed
end was melted in the flame of a spirit lamp, when the gas
escaped with force. Bacteriums were found.

Expts. 24, 25, 26. (3) April 16th. Were all prepared in
the same way. The capacity of the flasks was 550 c.c.; the
contents were beef juice and water 17 c.c., urine 7 c.c. The
flasks were folded in a napkin, immersed in water, which was
gradually heated to the boiling point, and each then exposed
to it for thirty minutes. The film formed in 26 on the fourth
day, and in 24 and 25 on the fifth, and were all subsequently
found to contain Bacteriums.

Expts. 27, 28. (3) April 24th. Two flasks, each of 550
¢.c. capacity, and each containing about 20 c.c. of beef juice
and urine, were hermetically sealed at the temperature of the
room, wrapped in cloth, and exposed for two hours to boiling
water. The film formed on the fourth day, one of them was
opened on the fifth, and the other on the eleventh, and both
found to contain Bacteriums.

Expts. 29, 30. (1) February 17th. In both of these the
contents of the flasks were solutions of sugar and gelatine in
water, to which fragments of cabbage leaves were added.
The air was introduced through a Bohemian glass tube, filled

VOL. I1I.—NEW SER. I

116 WYMAN, ON THE FORMATION OF INFUSORIA.

with asbestos and platinum sponge, and heated to redness.
The materials were boiled thirty minutes. In 29 the film
was formed on the twenty-ninth, and the flask opened on
the thirty-ninth day. he solution was found to contain
Bacteriums and cells filled with them. In 30 the film was
formed on the seventh day, and Bacteriums were found on
the twenty-third, when there was a slight odour of putre-
faction.

Expts. 31, 32, 33. (2) March 24th. Thirty grains of sugar,
20 cc. of beef juice, 158 c.c. of water, were divided into
three parts, and each part put into a flask ‘of 550 c.c. capacity,

and boiled fifteen minutes. No film was formed in either of

them. 33 was opened on the thirtieth day; ferment cells
and some filaments of a doubtful vegetable appearance were
found. 382 was opened on the forty-second day, and found
to contain ferment cells in large numbers, in different stages
of cell multiplication; as in 32 there was an escape of gas.

Exp. 34. (3) March 27th. Juice of mutton, in a hermeti-
cally sealed flask, was boiled five minutes in a Papin’s digester,
under a pressure of two atmospheres. A film formed on the
fourth day. It was opened several days later, in the presence
of Prof. Gray, and found to contain Vibrios and Bacteriums,
some of them moving with great rapidity.

Exp. 35, (3) The same as the preceding, and boiled in
Papin’s digester ten minutes, and under the pressure of five
atmospheres. No film was formed. The flask was opened
on the forty-first day. Monads and Vibrios were found,
some of the latter moving across the field. No putrefaction ;
the solution had an alkaline taste.

Exp. 36. (3) March 28th. Beef juice was filtered and
boiled, as in the preceding experiment, fifteen mmutes, under
two atmospheres. Opened on the forty-first day, and no
evidence of life was found. When the end of the flask was
heated, previously to opening, it collapsed.

Exp. 37. (3) March 28th. The same as the preceding ;
boiled fifteen minutes, under five atmospheres. Opened on
the forty-first day, and no evidence of life was detected.

We have here a series of thirty-three experiments, pre-
pared in different ways, in which solutions of organic matter,
some of them previously filtered, having been boiled at the
ordinary pressure of the atmosphere for a length of time,
varying from fifteen minutes to two hours, and exposed to
air purified by heat. In four instances, viz., in expts. 4, 5,
8, 9, the contents of the flasks were unchanged at the time
they were opened; but in all of the rest, Bacteriums, Vibrios,
or other organisms appeared. In nearly every instance their

+

WYMAN, ON THE FORMATION OF INFUSORIA. ELT

presence was indicated, in the early stage of the experiments,
by the formation of a film, which took place in some on the
second, and in others not until the nineteenth day, and was
afterwards proved by a careful examination with the micro-
scope. Prof. Asa Gray witnessed the openings of some of
these flasks, and satisfied himself of the presence of Infusoria
in the contents. Vibrios, Bacteriums, and Spirillums wera
the most frequently found, and in addition to these, as in
expts. 10, 11, 12, 29, 31, 32, 33, either ferment cells, monads,
or Kolpoda-like bodies were seen, some of them having ciliary
movements. Those forms which were observed the most fre-
quently are among the lowest, if not the lowest of all known
organisms.

In many instances, a solution like that in the sealed flasks,
and boiled for the same length of time, was exposed to the
ordinary air of the room, in an open flask. Although the
same forms were found in the two, they appeared much more
rapidly in the open than in closed vessels, and the contents
of the former soon became putrid, while those of the others,
at the time of opening, were mostly not, and in a few in-
stances only slightly so.

We have, in addition, four experiments, viz., 34, 35, 36,
87, made under increased pressure,and sealed by the third
method; 34 and 36 were boiled five and ten minutes respect-
ively, under two atmospheres, and 35 and 387, under five
atmospheres for ten and fifteen minutes respectively. Evi-
dence of life, consisting of Monada and Vibrios, was found
in 84 and 35, but none in the others.

The result of the experiments here described is, that the
boiled solutions of organic matter made use of, exposed only to
air which has passed through tubes heated to redness, or en-
closed with air in hermetically sealed vessels, and exposed to
boiling water, became the seat of infusorial life.

The experiments which have been described, throw but
little light on the immediate source from which the organisms
in question have been derived. Those who reject the doctrine
of spontaneous generation in any of the forms in which it
has been brought forward, will ascribe them to spores con-
tained either in the air enclosed in the flask, or in the
materials of the solution. In support of this view it may be
asserted, that it has been proved by the microscopical investi-
gations of De Quatrefages, Robin, Pouchet, Pasteur and others,
that the air contains various kinds of organic matter, con-
sisting of minute fragments of dead animals and plants, also
the spores of cryptogamous plants; and certain other forms,

118 WYMAN, ON THE FORMATION OF INFUSORIA.

the appearance of which, as De Quatrefages says, suggests that
they are eggs.* We have made some examinations of our
own on this subject, but it would be unnecessary to give the
results in detail. We will simply state, that we have carefully
examined the dust deposited in attics, also that floating in
the air collected on plates of glass, covered with glycerine,
and have found in such dust, in addition to the débris of
animal and vegetable tissues, which last were by far in the
greatest abundance, the spores of Cryptogams, some closely
resembling those of Confervoid plants, and with them, but
much less frequently, what appeared to be the eggs of some
of the invertebrate animals, though we were unable to identify
them with those of any particular species. We have also
found grains of starch in both kinds of dust examined, to the
presence of which Pouchet was the first to call attention.
When compared with the whole quantity of dust examined,
or even with the whole quantity of organic matter, both eggs
and spores may be said to be of rare occurrence. We have
not in any instance detected dried animalcules which were
resuscitated by moisture, and when the dust has been mace-
rated in water, none have appeared unti! several days after-
wards, or until after a lapse of time, when they would ordinarily
appear in any organic solution.

Those who advocate the theory of spontaneous generation,
on the other hand, will doubtless find, in the experiments
here recorded, evidence in support of their views. While
they admit that spores and minute eggs are disseminated
through the air, they assert that no spores or eggs of any
kind have been actually proved by experiment to resist the
prolonged action of boiling water. As regards Vibrios, Bac-
teriums, Spirillums, &c., it has not yet been shown that
they have spores; their existence is simply inferred from
analogy. It is certain that Vibrios are killed by being im.
mersed in water, the temperature of which does not exceed
200° Fahr. We have found all motion, except the Brownian,
to cease even at 180° Fahr. We have also proved by several
experiments that the spores of common mould are killed,
both by being exposed to steam and by passing through the
heated tube used in the experiments described in this article.
If, on the one hand, it is urged that all organisms, in so far as
the early history of them is known, are derived from ova, and
therefore that from analogy, we must ascribe a similar origin
to these minute beings whose early history we do not know,

* See an abstract of Pasteur’s “ Researches on Spontaneous Generation,”
‘Am. Jour. Science and Art,’ vol. xxxii, ], 1861.

WYMAN, ON THE FORMATION OF INFUSORIA. 119

it may be urged with equal force, on the other hand, that all
ova and spores, in so far as we know anything about them,
are destroyed by prolonged boiling; therefore, from analogy
we are equally bound to infer that Vibrios, Bacteriums, &c.,
could not have been derived from ova, since these would all
have been destroyed by the conditions to which they have
been subjected. The argument from analogy is as strong in
the one case as in the other.

CamprincE, U.S.; Muy 9th, 1862.

TRANSLATIONS.

On the Structure of the Vatve in the DiaToMAcE®, as com-
pared with certain Siliceous Pellicles produced artificially
by the decomposition in moist air of Fluo-silicie Acid Gas ,
(Fluoride of Silictum.) By Prof. Max Scuvurtze.*

Tue following pages contain only an abstract of Professor
Schultze’s observations, which are too long to be given en-
tire. The subject appears to be one of considerable interest,
notwithstanding that, so far as the nature of the marking on
the Diatomacez is concerned, opinions may not, at the pre-
sent day, be so much divided in this country as the author
appears to think. —

On the addition of sulphuric acid to a mixture of pow-
dered fluor spar and sand, an immediate evolution of fluoride
of silicium takes place, as is evidenced by the white fumes.
This whiteness, as is well known, is produced by the presence
of minute particles of silex arising from the decomposition of
the fluoride on its coming in contact with the aqueous vapour
contained in the atmosphere. If a solid body be exposed to
these vapours, a portion of the silex will be deposited upon it
in the form of a fine, white powder, the quantity of which is
greater in proportion to the amount of aqueous vapour pre-
sent in the air. If the experiment is performed in a wide-
mouthed flask, in the neck of which a short tube of mois-
tened filtering paper has been placed, the siliceous deposit is
so abundant on the inner surface of the tube that its calibre
is soon, either entirely or partially, filled with a snow-like
mass. But even without the moist paper tube, a gradual
deposit is formed at the mouth of the flask, which, in the
course of a day or two, will usually be found occupied by a
plug of finely divided silex.

The peculiar microscopic character of the siliceous deposit

* €Verhandl. d. Naturhist. Vereins der preussisch. Rheinland u. West-
phal.,’ Jahr. xx, p. 1,

MAX SCHULTZE, ON THE DIATOM-VALVE. 121

thus produced was first pointed out to the author by Pro-
fessor Heintz, of Halle, some years ago. The silex is depo-
sited in the form of thin-walled vesicles, of various dimen-
sions and forms, as spherical, pyriform, or subcylindrical, and
usually filled with air, so that they float on the surface of
water. If some of the deposit be crushed between two
pieces of glass, and examined with a power of about 300
diameters, a marking will be perceived on the outer or convex
surface of many of the fragments of these vesicles similar to
that of many Diatomacez, such as Pleurosigma, Coscino-
discus, &c. Rounded elevations, more or less hexagonal at
the base, and more or less regularly arranged, cover the sur-
face of the siliceous pellicle, and not unfrequently this kind
of marking is so regular as to give the fragments exactly the
appearance of portions of diatomaceous valves.

This remarkable circumstance struck the author very
strongly, but the investigation of the subject was not pur-
sued until his attention was again awakened to it by the
appearance of a paper by H. Rose, “ On the Different Condi-
tions of Silicic Acid,’ in Poggendorff’s ‘ Annalen’ for 1860,
p-. 147, m which that chemist pointed out more fully than
had previously been done the difference between amorphous
and crystallized silex, with respect to their physical and
chemical properties.

In this paper especial stress was laid upon the difference
in the specific gravity of the two forms as a diagnostic
character between them, although the existence of such a
difference had been, to some extent, previously known.

In crystalline silex the sp. gr. is pretty constantly 2°6,
whilst in the amorphous form it never exceeds 2°3, and is
usually much under that, and even may not exceed 1°8.

Under the circumstances, therefore, it became a matter of
considerable interest to determine the specific gravity of the
silex deposited in the way above mentioned. The results of
three experiments made by the author at different times, to
determine this point, gave as the sp. gr. of this form of silex
—2°437, 2°61, 2°58, or a mean of 2°54.

The appearances presented under the microscope by the
siliceous pellicles were such as to suggest that they were due
possibly to crystallization. The minute elevations on the sur-
face, when viewed on the side, often appear sharply acuminate, so
as readily to convey the impression that they are formed by
minute crystals of silex ; and this impression is strengthened
at first sight by their sharply defined, hexagonal bases, when
viewed vertically. The circumstance, again, that these eleva-

122 MAX SCHULTZE, ON THE DIATOM-VALVE.

tions are sometimes rounded at the summit and circular at
the base, might be attributed to the accidental interference
of free hydrofluo-silicic acid, &e. But experiments to elimi-
nate the action of this agent showed that it had nothing to do
with the variety of appearance in the elevations.

The subject presented no less interest as regards the ex-
planation of the peculiar structure of the diatomaceous valve.
Most of the manifold species of these organisms are charac-
terised by the presence on their outer surface of certain
differences of relief, referable either to elevations or to de-
pressions disposed in rows. The opinions of microscopists
with respect to the nature of this marking are divided. Whilst
in the larger forms and those distinguished by their coarser
dots the appearance is manifestly due to the existence of
thinner spots in the valve, we cannot so easily explain the
cause of the so-termed striation or punctation in Pleurosigma
angulatum, and similar delicately marked forms. In these
it often seems as if the appearance were due to pyramidal
elevations, with hexagonal bases, and standing in regular rows,
exactly like those observed in the siliceous vesicles above
mentioned.

In any case, it seemed likely, since the marking just
noticed is observed to be essentially alike in many different
species of diatoms, that its ultimate cause were to be sought,
less, perhaps, in any organic formative process, than in the
deposition of silex under the same laws as those by which its
deposition in the other case is regulated. Were this ultimate
cause shown to be crystallization, the question would be
solved.

But in other cases, that the secretion of amorphous silex
also occurs in the diatoms is undeniable. The specific gravity
of the diatoms in the so-termed infusorial earth of Liine-
biirger-Haide has been determined by Graf. Shaafgotsch to
be 2:2, showing clearly that in this case the silex is in the
amorphous condition. But the diatoms in this deposit do
not belong to those characterised by the surface marking,
which, as has been hinted, might be referred to crystalli-
zation. They are fresh-water forms, whilst that kind of
‘marking is more especially peculiar to the marine diatoms in
general. It may- be supposed that the sea-water is favor-
able to the deposition of silex in the crystalline condition.
The author was induced, in consequence, to take considerable
pains to determine the sp. gr. of the marine diatoms, col-
lected together in considerable quantity, but in vain, owing
to the circumstance_that they are so abundantly mixed up

MAX SCHULTZE, ON THE DIATOM-VALVE. 123

with other siliceous bodies of clearly amorphous nature, such
as sponge-spicules, Polycystina, &c., as to render their sepa-
ration impossible.

But how is it that, according to Ehrenberg and others, the
diatom-valves do not possess double refraction, like crystallized
silex? In reply to this, it may be said that Hugo von
Mohl has lately asserted,* in opposition to previous state-
ments, that, with the very essential improvement in the
polarizing apparatus imtroduced by him, P. angulatum, with
its hexagonal spots, appears so distinctly doubly refractive, that
even the hexagons on the surface may be perceived with the
Nicol’s prism, and consequently upon a dark field.

It may be added that the artificial siliceous pellicles are
very distinctly doubly refractive. Thus, on this account,
there is nothing opposed to the explanation of the structure
of certain diatomaceous valves, as being due to crystallization
of the silex. And this supposition is materially supported
by the results of the experiments above related, with respect
to the specific gravity of the pellicles. These results are,
at any rate, compatible with the notion of a mixture of
erystallized and amorphous silex in those bodies.

But further investigation rendered the correctness of this
assumption in the highest degree doubtful, and it soon be-
came quite certain that neither in the artificial siliceous
pellicles nor in the diatom valves are the peculiar forms due
to a crystalline structure.

In the first place, it clearly appeared that the pellicles
in question are not, as it was at first supposed, pure silex.
It was manifest further that—(1). These pellicles contain a
constant quantity of fluorin or of fluoride of silicium. When
the latter was expelled bya red heat, the substance was found
at once to possess the low sp. gr. of amorphous silex. (2).
The phenomena of double refraction afforded by them are
not the same as those exhibited by rock crystal; that is to say,
not lke those presented in a body with a positive axis of
double refraction, but resembling what is seen in substances
with negative double refraction. (3). The appearances de-
seribed by H. von Mohl, and confirmed by Valentin, as being
due to double refraction, exhibited in certain diatoms, are
not phenomena due to double refraction at all, but are to be
referred to depolarization by refraction. They are no longer
visible when the valves are immersed in Canada balsam or
other medium possessing a similar refractive power to silex.

The author then proceeds to detail the methods by which

* Pogegendorfl’s ‘ Annalen,’ 1859, Bd. eviii, pp. 179—185; ‘ Botanische
Zeitung,’ 1858, p. 10.

124 MAX SCHULTZE, ON THE DIATOM-VALVE.

the chemical composition of the pellicles was determined by
Professor Landolt, for which we must refer to the original,
and goes on to discuss their doubly refractive property above
referred to. The existence of this property in them is readily
shown by means of the common polarizing apparatus, although
for the closer study of the phenomena it is necessary to em-
ploy H. von Mohl’s tluminating lens m connection with the
lower Nicol’s prism.

Owing to the great differences presented by these pellicles
as regards thickness, it is obvious that the phenomena of
double refraction will vary very much in distinctness. In the
thinnest, most delicate, and immeasurably fine pellicles, they
can searcely be perceived at all; whilst, on the other hand,
it increases in distinctness in proportion to the thickness.
The vesicles best fitted for examination in this regard are
those of a nearly spherical form, with thick walls, on whose
surface minute elevations are seen arranged in regular rows,
as shown in fig. 1 (Pl. VIII, 8). A hollow sphere of this kind
appears under a Nicol’s prism, as an illuminated ring on a
black ground; the width of the ring differing according to
the thickness of the wall. The ring is subdivided into four
quadrants by a black cross. It exhibits no colours. As re-
gards the elevations on the surface, it is obvious that those
situated in the centre of the sphere, and consequently whose
points are presented to the observer, exhibit no indication of
double refraction, whilst those at the periphery of the sphere,
nearer the light, possess the power of double refraction the
more distinctly the more nearly the direction of their axis
approaches the horizontal.

The author then proceeds at considerable length to com-
pare the phenomena of double refraction exhibited in the
artificial siliceous vesicles with what is observed in other sili-
ceous bodies or minerals, such as opal, hyalite, different va-
rieties of siliceous sinter, silicified woods, &c. The general
result at which he arrives is that, as regards structure and
optical property, there are two kinds of amorphous siliceous
minerals—l, those which are perfectly homogeneous, and
which exhibit no indication whatever of double refraction, of
which the precious opal is a good example; and, 2, those
whose structure presents a fine, concentric lamination, and
which form spherical or botryoidal masses. These exhibit
double refraction, which property is connected with the lami-
nated structure, and is always negative. To this class belong
hyalite, siliceous sinter, and other allied minerals.

The production of these phenomena, as the consequence of
the unequal tension of the different layers, is then very clearly

-

MAX SCHULTZE, ON THE DIATOM-VALVE. 125

explained by reference to experiments with unequally heated
or cooled glass-globules, starch, &c. The subject is also well
illustrated by an experiment with minute homogeneous glass-
globules, coated with successive layers of collodion, and which,
when immersed in Canada balsam, exhibit very distinctly,
under a Nicol’s prism, the property of negative double re-
fraction.

Returning now to the further consideration of the struc-
tural and sculptural conditions exhibited in the artificial
siliceous pellicles, and to the comparison of the latter with
the apparently similar markings on the diatomaceous scales,
Professor Schultze goes on to remark that the surface of the
bodies in question, when their formation has taken place
gradually and uninterruptedly, almost always presents minute,
more or less sharply acuminate elevations, disposed in regular
or irregular order.

The smaller they are the more regular usually is their
arrangement, instances of which will be seen in figs. 7, 8, 9,
which represent the appearance seen in these pellicles under
a magnifying power of 350 diameters. Viewed in front, these
preparations closely resemble the valve of Pleurosigma angu-
latum, as it appears under a power of 800 diameters with one
of Amici’s or Hartnack’s immersion-lenses. The most marked
difference is in fig. 9, which represents a side view, at the
borders of which the elevations are distinctly visible, an ap-
pearance which does not exist in the diatom in question. But
a still finer punctation, visible only under the highest powers,
may be observed in the thinner, artificial pellicles, so that a
series of test-objects for any lenses hitherto constructed might
be chosen from among them.

This finer kind of relief-sculpture, however, affords but
little insight into its nature. The only impression conveyed
by it is that the entire pellicle, or, at any rate, its outer sur-
face, is constituted of minute, closely contiguous spherules,
some of which are acuminate.

Far more instructive are the larger hemispherical or conical
elevations, which may frequently be seen, disposed with great
regularity, as in figs. 3, 5 ; sometimes intermixed with smaller
ones, either regularly or irregularly (fig. 10). These elevations
are either regularly or irregularly hexagonal at the base, or
even circular, as infig. 10. If the specimens be immersed in
water, with the summits of the elevations pointing upwards,
these appear as bright points in a dark field when the micro-
scope is focussed accurately upon them, the appearances pre-
sented varying, however, it is almost needless to say, accord-
ing to the focal distance at which the object is viewed, though

126 MAX SCHULTZE, ON THE DIATOM-VALVE.

all are reconcilable with the existence of conical, acuminate
elevations, such as are represented in the side view in fig. 9.
Another set of appearances may be illustrated by figs. 6 and
6 a, the latter being the profile view. These are found when
the elevations, instead of being pointed or acuminate, are
rounded and obtuse at the summit. The elevations in this
case, when viewed at the proper focal distance, are distin-
guished by their presenting one or more concentric rings.
The appearances presented in both cases—that is to say, in
the pointed or acuminate elevations, and in the rounded or
obtuse ones—are all explicable upon the assumption of their
being composed of superimposed Jamin, gradually diminish-
ing in size.

It is to be observed that, however constant is the occurrence
of these elevations on the outer surface of the vesicles, the
inner surface, more especially in the thicker-walled ones, is
always smooth and even.

What has been said above with respect to the structure of-
the siliceous vesicles suffices to afford a notion as to the
mode in which their gradual formation occurs; and repeated
observations leave no doubt that this takes place in the fol-
lowing way :—The first deposition of silex is in the form of
minute spherules or lenticular particles, which usually aggre-
gate themselves into pellicles, constituting, for the most part,
spherical or cylindrical vesicles, which, however, never, or at
any rate very rarely, appear to be entirely closed. The size of
these siliceous particles varies extremely, for reasons which
are not, in all cases, easily determined, but which have mani-
festly some relation to the rapidity w ith which the evolution
of the fluoride of silicium takes place. Fig. 4 represents a
transverse section of a portion of a vesicle “composed of the
larger kind of lenticular particles. These particles at first
project equally on both surfaces; but this condition is soon
altered, owing to the circumstance that the continued depo-
sition of silex does not go on uninterruptedly over the whole
outer surface, but only or chiefly on the elevations, which,
consequently, assume the form of convex lenses, which, as
they increase in size and interfere with each other, gradually
acquire hexagonal outlines. The pellicle, however, increases
in thickness internally as well, but on this aspect the deposi-
tion goes on uniformly over the surface, the consequence of
which is that the hollows are gradually filled up and the
elevations obliterated (fig. 3). It seems probable that this
internal thickening may go so far as wholly to obliterate the
cavity; and thus a solid spherule of silex is formed, pre-
senting, as above stated, the optical properties of hyalite ;

MAX SCHULTZE, ON THE DIATOM-VALVE. 127

though some of these solid spherules may also arise from
deposition on the outer surface of originally very minute
spherules.

Passing over the extremely various and often very deli-
cate structures detected by microscopic examination among
these siliceous bodies—all of which, moreover, are referable,
in one way or another, to the fundamental type above de-
scribed—the author proceeds to discuss the question of the
structural relation between these artificial pellicles and the
valves of diatoms, many of which exhibit in their markings
so close a resemblance.

The similarity between the finely marked diatom-valves
which exhibit three sets of lines—as, for mstance, in Pleuro-
sigma angulatum, &e.—with some of the similarly finely
marked artificial pellicles (as shown in figs. 7 and 8) is so
great, that at first sight the sculpturing would seem to be
identically the same. In the one case, as in the other, a
central or direct illumination brings into view minute points,
disposed in regular rows, whilst oblique illumination pro-
duces three sets of lines, cutting each other at an angle of 60° or
120°. In the one case, also, as in the other, with central illu-
mination the appearance alters according to thefocal distance at
which the object is viewed ; sometimes regular hexagons being
brought into view, whilst at another merely minute serial
dots are visible. But the marking, he states, in Pleuro-
sigma angulatum and allied forms comes so close to the
boundary of the recognisable, that a clear perception of the
systems of lines or elevations by means of central illumination,
and without the aid of artificial illumination—as by a con-
denser, &c.—is possible but with few microscopes. So far
as he is aware, this object can be effected only with the most
powerful combinations constructed by Amici, Nachet, and
Hartnack, Nos. 9 and 10, & immersion, or more recently by
the latter’s No. 9 without immersion. In fact, under such
circumstances, an investigation with respect to the true fun-
damental cause of so obscure a marking may be termed bold.
Is it due to pyramidal elevations on the surface, as on the
thicker pellicles (fig. 5), or to depressions or conical hollows ;
or is the appearance due to some totally different structure
in the substance itself of the valve, and having nothing to
do with differences of relief on the surface ?

The answer to these questions has been often sought, but
it has by no means been unanimous. The only thing that is
quite positive is that the marking in question is due to actual
differences of relief on the outer surface of the valve.

128 MAX SCHULTZE, ON THE DIATOM-VALVE,.

Wenham* was struck with the happy thought of preparig
galyano-plastic impressions of diatoms, which were in his
hands perfectly successful, and represented impressions
of the systems of lines or dots. For this purpose he
selected only two species, Pleurosigma balticum and P. hippo-
campus, both of which are among the very finely marked
diatoms, though far more easy resolvable than Pleurosigma
angulatum. They differ from the latter also in the circum-
stance that, when we view the systems of lines more particu-
larly as brought out by oblique light, in the former two
species only two sets will be perceived, crossing each other at
a right angle, whilst in P. angulatum three will be seen inter-
secting each other at an angle of 60°. An explanation,
therefore, of what is seen in the former need not be equally
true of the latter. But the general aspect of both species,
except in the above respect, is so much alike that no one
could object to the application of Wenham’s explanation of
what is seen in P. balticum to the appearance presented in
P. angulatum. It is true that Schacht+ has lately given a
description of the marking which might raise a doubt whether
the three sets of lines in question are really situated on the
surface of the object. He says—“ In order to display each
set of lines, it is in many cases necessary, besides the turning of
the stage, to alter the focus somewhat, from the circumstance
that each of the three sets of lines belongs to a distinct layer
im the valve, and consequently is placed a little above or
beneath the other.” And this he says notwithstanding that,
as he himself allows, all the three sets may be brought into
view at once. Further on it is said—“ The horizontal lines
appear to be the deepest seated, and are, perhaps, on that
account the most faintly marked.” The apparently moniliform
structure of these diatom-valves, consequently, according
to Schacht, is deceptive, and is only perceived in case the suc-
cessive sets of lines, when, as under certain circumstances,
they come into view simultaneously, are viewed altogether.
Upon what conditions, therefore, he considers the striation
really to depend remains obscure, although in a subsequent
passage Schacht, in explaiming the matter, employs the ex-

* ¢ Quart. Journ. Mic. Sc.,’ IIT, 1855, p. 244. It does not appear that
Mr. Wenham’s experiments were limited to the two species named, as he
says that he had “obtained distinct impressions of the markings of some
of the more difficult Diatomaces, such as V, balticum, P. hippocampus, &e.,
leaving,” he goes on to say, “no doubt of their prominent nature.” But
whether this prominence belongs to the areole or intermediate lines does

not appear.—Eps.
+ ‘Der Mikroskop und seine Anwendung,’ 1862, p. 29.

MAX SCHULTZE, ON THE DIATOM-VALVE. 129

pression of “ raised ridges,” three sets of which, according to
him, of equal breadth and decussating with each other at an
angle of 60°, exist in P. angulatum. From this it would
seem that he had given up the notion that the sets of lines
were situated at different levels, as “raised ridges” can
hardly be imagined to exist except on the surface.

When any one of the three species of Plewrosigma above
named is examined under a high magnifying power and with
a central illumination, rows of points will be seen on its
surface, varying in brilliancy according as the body of the
instrument is raised or lowered. In P. hippocampus and
balticum these points are placed in two series at right angles
to each other, whilst in P. angulatum they form three series, de-
cussating, as above said, at an angle of 60°. They may be viewed
either as bright spots upon a dark ground or as dark ones
upon a bright ground,* and it has been disputed which ap-
pearance indicates the “ proper focal distance.”’

Welcker’st excellent, though strangely neglected observa-
tions, have shown the futility of such a dispute. By them
we are at once enabled, in the most precise way, to answer
the next interesting question, viz., as to whether the points
on the surface are the expression of elevations or of depres-
sions. The readers of the ‘ Microscopical Journal’ are
aware that, with respect to this point, much contention has
been carried on in England, and that the opinions of micro-
scopists with respect toit have been directly opposite. Whilst
Carpenter, confessedly one of the greatest English authorities
on any questions of microscopy, and, with him, many other
observers, holds these points to be depressions, relying, in sup-
port of this view, as does Harting, particularly upon the analogy
with the more coarsely marked diatoms, in which the marking
on the surface certainly depends upon series of depressions, the
opposite view has, nevertheless, continued to gain ground,
and to be advocated by uo less skilful observers. Amongst
the more eminent of these is Dr. Wallich,t who, by the use
of oblique light—which he prefers in all cases—believes that
he has ascertained beyond question, that the marking on P.
angulatum, balticum, &c., is produced by pyramidal sharp
facets, and finely acuminate elevations on the surface.

* Hall, ‘Quart. J. Mic. Sc.,’ IV, Pl. XIII, fig. 2.

Ibid., VII, p. 240, and VILL, p. 52.

‘Ann Nat. Hist.,’ Feb., 1860. Vide also ‘Q. J. Mic. Sc.,’ VI, 1858,
p. 247, where it will be seen that in some caes, as, for instance, in Zricera-
tium favus, Dr. Wallich recognises the existence of distinct hexagonal cells
on the surface. Though he is inclined (ib. vili, p. 142) to deny that any

ney exists between the marking on that genus and that of Plewrosigma,
c.

130 MAX SCHULTZE, ON THE DIATOM-VALVE.

Amongst other observers who are inclined to adopt this view
may be cited Mr. G. Norman, of Hull, than whom few pos-
sess a more intimate knowledge of diatoms.* It is curious,
in this state of the question, that the method of observation
proposed by Welcker, though not for this special purpose,
should not have been employed. Welcker states, as a means
of distinguishing, in all transparent objects, superficial eleva-
tions from depressions, that elevations appear brightest when
the body of the microscope is raised, whilst depressions, on
the contrary, are brightest when it is depressed. If we start,
then, with the body of the microscope at a medium height,
or lowering it gradually upon the object from a height alto-
gether out of focus, in this case elevations on the surface will
first appear as bright points on a dark ground, and depres-
sions as dark points on a bright ground, until, as we con-
tinue to lower the tube, the image in either case is reversed.
It is only requisite to observe that the object should be
mounted in a medium having a lower index of refraction
than itself.

The reason of this is, as stated by Welcker, because the
elevations act as convex and the depressions as concave
lenses, the bright points representing the focus of each re-
spectively, and consequently corresponding in the one case to
the summit of the elevation and in the other to the bottom
of the depression.

. In proceeding to apply this rule to diatoms, it will be most
convenient to select dry preparations, in which the first con-
dition, viz., that objects should be placed in a less refractive
medium, is fulfilled, and in which also, as is well known, the
superficial markings are most readily made out. But even
with a magnifying power of 1000 diameters and more, and
with excellent lenses, capable of distinctly bringing out the
markings on P. angulatum with direct illumination, we shall
soon be convinced that the subject, even as regards the more
easy images of P. balticum, attenuatum, and hippocampus, still
presents unforeseen and almost insuperable difficulties.

An indispensable precaution to be taken to ensure success
in this inquiry is that an individual point in the marking
should be so distinctly fixed upon that it may be recognised
under various alterations of the focus. But the points and
series of points of the diatoms above named are so closely
approximated that this object demands considerable effort
and skill. ‘The author thinks he has been successful in the
attempt in the case of P. balticum, and has satisfied himself

* «Quart. Journ, Mic. Sc.,’ July, 1862, p. 212.

2

MAX SCHULTZE, ON THE DIATOM-VALVE, Le

that although, upon gradually focussing down upon the sur-
face, clear points, though not altogether precisely defined,
come first into view, and then dark ones, the two sets of
points do not correspond with each other, but that the dark
points make their appearance between the bright ones which
first came into view. When the clear points are ill defined,
the dark ones, on the other hand, are very distinctly shown,
quadrangular in P. dalticum and hexagonal in P. angulatum.
These dark points, again, when the tube is still further
lowered, in their turn become bright, a second time to become
dark when the tube is still further depressed. Lastly, the
lowering of the tube being continued, we again have a sort
of confused or blended image of bright poimts. Thus, for
instance, in P. angulaium, in which the succession of dark,
bright, dark, is very manifest, an indistinct appearance of
bright points precedes all.

The explanation of these alternating images is not easy,
according to Welcker’s idea, though everything seems to the
author to signify that it takes place in the following manner :
—The dark points brought into view upon the accurate focus-
ing arrived at by the lowering of the tube manifestly repre-
sent depressions. The indistinct bright points by which they
are preceded do not coincide exactly with them in position, but
may rather be said to be contiguous to them, and to represent,
consequently, the dorders of the depressions. The dark points
which, more particularly in P. angulatum, are seen arranged
with beautiful regularity over the whole surface of the valve,
present, on the further lowering of the tube, a bright appear-
ance, whilst at the same time their borders become darker.
At this point the bottom of the depression may be said to
have been reached. So far all is clear. The borders of the
pits form the system of ridges, which by oblique illumination
appear as the lines. The intermediate pits, either quadran-
gular or hexagonal, according to the number of the ridges, are
seen as dark points so long as their bottom is not distinctly
in focus. But the borders also of the depressions, when the
tube is raised, may appear like illuminated points, because
at the spots where two or three ridges decussate, or where
one of them is abruptly bent, the reflection of the light gives
the deceptive appearance of a projecting eminence or point.
This latter appearance, however, as has been stated, is of an
indistinct kind. It follows, therefore, that neither spherical,
conical, nor pyramidal elevations are the cause of the punc-
tated appearance on the surface of the above-named species
of Pleurosigma, although the decussating sets of ridges may

VOL. 111,—NEW SER. K

1382 MAX SCHULTZE, ON THE DIATOM-VALVE.

at the points of intersection, afford an appearance resembling
that of tubercular elevations.

But how is the circumstance to be explained that, upon
the still further lowering of the tube, the appearance of the
bright points corresponding to the bottoms of the depressions
is again succeeded by that of dark ones? With respect to
this, the author is only able to surmise that on the inner sur-
face of the valve there is a sculpturing similar to that on the
outer ; and, consequently, that when, by the lowering of the
tube, the borders of the inner depressions are brought accu-
rately into focus, the depressions themselves appear as dark
points. And in the same way may be explained the ultimate
indistinctness of the previously bright, punctiform markings.

In cases where two sets of lines intersect each other at a
right angle, as in P. balticum, hippocampus, and attenuatum,
the disposition of the ridges at once suffices to account for
the arrangement of the quadrangular interspaces. But it is
not so easy to explaim the disposition of the hexagons prog
duced by the three sets of ridges intersecting each other at
an angle of 60° which exist in P. angulatum and its allies.
It is most natural to suppose that they would be arranged
like the cells in a honeycomb, that is to say, in the manner
shown in fig. 11. An arrangement of this kind is figured
amongst others by Carpenter and Mr. Ch. Hall.* Schacht,
however, gives a different view of the arrangement of the
hexagons. According to him, they are not in accurate
mutual contact, like the cells in the honeycomb, but so dis-
posed as to leave between them minute triangular spaces.
These interspaces, then, might either, like the hexagons
themselves, represent depressions, or might be elevations, and
in this case conduce to the formation of the borders of the
depressions. The author has never been able to see these
triangular interspaces, and cannot coincide in Schacht’s
opinion as to the boundaries between the hexagons being
formed by sets of continuous elevated ridges. That the
hexagons are arranged as figured by Mr. Hall, that is to say,
like fig. 11, is fully established to the author’s satisfaction
by some photographic representations procured by the aid of
Hartnack’s combination. According to these figures,'the lines
in each set are not continuous in a straight direction, but
are bent at short intervals, atan angle of 120°. These bends
are, however, so close together as to be imperceptible with the
power usually employed in the examination of P. angulatum,

* «Quart. Journ. Mic. Sc.,’ Vol. IV, 1856, Pl. XIII, fig. 2. Vide also
* Micrographie Dictionary,’ 1856, pl. xlvii, fiys. 41 and 48, the former of
which is copied from a photograph by Mr. Wenham.

MAX SCHULTZE, ON THE DIATOM-VALVE. 133

that is, with one of from 500 to 800 diameters. It is especially
by oblique light, under which only it is generally the case that
the sets of ridges appear as continuous strie, that the illusion
becomes perfect that we are beholding sets of lines running
in a perfectly direct course ; whilst observation with direct
illumination, provided that the lenses have sufficient defining
power, discloses the true state of things. By such a light,
with Hartnack’s immersion-lens No. 10, Fig. 11, represent-
ing a portion of the surface of the valve of P. angulatum,
was drawn.

The author then proceeds briefly to discuss the nature of
the appearances presented in the more coarsely marked
diatoms, such as Coscinodiscus, Eupodiscus, Biddulphia, and
Isthmia, and shows that these appearances may be explained
in the same way as those of Pleurosigma. In Isthmia, more
particularly, he says, it may be readily shown that the quad-
rangular areolz are not elevations on the surface, but rather
holes in the valve, which consequently is formed of a kind of
lattice-work, like that of many of the Polycystina. In Coscino-
dicus and Eupodiscus the existence of a similar network is not
so easily made out, that is to say, it is difficult to determine
whether the areolz represent actual openings in the valve, or, as
is more probable, are not merely very thin spots. In specimens
of these diatoms mounted in Canada balsam the appearances,
explained according to Welcker’s plan, are not reconcilable
with the view of the areolz being depressions, but the reverse.
This the author explains by stating that the Welckerian phe-
nomenon is reversed in objects immersed in a medium of
greater refractive power than themselves. In specimens im-
mersed in water, or dry, the true appearances are at once dis-
played.

It is thus shown that the sculpturing, both in the coarsely
and in the finely marked diatom-valves, although at first
sight apparently allied to what is seen on the surface of
the siliceous pellicles, is in reality due to wholly different
conditions.*

* It may be as well here to recall to microscopical observers that, on the
occasion of the reading of Dr. Wallich’s paper on the diatom valve (*Q. J.
Mic. Sc.,’ VIT1, p. 129), Mr. Wenham, whose opinion on any matter of the
kind is of the greatest weight, stated that with an object-glass of his own
construction, with a focal distance of jth inch and a large aperture, he had
ascertained beyond doubt that in P. angulatum and some others the valves
are composed wholly of spherical particles of silex, possessing high refrac-
tive properties. And he showed how all the various optical appearances in
the valves of the Diatomacew might be reconciled with the supposition that
their structure was universally the same. It would be interesting to know
whether Mr. Wenham retains this opinion.—Eps,

134 KEFERSTEIN, ON SAGITTA.

The paper concludes with some observations upon the
phenomena afforded by diatom-valves under polarized light.
H. v. Mohl has stated* that he observed, by means of his
improved polarizing apparatus, phenomena of double refrac-
tion in the shells of certain diatoms, as, for instance, in P.
angulatum, and his observations have since been confirmed
by Valentin.t| The double refraction, according to v. Mohl,
is so powerful that under a Nicol’s prism even the hexagonal
points on the surface may be seen. It was these observations
that suggested to the author that the appearances presented
in the Pleurosigma valve might be due to siliceous crystals.

As this idea, as has been shown, is not maintainable, to
what cause is the phenomena of double refraction to be
assigned? ‘There is no doubt of the correctness of H. v.
Mohl’s account as applied to dry valves, but when they are
mounted in Canada balsam or other highly refracting
medium the appearance is at once destroyed. There can
be no doubt, therefore, that the phenomenon is due, not to
double refraction, but to what the author terms depolarization
by refraction, as is exhibited in one of Nobert’s tests when
seen through ground glass or through fine, crossed lines.
The very faint appearance witnessed, more especially in the
thicker diatoms, quite at the edge of the valve, even when
mounted in balsam, the author explains on the supposition
that their structure may be laminated, and consequently that
_the substance at different depths is in a condition of varying
tension.

On Sacitta. By Proressor KErersteIn.

Prorrssor Krrersrein, of Gottingen, in his recently pub-
lished ‘ Investigations on the Lower Marine Animals,’{ has
a short communication entitled “Some Remarks on Sagitta,”
of which the following is a translation.

Ovary.—In specimens of a Sagitta about 9 mm. in length,
which was taken pretty frequently at St. Vaast, and which
agrees for the most part with that so admirably described by
R. Wilms, and denominated by Joh. Miiller S. setosa, I found

* ‘Botanische Zeitung,’ 1858, p. 10. - Poggendorfi’s ‘Ann.,’ 1859,
Bd. 108, pp. 179—185.

tT ‘ Die Untersuchung der Pflanzcu-oder der Thiergewebe in polarisirtem
Lichte,’ 1861, p. 203.

{ Forming Part 1 of vol. xii of Siebold and Kolliker’s ‘ Zeitschrift fur
wissenschalftliche Zoologie,’ 1862.

KEFERSTEIN, ON SAGITTA. 135

the ovary in every respect just as Wilms has already described
it. Along its outer side is the thickened ovarian wall, and
within this is excavated the oviduct, which probably possesses
an internal orifice in front, and, posteriorly, opens externally
in the well-known papilla.

Krohn has likewise observed this canal in all sexually
mature individuals; he regards it, however, not as an ovi-
duct, but as a seminal receptacie. I found this canal almost
always filled with the long, thread-shaped zoosperms, which
projected in a tuft from the papillary orifice of the ovary,
and thus, likea probe, indicated the opening of the lateral
canal in this papilla. At its anterior end I could, indeed,
directly make out no entrance of the canal into the ovary,
and am, therefore, unable to determine whether it be an ovi-
duct or seminal receptacle, though the former seems to me
the more probable, especially because I almost constantly
found within the ovary several very large eggs, which ap-
peared to be undergoing development. One must infer from
this an internal fecundation of the ova; but the observed
condition of the eggs agreed so little with the history of their
development given by Gegenbaur, that I dare not venture
any positive opinion.

Setigerous tufts—As Wilms and Krohn have already
pointed out, little bundles of fine, stiff, often very long hairs,
occur on the surface of Sagitta, when uninjured. Usually
these sete are pretty regularly disposed behind one another
in a dorsal and ventral series, and the fins are placed
between these series along the body, so that at first sight one
is reminded of the setigerous tufts of the Annelids. But
the setze of Sagitta, as Krohn has already stated, and as I
have particularly observed in S. serrato-dentata, Ky., of Mes-
sina, rests on the epidermis, composed of rounded clear cells,
‘037 mm. in length, with granular contents, which is raised
up into an eminence beneath each setigerous tuft. The sete
are merely outgrowths of the membrane of one of these epi-
dermie cells.

If one of the above epidermic,eminences be examined with
a high magnifying power, it seems to be traversed from its
base to the setigerous cells by a fibrous tract, which can be
traced backwards to the so-called ventral saddle, in which
these fibrous tracts terminate in a radiate manner. Krohn,
as is well known, has declared this (often very large) ventral
saddle to be a nervous ganglion; in regard to which point I
myself, with W. Busch, cannot doubt that this excellent
investigator has fallen into error, for the ventral saddle lics
outside the muscular coat of the animal, and stands in no

186 KEFERSTEIN, ON SAGITTA.

connection with the brain which can be perceived within
the head. But what significance should be ascribed to this
ventral saddle, I am not able to say; and one looks in vain
for any hint with reference thereto from the development of
Sagitta as observed by Gegenbaur.

Eyes.—The two eyes, as is known, are placed in the in-
tegument on special rounded ganglia, which, by means of a
nervous filament, are brought into connection with the
cerebral ganglion lying in front of them. The eyes consist
of a quadrangular mass of pigment, which probably conceals
a retina within, and, externally, supports on either side about
four or five small, oval, brilliant, crystalline cones; on the
lateral aspect of the pigment spots, however, the crystalline
cones are wanting, or, at least, are reduced to two smaller
ones in front and posteriorly. I have not observed the
contour which Wilms remarked on this outer side of the
pigment spot, and was inclined to regard as a cornea or lens ;
and to me, with Leydig, it appears probable that the struc-
ture of the eye of Sagitta approximates, on the whole, to
that of the Arthropoda—perhaps of the Daphnide.

A few figures accompany the original paper. It will be
remembered that our volume for 1856 contained a full
abstract of what was then known of the structure of Sagitta,
together with references to the works of other writers.*
.This was followed, in 1859, by a translation of Gegenbaur’s
‘Memoir’ on the development of the same organism. More
recently, Gegenbaur (‘Grundziige der vergleichenden Ana-
tomie,’ 1859, p. 138) has reiterated his former views concern-
ing the systematic position of Sagitta, by founding for its
reception a distinct class, OnstrLMINTHES, between the Ne-
matoidea and Annelida.

* To the list there given add Gervais (‘ Ann. }Frang. et étrang.,’ 1838,
p. 127); Hersted (* Vedens. Med.,’ 1849, p. 26) ; J. Miller (‘ Archiv,’ 1847,
p. 158); Gosse (‘‘Tenby,’ 1856, p. 175); and Leydig (‘ Lehrbuch der His-
tologie,’ 1857, p. 261).

NOTES AND CORRESPONDENCE.

Cell for viewing Entomostraca.—The motions of many of
the Entomostraca are so rapid and fitful that restraint
must be adopted to observe them; but this, in the case of
many of them, prevents a good view from being obtained of
their wonderful coverings, and also of their peculiar move-
ments. Having a strong wish to see them entirely at liberty
and to watch the peculiar mode of opening and shutting of
the carapace, I contrived a small cell, which so completely
answers the purpose as I hope may justify my bringing it
under the notice of those interested in those exquisite little
creatures. ‘The cell is formed out of a piece of glass tube,
-§,ths of an inch in diameter and 1th of an inch deep, and
it cemented on the centre of an ordinary glass slide by
marine glue applied to the edges of the piece of tube, so that
the cell is quite transparent, and holds just a drop of water,
but leaving ample room for the active little creatures to move
freely about. This tiny cell is quite within the field under
a two-inch object-glass, which is generally sufficient to
observe all their motions ; but should the inch be required, so
much of the cell remains within the field that the slightest
touch of the stage movements suffices to keep the object
constantly in view. By this little contrivance I have been
enabled to view Daphnia and Cypridia in a way that I was
never able to do before, when I had to restrain their motions
in an ordinary live box.—Josrra Davison, Newcastle-upon-
Tyne.

Vegetable Amceboid Bodies—In Hofmeister’s work on
the Higher ‘ Cryptogamia’ (Ray Society, 1862), pp. 162-8,
occurs the following passage, which possesses much interest
in regard to the ameeboid conditions of vegetable cells.
Speaking of the spore-mother-cells of Phascum cuspidatum,
he says, “ Individual points of the primordial utricle some-
times exhibit slow expansions and contractions similar to

138 MEMORANDA.

those of many of the inferior animals; for instance, the
smaller Amcebe. It is especially in such cases that the
delicate mucilaginous membrane which encloses the cell-
contents may be most clearly observed.’ This observation is
not accompanied by any reference to other observers, and,
therefore, being independent, is of more value, especially
coming, as it does, from so accurate and careful a writer.
It agrees with the same condition which I have before pointed
out in this Journal, as occurring in the mother-cells of the
gemma of Volvox globator.—J. Braxton Hicks.

The Microscope in a Police Court.—It is not often that we
have to repott the proceedings of our police courts. The
following case, however, conveys so obvious a lesson that we
give it for the benefit of our readers.

GrirFitus v. Stevens.—The plaintiff, a pharmaceutical
chemist, sued the defendant, an auctioneer in King Street,
Covent Garden, for the sum of 17s., under the following cir-
cumstances. The plaintiff had attended a sale in King
Street, in December last, and bought lot 418, described as
“a two-inch achromatic, by Smith and Beck.” It was after-
wards found that the glass was not one of Smith and Beck’s,
but only asingle lens, and comparatively worthless.

Mr. A. W. Griffiths deposed that he had attended the —
defendant’s sale on the 20th of December, and had purchased
the object-glass produced for the sum of 17s. He had since
ascertained that the glass, although put into a genuine box of
Smith and Beck’s, was spurious, and of little value. Had
applied to the defendant, who referred him to a Mr. West, of the
Strand, optician, as the person who had sent the object-glass
for sale; but he (plaintiff) had failed to obtain any redress,
and had therefore instituted the present proceedings. On the
day when the summons was first made returnable, Mr. Beck,
of the firm of Smith and Beck, had atteuded to give evidence
but was not now present.

Mr. J. Bland, pharmaceutical chemist, stated that he pos-
sessed a microscope of Smith and Beck’s make, and could
say, from his knowledge of their style of work, that the glass
was not of their manufacture; it was only a single lens,
whereas it should, if genuine, have been a combination of
four or six lenses arranged in the same tube. The witness
was about to mention something said by Mr. Beck in his
presence, but was stopped by the learned judge, who said he
could not receive matter of conversation as evidence.

The defendant being called upon, stated that no application

MEMORANDA. 1389

was made to him on the subject until after he had settled
accounts with the person who had sent in the glass for sale.
It had been given out in the room at the time of the sale that
the glass was not Smith and Beck’s, but he chiefly relied on
the conditions of sale printed on the catalogue, one of which
was to the effect that “the lots were to be taken away with
all faults and errors of every description,” and which, he con-
tended, relieved him from all liability.

Mr. Bland being recalled, said, in answer to his honour,
that he had been present at the sale, and had himself, when
the next lot (also described as by “Smith and Beck’’) was
put up, called out “the box is Smith and Beck’s, but the
glass is not.” He had heard no such remark by any person
with reference to lot 418.

His Honour said that the condition of sale on which de-
fendant relied, although it might have protected him as an
accidental dona fide error, was clearly of no force in case of
fraud ; in the present instance here was an article explicitly
described in the catalogue as “‘an achromatic by Smith and
Beck,” and put up in one of their genuine boxes, with their
name and address engraved upon it, so as to deceive any
ordinary person. He thought it would have been more satis-
factory if some one from Smith and Beck’s had been in
attendance; but looking at the fact that the plaintiff’s witness
had given evidence that he was acquainted with such matters,
and that the article was not what it was described to be, the
plaintiff was entitled to recover. He would, however, if the
defendant desired it, adjourn the hearing of the case at his
expense, for the production of further evidence.

The defendant declined to accede to this suggestion, and
judgment was given for plaintiff, with costs.

PROCEEDINGS OF SOCIETIES.

Microscoprcsan Socrery.

January 14th, 1863.
R. J. Farrants, Esq., President, in the Chair.

Sir James Tyler, T. 8. Scott, Esq., John Povot, Esq., Dr. G.
Ciaccio, and Mr. Alfred Sanders, were balloted for, and duly
elected members of the Society. Verbal communications were
made by the Rev. J. B. Reade, “ Ona Mode of Preparing Desmids,
and on the Microscopie Structure of a Fragment of African
Sculpture ;’ and by.H. Deane, Esq., ‘‘ On the Fibres and Smut of
Wheat.”

February 11th, 1868.
ANNIVERSARY MEETING.
R. J. Farrants, Esq., President, in the Chair.

Reports from the Council, on the progress of the Society, from
the Auditors of the Treasurer’s accounts, from the Library and
Instrument Committee, were read.

The President delivered an address, showing the progress of the
Society during the past year, and also of microscopical science
during the same period.

In his address the President announced that Mr. T. Ross had
signified his intention of presenting the Society with one of his
best microscopes, with all the recent improvements, and that
Messrs. Powell and Sealand and Smith and Beck had also sig-
nified their willingness to let the Society have their object-glasses
on very favorable terms.

The thanks of the meeting were returned to Mr. Ross and
to the other instrument makers mentioned for their very liberal
offer.

The Society then proceeded to ballot for Officers and Council

PROCEEDINGS OF SOCIETIES. 141

for the year ensuing, when the following gentlemen were declared
duly elected :

As President—Charles Brooke, Esq.
As Treasurer—C. J. H. Allen, Esq.

‘George E. Blenkins, Esq.

As Secretaries— iF C. S. Roper, Esq.

Four Members of Council :

W. H. Ince, Esq.

J. R. Mummery, Esq.

Charles Tyler, Esq.

Robert Warington, Esq.
In the place of—

A. Brady, Esq.,

Jabez Hogg, Esq.,

E. G. Lobb, Esq.,

Tuffen West, Esq.,

who retire in accordance with the regulations of the Society.
The thanks of the meeting were returned to R. J. Farrants,
Esq., for his services as President during the past year.

March 1st, 1863.
Cartes Brooxe, Esq., President, in the Chair.

E. C. Northcott, Esq., J. D. Alleroft, Esq., G. Torr, Esq., and
J. De Castro, Esq., were balloted for, and duly elected members
of the Society.

The following papers were read :—“ On some new Species of
Diatomacex,”’ by Dr. Greville. ‘On the Formation of Carti-
lage,” by Dr. Beale.

Tap Lirprary anpd PuinosopHican Soornty, MANCHESTER.
Mioroscopican SEcTion.
15th December, 1862.
Mr. J. G. Lywpz, F.G.S., M. Inst. C. E., in the Chair.

Mr. Alfred Fryer was elected a member of the section.
Captain Moodie, of the R.M.S.S. Canada, presented two sound-

14.2 PROCEEDINGS OF SOCIETIES.

ings taken off Nova Scotia. Captain Thomas Millard, of the
barque, First of Alay, presented specimens of anchor mud from
Montego Bay and the harbours of Kingston and Port Royal,
Jamaica; also a sounding from the banks of Newfoundland.

The Chairman stated that he was led to pursue Dr. Robert’s
suggestions on the use of magenta dye in examining tissues.
From experiments made since the last meeting of the section, he
finds that the dye has no power to colour living tissue, whether
animal or vegetable, but that as soon as life is extinct the action
of the dye commences. He is continuing the experiments, which
are of a most interesting character, and he hopes to lay the result
before the next meeting of the section.

Mr. Leigh considered it probable that so long as vital action
continued, ordinary endosmosis could not take place.

Mr. Mosley said that Mr. Hepworth had frequently tried
magenta for injections, and the results were not satisfactory,
as the colouring matter diffuses itself through the whole of the
tissues, giving an appearance of dyed flesh rather than that of
injected preparations. This appears to confirm the preceding
observations, and to account for the accumulation of colour where
the integument is thickest, by means of which Dr. Roberts dis-
covered the spot on the red blood-discs, as announced at the
previous meeting.

Mr. Leigh drew the attention of the section to the adulteration
of size as a cause of mildew in cotton goods.

Mr. Watson named the investigations made by Mr. Thompson
about twenty-five years ago, as to the cause of mildew in madder
purple-printed cottons shipped to hot climates. It was attri-
buted to the starch employed in finishing the goods, which, acted
upon by moisture, heat, and pressure, had given rise to an organic
acid which discharged the colour.

Mr. Hurst described his experience of mildew on printed
cottons and upon dyed fustians at Gibraltar and Calcutta. In
most cases it appeared in spots and round patches, which
affected the colours. On the fustians, he had no doubt, it was
caused by the growth of a fungus, as the surface of the spots was
sensibly raised.

Mr. Mosley considered there might be several kinds of mildew ;
that upon the fustians might be attributed to the bone size with
which those goods were generally finished, and known by the
characteristic smell. Mr. Mosley also exhibited a pattern of
gray calico, which had become discoloured and quite rotten in
irregular patches, from mildew; it had Jain for some time ina
damp place, under pressure; there was this peculiarity about it,
that the coloured patches whilst damp were quite tender, but on
exposure to the air and drying the cloth had recovered its
strength.

Mr. Heys remarked that twenty years ago he was engaged
in the manufacture of fine muslins; it was usual to soak the
weft in soap suds, to facilitate the weaving; and it was found the

2 gia, ey Po

PROCEEDINGS OF SOCIETIES. 143

cloth was most liable to mildew during hot, close, summer weather,
and the greater the quantity of goods heaped together the more
rapidly would mildew set in. The flour from which the size was
made was always the best that could be purchased.

Mr. Heys exhibited mounted specimens of the fibres of the
Zostera marina, and stated that, as the fibre is considerably
finer than the finest Sea Island cotton, it might probably be of use
in the manufacture of fine muslins for ladies’ dresses, if it were
possible to obtain a supply, and separate the fibre from the plant
by machinery. Mr. Heys also exhibited mounted specimens of
Queensland cotton, lately sold at 5s. per pound; the fibre is very
regular in size, and much more cylindrical than other cottons ;
also several specimens from ripe and unripe pods, and Mr. Heys
expressed the opinion that great advantage would arise from
a regular and careful examination of cotton-fibre taken fresh from
the plant through every stage of growth.

19th January, 1863.

Mr. Josppn Srtprsoruam, Vice-President of the section, in the
Chair.

Captain Isaac Tessyman, of the ship dan Mary, presented
four soundings taken off the coasts of Patagonia, Singapore, Malay
Peninsula, and at Algoa Bay, during his late voyage to San Fran-
cisco, Singapore, &c.

Captain J# B. Husband, of the ship d/wtlah, presented three
soundings taken off Orissa, and the Black Pagoda on the coast of
Bengal.

Mr. Latham presented mounted slides of the skin of the
Murena guttata, cocoon of silk worm, and cuticle of Gladiolus.

Mr. John Slagg, jun., presented mounted specimens of floats
and ovaries of Lanthina; shells of ditto; berry of Fucus natans
covered with Membranipora; and Criseis aciculata, a Pteropod.

Mr. John Hepworth referred to the mildew mentioned in the
proceedings of the previous meeting, which had been observed at
Gibraltar on fustians stiffened, with bone size, and stated that he
had noticed a peculiar fungoid growth upon mounted sections of
bone, and that it would be desirable, if possible, to compare them.

Mr. John Leigh, M.R.C.S., read a paper “ On the Use of
Dialysis in Microscopical Investigations.”

After describing the researches of Professor Graham, the pre-
sent Master of the Mint, and explaining the nature of the divi-
sion into two classes of all natural bodies, namely, into erystalloids
and colloids, their affinities and means of separation, the ‘author
proceeded to describe some curious bodies found in cleaning
out a steam-boiler, which have almost exactly the external form
and internal structure of the concretions formed by Mr. Rainey,
and figured in Dr. Carpenter’s work on the microscope, third

144 PROCEEDINGS OF SOCIETIES.

edition, p. 769. They are composed chiefly of carbonate of lime
and organic matter, aggregated in the presence of the aluminous
colloidal mud in the boiler, and are, on a large scale, a singular
illustration of Mr. Rainey’s experiments. The author then en-
larged upon the advantages of this method of investigation to the
microscopist and chemist, who may go hand in hand in the
examination of the crystalloidal constituents of organic bodies.
“ The microscopist (says the author) will often be able to direct his
fellow-worker into new channels of research. A careful study of
minute crystals, with accurate measurements of their angles and
observations on the effects of polarized light, may, to speak
medically, lead to an accurate diagnosis of them, as is afforded to
the tests of the chemists, to whose larger operations they may be
referred for further analysis. Dialysis affords us the means
of separating the saline constituents of the juices of plants from
the salts fixed in their tissues, and similarly in regard to animal
bodies. By one or more dialytic operations on a limited scale
the erystalloids of any vegetable juice may be obtained in solu-
tion of great limpidity, and by careful evaporation over a water
bath they will crystallize out in a state fit for examination.”
Mr. Leigh concluded his paper by the quotation of some apposite
remarks by the late Professor Johnstone, of Durham, and exhi-
bited the small trays he uses in his experiments, consisting of a
double rim of gutta percha securing a disc of parchment paper in
the form of a sieve; also specimens of the mulberry-shaped
nodules found in a steam-boiler, as before named.

The Chairman said that for minute experiments he had used the
parchment paper in the form of a filter. +

Mr. Dancer stated that porous earthenware could be advantage-
ously used as a dialyser.

Professor Williamson indicated a number of subjects upon
which dialysis would probably throw light, both in vegetable
and animal physiology. He especially dwelt upon the pheno-
mena of calcification and silicification, illustrating his remarks by
reference to what occurs in the formation of calcareous and silicious
growths in the colloid sarcode of sponges and polypifera, in the de-
velopment of the dental plates of the teeth of Echinus, in the cal-
cification of the derms of the crustacea, the shells of mollusea, the
scales of fishes, andin the chondriform and membraniform bones
and teeth of the vertebrate animals. The professor suggested that a
natural process of dialysis probably underlay all these formations.
He specially called attention to the close resemblance subsisting
between the primary spherical and concentric granules seen
in the derms of the crustacea, in the scales of eycloid and ctenoid
fishes, in the outermost layers of many teeth, and the artificial
concretions produced by Mr. Rainey, to which Mr. Leigh alluded
in his paper. Professor Williamson further suggested for in-
quiry, how far the structureless basement membrane seen under-
lying the calcareous layer of many calcified structures (¢.g., the
pulp-membrane of the tooth), played some part equivalent to the
parchment dialyser of the Master of the Mint.

PROCEEDINGS OF SOCIETIES. 145

Mr. Mosley read extracts from a report to the Cotton Supply
Association, of a microscopical examination of a sample of cotton
supposed to have some peculiarities. On comparison with good
American cotton, it was found to contain a greater proportion
of round and partially flattened filaments, all more or less twisted,
but full and well developed; the polarized colours were more
bright and vivid, all indicative, he considered, of strong and
vigorous growth in a congenial soil, and careful gathering when
the pod was at its highest stage of development. The fibres
varied in size, from flattened ribbons of ;3,5 of an inch broad to
cylindrical fibres of ;4,;5 of an inch in diameter, the variation
being due mainly to the amount of compression of the cylinder
rather than to actual difference in bulk. The staple measured
from linch to 13 inch in length. The contrast with some inferior
cottons was strongly marked, as regards their twisted, flat, tape-
like appearance, and faint polariscopic colouring, which he attri-
buted either to weakly growth or to having been picked from
over-ripe pods, when the fibre had become dry and sapless. Too
little is, however, known to form an exact opinion; dissection of
buds and pods in all stages of growth would be necessary for
a full and exhaustive investigation of the subject.

In reply to a question from Dr. Robertson, Professor William-
son stated that, like all vegetable hairs, the cotton-fibre in its
early stage is unquestionably cylindrical.

Mr. Sidebotham exhibited a convenient and effective form of
<a microscope, by Mr. Dancer, suitable for naturalists and
others.

Mr. Brothers exhibited a mounted slideof Foraminifera, and a
drawing of Coleochete scutata, a minute fresh-water alga.

Mr. Whalley exhibited Trichoda lynceus, marine infusoria;
also an objective, ;'; of an inch focus, by Messrs. Powell and
Lealand.

16th February, 1863.

Mr. Josepn SiprzoruamM, Vice-President of the Section,
in the Chair.

Captain Fletcher, of the ship Tigris, presented a portion of
harbour mud from Singapore, and five soundings from the coasts
of Java and Sumatra.

Mr. R. D. Darbishire presented specimens of mud and fossil
shells (received through Dr. P. P. Carpenter), from the post-
pliocene or latest tertiary deposits at Logan’s Farm, Mile End
Quarries, near Montreal, Canada, described by Sir C. Lyell’s
‘ First Travels in North America,’ vol. ii, p. 135, and in papers
by Dr. J. W. Dawson, in the ‘ Canadian Naturalist, 1858 and
1859. Mr. Darbishire, in a note to the Secretary, stated that
one of the peculiarities of the deposit is that it seems to have
been formed in a quiet hollow{; spicula of sponges are found in
position, as if the sponge had grown, and been quietly buried
on the spot. Amongst other fossils are many kinds of Forami-

146 PROCEEDINGS OF SOCIETIES.

nifera and a siliceous, close-textured sponge, referred to Tethea,
of the species Logani, which is now found in water from the
tide line to 200 fathoms deep. Mr. J. H. Nevill undertook to
examine and report upon the specimens.

Mr. H. A. Hurst presented a copy of Part iv, vol. xii, of the
‘Journal of the Agricultural and Horticultural Society of India,’
published at Calcutta, containing the prize essay “On Cotton
Cultivation in India from Foreign Seed,” by Dr. J. Shortt, F.L.S.,
Zillah Surgeon, Chingleputt, for which the prize of 1000 rupees
and the gold medal of the Manchester Cotton Supply Association
were awarded.

Mr. Hurst read a paragraph from page 499, relating to the
early stage of the cotton-pod, which, bearing on points lately in
dispute, is given entire :

“On examining a cotton-pod soon after the ovary has been
impregnated (which is known by the change in colour and the
fading of the petals or flower leaves, or corolla), it is found to
contain a number of seeds, according to its particular variety.
If a single seed be separated and examined by the naked eye,
nothing is visible; but when seen through the microscope,
it is found covered with a villous coat, formed apparently of
elongated cells, jomed end to end. These are filled with sap.
The young seed itself is somewhat pear-shaped, and resembles in
miniature some of the China candied fruits, with the frosted
crystals of sugar covering it. On letting out the contents of a
single cell, it is found to consist of granular cells, containing a
centro-lateral nucleus. On examining a pod between three and
four weeks old, the seed still retains somewhat of its pyriform
shape, and appears quite shaggy; the fibres, tapering to a point
at their free ends, resemble hollow cylindrical tubes, filled with
fluid and vary in length; and on submitting a single fibre com-
pressed between pieces of glass to the microscope, the flattened
surfaces become distinctly visible. Again, on substituting a
mature fibre before it gets dried, the filament is found to consist
of tubular hairs, which are now quite cylindrical. After the
dehiscence of the mature capsule, by the contraction and separa-
tion of its valves, the wool becomes dry from exposure. A fila-
ment now placed under the microscope is found to resemble a
flattened piece of tape twisted upon itself, and apparently formed
of an extremely thin and transparent membrane, interspersed with
dark, granular matter, which, after a certain time, disappears in
some of the varieties.”

Mr. J. G. Lynde, F.G.S., M. Inst. C.E., read a paper “ On
the Action of Magenta upon Vegetable Tissue,’ in which he
described a series of experiments upon cuttings of Vallisneria,
immersed in a solution of that dye in glass cells under the
microscope, with its effects upon the circulation and the cell con-
tents of the plant. He found that so long as vital action con-
tinued, the cell-walls and moving chlorophyll retained their green
colour; but the injured cells were immediately deeply reddened,

~

_——— se ey ee

en

PROCEEDINGS OF SOCIETIES. 147

and their contents gradually acquired the same colour, the
intensity of which was in proportion to the thickness or density
of the tissue. Between the cell-walls it would appear that there
exists an intercellular membrane, devoid of vital action, which
becomes rapidly coloured whilst the circulation continues active.
On the inner surface of the cell-wall, whilst rotation is going on,
the author observed a luminous stratum, suggesting the action
of cilia; but in every observation, as the dye permeated the
tissue and the circulation ceased, the inner cell-wall became
covered with irregular markings, either corrugated or having
raised excrescences, scarcely alike in any two cells; in no case
were the markings visible until the rotation had ceased, and they
had the appearance which would be produced by cilia* falling
against the cell-wall in all positions upon the suspension of vital
action.

The chlorophyll-vesicles appear in three forms—in a gelatinous
sac or mass, rotating altogether in the cells ; as independent vesi-
cles, apparently homogeneous in their structure, rendered opaque
by colouring matter; and lastly, as independent vesicles, some-
what increased in size, of a pale-green colour, and almost trans-
parent, containing nuclei, one, two, or three in number, which,
in reality, appear to be smaller vesicles within the parent,
similar to Volvox globator, without rotatory motion. The chloro-
phyli-vesicles appear to resist the action of the magenta for some
time after the rotation has ceased, indicating a vitality to a
certain extent at least independent of that in the cell. In some
of the experiments a few of the cells assumed a purplish colour,
whilst in the adjoining cells the circulation was active, and the
chlorophyll green ; in those purple cells the chlorophyll appeared
to be decomposed, and the cell nearly full of very minute dots,
swarming like the granules in Closteriwm lunula; upon this
point the author offered no opinion. The observations were
made with 1th and ith objectives, and the paper contained
minutie of several experiments, such as the hours of observation,
temperature of the room, and other particulars.

Dr. Roberts observed that Mr. Lynde’s remarks upon the
separate vitality of the cell and cell-contents were very suggestive ;
he had noticed that fresh blood-dises (for instance, from a pricked
finger) were not immediately affected by magenta, but that time
was required for the dye to permeate the tissue.

Mr. Neville exhibited a new form of cell, cut out in card-

* Eminent microscopists do not entertain the idea that the circulation in
Vallisneria is due to ciliary action. “‘ This appearance is decidedly affirmed
by Mr. Wenham to be an optical illusion.” (See quotation by Dr. Carpenter,
‘The Microscope and its Revelations,’ 3rded., p. 408, from Dr, Branson
and Mr. Wenham, ‘ Quarterly Journal of Microscopical Science,’ Vol. ILI,
1858, pp. 274 and 277.) This opinion was possibly formed upon observa-
tions made during vital action, and may be modified upon examination of
the (supposed) dead and dying cilia, rendered visible by the action of the
magenta dye.—Secretary Mic. Section.

VOL. III.—NEW SER. L

148 PROCEEDINGS OF SOCIETIES.

board, containing seven divisions for seven different objects; it is
very suitable for Foraminiferze, Diatomacee, &c., and may con-

tain seven species, to economise space in cabinets and facilitate.

exhibition. The perforations are about a quarter of an inch in
diameter, and made with a saddler’s hand-punch; the dise is
then covered with black varnish, and secured to the glass slide.

Mr. J. B. Dancer exhibited new cells for opaque objects of.
various sizes; they are made of a composition, and cast in a

mould.

Mr. J. G. Dale exhihited, with the polariscope, crystallized films
of picrate of aniline and of santonine; they were rich in colour,
and some of the forms are believed to be new.

SouTHAMPTON MicroscopicaL Socrery.

The second annual soirée of the Southampton Microscopical
Society was held in the new Hartley Institution, on the evening
of Thursday, December 11th. The members meet once a month,
when a paper is read, illustrated by specimens, and once annually
the society makes a public demonstration in this way of its year’s
work, in order to increase the taste for microscopical science in
the town and neighbourhood. This gives an opportunity also for
bringing together on the common ground of science many who do
not generally mix together socially—the gentry of the town, the

magistrates, the town council, the professional and commercial’

classes, meet together in a large evening party. The new Hartley
Institution is a noble building, and its hbrary, class rooms,
museum, and theatre, brilliantly lighted and filled with a well-

dressed crowd, the tables covered with a large number of excellent’

microscopes, surrounded by ladies full of curiosity and interest,
was a gay and lively sight. About 1200 visitors were present
during the evening, which seemed to be much enjoyed by all.

The following is the programme of the evening’s proceed-
Ings :

Messrs. Smith and Beck exhibited several binocular micro-
scopes, their beautiful transparent injections, especially one of
the brain, being a source of great attraction.

Mr. S. Hichley also exhibited specimens of his microscope, and
a selection of photographic views of microscopic natural history
and other subjects by the oxyhydrogen lantern, which he is now
engaged in bringing out for educational purposes. Some of the
views were from photographic negatives by Dr. Maddox, of South-
ainpton.

The address was delivered by the President, Dr. Bullar.

He began by expressing the pleasure the members felt at
seeing their friends again at their second annual soirée, the
object of which was, not to teach microscopical science, but to
excite the curiosity ‘of those who have no knowledge of it, and

Bi Mees, ee eS ee

<

PROCEEDINGS OF SOCIETIES. 149

who are unaware of the pleasure it affords. As so many ladies
were present, he suggested that it was a branch of science they
may both delight and excel in, for it deals with the most delicate
objects, requiring the finest touch and handling, all of which dis-
play exquisite workmanship, and many consummate beauty. He
directed attention to some enlarged drawings made by two ladies
from the objects under the microscope, which, for accurate draw-
ing and taste, could not well be exceeded; and he remarked that
if ladies with leisure would devote the same patience they exer-
eised in fancy work to microscopical investigations, not in a
desultory way, but following up one subject, they might add to
our discoveries as well as to their own interest in life. And if
ladies did not pursue it themselves, they might create a taste for
natural history in their families, and thus become the mothers of
the minds of future naturalists. Carlyle described Dr. Arnold’s
house as a “temple of industrious peace;” and it is in such
temples, with their guardian priestesses, that tastes are best cul-
tivated, which, in after life, have the pleasantest recollections ;
and, as age advances, the mind, interested in all kinds of truth, re-
mains fresh and young, a source of comfort to itself and of light
and joy to all around it.- After directing attention to some of the
microscopical specimens of most interest to such a company, Dr.
Bullar thanked the town council for lending the handsome and
commodious rooms of the Hartley Institution for the legitimate
purpose of increasing taste in science in Southampton, and he
thus concluded:—“ Living as we are amongst so many new
wonders, in an age which paints in an instant our portraits by
the light, sends our messages by the electric force with the
velocity of a wish, carries our bodies and our merchandise by con-
summate mechanisin, moved by steam, over earth and sea, with
the speed of the storm and the certainty of time, and brings and
concentrates with the same rapidity, from every portion of the
globe, its freshest news for our daily reading—which, by a refined
optical chemistry, discovers, by the colours of light, the actual
mineral constitution of the sun—with the telescope not only
discloses, but photographs the mountains and the valleys, the
extinct volcanoes, and the sterile rocks of the moon, and resolves
the distant night clouds of light into systems of starry worlds—
and, in the other direction, looking downwards instead of up-
wards, by our microscope reveals new worlds of living beings in
the water we drink and in the dust we tread upon—living
amidst such wondrous realisations of the scientific hopes and dim
anticipations of the most sanguine philosophers of former days,
these marvels seem to us so common that we are apt to forget our
high privileges, and not sufficiently to dwell upon and to rejoice
in the fuller life and more extended knowledge and wider range
of beauty that is opened to us. For with such advantages
lavishly bestowed on us, we only need the common use of our
faculties—the eyes awake to see, the mind attentive to observe,
the heart open to feel, this wondrous world. of ours—in order to

150 PROCEEDINGS OF SOCIETIES.

live and breathe “in an ampler ether, a diviner air,” than a world
of lower pursuits or amusements affords. And thus may we not,
from the lessons of science, imbibe an antidote to that critical
habit which, studying imperfections and indulging in discontent,
makes the mind equally disagreeable to itself and to others?
Science gives us a wiser lesson. She also studies imperfections,
but not to grumble at them, not to feel uncomfortable or discon-
tented, but to discover their meaning and to find in apparent irregu-
larities the proof of the working of the same law which, in happier
circumstances, results in perfect symmetry. We have, however, no
wish to overrate science, and especially its popularisation. There
are higher aims than those of mere science, which can never radi-
cally improve the race nor give to man the happiness he needs.
Christianity alone can do this. But science cannot be divorced
from Christianity. It was one of the great objects of Lord Bacon
in the advancement of science, to show by what discipline the
mind may be freed from its imperfections so that she might see
truth in clear outline, uncoloured and undistorted by passions,
prejudices, and habits. To observe nature and to discover her
“open secrets’’ requires (as Bacon taught) a mind as true and
clear as our present glasses. And the spirit of truth which
Christianity gives under her own conditions must be the very
same spirit which science requires; and he must have (other things
being equal) the clearest insight into her laws who has that simple,
unbiassed love of truth which accompanies singleness of purpose
and purity of heart.

Pe
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ORIGINAL COMMUNICATIONS.

Some Remarks upon Licut. A Paper read before the
Microscopical Society of Newcastle-upon-Tyne. By
B. 8. Proctor.

Ir can scarcely fail to have struck every microscopist that
the white materials of everyday life, when submitted to the
keen gaze of microscopical examination, display bright re-
flecting surfaces and clear transmitting substance ; that black
substances are also shining, though in a less degree and
having less transparency ; and that the most opaque materials
transmit more or less light when in thin section.

Having noticed such commonplace facts, I was led to ask
myself—

What is the difference in the appearance of transparent
and opaque white powders? Are white organic materials ever
opaque ?

And I entered the same on a list of subjects which I keep
for future examination. These questions had not long been
there before they were followed by another entry.

Are all opaque substances black when in a fine state of
division, as copper, iron, silver, platina ?

How far is blackness coincident with opacity and hetero-
geneousness or division ?

How far is whiteness coincident with transparency and
heterogeneousness or division ?

Is anything opaque? If not, what is the nature of the
phenomena of proximate opacity, black, white, and coloured ?

Having these questions entered on my list, and kept in
my mind by occasional reference to the same, they have sug-
gested a variety of thoughts and observations, which I now
propose to present to you, hoping that their enunciation will
afford you a pér-centage of the mterest which their elabora-
tion has afforded myself.

In the pursuit of physical science, we can scarcely ask our-
selves for an explanation of any simple phenomenon without

VOL. I1I.—NEW SER. M

152 PROCTOR, ON LIGHT.

being led into another question and another ; each step opens
out new paths on every side, all inviting us to a journey of
discovery. I began by asking, Is every white body trans-
parent? But where shall I end? As white as fine linen, flour,
chalk, as white as snow. They are all poor comparisons, dull
examples, nothing to be compared to many of the chemical
precipitates. Precipitated chalk far outshimes the natural
varieties, and fine qualities of carbonate magnesia outshine it.
Of a great number of substances I have compared, Howard’s
carbonate of magnesia is the whitest, and microscopical exami-
nation indicates that it consists of clear, colourless particles,
but very minute. White lead consists of particles equally
minute, and also transparent, but of a yellow-brown colour
by transmitted light; consequently, when seen in bulk, it
appears of a less pure white. Why should not magnesia be
used as a pigment? A painter will tell you it has not sufficient
“body ;” and now comes the question, What is “ body,” and
why has one white powder more than another? Before we
can give an intelligent answer to this question, we must take
into account the laws which govern the transmission, absorp-
tion, and reflection of light.

Light falling obliquely upon a plate of glass is partly re-
flected, partly transmitted, until it comes to the under sur-
face of the glass, where it is asecond time partly reflected and
partly transmitted; the reflected portion again meeting the
upper surface, is subjected to further division into reflected

and transmitted light; the reflected portion meets the lower

surface, is turned up again, and so ad infinitum.
In the diagram we have roughly sketched the path of a
ray.

10 LA t2 93

A and B are sections of glass plates: 1, is the incident ray ;
2, 3, 4, 5, &e., indicate the reflections it undergoes within the
substance of the glass, the intensity of the beam becoming

PROCTOR, ON LIGHT. 153

rapidly less from the loss it sustains, by a portion being
transmitted at each reflection; 10, 11, 12, and 13, indicate
the portions transmitted through the upper surface of the
glass from the reflected rays, 3, 5, 7, and 9, respectively ;
14, 15, 16, and 17, indicate the portions transmitted through
the lower surface of the glass from the primary ray 2 and
the rays 4, 6, and 8, respectively ; the ray 14 describes a
path in B similar to that described in A, by the other portion
of the primary ray, but at its second reflection it is jomed
by the ray 15, and at its fourth by the ray 16. Its second
reflection is accompanied by a transmission of a portion
through the upper surface of B, which then re-enters A,
undergoing again the same series of transmissions, reflections,
and passages from one plate to the other, an indefinite, if
not an infinite number of times; and if, instead of two plates
there were twenty, the same would go on in a much more
complicated series.

Only a small portion of light finding its way through the
whole series of plates, and all the remainder being reflected or
absorbed during its many passages backward and forward,
the proportion of light reflected at each surface, compared
with that which is transmitted at the same, depends upon the
amount of refraction which the transmitted portion under-
goes; and the amount of refraction depends upon the angle
of incidence, and the comparative densities of the glass and
air, or other media with which we are dealing. If instead of
air between the plates we have water, there will be less re-
fraction at each surface, because of the less difference in the
densities in the two media; consequently, there will also be
more transmission and less reflection; the bundle of plates
will become, as a whole, more transparent.

We have here three bundles of glass plates; in one there
is air intervening, and you will observe it has considerable
opacity, and reflects much light ; in the second there is water
between the plates, and it is more transparent, and reflects
less ight; the third, in which spirit of turpentine replaces
the air, is so transparent, and reflects so little light from the
interior plates, that we might almost suppose it a solid block
of glass. I have been speaking of the action of the surfaces,
but every plate, however thin, consists of something more than
two surfaces, and the substance which intervenes exerts what
is called an absorbing power over the light as it passes
through it. Though I do not think absorption a correct
expression of what takes-place, I will submit to the conven-
tionality, and use it till something more correct is adopted.
Supposing the bundles of plates to consist of a countless num-

154 PROCTOR, ON LIGHT.

ber, with air intervening, we have a considerable amount of
light reflected ; the light which penetrates the series becomes
rapidly less; from the effects of reflection and absorption,
it becomes at a given depth quite inappreciable. We replace
the films of air by water; less light is reflected, as has been
explained, the light is transmitted more freely, consequently
it descends to a greater depth before it becomes inappreci-
able. If the water is replaced by Canada balsam, the re-
flection is again diminished, while the transmission is facili-
tated; and this takes place even though the balsam absorbs
more light than the water, and the water more than air;
but it is self-evident that if the reflecting power had con-
tinued the same, while the absorbing power had increased,
there would have been a diminution both in the reflected and
transmitted light. From these considerations we may state
as arule that, of bodies with plane surfaces, the reflecting
power is greatest when the density is greatest, the laminz
thinnest, the intervening medium lightest, and the absorbing
power of the two least. The reflecting power is least when
the density is least, the substance homogeneous (free from
lamination, &c.), and the absorbing power greatest. We have
thus come to a conclusion regarding the first essential of a
white or a black surface, viz., the circumstances regulating
the amount of light reflected. A second essential is that all
colours shall be reflected equally ; for if one colour is re-
flected more than another, instead of having gradation from
black to white, we have shades of the reflected colour. We
will suppose, therefore, that our surface reflects all colours that
fall upon it with equal facility, and now pass on to the third
element. If the surface is a perfect plane, light falling on it
is reflected at an angle equal to the angle of incidence, with-
out suffermg other changes in the character of the beam;
consequently when the eye is directed to a given point on the
surface, a line drawn from the surface at an equal angle on
the other side of the perpendicular will point to the source of
that light which enters the eye. If that source emits blue,
red, or yellow light, blue, red, or yellow light will enter the
eye, and the surface reflecting it will appear to have such a
colour. How, then, can any smooth surface appear white
when surrounded by objects of all colours? ‘The fact is, no
flat, smooth surface appears white when surrounded by ob-
jects of various colours.

If you have a surface of polished silver, it reflects and ap-
pears of the colour of the objects from which the reflected
light emanates. If the silver, instead of being polished, is
dead white, it apparently ceases to reflect the colours of the

PROCTOR, ON LIGHT. 155

objects; but the microscope reveals the truth, that now the
surface is not one smooth plane, but consists of an infinitude
of curves, each reflecting all the colours of the surrounding
objects; but so minute are these reflections that, to the naked
eye, they cannot be separably distinguished, and the result
is an impression of uniform colour; or if the various colours
fall upon it in due proportion, its appearance is white: this
is the nature of what takes place upon all white surfaces.
You will say, How will it apply to such materials as porce-
lain, which have not a dead-white, but a polished-white, sur-
face? In reply, I must direct your attention to the fact that
in glazed porcelain there are two distinct reflections—that
from the glazing is similar to that from the polished silver,
but the glazing is transparent, the light passing through it
falls upon matter which reflects lght in the same condition
as that which is reflected from the dead-white silver.*

Now let us return to the subject of “ body,” and we under-
stand at once the difference between the white lead and the
magnesia. They are both transparent in their individual
particles, but the magnesia more so. They are both bodies
possessed of considerable refractive power, but the lead more
so. When air intervenes between their particles, the reflec-
tive power of both so much exceeds that of air that they are
highly reflecting and very slightly transmitting ; but the less
absorbing power of the magnesia makes it the whitest—the
more reflecting of the two. But when oil intervenes, as would
be the case if they were used for pigments, the refractive
power of the magnesia so nearly coinciding with that of the
oil that much transmission and little reflection is the result,
this constitutes what painters call want of body. But the
lead so greatly exceeds the oil in refracting power that its
reflective property is not much interfered with, and even with
its greater absorbing power it reflects much and transmits
little hght, this being what painters call great body.

I have here specimens of carbonate of magnesia and white
lead. You will observe that the magnesia, when dry and seen
by transmitted light, consists of small particles which are
transparent when seen singly, but look opaque where they are

* The manner of its reflection, however, being somewhat analogous to
that of the bundle of plates, for the porcelain consists of transparent particles
superposed upon one another, the various particles having different powers
of transmission, reflection, and refraction, you will at once perceive that
the same circumstances which changed the amount of one or other property
in the bundle of plates will do the same in the porcelain. The more nearly
the various parts have the same refractive power, the more light will be
transmitted, the less reflected.

156 PROCTOR, ON LIGHT.

aggregated. The white lead is somewhat yellowish, evidently
transparent, but not so clear as the magnesia.

By reflected light the magnesia is comparable to a fine
sample of crystalline moist sugar, and the lead has an evident
lustre and transparency, though in a less marked degree than
the magnesia.

In those specimens mounted with balsam the magnesia is
seen to be very transparent, consisting principally of roundish
bodies, which have a dark centre when beyond focus and a
bright centre when within focus, showing that the magnesia
has less refracting power than the balsam. The white lead is
very evidently transparent, and has bright centres when be-
yond focus, which are diffused when it is brought within the
accurate focus, showing that the lead has greater refracting
power than the balsam.

I have here two specimens of white lead, to illustrate the
difference between that made by the usual troublesome pro-
cess and that made by some of the more speedy processes
which have at various times been tried, but have always fallen
out of use again, because the precipitated lead was deficient in
body, in consequence of its consisting of larger particles, as
you will perceive. In commercial white lead the larger par-
ticles are aggregations of smaller ones, consequently look
white and opaque, but in the precipitated variety they are
solid crystals, clear and transparent.

_ I fear you will think I have occupied too much time with
a matter more interesting to painters than to microscopists ;
but this is not the case, it is a subject of general optical in-
terest, and specially connected with the mounting of micro-
scopical objects. Why are sections of wood mounted dry if
to be viewed as opaque objects, and in balsam if to be exa-
mined by transmitted light? What I have already said has
answered the question. Why are starches best seen when
mounted in gelatinous media? When examined dry, the
great refraction the light undergoes in passing through them
makes them appear black, except one small focus of light ; if
mounted in balsam (the refracting power of which so nearly
concides with their own), their minute structure becomes
invisible from the exceeding transparency imparted, accord-
ing to the rule already pointed out. To overcome the lens-
like power of the granules, without rendering their super-
ficial markings invisible, we require to select a medium of
refracting power between that of air and of balsam, and this
we find in gelatine, &c.

I have here three mountings of tous-les-mois, in illustra-
tion of this fact. You will observe that which is in balsam

PROCTOR, ON LIGHT. 157

has a dark centre while it is beyond focus, is uniformly light
at focus, and has a bright centre when within focus, indicat-
ing that the balsam has a higher refracting power than the
granules; with that mounted in the gelatinous medium, you
will find that the effects of increasing and diminishing the dis-
tance from the object-glass are reversed, indicating that the
starch has now a refracting power above that of the medium
in which it is enveloped, and the markings on its surface are
in this mounting much more distinct. No doubt similar
attention to the mounting medium would, in many other
cases, produce a like improvement in the appearance of the
object. I will only adduce another example—two mount-
ings of shell; that in gelatine shows the laminations more
distinctly than that in balsam.

Various other matters, more or less important and inte-
resting to the microscopist and optician, might be treated of,
in connection with this part of my subject, but contenting
myself with what I have said, I will revert to some of the
other questions raised at the beginning of my paper.

Are white organic materials ever opaque ?

Are all opaque substances black when in a fine state of
division ?

How far is blackness coincident with opacity and hetero-
geneousness or division ?

How far is whiteness coincident with transparency and
heterogeneousness or division ?

Is anything opaque ?

Is anything opaque? That is the question which ought to
have preceded and superseded some, at least, of the others.
We can only answer it inductively from the results of nume-
rous observations. Glass is a transparent substance, approxi-
mately so, that is to say; for if we look through a plate of
glass edgeways, we find it stops a great deal of light. It is
not so transparent as pure water—and even water, as pure as
it could be obtained by distillation, was proved by Professor
Tyndall to have a blue-green colour when light was passed
through fifteen or sixteen feet of it. A sheet of paper looked
coloured seen through the water, but white seen through the
same thickness of air. Is air, then, our only perfectly transpa-
rent medium? Even air is far from transmitting all the light
which enters it. A comet is almost incalculably more transpa-
rent than the earth’s atmosphere. The light of a star passing
through hundreds of thousands of miles of a comet’s atmo-
sphere and nucleus loses less light than in passing through
the thin stratum of air which covers the earth ; yet even the

158 PROCTOR, ON LIGHT.

comet is imperfectly transparent, and we do not know whether
even the luminiferous ether itself allows the passage of hght
without some loss, but we know that glass is as much opaque
compared with it as gold is when compared with glass; and
from this we readily learn to believe that transparency and
opacity are only comparative terms—that nothing transmits
all the light, and nothing is entirely impervious to light; and
this supposition is confirmed by experience, so far as I have
been able to examine so-called opaque bodies in a way which
gave reasonable prospect of satisfactory results. I will not
trouble you with a detailed account of the experiments, but
simply refer you to the table, and the objects to be seen
under the microscopes :

LIGHT TRANSMITTED.

Through Gold leaf. . . . .is Green.
sa 5, tempered ... 0"! sBEOWa.
4S » chemical films . Gray-violet.

is aS powder. Red, purple, or blue.
~ Silverleaf . . . Gray-violet.

», Chemical films . Purple or brown.
a CORDES sos puedes) SA ermeed.

Ey Antimony “1. si s~ yy eras

mf NESENIC 7 io oe elie nahi le hn, ee Wa

$3 PARTING) 4 5 Tul asaotpeeng CREE

:; Palladimm oc eee «iis Ronen

ey Rhodium. .. . .,.... Brown or blme:
pats, CRATCORL (25. : «suet a RCE

me Todine.-.. .. .., Red-brown:

There are several objects on this list of which I have not
got specimens; they will be found fully described, and their
mode of preparation explained, in a paper by Faraday on
“Gold in relation to Light,” which was published in the
‘Philosophical Magazine’ a year or two since.

The tempered gold and silver leaf are remarkable for their
great transparency, compared with that which has been
beaten since it was annealed. May we suppose that the
greater mobility in the molecules which characterises the
annealed metal facilitates the luminous undulations? Or
that there is an increased distance between the molecules
which allows of the undulations passing more freely between
them ?

The chemical film of silver has two colours—inky purple
at one part, and brown at another; probably others of the

PROCTOR, ON LIGHT. 159

metals will be found by different observers to have colours
different from those here attached to them.

The antimony and arsenic were deposited from their com-
binations with hydrogen, as usually practised by the analyst.
Of course this metallic arsenic must not be confounded with
its white oxide, which is known by the same name. The spe-
cimens of charcoal are prepared from cork, pith, and common
deal. Their tissues are not disintegrated by burning, and
this affords us a ready means of obtaining amorphous carbon
in thin films. In the deal charcoal the glandular deposits
which characterise the vessels of coniferous trees may still be
observed.

Returning to our questions, “ What is the nature of proxi-
mate opacity?” The illustrations which I have given show
that most bodies transmit a coloured light, the colour deepen-
ing as the thickness increases, until it is so dark that we
call it opaque ; but there is no reason why all colours may
not be absorbed equally, and then we have gray light trans-
mitted. This is the general result, as might be expected,
with a heterogeneous body consisting of particles of various
refracting powers, and each individually of little absorbing
power. In most instances we find the opacity caused by
both a considerable absorbing power and the action of
heterogeneousness, as explained when treating of the bundle
of plates.

It is more convenient to use words in their generally re-
ceived meaning, therefore I will continue to call bodies opaque
which, under ordinary circumstances, transmit no appreciable
light ; and, with this qualification, again ask, “ Are all opaque
bodies black when in a fine state of division ?” The question
was suggested by the fact that copper, deposited by electro-
type, is of its usual colour if the current is of suitable inten-
sity ; it becomes granular and purple brown if the current is
somewhat too powerful, and becomes pulverulent and almost
black if the current is very intense. Iron, reduced by
chemical means from its oxide, without undergoing fusion, is
bright, dark gray, or almost black, according to the degree of
comminution in which it is obtained. Platinum obeys the
same rule. Coke is a shining gray where the surface is
smooth ; but when finely powdered, is black. So we might
multiply instances; but there are exceptions, and they prove
that though it may be a rule it is not a law. I will only
adduce one example, that is, gold. Faraday has shown that it
is a ruby red, a fine blue, purple, brown, &c., under different
circumstances, but he did not obtain it black.

The other two questions, regarding the blackness or

160 PROCTOR, ON LIGHT.

whiteness of substances in a fine state of division, and how
far that is dependent upon their degree of opacity or trans-
parency, may be shortly dismissed, for we have already con-
sidered the action of comminution on bodies of considerable
transparency, and we have concluded that all substances are
in some degree transparent. We have only now to repeat that
reduction to a powder produces subjacent surfaces which re-
flect some of the light which passes through the first surface ;
the greater the degree of comminution, the more light is re-
flected from the subjacent substances. But reducing a substance
to powder, by converting its surfaces into numberless facets,
inclined at all conceivable angles to the general plane of re-
flection, diminishes the amount of light availably reflected
from the primary surfaces, which will be more clear by con-
sidering it with the diagram before us.

In the diagram we have four eyes looking at different
kinds of surfaces:—No. 1 will receive a certain amount of

light reflected from the plane surface. No. 2 will receive little
more than half the quantity ; it is supposed to be looking at
a grooved surface in which the dentations are flat on the top,
and separated by indentations of an equal width; half the
light falls upon the tops of the ridges, and is reflected the
same as from the plane; the other half falls into the grooves,
and cannot reach the eye, except after many reflections and
much loss. No. 3 looks at a serrated surface, in one portion

NS ce a ee Ce ee

a OOD etry

A
:
4
i:

PROCTOR, ON LIGHT. 161

of which A, the teeth, point from the eye; a considerable portion
of light falls under the teeth, and is thus hidden from view ;
in the other case, at B, the eye sees principally the under or
shady side of the teeth. The fourth eye is represented as
looking at a powder, which, from its irregular nature, may be
supposed to combine those various actions and many others
tending more or less to detract from the amount of light
entering the eye by direct reflection; there may be just as
much reflected, but part being reflected from one particle to
another, is more or less lost to sight. But if the particles of
this powder are transparent, a portion of light is transmitted
through several particles, one after another, and from the
surface of each of these a portion is reflected, adding to the
general luminosity. Probably the great reflecting power of
white powders is partly due to some of the particles receiving
the incident light at such an angle that the transmitted por-
tion undergoes total reflection from their under side. I shall
have occasion to notice total reflection again presently, and
in the mean time I may remark that we should expect, from
what I have been just pointing out, that a finely laminated
material, such as this specimen of mica, would have the
greatest possible reflecting power. I shall draw attention to
this laminated mica again in speaking of lustre, and you will
have the opportunity of observing that it really is a very
powerful reflector.

Reverting to the powder, we may say that, with a certain
degree of fineness, the quantity of light refiected from the sub-
jacent surfaces depends upon the absorbing power—the more
absorbing power, the less light.

Thus we conclude that bodies become lighter coloured by
powdering, if the absorbing power is so small that the reflec-
tion from the subjacent surfaces more than compensates for
the loss of reflection from the breaking up of the primary
surface ; and they become darker if the absorbing power is so
great that the reflection from the subjacent surfaces does not
compensate for the loss of reflection caused by the breaking
up of the primary surface.

So far I have endeavoured to make our progress slow and
sure, but I wish to lead you through a variety of other con-
siderations which would render my paper too lengthy if treated
in the same careful manner; I will, therefore, treat the remain-
der of the subject more briefly, more lightly, indulging in more
speculation and less examination, and, I trust, it will be
equally suggestive and less tedious than that which is

ast.

What is light? Undulation in luminiferous ether. What

162 PROCTOR, ON LIGHT.

is heat? A motion in the molecules of matter. So, at least,
they are commonly defined.

If heat is a motion in the molecules of matter, it cannot
radiate except in the presence of matter. If radiation takes
place with the velocity of light, we can only suppose it to be
an undulation; if it takes place through inter-planetary
space, we can only suppose it to be an undulation in lumini-
ferous ether. What is heat? An undulation in luminifer-
ous ether.

Light is only known tous through the nerves, and through
the chemical action it exerts upon matter. A sensation and
a chemical force, both of which we attribute to motion in
the molecules of matter. Light a motion in the molecules of
matter ?

You perceive how readily the definition of one has been
made to fit the other. How indefinite is our idea of any
force in the abstract. We know the forces only through their
effects upon matter; and though we wish to comprehend
the cause which produces this effect, we must be very cautious
in adopting any definition, for by confining our ideas within
a false boundary, we may blind ourselves to the reception of
truths which would otherwise flow upon us.

The time was—not long ago—when it was thought that
light could be deprived of its heating power; when it was
thought that light falling upon a black body was annihilated
or absorbed. But the doctrine of the conservation of force
has dispelled that of annihilation, and the theory of absorp-
tion is no more tenable. Expose some charcoal to sunshine
for a thousand years, it goes on absorbing with undiminished
power; but set fire to the charcoal, and will you behold that
that thousand years of glorious sunshine is concentrated into
a few moments? No! For it is not there to come out. The
sunshine which has poured into it is no more there than if
you had poured water into a sieve. It has been coming out
as fast as it went in. It fell upon the charcoal as light, but
it left it as heat, or some other invisible modification of
force.

There is no such thing as annihilation, no such thing as
absorption of light. Dark bodies only have the greater
power of converting it into something else, a power probably
the converse of that possessed by phosphorescent and fluo-
rescent bodies, which convert some invisible rays into lumi-
nous ones.

The time was—not long ago—when light was believed to
be reflected from the surfaces of bodies. And now it is only
when we are on our guard that we bear in mind the thick-

PROCTOR, ON LIGHT. 163

ness of matter required to reflect a ray. We know that in
a soap-bubble we often see patches so thin that they do not
reflect light, though they are still possessed of two surfaces.
Faraday observed that some of the gold leaves he experi-
mented with, when reduced very thin by chemical means,
lost part of their reflecting power, though they continued to
be free from any material injury to their surface or integrity ;
and the proof that some depth of matter, or, as Faraday ex-
presses it, more than one thickness of atoms, is concerned in
ordinary reflection. It is interesting to speculate upon the
nature of the phenomena, and the motions of atoms which
take place in reflection, and upon the influence of this neces-
sary thickness of matter. Is the luminous wave only re-
flected in one phase of an undulation? If matter at some
depth, however small, beneath the surface, continues to reflect
light, at what depth does it cease to do so? Does it ever
cease to do so? Or does the transmitted ray, as it speeds on
its journey, always send back a beam in the opposite direc-
tion ?

Different kinds of reflecting surfaces have different appear-
ances; this is probably due in some measure to the effect
produced upon the light by its passage into and out of that
thickness of matter which is concerned in ordinary reflection.

Of homogeneous matter we have opaque and transparent,
the former giving metallic lustre, the latter vitreous. As a
general rule, if not a universal, we find the more nearly a
substance approaches the metals in opacity the more it
resembles them in the nature of its lustre. Thus, sulphurets
are in many cases very nearly opaque, and very like metals
in the nature of their lustre. Carbon in its opaque form
is a brilliant steel gray, while its transparent form has the
vitreous lustre.

A micaceous or pearly lustre is the result of the super-
position of a number of films of transparent material, the
reflection from the first surface being added to by the reflec-
tions from the subjacent surfaces.

I use the word micaceous in preference to pearly, because
the latter word so often is understood to mean iridescent, like
mother-of-pearl ; but the lustre now spoken of is free from
prismatic colours. You will see it nicely illustrated in the
specimen I exhibit, which is a little circular piece of mica,
which, by heating, has been split into thin lamine at the
edges. These lamin, when taken separately, are still trans-
parent ; but the great number of them, with air between each,
scarcely admit the passage of any light, but reflect a great
deal; while the middle of the disc, which contains the same

164 PROCTOR, ON LIGHT.

amount of the same kind of matter, only wanting the air,
transmits light freely and reflects but little.

A waxy lustre has the reflection from the primary surface
supplemented by reflections from irregular particles beneath
the surface; we have the phenomena also illustrated, and
that on a larger scale, in polished marble and glazed earthen-
ware, while the earthenware without a glazing reflects light
without the appearance of lustre to the naked eye. I would
willingly have enlarged upon the subject of lustre and its
theories, but time is outstripping me, and I must hasten on.

The colour reflected from a substance is not always the
same, and not always different from that transmitted. It is
often, evidently, only with a conventional correctness that we
state the colour of a material. We say gold-leaf is yellow,
but we might also say that it is green—the transmitted light
being different in this case from the reflected. But, further
than this, we may say that gold is yellow by reflected hght ;
but only as a convenient and conventional statement is it
admissible, for we have seen that gold is brown, yellow, red,
purple, and blue. It might be difficult to prove that these
colours were any of them purely reflected. We have just
seen reason to believe that reflection is always accompanied
by transmission through a certain depth—that is, “ through
that thickness of matter concerned in ordinary reflection ;”
and we have just speculated upon the probability of trans-
mission being always accompanied with some degree of re-
flection. I might instance a long list of colouring principles,
each of which reflects a colour different from that which it
transmits, but I will only draw your attention to my specimens
of the familiar mauve and magenta, which reflect respec-
tively green and yellow light. I cannot, however, leave the
subject of reflection without questioning the correctness
of another common statement, When light falls upon glass
and is reflected, we say the glass reflects it; overlooking, it
often happens, that the rare medium is, equally with the
denser, concerned in the reflection which takes place. From
a bright surface of glass in air there is considerable reflec-
tion; from the same surface when under water there is com-
paratively little, and if immersed in turpentine there is
almost none. Is it not the surface of air, water, and tur-
pentine, in contact with the glass, in these several instances,
which reflected the light? Ifso, we may say that air reflects
most light, water less, and turpentine least. If it is the glass
which reflects in all three cases—the glass reflects most light,
the glass reflects less light, and the glass reflects least light.
Do not suppose that I wish to persuade you that the glass

PROCTOR, ON LIGHT. 165

has no part in the reflection; I only wish to show, in a striking
manner, that it isnot the only agent—it is but a partner in the
firm which does the business. A very good illustration of
these two propositions is found in the total refiection which we
observe most conveniently with a prism. The lhght entering
by the surface A falls upon B, and is reflected through C. The
brilliancy of the reflection is inteuse when air is in contact

nae ke
a

i”
eg

with the surface B; but if you bring a second prism in con-
tact with it, as at D, the reflection ceases, and the ray passes
straight on. If it was the surface of the glass which reflected,
why not have a greater reflection when you have two surfaces?
But if it is the air which reflects, the displacing of the air
by the second glass surface accounts for the reflection ceasing.
If you place water there, you have a reflection very much
less than from air, but very perceptible; with turpentine it is
scarcely visible ; and if mercury is substituted, the reflection,
though greater than with these other materials, is yet de-
cidedly inferior to that from air. No reflecting surface with
which we are acquainted will bear any comparison with the
brilliance of air, when total reflection from its surface is
obtained in this way. Let me caution you not to misunder-
stand me on this point. I do not say that total reflection
cannot be obtained from anything else but air; but that, in
practice, it is always obtained from a surface of air in con-
tact with glass or some other highly refracting substance,
the glass as well as the air being requisite for its production.

In quitting the subject of reflection, I may remark that
the brilliant surfaces of mercury, polished silver, &c., do not
reflect so much light as we might suppose from their bright-
ness ; even common white paper reflects as much.

To illustrate this I have formed a little conical shade of
white paper; under it is a convex reflector, formed by silver-
ing the concave side of a watch-glass, and on the middle of

166 PROCTOR, ON LIGHT.

the reflector is a little white-paper label. While covered by
the shade the reflector appears of a dead-gray colour. It
reflects abundance of light, but it wants the reflected shadows
which are essential to the appearance of lustre, and while it
is thus uniformly illuminated we easily perceive that the
white paper reflects more light than the silver.

As the uniform light obtained by the use of these white-
paper shades very much facilitates our estimate of the reflect-
ing power of the objects under them, we will do well to com-
pare the laminated mica and carbonate of magnesia with the
white paper and silver. Under the other paper shade I have
placed a small article of polished silver, just to draw your
attention to the remarkable analogy between the appearance
of a polished surface with this uniform illumination and the
dead-white silver under ordinary circumstances.

Sir D. Brewster, and other writers on optics, give the
length of a wave of white light, the number of undulations
in an inch and the number in a second, calculating it as
the mean of the number of undulations in the coloured rays,
apparently forgetting that it is not the mean but the sum of
the colours which forms white light—the mean being, ac-
cording to Brewster’s own table, yellow, with a tinge of
green; various writers have, probably, copied from the same
source without investing thought upon the subject, one in-
dication of which is, that several say so many millions of
millions, whereas it would be more natural to say so many
billions. I will just give you Brewster’s figures, and then
pass on:

Length in parts of an inch. | No. in an inch. ja ae ae
White . .0°:0000225 44-444 541
Yellow . . 0:0000227 44.000 535
Yellow-green 00000219 | 4.5600 555

You observe the numbers given for white light are the same
that would belong to a colour between yellow and yellow
green. White light, we may conclude, is not a definite un-
dulation, nor a definite mixture of undulations, but a variety
of mixtures of undulations, in any of which mixtures the
average length of an undulation is that given by Brewster and
others, but the number in an inch or a second is incalculable
and indefinite. The length of the undulations in a pure un-
mixed colour is probably definite, and we have no reason to

a
a
P

PROCTOR, ON LiGHT. 167

object to the measure and number usually adopted; we shall,
therefore, accept them for further argument.

The length of an undulation of violet light is seventeen
milhonths of an inch; the red undulation twenty-six mil-
lionths, or about one half longer; undulations longer or
shorter than these not being visible. The colours observed
in soap-bubbles and other thin films are produced by inter-
ference of the luminous waves. The colour produced depends
upon the relation between the thickness of the film and the
length of a wave of light. A film of air four millionths of
an inch thick produces the same colour as a film of water
three millionths, or of glass two and a half millionths of an
inch thick. Therefore we conclude that the length of the
light-wave varies with the medium. An undulation in air
‘measuring four will measure only two and a half when it
enters glass, and will again elongate to its former measure on
its exit. From these premises we may deduce various inter-
esting conclusions. Faraday found that gold-films were iri-
descent when they were only one tenth the thickness at which
air ceases to be iridescent. May we then conclude that
light, while passing through gold, consists of undulations only
one tenth the length of those in air? Newton found that
the thickness of films of a given colour was inversely propor-
tionate to their indices of refraction. May we then conclude
that gold has a refracting power in like proportion? If we
say that luminous undulations, which in air measure twenty-
two millionths of an inch, look yellow when they enter the
eye, and in that organ measure one third less, in consequence
of its refracting power, then we come to the singular conclu-
sion that the blue sky is yellow, sunshine is red, and the rosy
tints of evening are not luminous at all till they enter the
-eye. Ifthe colour depends upon the length of the light-wave,
and the length of the wave depends upon the refracting power
of the medium through which it is passing, every beam of
light changes colour; red it may be on its passing through
the region of the stars, yellow or green it may be when it
enters the air, blue or violet when it enters water, non-lumi-
nous as it passes through glass. But if light, which we per-
ceive as violet while it exists in the aqueous humour of the
eye, was red originally, what colour must that light be which
we perceive as red? Its undulations in air must be too long
to be luminous. This introduces us to the solemn thought
that all this vast universe is dark! Light exists only in the
eye. It is only a sensation, a perception of that which in
nature exists as a force capable of producing a sensation.
We would feel grieved at the thought of light and sound

VOL. I1I.—NEW SER. N

168 HOBSON, ON INDIAN DESMIDEX.

having no tangible existence independent of ourselves were
it not for the glorious hope that all nature is full of forces
equally grand, forces which we have not the power of per-
ceiving, but which, with a higher development of our organ-
ism, may be sweet as music and genial as sunshine.

[In acceding to the request of the Newcastle Microscopical
Society, that I would allow the preceding paper to be pub-
lished, I think it but justice to myself, as well as to my
readers, to state that it was written with the expectation of
its being heard only by personal acquaintances; and its
object was not so much to establish any new facts, as to
draw attention to, and stimulate thought upon, a few com-
monplace phenomena and observations.

The former circumstance must be my apology for the
colloquial style in which it is written ; and the latter circum-
stance will, I hope, excuse the free use I make of speculation
and queries. It was not necessary for my purpose that
speculations should be well considered, so long as they were
suggestive of interesting considerations. ;

11, Grey Street, Newcastle.

Notes on Inp1an Desmipex. By Jut1an Hozson, Bombay
Staff Corps, Mahabuleshwar.

I rorwarp for publication two drawings of a Micrasterias
and of a species of Docidium, to-
gether with a description of the
latter. They are, I think, new
species. The Micrasterias appears
to be something allied to M.
Baileyt, Ralfs (pl. xxv, ‘ Suppl.’),
but that form is not in the least
serrated. The Docidium, in some
degree, resembles the one figured
in the same plate, but the teeth
in the form I propose calling D.
pristide are very acute, and the
terminal processes differ greatly.
These two species are very com-
mon here, but nowhere else in
the Bombay Presidency have I come across them. I have

x 350 diam.

HOBSON, ON INDIAN DESMIDEX. 169

met with upwards of half of the Desmidez described by
Ralfs up here. It may be that the climate is so much more
like that of England than it is down on the plains. Many
English ferns are met with here that are never found in the
plains, and the same may also be said of the mosses.

DESMIDEX.

1. Docidium, Bréb.
1. D. pristide, Hobs.

Frond slender, constricted at the middle ;
suture strongly marked, but not projecting
on the sides; segments about nine times
longer than broad, each with about twelve
whorls of sharp, tooth-like projections, much
resembling the saw-shaped weapon of the
saw-fish.* Each tooth on the segments
is visible, in their empty state, under its
own focus. Terminal processes of very pecu-
har form.

Hab. In the streams running through
the Chinamen’s Gardens, near the lake at
Mahabuleshwar; very common.

This species can hardly be identical with
Professor Bailey’s D. verticillatum, inasmuch
as the teeth are sharp, and not obtuse, as in
that species; nor are the terminal processes
alike, which in the present species differ
from those of any other species of Docidium
with which I am acquainted.

2, Micrasterias, Ag.
1. WM. Mahabuleshwarensis, Hobs.

Frond oblong, rather longer than broad,
slightly constricted in the middle, The sur-
face of the frond is covered with small
granules, distinctly visible, bordering the
whole of the sinuses. Segments trilobed ;
lobes bipartite, the end ones considerably
exserted, having a broad but shallow notch,
concave ; sinuses serrated.

Length of frond . . . . » goth of an inch.

200
1

Breadth ,, ET oc rel ke a

* Whence the specific name.

170 ROBERTS, ON BLOOD-CORPUSCLES.

Hab. In the streams running through the Chinamen’s
Garden, near the lake at Mahabuleshwar, about 5000 feet
above the sea-level.

In this form each angle of the end lobe appears to be
bifid; but as the longer ends come into focus before the
shorter ones, I am of opinion that the shorter ones are the
ends of the opposite side, which only slightly come into view,
and give the bifid appearance ; but with a Wenham’s binocular
this would easily be proved. The ends are narrow, and
minutely toothed.

May 12th, 1863.

On Pecutiar AppEarances exhibited by BLoop-coRPUSCLES
under the influence of Sotutions of Macunta and Tannin.
By Wirx1am Rozerts, M.D., Physician to the Manchester
Royal Infirmary. Communicated to the Royal Society
February 18, 1863.

(‘ Proc. Roy. Soe.,’ vol. xii, p. 481.)

Tue object of the following paper is to give an account of

certain observations which seem to indicate that the cell-wall .

of the vertebrate blood-disc does not possess the simplicity
of structure usually attributed to it.

It is well known that the blood-corpuscles, when floating
in their own serum, or after having been treated with acetic
acid or water, appear to be furnished with perfectly plain
envelopes, composed of a simple homogeneous membrane,
without distinction of parts. But, as will appear from the
observations here to be related, when the blood is treated
with a solution of magenta (nitrate of rosanilin) or with a
dilute solution of tannin, the corpuscles present changes
which seem irreconcileable with such a supposition.

Attention is first asked to the effects of magenta. When
a speck of human blood was placed on a glass slide and
mixed with a drop of a watery solution of magenta,* the
following changes were observed. ‘The blood-discs speedily
lost their natural opacity and yellow colour; they became
perfectly transparent, and assumed a faint-rose colour; they
also expanded sensibly, and lost their biconcave figure. In

* The solution I found to answer best in these experiments was a nearly
saturated solution of nitrate of rosanilin, made by boiling the salt in water,
and filtering after it had stood twenty-four hours, then diluting slightly with
water to prevent precipitation.

ROBERTS, ON BLOOD-CORPUSCLES, 171

addition, a dark-red speck made its appearance on some
portion of their periphery. The pale corpuscles took the
colour much more strongly than the red; and their nuclei
were displayed with great clearness, dyed of a magnificent
carbuncle-red. Many of the nuclei were seen in the process
of division, more or less advanced; and in some cells the
partition had resulted in the production of two, three, or
even four distinct secondary nuclei.

These appearances were first observed in freshly drawn
blood from the finger. Subsequently blood from the horse,
pig, ox, sheep, deer, camel, cat, rabbit, and kangaroo, was
examined in like manner. The effect on the red corpuscles
(to which all the observations hereinafter recorded are ex-
clusively confined) was, in each instance, the same as in
human blood.

The nucleated blood-dises of the oviparous classes, when
treated similarly, yielded analogous results. The coloured
contents were forthwith discharged; the central nucleus
came fully into view, and assumed a deep-red colour; the
corpuscles expanded, they lost something of their oval form,
and approached nearly, or sometimes quite, to a circular out-
line. Lastly, there appeared on the periphery a dark-red
macula, of a character and position resembling that seen on
the mammalian blood-dise. Such a macula was detected in
the fowl, in the frog, and in the dace and minnow.

Owing, however, to the large quantity of molecular matter
floating in the serum, and which was coloured by the magenta,
difficulties were found in preparing specimens which carried
conviction that the macula in question was not an adhering
granule. It was also found that it required a nice adjust-
ment of the relative quantities of the solution and of the
blood to bring it out. It was only when the right proportions
were hit, and especially when the discs were made to roll
over in the field of the microscope, that the existence of a
coloured particle organically connected with the cell-wall
could be satisfactorily made out. The best specimens were
prepared from human blood drawn in the fasting condition,
and from the blood of a kitten two days old.

From well-prepared specimens of human blood the follow-
ing particulars were gathered (see fig. 1) :—Nearly every
dise possessed the parictal macula; it could be distinctly
recognised in nine tenths of them, and in several of those
in which it was not at first visible it came into view as the
corpuscles revolved in the field.

The macula was clearly situated in the cell-wall, and not
in the interior of the corpuscle. Usually it appeared as if

172 ROBERTS, ON BLOOD-CORPUSCLES.

imbedded or set in the rim of the disc, like the jewel in a
diamond ring; but sometimes it occupied various positions

TGS,

A. Human blood. —_-B. Fow!l’s blood treated with magenta.

on the flat surfaces, and when so placed the spot was difficult
or impossible to detect.

It commonly presented a thickly lenticular shape; some-
times it was square, and occasionally in appearance vesicular.
(Fig. 1, A, a.) In some instances, and especially in long-kept
specimens, the particle was seen to stand out on the outline
of the disc like an excrescence. Still more rarely, instead of
a spot, a thick red line ran round the circumference for a
quarter or a third of its extent. (Fig. 1, A, 0.)

As arule, it was extremely minute, covering generally not
more than a twentieth or thirtieth of the circumference; but
there was a considerable variation in its magnitude and dis-
tinctness. Very rarely two specks could be seen; but the
occurrence of adhering granules rendered the verification of
this point extremely difficult.

This description applies, so far as the inquiry has yet been
prosecuted, to the mammalian blood-dise generally, making
allowances for differences in size. In the camel the macula
occupied indifferently any part of the oval outline. ,

Among the oviparous classes, the blood of the fowl, frog,
dace, and minnow, has been most fully examined (see fig. 1, B);
but the blood of the sparrow, duck, goose, and turkey, was
also searched, as well as that of the newt and carp.

In all of these a tinted particle appeared, more or less
constantly, in the cell-wall, when the corpuscles were treated
with magenta.* The presence of a central nucleus in these

* Tn order to bring out the best results, it was found requisite to modify
tle strength and quantity of the solution for the different kinds of blood,

ROBERTS, ON BLOOD-CORPUSCLES, 173

classes caused the macula to be invisible more frequently than
in mammalia, inasmuch as it suffered eclipse when situated
over or under the central nucleus.

In the fowl, dace, and minnow, it was found easy to bring
out the parietal macula; in the fish two spots were not un-
frequently seen. The macula was situated indifferently on
any part of the periphery, and sometimes it projected from
the surface. When happily prepared, the specimens were
even beautiful. The central nucleus was dyed of the finest
red; and on the delicate outline of the cell-wall hung the red
parietal macula, offering a not altogether fanciful resemblance
to the astronomical figures representing the moon coursing
in its orbit round the earth.

At this stage of the inquiry it was conceived that an im-
proved demonstration might be obtained by fixing the dye
with a mordant, and then subjecting the corpuscles to a
lavatory process, so as to get rid of the floating granules
which so much interfered with the view. For this purpose
a solution of tannin (which is one of the mordants for
magenta used in the arts) was employed, and some advan-
tage was found therein. When a solution of tannin, of
three grains to the ounce of water, was added to blood that
had already been dyed with magenta, it was found that the
parietal macule had their colour intensified, and that they
became more conspicuous objects. The investigation was,
however, not pushed any further in this direction, for it was
found that tannin alone produced an even more remarkable
effect than magenta. To this effect I now desire to draw
particular attention.

When a solution of tannin, of the strength of three grains
to the ounce, was applied to human blood, or to that of the
horse, ox, sheep, pig, or cat, the blood immediately became
turbid ; and when a drop was placed under the microscope,
the corpuscles were found greatly changed, as represented in
fig. 2.

Each corpuscle appeared to have thrown out a bright,
highly refractive bud or projection on its surface. The pro-
jections were usually about a fourth part of the size of
the corpuscle on which they were fixed ; but they varied con-
siderably. Some were only minute bright specks in the cell-
wall; others were half or even two thirds as large as the
corpuscle itself, Very rarely (in mammalian blood) two such

This, doubtless, depended upon the varying densities of the liquor sanguinis
and cell-contents in different animals,

174 ROBERTS, ON BLOOD-CORPUSCLES.

projections were seen; and as rarely a corpuscle was devoid
of any.

The projections were commonly round or dome-shaped,
bordered with a deeply refractive outline. Frequently a

Human blood after the action of tannin.

a. Double pullulation.

b, 6. Hooded modification.

c. Outline of the cell seen continuously through the pullulation.

d. Bursting of the pullulations independently of destruction of the cell.

minute, apparently vesicular body could be seen within this
outline, and then the projection presented a curiously hooded
aspect. (Fig. 2, 6,0.) In a urinary deposit from a lad twelve
years of age, containing pus and blood, nearly every blood-
disc. presented the hooded appearance after the addition of
tannin.

The blood of the fowl, turkey, duck, and goose, showed
exactly analogous phenomena with the same reagent. (Sce
fig. 3.)

“The projection had sometimes the hooded character with a
vesicular body within; sometimes the projection offered no
such distinction of parts. It was situated indifferently on any
part of the periphery. In all the birds examined a second
projection was as rare as in mammalia.

ROBERTS, ON BLOOD-CORPUSCLES. 175

Of fish, the dace, minnow, and carp, were examined. The
tannin solution produced a similar effect to that seen in the fowl
—with this difference, that a large number of corpuscles had

Blood of fowl after the action of tannin.

two projections instead of one. In the carp double and single
projections occurred in about equal proportions; in the
minnow double projections were all but universal. The
second projection was situated sometimes at the opposite pole
of the disc, sometimes in near proximity to its fellow, or at
any point between. Very rarely a third projection was seen
in the dace.

In the blood of the frog there was a strong tendency to the
indefinite multiplication of the projections; two, three, four,
and eyen five, would rise in succession on the surface of the
disc. It appeared, too, not unfrequently as if the entire outer
membrane of the cell was detached from the parts beneath, and
raised into eight or ten unequal elevations, giving the outline
of the disc an irregularly crenate appearance.*

The formation of these singular projections, or pullulations,
on the blood-discs could be watched without difficulty by
placing a drop of the tannin solution beneath the covering

* There isa certain adjustment of the proportions between the tannin
solution and blood required to bring out the effects described in this paper ;
but the proper proportions are, practically, very easily found after a few
trials for each kind of blood. In mammalian blood one drop of blood mixed
in a conical glass with four or five of the solution generally answered per-
fectly. Any considerable,excess of blood or solution above these proportions
caused destruction of the corpuscles.

176 ROBERTS, ON BLOOD-CORPUSCLES.

glass, and permitting a little blood to insinuate itself into the
solution under the microscope. As the blood flowed m and
mingled with the tannin, the corpuscles were observed gra-
dually to enlarge, and then suddenly, without previous warn-
ing, to shoot out the projection. As a rule, it does not
appear to grow afterwards. The phenomenon was finely seen
in the defibrinated blood of the fowl after it had been allowed
to sink through a column of syrup (sp. gr. 1025) im a test-
tube. Fowl’s blood washed in this way was mixed, in a little
glass, with about five times its volume of the tannin solution,
and a drop immediately put under the microscope. The
discs first enlarge and become rounded, and the central nu-
cleus comes into view. In thirty or forty seconds the pullu-
lation begins ; and each corpuscle, with instantaneous rapidity
and without previous sign, throws out its bud. The disc
itself suffers not the least disturbance during this act; it pre-
serves its symmetry unchanged, as ifit had no concern, beyond
that of proximity, with the sudden apparition on its surface.

No visible rupture of the cell-wall took place. The cir-
cular outline of the latter could sometimes be distinctly fol-
lowed through the projection (fig. 2, ¢); and as the altered
corpuscles revolved in the field of the microscope, the projec-
tion appeared to be organically connected with it, but to
form no part of its cavity. In the human blood-discs the
application of acetic acid, soon after the tannin, caused, on
two occasions, the pullulations gradually to subside, and
finally to disappear, and then the disc resumed its original
circular outline. I failed to produce this “redux” effect in
the fowl; and did not always sueceed with human blood,
probably because the change produced by the tannin had
gone too far.

The modification noted under the term “ hooded” appear-
ance depends, I believe, upon secondary conditions of con-
centration and quantity of the tannin solution in comparison
to the blood. When the hooded condition has been watched
in the act of occurrence, it was noticed that the outer hood
was shot out first, and instantly after this the highly refrac-
tive vesicular body made its appearance within. The con-
tents of the hood (excluding the vesicular body) appeared
usually to refract the light like the body of the cell, or even
less strongly ; sometimes, however, more strongly. ©

The effect of tannin did not cease with the production of
the elevations just described. At first the cells and their
projections preserved their elasticity; but after a while (a
few minutes, or several hours, according to the proportions
used) the corpuscles and their projections become solid, and

ee a. a | ee ee, ee

tags te

ROBERTS, ON BLOOD-CORPUSCLES. 177

they could be cracked by pressure under the microscope like
starch-granules. More slowly the same destruction overtook
the corpuscles spontaneously; and this significant fact was
observed in the course of it:—sometimes the cell ruptured
before the projection, the latter persisting as a bright granule
amid or near the débris; sometimes, on the other hand (in
the horse), the projection broke up before the dise to which
it was attached. In this latter case the hood (if there were
any) broke up first into a scattered nebula of granular appear-
ance, and then the nucleolus-like body within burst into
three or four bright fragments. (Fig. 2, d.) This train of
events seemed to remove all doubt as to the complete isola-
tion of the projection from the cavity of the disc. Last of
all, the disc itself began to crack; in a few days all my spe-
cimens were thus destroyed.

In addition to magenta and tannin, the following sub-
stances were tried, but they did not produce phenomena in
the least analogous with the foregoing :—gallic acid, ferro-
cyanide of potassium, santonine, sulphate of magnesia,
alcohol and water, solutions of carbolic acid, of atropine,
morphia, iodine, sugar, gum, glycerine, and infusion of
coffee.

A solution of picric acid produced the appearance of a
parietal particle like that brought out by magenta, except
that it was not coloured. An exactly similar appearance was
on one occasion observed in blood-corpuscles in the urine of
a patient with acute Bright’s disease.

When magenta was applied after the process of pullulation
had taken place, the projections were found to take the dye
strongly, and especially the vesicular body within the hood.
By this proceeding beautiful and remarkable objects for
microscopical examination were obtained. In the fowl, dace,
and minnow, the projection was tinted earlier than the central
nucleus—probably from its more ready access to the pig-
ment. The explanation of these appearances presents great
difficulties, and in the present state of the inquiry can only
be offered provisionally.

The effect of the magenta solution is not merely to tint,
and so render visible a very minute body. In watching the
effect of magenta, the first thing observed is that the natural
yellowish colour of the dise is discharged, and that a faint
rose tint is assumed in its stead. The discs at the same time
lose their biconcave shape. The parietal macula is rather
“ brought out” than revealed, and the action of the solution
is, to a very great extent, of a simply osmotic character. -

The action of the tannin solution is likewise in the main

178 ROBERTS, ON BLOOD-CORPUSCLES.

of a similar nature, but modified in some very peculiar man-
ner. Its first operation is to cause the corpuscle to en-
large by imbibition, and this goes on progressively until at
length the cell is destroyed. If the solution be strong, this
destruction supervenes at once. ‘The tannin also unites with
the cell-contents and coagulates them, imparting to the cor-
puscle, finally, a solid consistence. The conditions of the
imbibition are disturbed by the previous application of ma-
genta; for no pullulation, or at most only traces, occurs when
the corpuscles are treated first with magenta and then with
tannin.

The bearing of these observations on the current views
respecting the structure of the vertebrate blood-dise is im-
portant. They seem to warrant the inferences drawn in the
two following paragraphs:

1. The exact identity of the appearances produced in the
blood-dises of the ovipara with those observed in the mam-
malian corpuscles lends strong support to the view that these
corpuscles are homologous as wholes; and that the mam-
malian blood-dise is not the homologue of the nucleus of the
coloured corpuscle of the ovipara, as was conceived by Mr.
Wharton Jones.

2. The observations likewise lead to the belief that the
envelope of the vertebrate blood-disc is a duplicate mem-
brane; in other words, that within the outer covering there
exists an interior vesicle, which encloses the coloured con-
tents, and, in the ovipara, the nucleus.

Dr. Hensen,* of Kiel, had already, in 1861, convinced him-
self, from wholly different observations, that the blood-
corpuscles of the frog possess such a structure. On this
view the blood-corpuscle is anatomically analogous to a
vegetable cell, and the inner vesicle corresponds to the
primordial utricle.

The present observations indicate, by direct proof, a dupli-
cation at only one or, at most, two points in the blood-dises
of mammals and birds. Nevertheless certain appearances,
occasionally observed, favour the notion of a complete dupli-
cation. (Fig. 1, 0.)

The admission of this hypothesis, however, scarcely re-
moves the difficulties sufficiently to permit a tenable expla-
nation to be offered of the appearances described in this
paper. Yet, as it may prove suggestive to some other
inguirer, I will not suppress what appears to me the expla-
nation least open to objections. It might be conceived that
the cells enlarged by imbibition, until at length the less dis-

* ¢ Zeitschrift fiir wissench. Zoologie,’ Band xi, p. 263.

Se. ee er

CARTER, ON THE COLOURING MATTER OF THE RED SEA. 179

tensible inner membrane gave way, and permitted an extra-
vasation of a portion of the cell-contents between it and the
outer membrane, its own continuity being in the meanwhile
instantaneously restored by cohesion of the ruptured borders.*
In this way a microscopic drop of the cell-contents would be
lodged between the outer and inner membrane, and com-
pletely severed from the general cell-cavity. The peculiar
modification spoken of as the “ hooded”? appearance might be
due to imbibition of fluid between this microscopic drop and
the outer envelope.

The chief difficulties in the way of this explanation arise
out of the differences of nature which appear to exist between
the projection and the general cell-contents of which it is
supposed to be a detached portion. The projection refracts
light much more highly than the cell-contents; it also is
deeply dyed by magenta, whereas the cell-contents are only
very feebly so.

In conclusion, it may be added that important advantages
may be expected from the use of magenta in histological
researches. Its inert chemical character, its prodigious tint-
ing power, and its solubility in water, eminently fit it for such
a purpose. It will probably prove of especial use in bringing
into sight objects which otherwise evade the visual organs
from their absolute colourlessness and transparency, and from
the equality of their refraction with the medium in which
they exist.

Nore on the Cotourtne Matter of the Rep Sea.
By H. J. Carter, F.R.S., &e.t

To those who have sought for all that has been published
on the colouring matter of the Red Sea, it will be well known
that the excellent memoirs on this subject by M. C. Montagne
in 1844, and M. C. Dareste in 1855 (both in the ‘Ann. des
Se. Nat.,’ the former in sér. 3 (“ Bot.”’), t. ii, p. 331, and the
latter in sér. 4 (“ Zool.’’), t. i, p. 179), are the most elaborate.

* In ihe same manner as a soap-bubble, when bisected, instead of coi-
lapsing, forms, in virtue of the adhesiveness and fluidity of its envelope, two
new and perfect bubbles. ‘That the cell-wall of the blood-dise possesses
some such endowment seems highly probable. I have on several occasions
witnessed, after adding magenta, the total extrusion of the nucleus, both in
the frog and in the newt, without the least collapse of the corpuscles.

+ Extracted by permission from the ‘Annals and Mag. Nat. Hist.,’
March, 1863, vol. x1, p. 182.

180 CARTER, ON THE COLOURING MATTER OF THE RED SEA.

But to Ehrenberg is due the merit of having first described
(in 1826) the nature of the organism from which this
colouring matter is derived. He found it in the Bay of Tor
itself, pronounced it to be an Oscillatoria, and called it Tri-
chodesmium erythreum, which Montagne has advisedly changed
to T. Ehrenbergiu.

No one who has read Montagne’s memoir, and seen his
illustration together with the organism itself, can doubt that
the chief source of the red colour of the Red Sea is owing
to the presence of this little Oscillatoria. Nor can any one
doubt, who has read M. Dareste’s memoir, that this is not
the only organism which colours the sea red in different parts
of the world.

It was to confirm the observations of the latter, as well as
to record the fact itself, that I wrote the paper in these ‘Annals’
for 1858 (vol. i, p. 258), entitled ‘On the Red Colouring
Matter of the Sea on the Shores of the Island of Bombay,”
wherein it is shown that this colour depends on the presence
of a Peridinium (P. sanguineum, Cart.) in innumerable
quantities, in which the chlorophyll at first is green, then
becomes yellow, and lastly red, when the latter, mixing with
the oil-globules generated pari passu in the cell, gives rise
together to greater opacity, and thus reflecting more strongly,
makes the presence of the Peridinia more evident, and causes
the sea in which they are contained rapidly and almost
suddenly to become of a vermilion or minium-red colour;
after which, the Peridinium falls to the bottom and thus
disappears, as if this were the termination of a cycle in its
existence.

Tt was not, however (although I had formerly spent many
months on the coasts of Arabia), until returning to England
in June, 1862, on board the Peninsular and Oriental Company’s
steamer ‘Malta,’ that I had an opportunity of seeing the colour
of the Red Sea which is produced by Trichodesmium Ehren-
bergii—a circumstance to which I should not have alluded
had not Montagne appended to his memoir certain queries
which, in part, I can answer, at the same time that, with much
diffidence, I offer a few remarks on Montagne’s generic cha-
racters of this organism, which are repeated by Kiitzing in
his ‘Species Algarum.’

Commencing, then, with a short account of my own ex-—

perience of Trichodesmium Ehrenbergii in the Red Sea, I
would observe that, on the 3lst of May, 1862, when approach-
ing Aden, we passed through large areas of a yellowish-brown,
oily-looking scum on the surface of the sea, and that on the
2nd of June, when off the Arabian side of the first islands

CARTER, ON THE COLOURING MATTER OF THE RED SEA. 181

sighted in the lower part of the Red Sea after leaving Aden,
it again appeared, and we frequently passed through large
areas of it, sometimes continuously for many miles, until we
arrived off Jubal or the last island in the upper part of the
Red Sea, when, from a calm, we steamed into a strong
northerly breeze, accompanied by heavy sea, and saw no more
of it. Once only I saw a portion of brilhant red and one of
intense green together in the midst of the yellow.

The odour which came from this scum was like that of
putrid chlorophyll, well known to those who have had much
to do with the filamentous Alge, both marine and fresh-water,
but more familiarly to those who have not had this experi-
ence by that which comes from water in which green vege-
tables have been boiled—and hence very disagreeable..

I drew up some of this scum in a bottle, and found it to
be composed of little, short-cut bundles of filaments, like
Oscillatoria; for I had only a Coddington lens with me for
their observation; and on showing them to Mr. Latimer
Clark, the well-known superintendent for laying down the
telegraph-cable through the Red Sea, &c., to Kurrachee, who
was on board, Mr. Clark said that he had observed the
same phenomenon in the Sea of Oman, where he had ex-
amined the filaments of the little bundles with a microscope,
and had found them to be ‘ beaded,” to use his expression,
“ with rounded extremities.”

On arriving in England, I had no time for examining
microscopically the specimens which I had obtained, and
which had been preserved in an equal quantity of alcohol
added to the sea-water in which they had been taken, till
January (1863), when I found the little bundles, which were
still just visible to the unassisted eye, and like so much fine
“sawdust” (to which they have been aptly and commonly.
compared by previous observers, who have seen them without
knowing what they really were), varying in point of measure-
ment, although, on the average, perhaps about =}, inch long
by =, broad, containing about twenty-five to sixty filaments,

100
each of which is about =; inch long by z,,, broad, their
cells, which, of course, are so many discs, being sometimes
thinner, sometimes thicker, than the breadth of the filament,
with rounded cells terminately at the extremities where entire,
but square when the latter have been broken off from the
filament. The bundles bore no evidence of an investing
sheath, but of the filaments being held together by mucus
secreted from them generally.

Further into this description I need not enter, except to
state that the cell was a true Oscillatorial one, charged with

182 CARTER, ON THE COLOURING MATTER OF THE RED SEA.

a few granules suspended in its protoplasm, and that I saw
nothing hke sporidification.

The colour of the bundles to the unassisted eye was still
faint yellowish; but the filaments, under the microscope, were
faintly green.

Of the questions proposed by Montagne (op. cit., p. 355),
the second calls for more information on the size of the
bundles. This has been supplied above, so far as my obser-
vation extends.

The third question calls for information respecting the
presence of Trichodesmium in the Sea of Oman, &c., as
bearing upon the origin of the name “ Erythrean Sea,”
applied by Herodotus to all the seas washing the shores of
Arabia.

I have already stated that I saw the scum in the Gulf of
Aden, also that Mr. Latimer Clark had seen it in the Sea
of Oman; and the following extract from the late Dr. Buist’s
observations on the “ Tuminous and Coloured Appearances
in the Sea” (‘Proceedings of the Bombay Geographical
Society’ for 1855, p. 120) will show that it exists in the
upper part of the Indian Ocean. The account from which
this is taken was communicated to Dr. Buist by Dr. Haines,
as witnessed on board the “ Maria Somes,” in lat. 21° N.
and long. 42° E., and it stands thus:

“In May, 1840, when one third across from Aden to
Bombay, the aspect of the sea suddenly changed upon us,
and at once seemed as if oil had been poured upon its sur-
face. It was still as a mill-pond, and of a brownish, soapy
hue. The water, on being examined, was full of little fibrils,
like horsehair cut across, in lengths of the tenth of an inch
or so. A wine-glassful of it contained hundreds of them.

. . We sniled through them for about five hours ; 3 80
ae they probably extended over a surface of 500 miles.”

The occurrence, then, of Trichodesmium Ehrenbergu in
the Red Sea, the Gulf of Aden, the Indian Ocean, and the
Sea of Oman, is so far substantiated ; and as the yellow colour
in all instances probably passes into red, we have, apparently,
the explanation of the whole of these seas having been called
by the Greeks “ Erythrean.”’ I have not, however, heard
whether it has been seen in the Persian Gulf.

Further, we learn from M. Dareste’s memoir (op. cit.,
p- 208) that Jodo de Castro, in July, 1841, when off Cape
Fartak, which is about the middle of the south- east coast of
Arabia, found the sea so red that it appeared as if it had been
coloured with bullocks’ blood.

In my own experience of the Sea of Oman and the whole

CARTER, ON THE COLOURING MATTER OF THE RED SEA. 183

shore-sea of the south-east coast of Arabia from Muscat to
Aden, where, under its survey, I passed all the months of
the years 1844-45, and of 1845-46, with the exception of
those of the stormy monsoon, viz., June, July, August, and
September, the presence of the scum above described never,
to my knowledge, was once observed. J am, therefore, in-
clined to infer that it is chiefly confined to the sea some dis-
tance off shore. Yet Ehrenberg, in 1823, saw the Bay of
Tor covered with it, even up to the sands.

Lastly, I would advert (but, as before stated, with much
diffidence) to that part of the generic characters of Tricho-
desmium Ehrenbergv in which we find the expression “ prime
rubro-sanguinee, tandem virides,” first used by Montagne
(J. c., p. 8346), and then repeated by Kiitzing in his ‘ Species
Algarum,’ because the facts connected with the accounts
given of those who have seen the scum formed by T'richo-
desmium, together with my own experience of Algee generally,
lead me to the opposite conclusion, viz., that Trichodesmium
is at first green, and subsequently becomes red.

It is true that its chief colour in the Bay of Tor, when
seen by Ehrenberg, was red; it was red, like “red sawdust,”
when seen by M. E. Dupont in the Red Sea (ap. Montagne,
l. c.); but, on the other hand, what I saw in the Gulf of
Aden and in the Red Sea, together with what Mr. Latimer
Clark saw in the Sea of Oman, and Dr. Haines, as above
stated, in the Indian Ocean, was nearly all of a yellow oily
colour; and this is the appearance that I have heard gene-
rally assigned to it by those who have been in the habit of
traversing the seas mentioned.

Next to the yellow colour, red is the most prevalent, and
green least of all. Some of that seen by Ehrenberg was
intensely green; this was the case also with the green portion
that I saw with the red above noticed; while Ehrenberg saw
other portions of a less green colour. So much for what has
been stated respecting the colours under which Trichodesmium
has appeared.

We come now to the usual course presented by other Algze
in arriving at a red colour. If we take the Peridintum which
colours the sea red on the shores of the island of Bombay, we
shall find, as above stated, that it is at first green, then yel-
lowish, and lastly red. In the green stage, the contents of
the cell are so thin and watery that they easily allow the
light to traverse them, and thus the Peridinium passes un-
observed; but as they become inspissated, oil-globules gene-
rated, and the chlorophyll changed first to yellow and lastly
to red, these contents become more opaque; and thus the

VOL, III.—NEW SER, Oy)

184 CARTER, ON THE COLOURING MATTER OF THE RED SEA.

Peridinium, by reflecting much more light than it did at first,
comes rapidly into notice, and by its numbers gives a genera
red colour to that part of the sea in which it may be present.
The same is frequently—indeed, commonly—the course with
Euglena in fresh-water ponds. The little Protococcus which
colours the salt red in the salt-pans of the Island of Bombay,
is green ii the active period of its existence, but becomes
red, and settles down into the ‘still form” of the same
colour; while the common green Profococcus of the fresh-
water tanks loses its red spot in the still form, and gains it
again in the active or reproducing period of its existence. So
red Euglene cften becomes green; but the usual course
appears to be for the green to appear first.

The red colour also appears to herald the termination of
some period in the existence of the species. Thus the Peri-
dinium ahove mentioned, after becoming red, loses its cilia,
assumes the still form, and sinks to the bottom. The same
is the case with the Protococcus of the salt-pans of Bombay ;
but instead of adhering to the salt, it seeks out and settles
upon the crystals of carbonate of lime that are among those
of the salt. The chlorophyll changes from green to red also
in some of the resting spores of the confervoid Alge, as in
Spheroplea* and in Protecoccus pluvialis, where also in both
it becomes green again on germination, which led Cohn to
state that the green colour is connected with “‘ vegetation ”’
or the early part of the existence of the individual, and the
red with “fructification’’. or the terminationt. So that,
altogether, the passage of the colour from green to red in
the filament seems to be more likely than the opposite.

Thus, as the evidence regarding Trochodesmium in the seas
above mentioned is more, if anything, in favour of its yellow
than its red colour, and that it is also sometimes green, while,
in the common course, where alge present red and green
colours in their respective cycles of existence, the latter
appears first, and the Peridiniwm above mentioned passes
from green to yellow and then to red, &c., it seems not un-
reasonable to infer that Trichodesmium Ehrenbergii does the
same, and that, therefore, so much of Montagne’s generic
characters of Trickodesmium Ehrenbergii as relate to its
colour (viz., that it is “at first red and at length green”)
should be reversed.

If it were desirable to adduce evidence of the faint green
colour which Trickodesmium probably presents in the first
stage of its existence, from the observation, too, of probably

* Colin, ‘ Ann. des Sc. Nat.,’ 4° sér., t. v, p. 187.
+ Ray Soe. vol. for 1853, p. 519.

CARTER, ON THE COLOURING MATTER OF THE RED SEA. 185

the same organism in other parts of the world, one might
cite those of Péron, who likens it to “ poussiére grisitre,”’
and of Darwin, who compares it to ‘cut hay,” &c. (op. cit.);
but it seems better for this argument not to go beyond the
seas washing the shores of Arabia.

To what the “intense green,’ under which this organism
sometimes presents itself in the Red Sea, owes its production
Tam ignorant, unless it be indicative of sporidification, which,
from what I think that I have seen in Oscillatoria princeps,
seems to take place in this family, not from the conjugation
of its cells, but from the division of their contents into zoo-
spores. Much, therefore, remains to complete the history of
this little plant ; and this, unfortunately, can only be obtained
by watching it long and narrowly in its proper habitat.

TRANSLATIONS.

On the Conrtractite Fitaments of the Cynarea (Thistle ~

Tribe). By Dr. F. Conn.
(From the ‘ Zeitsch. f. Wissensch. Zool.,’ xii, p. 366.)

Tue following observations are contained in a letter in
the above Periodical addressed to Professor Von Siebold.

After referring to the circumstance that he had already on
a previous occasion noticed, in a communication to the same
correspondent, the most important facts relating to the con-
tractile filaments in plants belonging to the thistle tribe,
Professor Cohn proceeds to remark that in the Cynarez the
five filaments are inserted into the tube of the corolla, and
support at their extremities the anthers which, as in all the
Compositz, are conjoined into a complete tube.

‘At the time of flowering, this anther-tube is closed at the
end, and envelopes the pistil which arises at the base of the
corolla from the inferior ovary.

At this period the anther-tube rises about 4 mm. above
the summit of the corolla. When touched, pollen-masses are
extruded from its apex, and at the same time the tube
exhibits a peculiar twisting movement.

After about five minutes the experiment can be repeated ;
the pollen is again forced out of the tube, and the twisting
movement will be again witnessed.

Gradually, however, the pistil rises above the summit of
the anther-tube, and in proportion as it does so the irrita-
bility diminishes, until at length, when the stigma projects
4—5 mm. beyond the anther-tube, that property ceases to
be manifested at all.

But it is not till this time, when its lobes begin to diyari-
cate, that the stigma becomes capable of impregnation.

In general, not more than twenty-four hours at most elapse
from the beginning to the cessation of the irritability, and
frequently the space of time during which it exists is still
shorter.

COHN, ON THE CONTRACTILE FILAMENTS OF THE CYNARE. 187

In many Cynarez, when the irritability is not manifested,
this will be found to arise from the circumstance that the
flowers have been examined at too late a period. As a rule,
it may be said to be too late when the stigma is visible above
the anther-tube.

As is well known, the cause of these phenomena resides
wholly and solely in the filaments, which each time they are
touched instantly contract, and after a while extend them-
selves to their original length. The expulsion of the pollen
from the anther-tube depends upon the circumstance that the
tube, as the filaments shorten, is drawn downwards on the
pistil about 1—2 mm., and is afterwards pushed upwards
again. The contractility of the filaments is shown in the
most interesting manner in preparations in which nothing
but the anther-tube is left, and in which the five filaments
have been cut away from the corolla, and thus rendered free
to move independently. Under these circumstances they
exhibit the liveliest irritability whenever they are touched ;
retracting themselves, bending and twisting out, and again
becoming extended, and then bending over on the opposite
side, twining themselves together, &c., so that it is hardly
possible to escape the impression that we are witnessing the
movements of a Hydra, and not those of any part of a plant.

Professor Cohn has, on a former occasion,* pointed out
the laws by which these motions are regulated, and the con-
clusions he then arrived at have since been confirmed by the
further observations of Kabscht and of Unger.{

He has shown that the contractile filaments were ener-
getically affected by the electric current ; contracting instantly
under a feeble current, but again extending themselves after
a time, and then again manifesting irritability.

A powerful current kil/s the filaments instantly; the conse-
quence of which is that the contractile filaments do not again
extend themselves, but, on the contrary, continue to contract
more and more, until at the end of about an hour they are
not more than half their original length.

When killed by other means, as, for instance, by immersion
in alcohol, glycerine, or water, a similar shortening of the
filaments to less than half their original length is observed ;
it is clear, therefore, that this contraction cannot be due
simply to a shrinking, from desiccation. It may also be

* Ina paper in the ‘ Abhandl. d. Schlesisehen Gesellschaft. f. Vaterl.
Cultur, 1861. (An abstract of this valuable paper, by Dr. Arlidge, will be
found in the * Annals of Nat. History’ for March, 1863.)

+ ‘Botanisch. Zeitung,’ 1861.

t Ibid., 1862.

188 COHN, ON THE CONTRACTILE

remarked that after spontaneous or natural death the fila-
ments contract to the utmost.

Although, eventually, the pistil may project about 5 mm.
beyond the anther-tube, this arises in the smallest possible
degree from the growth of the pistil itself, after the flower
has burst. The true cause of the apparent elongation is
the retraction of the anther-tube by the shortening of the
filaments after their death, and in consequence of which the
tube will at length be found 1 to 1 mm. below the summit of
the corolla, above which, a few hours before, it had pro-
projected 3—4 mm.

Having a short time since obtained a new microscope by
Hartneck, Professor Cohn determined to investigate the
anatomical changes undergone by the contractile filaments in
their contraction.

In order to examine the filaments in the elongated irritable
condition, it is necessary, first of all, to remove the air with
which certain passages in the internal tissue are partially
filled, and owing to which the transparency of the tissue is
much impaired.

The air may be removed by placing upon a filament sur-
rounded with water, a covering-glass, upon which the ob-
jective is screwed down with moderate force, and so as to
subject the filament to a slight compression. The object is
then to be pushed for its entire length under the objective.

By this means the whole of the

Fie. a. Fie. ¥, air ls, as it were, squeezed out,
Wa oo and its place supplied with the

| | 1 water or glycerine, as the case
\| | may be; and the internal tissue

© | i = =? covering the epidermis readily
Gims=

brought in view.

ep

=
He
AU

of elongated cylindrical cells,

placed one above another, and

separated by straight, transverse
dissepiments. (Hig. a.)

Externally the filament is co-

* vered with an epidermis com-

iss 1 posed of similar cells, which, on

the upper side, are thicker and

convex, so that the filament appears, as it were, to be grooved.

| SSH TH The tissue of the filament con-

| i} | $= % = sists of a central vascular bun-

ATT La — eee aaa

Ne | —— dle, containing principally an-

H At if § ==; nular and closely wound spiral
VILL | | —3 vessels, and surrounded by rows

a

FILAMENTS OF THE CYNAREZ. 189

(Fig. d.) The epidermis, again, is covered by a tolerably
thick cuticle. Upon this cuticle rise peculiar, conical hairs,
composed of two flat, contiguous cells, and

whose gelatiniform, thickened membranes Fig. ¢.

are also covered by the cuticle. (Fig. c.)

When the interior cells of an irritable
filament in the state of elongation are placed
under a sufficient magnifying power and ac-
curately defined, or are exposed by a longi-
tudinal incision, they appear longitudinally
striated, as if furnished with longitudinal
fibres. (Fig. a.)

But m the state of contraction their aspect
is quite different, as is best seen in a fila-
ment which has already become shortened
below the summit of the corolla. At this
time the filaments have lost their vitality,
as is proved by the contracted condition of the primordial
utricle.

In this condition, if the air has been removed, all the cells
present close, transverse strie, as if the thin filament were
composed solely of spiral vessels. (Fig. 4). Those portions,
consequently, of the filament in which more especially short
cells exist exhibit the closest transverse striation, almost like
that of transversely striped muscle.

This appearance is due to the circumstance that the cells in
the act of shortening become very regularly and closely wrinkled.
The walls of the cells, consequently, appear to be very closely
and finely plaited, as many as from ten to twenty transverse
wrinkles occurring in the space of =}, mm. ‘The apparent
fibres which, as above said, run sometimes perpendicularly,
sometimes obliquely to the
longitudinal axis, correspond Mie. d.
exactly to these transverse» 237

wrinkles of the cell-wall. — dy —~
The corrugation is seen in ( If
all the cells, including those pe + ry

of the epidermis (figs. d and e),

=
except that, as regards the amp
innermost part, next to the

air-passages, the cells often remam un- Fie. ¢

wrinkled. REL
The corrugation of the cells, conse- ov a ae

quent upon their shortening, may be
observed to take place under the microscope, inasmuch
as the water or glycerine entering the air-ducts kills

190 COHN, ON THE CONTRACTILE

the cells more or less rapidly ; and as this takes place, the
outline of the cells becomes undulated, whilst at the same
time their walls are partially separated by a wider interval.
After a little time the transverse striation of the cells is
manifest throughout. The most extreme degree of shortening
of a filament, and at the same time the closest transverse
striation of its cells, is seen when it is brought in contact
with a drop of sulphuric acid; by this reagent all the cells
are rendered of a lemon-yellow colour, whilst the scattered
pollen-grains, from the coloration of their membrane, become
purple-violet. Concentrated sulphuric acid soon destroys the
cell-wall, leaving only the cuticle, which is ultimately black-
ened. Potass also colours the cells yellow and corrugates
them very deeply, whilst the membrane of the pollen-grains
assumes a beautiful brown-red hue. Nitric acid, which gives
the cells a pale-yellow colour (orange-red after addition of
potass), contracts the cell-membrane, but it causes a remark-
able distension of the cuticle, which is thus raised up in tie
form of an elevated pouch from the epidermis, and is de-
tached even from the hairs.

Tf the filaments are crushed under strong pressure, the cells
are unable to contract; but as soon as the covering-glass is
raised, all the cells in an instant exhibit the transverse stria-
tion. The rug, however, owing to the far too rapid contrac-
tion, are very irregular, and whole masses of cells, under
these circumstances, may be seen to become curved.

Although at present Professor Cohn has been unable to
observe the action of transitory irritation upon the form of
the cells, since the filaments which have been penetrated by
water no longer react, he entertains no doubt that the mo-
mentary contractions caused by irritants depend, equally with
the permanent shortening consequent upon death, upon the
transverse corrugation of the cells.

It would seem, therefore, that the contractile cells of the
Cynarez correspond in their behaviour essentially with those
of unstriped muscle, and we may now be said to be acquainted
with plants in reality (so to speak) furnished with muscles.

The contractile cells are distinguished by the extreme
delicacy of their wall, which is thinner than in any other
tissue with which Professor Cohn is acquainted. It is only
the extremities of the filaments upon which the anther is
supported that are found to be composed of short, square, very
thick cells, but these are evidently not contractile. Pro-
fessor Cohn had on a previous occasion shown that the fila-
ments become thickened in the same proportion that they
diminish in length. A filament, for instance, that before

FILAMENTS OF THE CYNARE. 191

it was irritated was —2+./” broad, became after irritation

1000
“u

2"; another, from a width of +128," acquired one of
wt 27 wi

=tao ls} and a third, from 4 became =1225/".

In close connection with this is the circumstance that the
cells before shortening are longitudinally, and after it trans-
versely, striated.

In his former memoir, Professor Cohn had come to the con-
clusion that, in their elongated condition, the cells of the fila-
ments were in a state of active extension, and that the shorten-
ing, either upon irritation or after death, depends upon a
relaxation, in consequence of which the elasticity which had
acted as an opponent to the expansion force, caused the con-
traction.

From this it would appear that the condition in the con-
tractile filaments would be the opposite to that of the con-
tractile animal tissue (muscle), inasmuch as in the latter the
contracted condition is regarded as the active one and the
elongated as the passive.

His later researches, he says, have served only to confirm
the notion that the shortening of the filaments is of a pas-
sive nature, and due to elasticity, and he is, on this point, more
than ever inclined to lay great weight upon the peculiar
thickness of the cuticle, which even im the most completely
shortened filaments exhibits no appearance of corrugation,
and consequently must be in the highest degree elastic, so
that it is able, after the death of the cells, to cause even a
powerful contraction of the filaments by a transverse corru-
gation.

He is also convinced that at least in the lowest animals, which
possess no muscles, but only a contractile parenchyma, a con-
dition obtains similar to that observed in the contractile vege-

table cells. In these animals also irritation causes a m omentary
and death an extreme and permanent contraction, consequent,
in fact, upon the elasticity of their cuticle, w hilst the exten-
sion and elongation is in them a vital, active process.

He refers, as a further instance of the same kind, to the
stems of the Vorticelle, which after death, as upon irri-
tation, are rolled up, and again acting, extend themselves,
and, again, to the processes of the Ameba, Actinophrys,
Difflugia, Arcella, and the Rhizopoda in general, in which the
elongation is manifestly an active process, whilst the same
organs, upon being irritated, as after death, contract into
a ball.

Experiments with contractile infusoria, which have been
irritated by an electric current from an induction-apparatus,
exhibit a perfect resemblance to the phenomena represented

192 ON THE ANATOMY OF SAGITTA.

in the contractile vegetable tissues. Trachelocera olor sud-
denly contracts its neck and shortens itself; on a stronger
current, it becomes flattened out, sarcode escapes and the
entire creature becomes diffluent, whilst exhibiting the well-
known wonderful contractions; the same thing takes place in
Paramecium aurelia.

Lastly, Hydra viridis exhibits exactly similar conditions.
The outstretching of its tentacles, the elongation of the body,
is manifestly an active proceeding. When at rest and after
death, it becomes shortened into an almost invisible particle.
In like manner, a weak induction-current causes an instanta-
neous contraction of the body; under a continued current of
the same strength, expansion graduallysets in again; a stronger
current causes a renewed contraction ; a very powerful shock
induces contraction to the utmost; but after this, expan-
sion no longer takes place, but instead, a gradual dissolution
of the body.

The contractile phenomena in the parenchyma of plants
and of the lower animals, consequently, so far as injury has
as yet gone, follow the same laws.

Nores on the Anatomy of SAGiTta.

Dr. H. A. Pacenstecuer* has described what he re-
gards as a new species of Sagitia, occurring at Cette. But
as, unfortunately, he appears to have met with only a single
specimen, his determination of its specific distinction cannot
be regarded as definitive.

The specimen observed was furnished on one side with
seven, and on the other with eight, large hooks. The
smaller hooks were placed in two groups on either side,
towards the middle of the under side of the upper lip. Hach
group consisted of five pointed spines, all directed backwards.
The two anterior groups were situated nearer to each other
than the posterior. A bundle of the minute, bristle-lke
hairs, which have been observed on the sides of the body in
other Sagitte, was in the present species noticed on each side,
even of the head. The abdominal, anal, and caudal fins con-
stituted a continuous expansion, surrounding the entire
hinder part of the animal. The caudal portion of the Sagitia,
though not more than 4 mm. long, was, nevertheless, filled

* ¢Zeitsch, f, wiss. Zool,, Bd, xii, p. 308, pl, xxix, fig. 8,

_ tau

ON THE ANATOMY OF SAGITTA. 193

with spermatic clements; the peculiar spermatophores were
already fully formed, and the ovaries were so much developed
as to be readily forced by pressure into the head. It would
seem, therefore, that the species is one of the smallest known.
The principal peculiarity which especially induced Dr. Pa-
genstecher to direct attention to the form, consisted in the
existence of a pair of special organs on the dorsal aspect of
the head, one on either side. These organs were placed at
the base of the upper lip, in front of the lateral bundles of
setz, externally and in front of the eyes. The organ itself
consisted of a minute tube or sacculus, imbedded in the
integument; the walls of the sacculus were coloured with
opaque, brown, and inky pigment-molecules. It appears
that these follicles opened on the sides of the head with a
minute orifice, surrounded by a firm, strongly refracting
border. Are these organs to be regarded as olfactory, or as
analogous with the glandular follicles which are found in the
cervical region in the Nematoda?

Leuckart and the author, in their common researches on
the lower animals (of Heligoland), have shown that in Sa-
gitta germanica the intestine is attached, not only by mesen-
teries, but also, as in the Nematoda, by a network of flattened
bands, and, consequently, that there can be no question of
the existence of a true perivisceral cavity.

In Sagitta gallica the most anterior border of the peri-
visceral space within which the intestine moves about freely
during the movements of the hook-disc, and at which border
these peculiar fixing bands are not seen, is distinguished by
the presence of a complete transverse circlet of delicate,
yellowish, oval cells, applied to each other by their lesser
diameter. The intestine passes backwards through this ring,
and by pressure the cecal end of the ovaries can be forced
in the opposite direction, towards the head. Externally to
this is the sac formed by the obliquely and intricately inter-
laced muscular fibrils. From this arrangement it follows
that the anterior portion of the intestine possesses great free-
dom of motion, in consequence of which the movements of
the oral disc and pharynx are much facilitated. The orga-
nization of the border of the upper lip, the circle of large
cells around the mouth, and many other peculiarities of struc-
ture belonging to the genus Sagitia, were also observed in
this species. It is not impossible that Busch saw and figured
the above-described organs in Sagitia, but he explained
them as being retractile and protrusile tentacles, of which,
however, Dr, Pagenstecher has been unable to perceive any
yestige.

REVIEWS.

On an Undescribed Form of Ameba.

Unper the above title, Dr. G. C. Wallich has lately pub-
lished some very interesting observations on “ Ameoebee, and
allied forms of Rhizopoda,” in the ‘ Annals of Natural His-
tory. * In certain ponds on Hampstead Heath he obtained
a curious form of Ameba in considerable quantities, and is of
opinion that the peculiar characters presented by them are
normal, although, perhaps, not permanent in their nature.
“ According to the descriptions of the commoner forms, such
as A. princeps, A. diffluens, or A. radiosa (which he believes
ultimately will be found to be mere transitory phases of one
species), it appears that the sarcode-substance is uniformly
differentiated into ‘endosarc’ and ‘ ectosare’—ain fact,
neither the outer layer of sarcode nor the more viscid
mass within is endowed with a more advanced degree of de-
-velopment at one point than at another.’ In the variety
which Dr. Wallich describes this is not the case, one portion
of the ectosare in it exhibiting a structure differing per-
manently from the remainder, being densely studded with
minute papille, “which,” says Dr. Wallich, “in the quies-
cent state of the creature, are of nearly uniform aspect and
size, and cause the surface upon which they occur to resem-
ble the villous structure of mucous membrane in outward
appearance. When the animal moves, these papille or villi
vary in length, and now and then several coalesce, so as to form
processes more nearly approaching the ordinary pseudopodial
character, although still of minute proportions. The villous
patch, which occupies probably from -=},th to —,th of the entire
superficies, appears frequently to be employed as a prehensile
organ, the creature being enabled through its agency to
secure for itself a continuous point d’appui, from which the
rest of the body is pushed or flows onwards.” True pseudo-
podia are not projected from this villous patch, but are freely
thrown out from the remaining portion of ectosare when

* ©Annals and Magazine of Natural History’ for April, May, and June,
1863.

DR. WALLICH, ON AMGBA. 195

needful. The prehensile power of the papillz is very great,
so much so that when undue pressure has been exerted upon
one of the Amcebe it has been torn asunder, the portion
provided with the villous area remaining attached to the
glass slide on which it had been placed for observation. The
great abundance of the Amcebe in question in the ferrugi-
nous ponds of Hampstead, more than 95 per cent. of all the
specimens being furnished with papille, has induced Dr.
Wallich to consider this as a distinct species, which he pro-
poses to call Ameba villosa. He, however, admits at the
same time the probability of all the species of Ameebee being
local forms of one and the same type. The largest specimen
which Dr. Wallich observed was =1,th of an inch in oes,
The villi, in their quiescent state, seem to be about +1,,ths
of an inch in average length. In some instances the
villous portion was placed on a long pedicle of ectosarc, so
as to give it the appearance of a brush. In these specimens
the villi seemed to have lost their prehensile power. In
many cases an infundibuliform orifice was observed in
the centre of the villous patch, from which numerous par-
ticles of matter were extruded, and also minute, perfectly
formed Amcebe, which Dr. Wallich regards as a proof of
viviparous parturition among Ameebe. The orifice was only
temporary, but recurred frequently in the same position in
various specimens and at various times. Dr. Wallich’s ob-
servations on the nucleus and contractile vesicle are extremely
interesting, and of great importance. He says, “The nucleus
consists of a pale, gray-coloured, spherical mass of granules,
towards the centre of which may occasionally be detected a
minute, clear nucleolus. J¢ is contained within a hyaline and
somewhat elongated vesicular cavity, but never occupies the en-
tire area of the latter.” This vesicular cavity is separable from
the rest of the Ameeba, as a clear, membranous capsule, con-
taining the granules of the nucleus. Dr. Carpenter and Mr.
Carter have both spoken of the existence of a vesicular boun-
dary to the nucleus, but they do not allude, Dr. Wallich be-
lieves, to the highly specialized membranous covering which
is SO remarkably manifest in A. villosa, and which seems to
approach more nearly to the vesicle of the Gregarinide. Dry.
Wallich assimilates it to the nucleus of Plagiocantha, Tha-
lassicola, Acanthometra, and Dictyocha. The position of the
nucleus in A. villosa is always, when at rest, in the vicinity
of the villous patch. With regard to the contractile vesicle
of Ameeba, Dr. Wallich is of opinion, from careful obser-
vation, that it is not formed by any definite wall, as Car-
penter and Carter have described it. In A. villosa the con-

196 DR. WALLICH, ON AM@BA.

tractile vesicle appeared merely as an internal fissure in the
sarcode-substance, and the existence of numerous vacuoles,
which continually form and coalesce, or disappear, whilst
under observation, seem to bear out this view of its nature.
Dr. Wallich also confirms Mr. Carter’s view, as opposed to
that of Lachmann and others, that the contractile vesicle in-
variably discharges itself externally, the orifice being extem-
porised and of very minute proportion. On treatment with
acetic acid and other reagents, no trace of a membranous en-
velopment to the sarcode-substance could be discovered, such
as has been described by Auerbach in JA. bilimbosa; but Dr.
Wallich found that, by improper adjustment of the focus or
want of proper illumination, the semblance of a double line,
indicative of a true membrane, could be produced.

He gives his conclusions on the relations between the ec-
tosare and endosare in the following words :—“ From these
facts it is obvious that the ectosarc and endosare are not per-
manent portions of the Protean structure, but mutually con-
vertible one into the other; and that it is an essential feature
of sarcode that, whilst the outer layer for the time being be-
comes, ipso facto, instantaneously differentiated into ectosare,
the same layer reverts to the condition of endosare under
the circumstances just described” —alluding to the forma-
tion of food-orifices. In the granular contents of the proto-
plasma, Dr. Wallich found numerous rhombohedral crystals,
about =1th of an inch in length, probably of lime. Such
crystals he has also observed in Huglypha, Arcella, and Acan-
thometra. As is well known, Professor Huxley observed
prismatic crystals in Thalassicolla. Certain bodies, which
Dr. Wallich terms ‘nucleated corpuscles” (probably iden-
tical with the discoid ovules of Carter), were also found;
their function is, perhaps, connected with reptcaeaee
Other corpuscles, Ee ger and nucleated, about the ;),,th an
inch in diameter, were met with. These he has termed
sarcoblasts, and considers them allied to the ‘ yellow bodies”
of Foraminifera, Polycystina, Thalassicollide, &c. In sound-
ings from the Atlantic bed Dr. Wallich met with minute
discoidal structures (previously detected by Professor Huxley),
which he termed coccospheres, and believed to be a step in
the reproductive process of Foraminifera. He now thinks it
highly probable that the sarcoblasts first become cocco-
spheres, or something equivalent, and are then developed ito
the perfect animal. This subject, however, he is about to
work out. Dr. Wallich’s observations are of the greatest
importance. The discovery of this new form of Ameeba,
with the peculiarities of structure it presents, places the’

ON THE NERVOUS SYSTEM OF THE NEMATODA. 197

Ameebe in general in quite a new light, assimilating them
more closely to other non-Rhizopodal genera, such as Tha-
lassicolla, Acanthometra, &c., and placing them, in Dr.
Wallich’s opinion, at the head of the Rhizopoda.

On the Nervous System of the Nematoda.

Tue nervous system of the Nematoda forms the subject of
an interesting paper by Dr. Anton Schneider,* whose pre-
vious contributions have contributed so largely to our
knowledge of the anatomy of that class of worms. His
first paper, ‘On the Lateral Lines and Vascular System
of the Nematoda,” appeared in 1858,+ and has been followed
by two others in 1860—* On the Muscles and Nerves of the
Nematoda,” ¢ and “ Remarks on Mermis.” § In his present
communication he continues his observations on the neryous
system, of which we proceed to give a brief abstract.

A nervous system was described, in 1816, by Otto, in
Strongylus gigas, but the first important contribution on the
subject was by Meissner, in 1853-55, who described what he
regarded as a complete system of nerves in Mermis albicans
and nigrescens. This was followed up by Wedl and Walter
in a detailed account of the same system in another species.
But the supposed nerves of these authors were shown by Dr.
Schneider in the latter two papers above cited to belong to the
muscular system; and his views have since been adopted by
Leydig. ||

Even with respect to the central nervous system, Meissner’s
views were entirely upset, what he regarded as such having
proved to be the esophagus. Dr. Schneider was unable also
to confirm Walter’s description of the central nervous system
in Oxyuris ornata. The true constitution, therefore, of the
nervous system in the Nemaiode remained in considerable un-
certainty. The only central organ that appeared likely to be
such was a pale band lying on the esophagus, first noticed
by Lieberkuhn, Wedl, and himself.

Since that period, Dr. Schneider has kept the subject in
constant: view, and believes that he is now in a condition
fully to describe both the central and peripheral nervous
systems in the Nematoda. He attributes the success he has

* * Archiv Anat., 1863, P it + Ibid., 1858, p. 426.
t Ibid., 1860, p. 224. § Ibid. 1860, p. 243. || Ibid., 1861, p. 605.

198 ON THE NERVOUS SYSTEM OF THE NEMATODA.

met with to a mode of dissection peculiar to himself, and the
want of which (though extremely simple) has hitherto pre-
vented the successful prosecution of the research. The central
nervous system constitutes a ring closely surrounding the
cesophagus, but not attached to it. On the other hand, it is
firmly connected by various processes with the walls of the
body. This arrangement suggested the mode of dissection
to be followed for its due display, and which is thus de-
scribed :—Cut off a portion of the anterior end of an Ascaris
megalocephala, for example, about half an inch long; then,
with a fine and sharp pair of scissors, slit up the walls of the
body together with the cesophagus; then cut off the lips and
remove the cesophagus, and spread out the walls of the body,
and the central nervous system will be seen lying uninjured
on their inner surface. The essential part of the proceeding
is the slitting up of the cesophagus as well as the walls of the
body. The preparation is much improved by the boiling of
it for a short time in dilute acetic acid, after which the cuticle
can be readily removed and the specimen rendered transparent
by glycerine. Specimens of A. megalocephala not fully grown
are better fitted for examination than older ones, owing to
their greater transparency. This dissection affords the
readiest and easiest view of the entire nervous system, but in
order to learn its minute structure numerous transyerse
sections are requisite. These sections must be very carefully
made with the sharpest possible knife. To allow of their
being properly made, the worm must be hardened, first in
spirit, and afterwards in chromic acid.

Dr. Schneider’s researches have been carried on chiefly in
Ascaris megalocephala and Oxyuris curvula. In A. megalo-
cephala the nerve-ring is placed about 2 mm. behind the oral
orifice. From it six cords are given off in front; four of
these (nervi submediani) arise nearly in the middle, between
the border of one of the lateral intermuscular spaces and the
middle line, though rather nearer the lateral space. The roots
commence with a broad base, which gradually narrows into
the slender cord. ‘Two other nerves (n. daterales) lie in the
middle of the lateral intermuscular spaces. These nerves are
completely imbedded in the substance of the lateral space,
and they may, with some pains and trouble, be at once dis-
sected out, or may be seen more readily, but still distinctly,
in simple transverse sections. Two strong nervous cords
pass backwards; they arise on the ventral side of the ring,
one on either side of the ventral line, towards which they
tend in a sort of arch and are continued a short distance, but
they cannot be traced beyond the arched anastomosis of

ON THE NERVOUS SYSTEM OF THE NEMATODA. 199

the water vascular system which lies a short distance behind
the nerve-ring. These are termed the rami communicantes.

In connection with these nerves are numerous ganglion-
cells, which are found either in the course of the fibres or
may be regarded as the points of origin of the fibres. The
submedian nerves are furnished with but few of those bodies.
The ganglion-cells are either dipolar, as are those occurring
in the course of the fibres, or unipolar. The lateral nerves
possess many more fibres than the submedian. ‘Their fibres
do not arise from the central ring alone. Numerous ganglion-
cells of various sizes lie on all sides of the ring, and which
are also unipolar and bipolar. Some might be termed multi-
polar, were it possible to determine that all the processes
arising from them were really nerve-fibres. These collections
of ganglia are termed ganglia lateralia.

A large mass of the kind is found in the ventral line im-
mediately behind the ring, and the cells composing it are,
probably, most of them connected with the rami com-
municantes. In these ganglia (ganglia mediana) two halves
may be distinguished, separated from each other by the tissue
of the ventral line. On each side of the ventral line are
placed six isolated ganglion-cells, two of which lie one be-
hind the other, near the ventral line, and three others usually
in the middle of the ventral space. These are unipolar.
Their processes pass forward, and enter the middle ventral
ganglion. The sixth cell is usually situated near the lateral
intermuscular space. It is bipolar, and sends one process
towards the median ganglion, and the other towards the
lateral space. These cells are termed the ganglia ventralia
dispersa.

In these latter may best be perceived the histological con-
nection between the nerve-cells and fibres. Each cell presents
a distinct nucleus and nucleolus. The nerve-fibres are of
some width, and when divided exhibit an elliptical section.
A distinct membrane may be perceived pretty clearly in the
cells, but not in the fibres. The latter consist apparently of
a homogeneous substance, resembling, when acted upon by
chromic acid, coagulated albumen. The structure of the
central ring is not so readily made out. In the fresh state
it is so elastic as to contract into about half its circumference
when separated from all its attachments. All that can be
stated with certainty is, that the ring is enclosed in a tough
and dense sheath, which also sends processes inwards into
its substance. This sheath is finely striated; the striz
appearing to depend partly on fine rugz, in part also upon
distinct fibres. On the exterior it presents no indication of

VOL. I1I.—NEW SER. P

200 ON THE NERVOUS SYSTEM OF THE NEMATODA.

true nerve-fibres, which are best displayed when the ring has
been boiled in dilute nitric acid, and torn asunder with
needles. The fibres then exhibit the same structure and
dimensions as the nervous trunks passing from the ring.
Besides the fibres, however, the ring also contains bipolar cells,
though in no great number,

The ring, as has been said, is closely connected with the
walls of the body. The connection is effected chiefly by four
bands, which appear to be, as it were, continued from the
lateral and two median intermuscular arez or spaces, and
by them the ring is divided into four equal portions. But
it is also closely connected with the muscular system by
transverse prolongations of the muscle-cells, which consti-
tute four bands, one of which is attached to each of the
quarters of the ring, being continuous, as it were, with the
sheath.

No further distribution of the nerves appears to have
been clearly made out, although the author has made nu-
merous and very industrious researches, which have shown
him many interesting facts in the minute anatomy and
arrangement, more especially of the muscular system, for
which we must refer to the paper itself.

With respect to organs of sense, he states that in Hnoplus,
Duj., Phanoglene, Nordm., and Hachilidium, Ehr., eyes are
indubitably present, aithough up to the present time no
‘nerves have been traced to these organs,

Of other organs of sense, he points out certain structures
which appear to be of the nature of tactile organs. These
are tubular hollows in the integument, filled with a fine
granular substance. On the exterior these follicles are either
Jevel with the surface or form small eminences of different
kinds. ‘These sort of papille are found in four different
situations, and they may be classified into—1. Oral papille,
varying in number from two to ten. 2. Cervical papille,
always two in number, and lateral.* 3. Caudal papille, also
always two in number, and lateral.t 4. Copulatory papillee,
situated in the caudal portion of the male, symmetrically, on
each side of the ventral median line. No nerves, however,
have as yet been traced to these organs, though Schneider
thinks the submedian and lateral nerves go to the oral
papille.

* The organs noticed by Dr. Pagenstecher in Sugitla gallica would seem
to be of this kind. (Vid. supra, p. 193.)

+ M. Bastian, in a paper read before the Linnean Society, and which will
appear in the ‘ Linnean Transactions,’ describes two organs of this kind (or
of the next?) in the hinder part of the body in the young Guinea-worm,

NOTES AND CORRESPONDENCE.

A Simple Trough for Zoophytes, &c,—Perhaps the following
cheap and easy method of constructing a small zoophyte
trough may be useful to some of your readers, as I have
found such articles extremely convenient in the examination
of small Sertularian and other zoophytes.

Take an ordinary glass slide and cut it with a diamond
into five pieces, A, B, C, D, E, as shown in fig. 1, or any

BRie,-1. Erg, 2,

glazier will do it for a trifle if the lines are first drawn with
apen. The piece A being thrown aside, cement C, D, E, in
their relative position on the middle of another slide, as
shown in fig. 2, with marine glue. The piece B is to be
cemented on the others, which it exactly covers, and the
trough is complete. Being cut from one piece, C, D, and E,
are certain to fit together. If more than one are being made,
the covers, B, may be cut from thin slides, and thick ones
may furnish the side pieces, C,.D, E. Objects are, of course,
introduced above, and are necessarily. kept close to the front
glass; this latter may be a square of thin glass for higher
powers, as it can be easily replaced if broken. The contents
ave retained by capillary attraction, even when the body of
the microscope is in an upright position ; and the affair is as
manageable on the stage as an ordinary object-slide-—Gronrer
Guyon, Ventnor, Isle of Wight.
Feb. 17th, 1863.

The Photography of Magnified Objects by Polarized Light.
—Crystals are generally looked upon as belonging almost ex-
clusively to the polarizing class of microscopic objects, Their

202 MEMORANDA.

forms are, perhaps, the most beautiful in nature; but when
we enter into their study, and penetrate somewhat deeply
into the mysteries of crystallography, we meet with a very
great drawback—the instability of certain crystals whose
forms we find ourselves utterly unable to reproduce. Many
of these endure for days, or even weeks, and then pass gradu-
ally away; whilst with others a second crystallization always
takes place, which robs the first form of all its beauty, or de-
stroys it altogether. In these cases, when the form illus-
trates some particular law, and it is desirable to preserve it,
the pencil is usually employed. But some of these crystals
exclude all chance of anything like a faithful drawing, by
their intricacy of shape and the wearying labour that would
be requisite to do them anything like justice. For these
reasons I have been making use of photography by polarized
light, and by this aid may be accomplished what could be
done in no other way. In proof of this, I may mention that
I have attempted by ordinary light a photographic impres-
sion of certain salts; but I found it impossible, as nothing,
except a faint trace of the outline, was produced upon the
plate, which is easily accounted for by the excessive tenuity
(and consequent transparency) of the crystals. Again, by
the use of common light the peculiar characters of certain
substances are totally lost, as the cross of starch, &c.; but
by the aid of the camera and polariscope all these may be
permanently produced upon paper.

The power, also, of polarized light does not appear to be in
any way inferior to that of ordinary light when used for pho-
tographic purposes; but I hope to be able to make some
more conclusive experiments in this matter shortly, as it is
absolutely necessary to employ a light whose power is con-
stant. Another curious fact which I have ubserved as to the
power of polarized light as applied to photographic purposes
is this: when the object upon the slide appears most per-
fectly illuminated by the ray which has passed through the
lower prism, we often find that the image in the camera is
but partially distinct, and that we shall be forced to make a
new adjustment of the mirror to procure an impression which
will develop uniformly.

As to the position, &c., of the microscope, there is little to
say, as it used in the ordinary manner of photographing mag-
nified objects which has been so often described. The re-
sults, however, are better when the selenite plate is not
employed, and the eae ene prism is placed immediately
over the object-glass. No. 1 eye-piece is, perhaps, the most
preferable when the greatest distinctness is desired.

MEMORANDA. 2038

Herewith I send you four specimens of crystals photo-
graphed by polarized light.* ‘The crystals of “tartrate of
soda” is magnified forty diameters, and may be produced by
neutralizing a strong solution of carbonate of soda with tar-
taric acid. A drop of this is then spread upon the slide, and
the water evaporated by heat, when the salt will remain in a
viscid state. The slide must then be laid in a dry place, free
from dust, and in a short time will be covered with crystals,
where the formless salt before lay. This will sometimes be
found to be accomplished in a day, but at other times a week
or two must elapse before the same result takes place, accord-
ing to the warmth and dryness of the atmosphere. The
crystal of sulphate of copper and magnesia is also magnified
forty diameters, and was obtained by the method I havee lse-
where described. The crystal of santonin is also magnified
forty diameters, but this salt requires a very different treat-
ment to procure good crystals. A small portion is placed
upon the centre of the glass slide, and this is then laid upon
a metal plate, underneath which a spirit-lamp must be kept
burning, in order that the temperature may not be lower
than 350° Fahr., but if it is raised above 400° the crystals
will turn brown. In a short time the santonin becomes
fused, and with a hot needle should be thinly and evenly
spread upon the surface of the slide, which should then be
allowed to cool slowly. When the surface has become
“fixed,” a fine-pointed needle may be employed to pierce it
here and there, when the crystals will spread from these cen-
tres and cover the plate. Castor oil must be used in mount-
ing them, as balsam is apt to dissolve them when the tempe-
rature is raised even in a slight degree. The difficulty in
preparing this salt is to know the precise moment at which
to start the formation of the crystals, as those produced be-
fore and after this moment are devoid of that feathery deli-
cacy which is their chief beauty. The crystals of tartar
emetic are magnified fifty diameters, and were produced in
the ordinary way. I have taken the trouble to describe the
production of these crystals, because I am not aware that
some of them have been before noticed as microscopic objects,
and they are well worthy of a place in the cabinet.—THomas
Daviss.

* We had intended to give copies of the beautiful photographs sent by
Mr. Davies, and which fully bear out his remarks, but find that the expense
of this mode of illustration would be far too great, and are, therefore,

obliged to forego what would otherwise have rendered his communication
far more complete.—[Eps. |

204 MEMORANDA.

On the Improvement of the Compound Microscope.—As I have
bestowed much time, labour, and thought, in the endeavour
to improve the construction of the compound microscope, I
avail myself of the pages of your Journal to communicate
the results to yourself and your numerous readers.

lst. It is imperative that the eye-piece be formed of two
lenses of equal foci, and that they be placed a focal length
apart.

Fond. These glasses must have as long a focus as can be
used without interfering with manipulation.

3rd. The field-glass and objective must be placed at their
combined focal distances apart.

Ath. The cavity of the eye-piece may be filled with a fluid
refractor, so as to represent a solid cylinder of glass cut from
a sphere.

The glasses I am using have a focal length of ten inches, and
the upper focus of the eye-glass is eight and a half inches
in length, so that my tube measures something within thirty
inches. The mist, darkness, and dirty London fog, met with so
generally, are principally owing to the eye-lens having a short
focal length; if, however, a glass be tried of greater focal
length than the field-glass, the image will appear very light
and clear, but with an unnatural glaze. Although a large
amount of power is lost by equalising the lenses, this is fully
made up by their long foci, necessitating increased distance
from the objective. The length of the foci, of course, increases
very materially the amount of light, which is gained further
by placing the eye-piece and objective proportionally nearer
together than is customary—the definition is at the same
time improved. The introduction of a refractive medium
between the upper lenses has the effect of magnifying the
field and image about half a diameter, without shortening the
foci of the instrument materially. With a simple 4rd-
inch lens for object-glass, I have the power of a 1th-inch
without the refracting medium, the light of a l-inch; at
least, an enlarged field definition, equalling, if not excelling,
that of a simple microscope, and without perceptible change
of colour—in fact, a most faithful magnified view of the
object.

Instruments may be made of length suitable to the stature
of the observer—F Rep. Curtis, Maryport.

16th June, 1863.

Infusoria in Moving Sand.—_Mr. James Blake writes as
follows from St. Francisco, California :—“I have enclosed

MEMORANDA. 203

some sand containing recent Infusoria, which, I have no
doubt, will resume their movements on being moistened.
They were collected on the moving sand-hills near this city,
at a place a few yards from the ocean, and where there is not
the least sign of vegetable life. My attention was attracted
to them by seeing some concretions on the surface of the
sand, which at the time was in motion from a strong wind.
I found that these concretions consisted of agglutinated
sand, the agglutinating substance being formed, as subse
quent observation showed, by Infusoria. I could find no
trace of organic matter in any of these concretions, which
might have formed a nidus for the development of the Infu-
soria, and I have every reason to believe that these were
developed in pure sand moistened with rain-water. I think
the presence of rain-water was necessary for their development,
as I had been over the same ground frequently before, during
the summer season, and had not noticed the concretions,
which I believe I must haye done had they existed. The
concretions were, in some instances, two or three inches long
and an inch or two thick, and, when dry, they possessed con-
siderable tenacity. I am unable to resolve the Infusoria into
anything definite, with a ¢ of Powell and Lealand’s.

[Our correspondent requests us to give some of the speci-
mens to persons acquainted with Infusoria, which we shall
be happy to do when they come to hand, which, we are sorry
to say, they have not as yet done.]

Prorrsson Exsenrn, of Wiirzburg, mentions the occurrence
of a new parasite, differing, it is said, essentially from Tri-
china spiralis, which infests the voluntary muscles of the frog.
It resides in the transversely striped fibrils, into and out of
which it bores its way, moving about from one locality to
another. ‘This migration is proved by the existeuce in con-
tiguous muscular fibres of cavities of a peculiar character.
The description of the Entozoa is not given.—Proceed. of

Wirzburg Phys,-Med. Society, 1862,

PROCEEDINGS OF SOCIETIES,

MicroscoprcaL Socrety oF Lonpon.

May 8th, 1863.

THE annual soirée of the Society was held this evening in the
great hall and other rooms at King’s College, and though the
requirements of the college obliged the Council to avail them-
selves of the accommodation during the Easter holidays, the
attendance of members and their friends was quite equal to the
usual average, and the exhibition of instruments and objects by the
instrument makers as large and fully as interesting as on any
former occasion. Absence from town, so customary at this season,
prevented several of the well-known supporters of the Society from
being present, and though the members contributed a larger num-
ber of instruments, they hardly made the same display as at some
of the previous annual meetings of the Society.

The most striking feature as regards the instruments was the
great increase and improved adaptation of the binocular arrange-
ment of Mr. Wenham to all classes of microscopes, from the most
elaborately finished and expensive stands of the first-class makers to
the cheap but more generally useful and instructive, educational
and student’s instruments, for which the demand is so rapidly
increasing. The stereoscopic effect, combined with really good
definition and abundance of light, rendered the display of objects
with low powers by this arrangement universally admired.

The exhibition of objects requiring very high powers is hardly
so well adapted to please the visitor as the preceding, but the
advance here made has been quite as great as in any other depart-
ment, and tl:e fine th of Messrs. Powell and Lealand, and the
zijth of Messrs. Smith, Beck, and Beck, were exhibited, under all
the disadvantages of a crowded room, in such a way as to show
clearly to the microscopist what might be expected from their per-
formance under the quiet and careful manipulation of the study.
The large exhibition of instruments and improved thin stages of
Mr. Ross also attracted a crowd of visitors to his table. It would
be impossible, however, to enumerate all the various contrivances

PROCEEDINGS OF SOCIETIES. 207

which have been invented to facilitate the growing taste for micro-
scopical research of which examples were to be found on the tables
of the Society, nor will our limits permit any detailed enumeration
of the various and often highly interesting objects exhibited,
though, as probably the greatest novelty, we may mention the
exhibition, by Messrs. Horne and Thornthwaite, of the production
of the new metal thallium by electric agency, which attracted
much attention. :

The number of microscopes exhibited was about 200, the greater
part of which, as will be seen by the following list, were from the
various instrument makers,

H. and W. Crouch ...... 2 PithiGGheE: 5° 25.0. Sonbvencer 15
eNO fiat ts as Es ox 10 Powell and Lealand ...... 6
Bee HIEY: fyi 30.0 ok es 6 Thomas Ross ............ 24
Horne and Thornthwaite 10 HIME ook. ea rt a ee 10
LE eS a amelie 10 Smith, Beck, and Beck 12
Ra PE 2 a See kee 6 DEO MOR ht csc gnne 12
Murray and Heath ...... 4 Popping Haste MAE 2
2 EES ee ee 12 Weedon! 7.415, 40. et 2
_ Oe 3 The Societys, 2. 2i ae 4

The remainder were shown by members of the Society. The walls
of the great hall were covered with a large collection of interesting
diagrams, kindly lent by Dr. Carpenter, Dr. L. Beale, Mr. Mum-
mery, aud others, illustrative of the microscopic anatomy of the
animal and vegetable kingdom; and Mr. F. Buckland kindly added
to the attractions of the evening by the exhibition of his tanks, and
by explaining the process of the artificial incubation of fish, the
wonderful organization of the young fry being at the same time
shown under the microscope.

May 13th, 1863.
CHARLES Brooks, Esq., President, in the Chair.

Dr. Pattison, Charles Cubitt, Esq., and J. L. Denman, Esq.,
were balloted for, and duly elected members of the Society.

The following papers were read:—“On some new Species of
Diatomaceze,’’ by Dr. Greville; ‘‘On the Nerves of the Cornea,
and their distribution in the Corneal Tissue in Man and Animals,”’
by Dr. Ciaccio.

June 10th, 1863.
Cuaries Brooke, Esq., President, in the Chair,

F. Hager, Esq., F. Lycett, Esq., J. Garnham, Esq., Alfred Boot,
Esq., Henry Crouch, Esq., and Charles Baker, Esq., were balloted
for, and duly elected members of the Society.

208 PROCEEDINGS OF SOCIETIES.

- A complete new microscope, with a series of nine objectives and
apparatus, comprising all the latest improvements, was presented
to the Society by Mr. Thomas Ross.

It was unanimously resolved—‘‘'That the most cordial thanks of
the Society be presented to Mr. Ross, for his munificent gift, and
that this resolution be suitably presented to him.”

Mr. Deane gave a verbal account of the microscopical investiga-
tion of a palimpsest Greek MS. belonging to M. Simonides, and
expressed his opinion that the same did not appear, from this ex-
amination, to be a forgery (as had been supposed), but that he had

every reason to believe it to be a genuine document;

in which

opinion Mr. Wenham, who had assisted him in the examination,

fully coneurred.*

At the close of the regular business the MS. was exhibited to the
meeting, and carefully examined by many of the members.

PRESENTATIONS TO THE MICROSCOPICAL SOCIETY,

1862-63.

October 8th, 1862.

Presented by

Intellectual Observer, Nos. 6 to9. The Editor.
The Canadian Journal, No. 40 ‘ . - Ditto:
Journal of Photography, nine numbers ; - -Ditto,
Photographic Journal, Nos. 122 to 125 ; Ditto.
The Annals and Magazine of Nasa gegiae Nos. 5s,

56, and 58 Purchased.

November 12th.

Dr. Carpenter’s Introduction to the Study of the Fora-

minifera. Ray Society The Author,

On the Germination, Development, “and Fructification of
the Higher Cuyptogamia, by Dr. W. Hofmeister.
Translated by F. Currey, Esq., F.R.S. :

F. Currey, Esq.

Dr. Carpenter on the Microscope, 3rd edition The Author.
The Popular Science Review, Nos. 4 and 5 The Editor.
The Intellectual Observer, No. 10. Ditto.

The Journal of the Proceedings of the Linnean Society,
Vol. VI, No. 24 =,
Transactions of the Tyneside Naturalists’ Field Club,

The Society,

Vol. V, Part 3 Ditto,
Memorias da Academia Real das. sciencias ‘de Lisboa, .

1854 to 1857 ; The Academy.
The Annals and Magazine of Natural History Nos. 57

and 59 . . Purchased.
Seven Slides of Diatomace . W. Ward, Esq.

a

* We have since been informed that there is reason to believe that this

opinion may proye erroneous.—[Eps.]

PROCEEDINGS OF SOCIETIES. 209

December 11th.

Presented by
The Quarterly docctal of the ae pies ss
XXIII, Part 4 ¥ The Society.
Intellectual Observer, No. 11 : x . The Editor.
The Canadian Journal, No.4). Ditto,

Notes on the Thysanura, by John Lubbock, Esq, F.RS. The Author.
Results of Meteorological Observations, Vol. I
Smithsonian Report, 1860 Smithsonian In-
Gene cy Miscellaneous Collections, Vols. if IL, stitute.

1 loa

Journal of Photography, Nos. 178 and 179 . ~The Bditor,
Photographic Journal, No. 127. . Ditto.
The Annals and Magazine of Natural History . Purchased.

January 14th, 1863.

The North Atlantic Sea Bed, comprising a Diary of the
Voyage on board H. MS. * Bulldog” in 1860, by

Gree Wallich,M.D:,&e. . The Author,
Popular Science Review, No.6. ‘ . The Hditor,
Intellectual Observer, N o. 12 ; 2 5 6 Datto:
Sculptor’s Journal, No. 1 ; ; . Ditto.
Canadian Journal, No. 42 : . Ditto,

Journal of Photography, Nos. 180 and 181. . Ditto.

Report of the Art Union of London, 1862. . The Society.
Annals and Magazine of Natural History, No. 61 . Purchased.
Twelve Slides— Deep- sea Soundings J. Hilton, Esq.

One Slide of Diatom Earth and a Bottle of Vibrio- Wheat C. Deane, Esq.

February 11th.

Journal of Photography, Nos. 182 and 183. . The Editor.
Intellectual Observer, No. 13 : ; . Ditto.
Sculptor’s Journal, No. 2 . Ditto.
Aunals and Magazine of Natural History, No. 62 . Purchased.

March \\th.

Intellectual Observer, No. 14 : ; . The Editor.
‘Sculptor’s.Journal, No. 3 : « Ditto.
Journal of Photography, Nos. 184 and NB 5 . Ditto.
Photographic Journal, No. 180 ; . Ditto.
Journal of the Geological Society, No. 73. . The Society.
Journal of the Linnean Society, No. 25 5 . Ditto.

Annals and Magazine of Natural History, No. 63 » Purchased.

May 12th.

Posthumous Works of ‘Dr. Robert Hooke . . F.C.S. Roper, Esq,
Beitrage zur Kenntniss panegesppistice Organismen
“* “yon G, Fresenius” . : ; > Ditto,

210 PROCEEDINGS OF SOCIETIES.

Presented by

Mikroskopische Studien aus dem Gebiete der mensch-

lichen Morphologie von J. Gerlach : . Ditto.
F. C. S. Roper, on the Genus Liemophora (paper) . The Author.
Intellectual Observer, Nos. 15 and 16 ; . The Editor.
Popular Science Review, No.7. : . Ditto.
Photographie Journal, No.131 . : . Dita:
Journal of Photography, Nos. 186 to 189. Ditto.

Transactions of the Linnean Society, Vol. XXIV, Part 1 ‘The Society.
Annals and Magazine of Natural History, Nos. 64.and65 Purchased.

Six Slides of Sulphate of Cadmium G. Norman, Esq.
Two Slides—Jsthmia enervis, Triceratium areticum . _C. Baker, Esq.
Two Shdes—Liemophora flabellata, Lic. splendida pl Cua Roper, Esq.

June 10th.

Planta Cryptogamica da ordem dos cogumelos do genero
Aspergillus, especie Glaucus, Dr. Carlos May Figueira The Author.
Quarterly Journal of the Geological Society, No. 74 . The Society.

Proceedings of the Linnean Society, No. 26 . . Ditto.
Intellectual Observer, No 17 : : . The Editor.
Photographic Journal, No. 133. : ~ Ditto:
Journal of Photography, Nos. 190 and 191. . Ditto
Annals and Magazine of Natural History, No. 66 Purchased.

Nine Slides—Zoophytes from Australian Algee (3),
Isthmia enervis (2), Licmophora flabellata, Meridion
circulare, Rhabdonema arcuatum (2) i . J. Stainton, Esq.

W. G. Srarson, Curator.

LITERARY AND PHILOSOPHICAL SociETY, MANCHESTER.
MICROSCOPICAL SECTION.
March 16th, 1863.

Mr. JosEPH SIDEBOTHAM, Vice-President of the Section, in
the Chair.

Mr. Watson presented specimens of Jungermannia tomentella
and asplenoides, collected on Baguley Moor.

Mr. Sidebotham presented specimens of the following mosses, in
fruit: —Fissidens ewilis, F. adiantoides, Grimmia pulvinata, Weissia
controversa, Bryum atropurpureum, &c., in a good state for micro-
scopical examination.

Mr. J. G. Dale, F.C.S., presented a specimen of crystallized film
of picrate of aniline; and in a note to the secretary explained his
method of preparation from picric acid and aniline. ‘The equiva-
lent of picric acid is 229 ; that of aniline is 93; and when dissolved
in strong alcohol in those proportions by weight, mixed and set

PROCEEDINGS OF SOCIETIES. 211

aside, the picrate of aniline will crystallize in yellow needles. The
film for the microscope is formed from a solution of these needles
in absolute alcohol, a drop of which being spread over a clean, hot
glass slide, the crystallized film is at once produced by the rapid
evaporation of the alcohol, if the slide be at the proper degree of
heat, which can only be found by repeated trials. If too hot, the
salt will melt and become partially decomposed ; if not hot enougb,
it will be crystallized in needles, or be deposited as an amorphous
film. When properly crystallized, circular radiated discs will ap-
pear, with more or less regularity, showing with the polariscope
very brilliant colours, and a black cross in the centre. The crys-
tallized films may be mounted in zew soft balsam; but a mixture
of chloroform and balsam dissolves them immediately.

The Natural History Society presented for distribution amongst
the members a number of beetles not required for the museum.

Mr. Nevill reported upon the fossil foraminiferous shells found
in the Montreal deposit, presented by Mr. R. D. Darbishire at the
last meeting. They were mostly in a fine state of preservation,
and many were as perfect as recent shells. He found—

Polystomella, Entoselenia marginata,
Nonionina umbilicatula, + globosa, very fine,
Polymorphina lactea, Patalina corrugata,
Miliolina seminulum, Textularia,
Entoselenia squamosa, var. sca- _Dentalina,

lariformis, Lagena vulgaris.
Ditto, of a peculiar form and

rare,

The Polystomella and Nonionina were in great profusion; the
other kinds were scarce; but Mr. Nevill was of opinion that re-
markably fine specimens might be found of all the various kinds, if
there were a larger quantity of material to operate upon. Mr.
Nevill was indebted to the worthy President of the section, Pro-
fessor Williamson, for verifying the names, and he presented to the
section mounted and named slides for the cabinet. No Diatomacez
were found amongst the material.

Dr. Alcock exhibited a young living salmon, about fourteen days
old, attached to part of the ovum. Dr. Alcock particularly called
attention to the form of the vertebral column, which, whilst young,
is similar to that of the lower grade of cartilaginous fishes when
fully grown; the skeleton of the salmon, however, becomes gradu-
ally changed, until at maturity it is that of the higher class of
osseous fishes.

Dr. Alcock also exhibited a lingual riband of the Patella athletica,
from Bray, in Ireland; he compared it with that of the common
limpet, Patella vulgata, and pointed out the differences in the form
of the teeth.

Dr. Roberts exhibited some mounted specimens of blood-cor-
puscles from an albuminous urine, which showed an appearance as

212 PROCEEDINGS OF SOCIETIES.

if the contents of the cells had separated from the ceil-wall, and
become aggregated round the centre like a nucleus. When these
corpuscles were treated with magenta, the central portion was
either not coloured at all or only faintly so, whereas the circum-
ferential portions became deeply tinted. By treating fresh blood
with an excess of a solution of carbolic acid, this appearance could
be produced at will. In the blood-corpuscles of the fowl a similar
effect was produced by the carbolic-acid solution: the cell-contents
appeared to detach themselves from the cell-wall and to collect
round the nucleus. The appearances presented strongly suggested
the idea that the cell-envelope of the blood-disc was a double mem-
brane; that the inner separated under certain circumstances from
the outer membrane and shrank in toward the centre. Dr. Hensen,
of Kiel,* seems to have convinced himself that such is the case in
the blood-disc of the frog, and he compares the inner membrane to
the primordial utricle of the vegetable cell. Of the prolongations
described by Dr. Hensen as stretching rapidly between the shrunk
inner membrane and the outer one, Dr. Roberts saw nothing. If
the said view of the structure of the blood-cells were substantiated,
it would greatly facilitate the explanation of the appearances pro-
duced in these cells by magenta and tannin.

Mr. Charles O’ Neill, F.C.S., exhibited a mounted fibre of Orleans
cotton, torn by a gradually increasing weight suspended to its ex-
tremity. It had sustained a weight (gradually increased) of 162
grains for many minutes. Mr. O’Neill stated that there were 143
such fibres in -01 grain of cotton, each fibre therefore weighing
less than the ten thousandth part of a grain. The strongest fibres
were capable of supporting more than two million times their own
weight. He is engaged in making experiments upon the tensile
strengths of various fibres by a special apparatus, but they are not
yet completed.

Mr. Brothers exhibited a number of fresh-water insects, larva, &e.

Mr. Parry exhibited the transverse section of a fossil palm, from
the Island of Antigua.

The following gentlemen were elected officers of the Society for
the ensuing year:—President: Edward William Binney, F.R.8.,
I.G.8. Vice-Presidents: James Prescott Joule, LL.D., F.R.S.,
F.C.S., &c.; Robert Angus Smith, Ph.D., F.R.S., F.C.S. ; Joseph
Chesborough Dyer; Edward Schunck, Ph.D., F.R.S., F.C.S.
Secretaries: Henry Enfield Roscoe, B.A., Ph.D., F.C.S.; Joseph
Baxendell, F.R.A.S. Treasurer: Robert Worthington, F.R.A.S.
Librarian, Charles Fredrik Ekman.

Of the Council: Rey. William Gaskell, M.A.; Frederick Crace
Calvert, Ph.D., F.R.S., &c.; Peter Spence, F.C.S.; George Mosley;
Alfred Fryer; George Venables Vernon, F.R.A.S. :

* €Siebold und Kolliker’s Zeitschrift’ for 1861, p. 263.

PROCEEDINGS OF SOCIETIES. 213

April 2th, 1863.

Professor WILLIAMSON, F.R.S., President of the Section, in the
Chair.

Mr. Charles O’ Neill, F.C.S., aud Mr. John Shae Perring, M.Inst.
C.I!., were elected members of the section.

Mr. John Slagg, jun., and Mr. H. A. Hurst, were elected
auditors of the treasurer’s accounts.

Mr. Alfred Fryer presented for distribution amongst the members
a number of impressions of an engraving of the Acarus sacchari
found in raw grocery sugar, from Mauritius.

Mr. Brothers stated that he had made some observations upon
the circulation in plants, and he found that a degree of heat which
would cause free circulation in Vallisneria entirely destroyed it in
Chara vulgata. Mr. Brothers also described the appearances pre-
sented by the cilia of Melicerta ringexs, which he had the unusual
opportunity of observing whilst the animal was outside its case in
a dying state. As the motion of the cilia gradually became fitful
and then ceased, it was apparent that tle cilia of the inner row are
much longer than those of the outer row, over which the former
appear to bend and to crush off whatever may be adhering to them
into the channel between the two rows. Thus are produced the
wavy lines and apparent onward progression of the cilia, which
render this, under suitable illumination, so brilliant and interesting
a microscopical object.

Mr. Charles O’ Neill, F.C.S., made a communication “ Upon the
Appearances of Cotton Fibre during Solution and Disintegration.”
These experiments referred to the application of Schweizer’s sol-
vent. Two strengths were used; the weaker contained oxide of
copper, equal to 4:3 grs. metal per 1000 and 47 grs. dry ammonia ;
the stronger contained 15-4 grs. metal and 77 grs. dry ammonia
per 1000. The latter is about the most concentrated solution which
can be made. Referring to the researches of Payen, Fresny, Peligot,
Schlossberger, and others, who have employed this solvent, the
author said the only experimenter who seemed to have worked in the
same direction with himself, and that apparently only to a small
extent, was Dr. Cramer, whose paper he had only been able to see
in a translation appended as a note to a memoir of M. Payen, in
‘Comptes Rendus,’ p. 319, vol. xlviii.

Mr, O’ Neill considers that cotton exhibits, under the action of
this solvent, (1) an external membrane distinct from the true cell-
wall or.cellulose matter; (2) spiral vessels situated either in or
outside the external membrane; (3) the true cell-wall or cellulose ;
and (4) an inner medullary matter. The external membrane is
insoluble in the solvent, and may be obtained in short, hollow
cylinders by first acting upon the cotton with the dilute solvent, so
as to gradually remove the cellulose, and then dissolve all soluble

214 PROCEEDINGS OF SOCIETIES.

matters by the strong solvent. If the strong solution is first ap-
plied, the extraordinary dilation of the cellulose bursts the external
membrane, and reduces it to such a state of tenuity that it is in-
visible. This membrane is very elastic, appears to be quite imper-
meable to the solvent, and when free from fissures protects the
enclosed matter from its action. It is not seen in cotton which has
been submitted to the action of alkaline acids and bleaching powder,
being either chemically altered, or, what is most probable, entirely
removed.

The spiral vessels are unmistakeably apparent, running round
the fibre in more or less close spirals, sometimes single, sometimes
double and parallel, and at other times double and in opposite
directions, or again seemingly wound close and tight round the
cylinder. They are well seen in the spherical swellings or beads,
but are prominent at the points of strangulations of long ovals
formed when the ends of the fibres are held tightly. They collect
in a close mass, forming a ligature, and are frequently ruptured,
the ends projecting from the side of the fibre.

The cellulose is enormously dilated by the weaker solvent, and
expands the external membrane into beautiful beads, which are
doubtless the result of the spiral vessels acting as ligatures at the
points of strangulation; at the open end of a fibre it can be seen
oozing out as a mucilaginous substance. The stronger solution
bursts the beads, or dissolves all the cellulose into a homogeneous
mass, amidst which the empty cuticular membrane and the spiral
vessels remain nearly unacted upon.

The substance called medullary matter is seen occupying the
axes of the fibres; it is nearly insoluble in the solvents, It may
be well seen projecting from the open end of a fibre where the
cellulose is exuding, and often remains im situ when the fibre has
quite disappeared. It has many appearances of being a distinct
body, but the author in some cases thought it might be only the
thickened or modified inner cell-wall; in others it looked like a
shrunk membrane, probably the dried-up primordial utricle. It is
generally absent or indistinct in old cotton, or cotton which has
been submitted to bleaching agents.

Mr. O'Neill intends to submit further details when his investiga-
tions are more advanced.

Mr. Hepworth stated that he had observed spiral markings in
Sea Island cotton, not subjected to chemical action, and that he

es calculated there would be about 50,000 spirals to an inch of
bre.

A PAPER

On the Structure of the VatveE of the DIATOMACES.
By Cuarues Stopper.

From ‘ Proceed. Boston Soc. Nat. Iist.,’ vol. ix, p. 2, 1862.
There are recorded a few observations which mention the exist-

PROCEEDINGS OF SOCIETIES. 215

ence of more than one plate of silex in the valve of some three or
four species of diatoms. Mr. Shadbolt (‘Trans. Mic. Soc.,’ Ist
series, vol. ili, p. 49) describes the valve of Arachnodiscus Japoni-
cus as consisting of two layers. Mr. Ralfs (‘ Pritchard’s Lnfusoria,’
4th ed., p. 839) says the valves of Actinoptychus undulatus “ fre-
quently consist of two dissimilar plates, one having the usual
character, the other being triradiate and minutely punctate, and
which has been described as a new species by Mr. Roper, who first
observed it detached from the true valve. He and others have since
found the plates in situ.’ Dr. F. W. Lewis (‘ Notes on New and
Rarer Species of Diatomaceze,’ Phil., 1861, p. 6), describing Navi-
cula marginata, speaks of ‘‘the outer siliceous plate.” Schleiden
(‘ Pritchard,’ 4th ed., p. 41) speaks of ‘‘two leaves lying one over
the other.” Mr. Brightwell says of the lorica of T’riceratium, that
“the valves are resolvable into several distinct layers of silex,
dividing like the thin layers of tale.’ (Pritchard, p. 49.) These
are all the authorities I can find that intimate the existence of more
than one plate of silex in the valve.

Ehrenberg describes several species of diatoms as “ veiled ’’—a
most happy term as expressive of the appearance of those species
to which it is applied. Neither Ehrenberg nor any other microsco-
pist has offered any explanation of the cause of this appearance.
Among the species thus distinguished are the four species of Helio-
pelta, though the fact is not mentioned in any of the published
descriptions, all of which are more or less imperfect.

Some time ago I found a broken specimen of Heliopelta, which
exhibited clearly portions of the valve with the normal characters
of the genus, and, extending beyond the broken edges, portions of
another and inner plate of an entirely different structure. A few
months since, Mr. J. 8S. Melvin gave me specimens of a diatom, as
possibly a new species. On examination of these I found that he
had obtained the inner plate of the valve of Heliopelta Leuwenhoehii
entire and perfect. I have since found other specimens in my own
collection. This plate under low or medium powers shows only
exquisitely fine lines; but with a high power (-4,) it is resolved into
minute spherical granules of silex, arranged in paralleled rows,
radiating towards the margin of the disc, placed in contact with each
other, and cemented together at their peripheries, the cement filling
the interstices. There is a distinct line corresponding to the divisions
of the compartments of the outer plate; a triangular blank at the
junction of these lines with the margin, a conspicuous feature in the
view of the perfect frustule; a star-shaped blank in the centre, the
rays of the star being in number one half of that of the compart-
ments of the disc. Heliopelta has the disc divided into six to twelve
rays or compartments, one half of them having distinctly hexagonal
areolz, the alternate half having an entirely different -kind of mark,
which has never been perfectly described or figured. Dr. Carpenter’s
description is, perhaps, the best, but his figure is one of the most
inaccurate. (‘Carpenter on the Microscope,’ Phil., p. 290.) The
blank star of the inner plate is also a conspicuous feature of the per-

VOL, III.—NEW SER. Q

216 PROCEEDINGS OF SOCIETIES.

fect disc, and the rays of this star always coincide with the compart-
ment last described. The inner plate also shows marks indicating
the position of the marginal (improperly so-called) spines; and under
a high power shows also faint impressions of the areolee of the outer
p ate, which I consider proof that the two plates were in actual con-
tact. It is this inner plate that gives the veiled appearance to this
aud other diatoms, and I take the “veil” in all cases as a visual proof
of the existence of the inner plate. Dr. Carpenter says of He/iopelta,
that a minute granular structure may be shown to exist over the
whole of the valve—‘* that the circular areolation exists in a deeper
ayer of the siliceous lorica.”’ f

Now, Il am certain that Dr. Carpenter was mistaken in this last
remark, though, perhaps, not in what he saw. He had simply
observed a valve with the inside toward the eye. I have repeatedly
seen them in this position, and with the same effect. I have also
found what I take to be the inner plate of an Omphalopelta entire ;
but the evidence of its connection with that genus is not quite
complete.

A few weeks since I found a broken specimen of Coscinodiscus ;
the hexagonal areola were large and distinct, and extending beyond
the broken edges, just as described in the Heliopelta, was another
part of the disc, which was simply granular, with a milky aspect.
This is the inner plate of the valve of that genus. Since that I
have found numerous examples of the same kind, and am now
satisfied that they are quite common, and that others as well as
myself must have seen them often before, without being aware of
their nature. Like the corresponding plate of Heliopedéa, this is
composed of spherical granules of silex, but instead of being in
close contact, they are distant, and joined or cemented together by
a thin plate of silex, the arrangement and place of the particles
being governed by that of the hexagons of the outer plate, one
granule being placed against each hexagon. By careful adjustment
of the focus of the instrument, with a power proportioned to the
size of the areolz, the granules can be seen in the centre of-the
hexagons ; care must, however, be taken not to confound an optical
effect with the appearance of the granules; each areole is a minute
lens, and so refracts the light as to give a bright or dark dot as
the focus is changed, and the granules themselves contribute to
this effect. Practice, however, will enable one to distinguish these
effects.

The species Eupodiscus, Argus, and Rogersi, present strong evi-
dence of the inner plates; so, also, do some specimens of Isthmia
nervosa, of Epithemia, Achnanthes, and Polymyaus coronalis. I
think I have seen indications of them in several otber genera. In
some of the Pinnularia and Navicula there are appearances which
I can explain only on the supposition that the valve is composed
of two plates, as suggested by Schleiden. Sufficient, I think, has
been proved to warrant the generalisation that the valve of the
Diatomacez consists of at least two plates of silex, the inner one
of a structure more or less differing from that of the outer, giving

PROCEEDINGS OF SOCIETIES. 217

that peculiar appearance to those species described as veiled,—partly
the cause of the dots in the hexagonal areole of some species,—and
often, probably, explaining the varying descriptions and figures of
different writers.

There is a difference of opinion among diatomists as to the shape
of the dots or marks of the very finely marked kinds, such as the
whole of the genus Pleurosigma, Smith, Gyrosigma, Hassal, Mr.
Wenham, by magnifying photographs of P. angulatum to 15,000
diameters, has proved, as [ think, that the areole of that species
(and undoubtedly of all the species with diagonal lines) have hexa-
goual areolee, exactly like those of Coscinodiscus. Professor O. N.
Rood, of ‘Troy, by the same process, has obtained photographs of
the same species (7000 diameters), which he thinks prove the
areolee to be circular. Professor Rood’s photographs show some
indications of the hexagonal form, and I believe the difference be-
tween his figures and Mr. Wenham’s must be owing to some
difference in the manipulation. The areolee of the coarsely marked
forms being unquestionably hexagons, it is probable, from analogy,
that those of the finer forms are so also. Mr. Wenham, as quoted
by Professor Rood, ‘‘states that he has ascertained by a 345th that
the markings of this object are due to spherical particles of quartz.”
(‘Am. Jour. Science,’ Nov., 1861, p. 336.) This observation, with
the discovery of the inner plate of the Coscinodiscus, and its struc-
ture, makes the analogy of the structure of the two genera complete,
and may be considered as proving the existence of the inner plate
in this genus.

Another point in the structure of the valve has been a subject of
much difference of opinion—some contend that the areole are ele-
vations, others that they are depressions. Dr. J. W. Griffiths gives,
in the ‘ Micrographical Dictionary,’ his reasons for considering them
to be depressions. I have reasons for thinking that neither party
has the true explanation of the structure. My opinion is that the
exterior of the shell is smooth or nearly so, and that the borders of
the hexagons, or other shaped areolze, and costze of the costate forms,
are internal projections from the outer plate, as on the under side
of the leaf of the Victoria Regia, intended to give strength to the
cell with the smallest quantity of material. This will explain the
trace of the hexagons seen on the inner plate of Heliopelta, as only
the projecting wall of the areola would come in contact with the
inner plate. Dr. Griffiths reasoned that the areolee were depressions
because they were the thinnest parts of the shell; the facts are
correct, but the inference may not be, as there is another explanation
of the phenomena.

In company with Dr. C. T. Jackson, I have dissolved a shell of
Coscinodiscus under the microscope, with caustic potash, and found
that the area of the cellules was dissolved before the walls, and that
therefore they are the thinnest parts, as Dr. Griffiths judged from
the optical effect.

218 PROCEEDINGS OF SOCIETIES.

Huxtit Micro-PuHiLosorpHicaL Socinrry.

The fifth sessional course of papers delivered by the several mem-
bers of this society terminated on March 20th last. These were
mostly of an interesting character, and the meetings were generally
well attended. An increasing interest in microscopical research is
manifest, and several additional applications for membership have
been made. Several new instruments have latterly been introduced
from the manufactory of Mr. Cooke, optician, of Hull, of exquisite
workmanship, compact design, and perfect stability. The society
in its pecuniary resources may be said to flourish, and withal to
present every fair prospect of utility and success.

An abridgment of some of the papers may be stated as under:

George Norman, Esq., the President of the society, in intro-
ducing the subject of diatomaceous deposits, stated his fears that
in the short time allowed for his paper little more than a discursive
glance could be given to the subject, and that, perhaps, on some
future occasion he would bring the subject again before the mem-
bers.

The occurrence of Diatomacez in a fossil state is, on the autho-
rity of Ehrenberg, constant in the chalk rocks. The President
stated that, so far as his own experience went, no traces had been
found in true chalk; perhaps, however, in the Paris beds the case
might be different.

The possibility of the flint nodules in chalk being the amorphous
state of former siliceous frustules was next touched upon. The
most important deposits occur in the pliocene and plistocene for-
mations immediately following the cretaceous rocks. ‘lhe enormous
deposits of Maryland, Virginia, and Algiers, were probably to be
. referred to this period. ‘lhe fresh-water deposits of Finland, Bo-
hemia, North America, Dolgelly, Toome Bridge, &c., were probably
of a far more recent date; these were all, at some remote period,
the beds of former lakes and morasses. The President alluded to
the extensive deposit he had himself visited at Toome Bridge, in
the county of Antrim. More recent deposits still are found under-
laying peat beds, containing diatoms, with few exceptions, identical
with forms now found living. The very ancient peat beds found
about twenty-five feet beneath the alluvium of the district of Hull
and neighbourhood contained very slight traces of Diatomacee. A
sample taken from a deep excavation at Spring Head had furnished
very sparingly Pinnularta cardinalis, a species which had hitherto
never been found recent. The ancient peat deposit and sunken
forest cropping out of the sands at Hornsea contained also Pennu-
laria cardinalis, mixed with many recent forms. This great bed
was probably the bed of a former mere like the existing Hornsea
Mere.

The President proceeded to state that, in all probability, the site
of the present Hornsea Mere would, at some future time, furnish a

PROCEEDINGS OF SOCIETIES. 219

diatomaceous deposit more or less rich. The sea would in time
wear away the narrow piece of land separating the mere from the
ocean sand, and mud would be deposited over the entire area, and
the mass of diatomaceous frustules, the accumulation of ages, would
be consolidated into a white mass, such as we find in any ordinary
deposit, the long rotting process having removed the brown endo-
chrome. An instance was given of the gradual formation of such
deposits before our eyes. Only the past summer the President had
obtained a piece of tolerably white deposit from the bed of the
Spring Ditch, which was in course of being filled up; it contained
all the recent species which have been known to exist there by the
previous examinations of microscopists. This once favorite locality
is now destroyed through the extension of public works.

In conclusion, the President hastily glanced over the various uses
these deposits were turned to, instancing such commercial products
as tripoli, plate powder, floating bricks for powder magazines on
board ship, &c.

The clays eaten by the natives of South America and in the in-
terior of Africa were also, probably, diatomaceous deposits like the
well-known Berg-Mehl of Lapland.

Mr. H. Prescott produced a paper, entitled “The History and
Physiology of a grain of Barley,” illustrating the germination of
barley in its most rudimentary form, and then tracing its growth
into a plant and the further development and structure of stem,
root, flowering, spike, spikelets with floral appendages, sexual
organs, pollen, starch, &c.

The peculiarities of growth of stem (straw) structure and the
various appearances of the inflorescence during different stages of
development were illustrated by numerous etchings.

On another occasion during the session, Mr. Prescott (‘On the
Structure of certain Seeds’’), failing time and opportunity to give
the meeting the benefit of any special studies that he might be
competent to undertake, which were still incomplete, thought that
a work bearing immediately on the subject, prepared for the use of
Government by Drs. Hooker, Carpenter, Graham, Lindley, &c. (a
copy of which he was fortunate enough to possess), might have
some interest for the meeting. Sketches and letterpress were both
valuable, as showing how master minds commanded and carried
through the working out of a subject quite new to themselves. In
this instance, as in the determination of gennine and adulterated -
coffee, the meeting would not fail to observe how well the micro-
scopic characters of the substances had been preserved in drawings
which bore the stamp of truth upon them. The elaborate re-
searches of Dr. Graham and others on the gravities of the different
substances in solution were equally admirable.

Mr. Hunter’s paper, ‘‘On the Structure of Animal Hairs,” was
illustrated by numerons slides, including different coloured human
hair, hairs from the several classes of animals, insects, &e., and
hairs from different parts of the body of the same species. Much
emphasis was laid upon the difficulty of identifying individual hairs,

220 PROCEEDINGS OF SOCIETIES.

and also the want of a suitable medium for permanent mounting of
specimens; the inefficiency of Canada balsam was shown by speci-
mens otherwise mounted (fluids) exhibited in contrast, although
balsam might answer best for dark ground and polariscope investi-
gations.

The so-called whale hair was handed round the tables—a sub-
stance showing most of the microscopic properties of both hair and
bone. The excellent felting properties of the hairs of the Carni-
vora and Rodentia was dwelt upon, and also the striking differences
in those of the Ruminantia.

The adulterations practised by some workers in ornamental hair
was illustrated by specimens mixed with hair from the alpaca and
some species of goat.

Beautiful slides from the Ornithorhyncus and Gopher (from the
banks of the Mississippi, lowa) were compared ; the only two kinds
examined having the combined properties of wool and hair from
the same root.

Mr. Ball, of Brigg, in Lincolnshire, read a very interesting paper
“©On the Anatomy of the Snail,’ which was illustrated by exquisite
dissections and preparations of all the principal organs. ‘The lan-
guage of ordinary comment fails to give due expression to the
Society’s appreciation of this gentleman’s labours and microscopic
productions.

Mr. Stather effectively exhibited the powers of the binocular
microscope.

A paper ‘On the Stings, Ovipositors, and the cutting parts of
the Proboscides of Insects”? was produced by Mr. Hanwell, show-
ing the general resemblance of these parts, in some instances as to
nearly appear identical. The nature of the true sting was shown,
the incising apparatus attached to the head compared with it, and
a classification made of the forms of the instruments used, from the
simple lancet to the more complicated apparatus of the highly
organized insects; the beautiful adaptation of means to ends, as
exhibited in the various kinds of ovipositors, was dwelt upon. The
paper was well illustrated by numerous slides prepared by this
gentleman.

Dr. Kelbourne King delivered an article “On the Nervous Tis-
sues,”’ illustrated by slides of the nerve-cells, of considerable interest
and beauty, and calculated to awaken the further attention of ana-
tomists and physiologists to these very important structures. Pre-
parations variously mounted in naphtha solution, glycerine and
gelatine—the two latter both plain and coloured with carmine—
were handed round, but, notwithstanding the beauty of carmine
preparations, in these instances the naphtha solution appeared to
afford a more minute structural detail.

Mr, Hendry exhibited the saccharo-polariscope, and the opposite
order of colour phenomena of grape and cane sugars, with great
effect ; also delivered a paper, with illustrations, ‘On Spermatozoa,”’
in the absence of Dr. A. M‘Millan, otherwise engaged; and upon
a third occasion introduced the subject of the connective tissues.

PROCEEDINGS OF SOCIETIES. 221

The session now terminated, embodying in its series of subjects
matter amply adapted to call forth the active energies of its various
members.

Wm. Henpry, Hon. See.

A Paper

On the EMBRYOGENY of CoMATULA ROSACEA (Linck). By Pro-
fessor Wyv1ILLE Tuomson, LL.D., F.R.S.E., M.R.LA., F.G.S.,
&e.

(From ‘ Proceed. Roy. Soc.,’ Feb. 5, 1863.)

Arter briefly abstracting Dr. W. Busch’s description of the early
stages in the growth of the young of Comatula, the author details
his own observations, carried on during the last four years, on the
development and subsequent changes of the larva. After complete
segmentation of the yolk, a more consistent nucleus appears within
the mulberry mass still contained within the vitelline membrane.
The external, more transparent, flocculent portion of the yolk lique-
fies and is absorbed into this nucleus, which gradually assumes the
form of the embryo larva, a granular cylinder contracted at either
end and girded with four transverse bands of cilia. This cylinder
increases in size till it nearly fills the vitellme sac, gradually
increasing in transparency, and ultimately consisting of delicately
vacuolated sarcode, the external surface transparent and studded
with pyriform oil-cells, the inner portion semifluid and slightly
granular.

The vitelline membrane now gives way, and, usually shortly after
the escape of the larva into the water, the third ciliated band from
the anterior extremity arches forwards at one point; and in the
space thus left between it and the fourth band, a large pyriform
depression indicates the position of the larval mouth. At the same
time a small, round aperture, merely separated from the posterior
margin of the mouth by the last ciliated band, becomes connected
with the mouth by a short, loop-like canal, passing under the band,
and fulfils the function of an excreting orifice. A tuft of long cilia,
which have a peculiarly undulatory motion, is developed at the
posterior extremity of the body. The larva now increases rapidly
in size, assuming somewhat the form of a kidney bean, the mouth
answering in position to the Aé/um. It swims freely in the water,
with a swinging, semirotatory motion, by means of its ciliated bands
and posterior tuft of cilia.

Shortly after the larva has attained its definite independent form
ten minute calcareous spicula make their appearance, imbedded
within the external sarcode-layer of the expanded anterior portion
of the larva, The ten spicula are arranged in two transverse rings
of five, the spicula of the anterior row symmetrically superposed on
those of the posterior. By the extension of calcareous network,

222 PROCEEDINGS OF SOCIETIES,

these spicula rapidly expand into ten plates, which at length form
a trellis enclosing a dodecahedral space, open above and below,
within the anterior portion of the zooid. Simultaneously with the
appearance of these plates, a series of from seven to ten calcareous
rings form a chain passing from the base of the posterior row of
plates backwards, curving slightly to the left of the larval mouth,
and ending by abutting against the centre of a large cribriform
plate, which is rapidly developed close to the posterior extremity
of the larva. Delicate sheaves of anastomosing calcareous trabeculae
shortly arise within these rings, and the series declares itself as the
jointed stem of the pentacrinoid stage, the basal and first inter-
radial plates of the calyx being represented by the already formed
casket of caleareous network. The skeleton of the Crinoid is thus
completely mapped out within the body of the larva, while the
latter still retains its independent form and special organs.

Within the plates of the calyx of the nascent Crinoid two hemi-
spherical or reniform masses may now be detected—one superior, of
a yellowish, subsequently of a chocolate colour; the other inferior,
colourless and transparent. The lower hemisphere indicates the
permanent alimentary canal of the Crinoid, with its glandular
follicle; the upper mass originates the central ring of the ambu-
lacral system, with its czeca passing to the arms. ‘The body of the
Crinoid is, however, at this stage entirely closed in by a dome of
sarcode, forming the anterior extremity of the larva. After swim-
ming about freely for a time, averaging from eight hours to a week,
and increasing rapidly in size till it has attained a length of from
1 to 2 mm., the larva becomes sluggish, and its form is distorted
by the growing Crinoid. The mouth and alimentary canal of the
larva disappear, and the external sarcode-layer subsides round the
calcareous framework of the included embryo, forming for it a
transparent perisom. The stem now lengthens by additions of
trabeculee to the ends of the joints. The posterior extremity
dilates into a dise of attachment. ‘The anterior extremity becomes
expanded, then slightly cupped; the lip of the cup is divided into
five crescentic lobes, corresponding to the plates of the upper ring;
and finally five delicate tubes, ceeca from the ambulacral circular
canal, are protruded from the centre of the cup, the rudiments of
the arms of the Pentacrinoid. At some stage during the progress
of these later changes the embryo adheres, and at length becomes
firmly cemented to some permanent point of attachment.

The author states his views as to the morphological and physio-
logical relations of the larval zooid. He believes that all the pecu-
liar independently organized zooids developed from the whole or
from a part of the segmented yolk in the Echinoderms, and which
form no stage in the development of the perfect form of the species,
must be regarded as assimilative extensions of sarcode, analogous
in function to the embryonic absorbent appendages in the higher
animals. For such an organism the term ‘‘ pseudembryo”’ is pro-
posed. In the Echinoderm subkingdom, although constructed
apparently upon a common plan, these pseudembryos present cyn-

PROCEEDINGS OF SOCIETIES. 223

siderable range of organization, from a somewhat complex zooid
provided with elaborate natatory fringes, with a system of vessels
which are ultimately connected with the ambulacral vascular system
of the embryo, with a well-developed digestive tract, and in some
instances with special nervous ganglia, to a simple layer of absorbent
and irritable sarcode which invests the nascent embryo. The pseud-
embryo of Comatu/a holds an intermediate position. It resembles
very closely in external form and in subsequent metamorphosis the
“pupa stage” of the Holuthuride, the great distinction between
them being that in the Holothuride the pupa has already passed
through the more active ‘‘ Auricularian’’ stage, while the analogous
form in Comatula has been developed directly from the egg.

West Kent Naturat History anp MicroscopicaL Socrery.

February 18th, 1863.
List of Officers.

President.—Frederick Currey, Esq., M.A., F.R.S., See.L.8.

Vice-Presidents.— John Penn, Esq., F.R.S.; John F. South, Esq.,
F.R.C.S.; and James Glaisher, Esq., F.R.S., F.R.A.S.

Treasurer.—ll. G. Noyes, Esq., M.D. Lond., M.R.C.P.L.

Hon. Secretaries.—Messrs. E. Clift and W. Groves.

Council. W. H. Brown, Esq., F.R.C.S.; M. Corder, Esq. ;
William Groves, Esq. ; W.G. Lemon, Esq., B.A.; Rev. R. H. Mar-
ten, B.A.; Flaxman Spurrell, Esq., F.R.C.8. : John Standring, Esq. ;
George Sweet, Esq.; James Taylor, Esq.; William Walton, Esq. ;
J. Jenner Weir, Esq.; Rev. J. G. Wood.

REPORT FOR THE YEAR 1862.
Read at the Annual Meeting, February \8th, 1863.
Frepertck Currey, Hsq., President, in the Chair.

The council of the West Kent Natural History and Microscopical
Society have the gratification of informing the members that the
prosperity of the society, both in respect to numbers and finances,
on which they felt they might justly congratulate them at the last
general meeting, still continues to attend it. They have indeed to
regret the loss of three of the former members, who have been re-
moved by death, and the withdrawal of five others, whilst twenty-
four new members have been admitted. And the council are re-
joiced to see, in the lengthened list of names, a proof of increasing
interest in the subjects the study of which the society seeks to
promote.

224. PROCEEDINGS OF SOCIETIES.

The meetings during the past year have been well attended, and
several of them have been rendered extremely instructive by the
exhibition of various rare and novel objects connected with natural
history or microscopical research.

A paper was read in October by James Glaisher, Esq., one of the
Vice-Presidents, and a very crowded meeting, at which many ladies
were present, listened to him with much pleasure as he detailed the
particulars of his late balloon ascents, made at the suggestion of the
British Association, and conveyed to his hearers, in a pleasing and
popular form, and by the aid of excellent diagrams, the scientific
results obtained by his aérial voyages. A paper also was read in
March by J. Slade, Esq., giving an interesting account of ‘ Shell
Structure.”

The past summer was not favorable for field-meetings ; one only
took place. The members who attended it were well pleased with
the results. Botany was the science selected for illustration, and a
list of about 240 plants met with in the day’s excursion was drawn
up by J. Mathewson, Esq.

The second soirée given by the society was held in June. About
300 ladies and gentlemen were present. More than fifty micro-
scopes belonging to members were placed on the tables, and many
objects of interest were exhibited. Among these were magnificent
specimens of algee and ferns from Australia and Japan ; British
birds’ eggs; insects from various foreign countries, shells, &ec.;
with numerous fossils and other geological specimens. The room
was beautifully decorated with choice exotics, lent by John Penn,
Esq., and refreshments were supplied to the company.

The additions to the library during the past year have been—

Williamson’s.‘ British Foraminifera.’

Carpenter’s ‘Introduction to the Foraminifera.’

Currey’s ‘ Hoffmeister’s Cryptogamic Botany.’

‘The Microscopic Journal’ for 1862.

‘Popular Science Review’ for 1862.

‘Manchester Philosophical Transactions,’ presented by the
Manchester Literary and Scientific Society.

A cabinet has been purchased for the reception of microscopic
slides, and more than fifty have been presented ; and it is hoped
that members obtaining any rare or,interesting object will forward
a duplicate for the use of the society. Soundings still continue to
be received from various parts of the world, some of which have
been examined, and several objects, especially Foraminifera, have
been obtained from them.

The number of members is now 113, including eight honorary
members.

The auditor’s report will show that the funds are in a satisfactory
condition.

Rules.
1, The society shall be called Tor West Kent Naturat Hrs;

PROCEEDINGS OF SOCIETIES, 225

TORY AND MricroscopicaL Society, and have for its objects the
promotion of the study of natural history and microscopic research.

2. The society shall consist of members who shall pay in ad-
vance 10s. Gd. each per annum, and of honorary members.

3. The affairs of the society shall be managed by a council, con-
sisting of a president, three vice-presidents, treasurer, two secre-
taries, and twelve members, who shall be elected from the general
body of ordinary members.

4, The president and vice-presidents shall not hold office longer
than two consecutive years; and the two members of council who
have attended the least number of meetings during the preceding
year shall retire, and be ineligible for the following year.

5. The president and other officers and members of council shall
be annually elected by ballot, The council shall prepare a list of
such persons as they think fit to be so elected, which shall be laid
before the general meeting, and any member shiall be at liberty to
strike out any or all of the names proposed by the council, and sub-
stitute any other name or names he may think proper.

6. The council shall hold their meetings on the day of the
ordinary meetings of the society, one hour before the commencement
of such meeting. No business shall be done unless five members
be present. ‘

7. Special meetings of council shall be held at the discretion of
the president or vice-presidents.

8. The council shall prepare and cause to be read at the annual
meeting a report on the general affairs of the society for the pre-
ceding year.

9. Two auditors shall be elected, by show of hands, at the ordi-
nary meeting held in January. They shall audit the treasurer’s
accounts, and produce their report at the annual meeting.

10. Every candidate for admission into the society must be pro-
posed and seconded at one meeting, and balloted for at the next;
and when two thirds of the members present are in favour of the
candidate, he shall be duly elected.

11. Each member shall have the right to be present and vote at
all general meetings, and to propose candidates for admission as
members. He shall also have the privilege of introducing two
visitors to the ordinary and field-meetings of the society.

12. No member shall have the right of voting, or be entitled to
any of the advantages of the society, if his subscription be six
months in arrear.

13. That the annual meeting shall be held on the third Wednes-
day in February, for the purpose of electing officers for the year en-
suing, for receiving the reperts of the council and auditors, and for
transacting any other necessary business.

14. Notice of the annual meeting shall be given at the preceding
ordinary meeting.

15. The ordinary meetings shall be held on the fourth Wednesday
in the months of October, November, January, February, March,
April, and May, and the third Wednesday in December, at such

226 PROCEEDINGS OF SOCIETIES.

place as the council may determine. The chair shall be taken at
8 p.m., and the business of the meeting being disposed of, the
meeting shall resolve into a conversazione.

16. Field-meetings may be held during the summer months at
the discretion of the council; of these due notice, as respects
time, place, &c., shall be sent to each member.

17. Members shall have the right of suggesting to the council
any book or object to be purchased for the use of the society.

18. All books in the possession of the society shall be allowed
to circulate among the members, under such regulations as the coun-
cil may deem necessary.

19. The microscopical objects and instruments in the possession
of the society shall be made available for the use of the members,
under such regulations as the council may determine; and the
books, objects, and instruments shall be in the custody of one of
the secretaries.

20. The council shall have power to recommend to the mem-
bers any gentleman, not a member of the society, who may have
contributed scientific papers, or otherwise benefited the society, to
be elected an honorary member; such election to be by show of
hands.

21. No permanent alteration in the rules shall be made, except at
the annual meeting, or a meeting specially convened for the pur-
pose by the president, and then by a majority of not less than two
thirds of the members present, of which meeting one month's
notice shall be given.

ORIGINAL COMMUNICATIONS.

Descriptions of New and Rare Dtatoms. Series X.
By R. K. Grevitie, LL.D., F.R.S.E., &e.

(Plates IX and X.)

RvuTiLaRiA, nov. gen., Grev.

Frustutes free, elongated, compressed, with a convolute
or nodulose central nodule (no median line or terminal
nodule), and minute radiate or decussato-punctate structure.
Valve (linear, keeled?) with a longitudinal row of puncta.

This is a most remarkable fossil genus, and its systematic
position exceedingly perplexing. I have reason to believe
that Mr. Kitton, of Norwich, who kindly sent me his cabi-
net specimens for examination, was the discoverer of the
first species, which he obtaimed from the Monterey deposit,
and named provisionally Nitzschia Epsilon, on account of the
resemblance of the nodule to the Greek letter. But this
nodule, conspicuous for its glistening appearance, as well as
for its singular convolution, appeared to me to separate it
from Nitzschia. Unfortunately no single valve occurred
among the specimens found by Mr. Kitton and myself; and
being unable with the instruments then in my possession to
satisfy myself regarding the structure, I sent the specimens
to my friend Mr. T. G. Rylands, who ascertained that the
frustule was really Nitzschoid, in so far that the valves were
keeled and furnished with a row of puncta. Still, the ex-
traordinary nodule forbade its association with the true
Nitzschie, aud I laid the subject aside until further informa-
tion could be obtained.

Recently two other diatoms have been discovered by Mr.
C. Johnson in the Barbadoes deposit, which are evidently

VOL. III.—NEW SER. R

228 GREVILLE, ON NEW DIATOMS.

closely allied to the Monterey specimens, having the peculiar
glistening nodules, Nitzschoid form, and marginal puncta.
Jn these the intimate structure is more visible; the pale
puncta distinctly radiating from the centre, and becoming
decussate towards the ends. There can be no doubt, I
think, that the three diatoms constitute a very natural genus.
As I have been unable to ascertain positively whether the
valves of the Barbadoes species are keeled (although I be-
lieve them to be so), I have inserted this character doubt-
fully. It will be perceived that I have framed the generic
character on the assumption that this little group belongs,
with Nitzschia, to the Fragilariee, and that the figures con-
sequently represent the front view. But it must be confessed
that, for a front view, the appearance is not a little strange.

Rutilaria Epsilon (Kitton), n. sp., Grev.—Frustule lanceo-
late, with linear, elongated, obtuse apices; nodule very
large, with three conspicuous convolutions. Length ‘0080’.
(Pl. EX dis. 12)

Nitzschia Epsilon, Kitton, in litt.

Hab. Monterey deposit; F. Kitton, Esq., C. Johnson,
Esq., R. K. G.

Frustules transparent, minutely and faintly punctate, the
puncta forming decussating lines ; margin with a row of dark,
conspicuous puncta. Central nodule very glistening, large,
occupying the greater part of the diameter of the frustule,
composed of a semilunate body, with the horns, as it were,
convolute, and having secondary horns arising out of and
a little to the exterior of the others, also more or less convo-
lute. A few large scattered puncta are generally present on
each side of the nodule. Although there are no terminal
nodules, there is sometimes the appearance of them, owing,
apparently, to some peculiarity of structure influencing the
transmission of light at the apices. The most remarkable
feature in this diatom is the nodule, which, as a rule, is
symmetrical, but here it is the reverse, and so whimsical in
its configuration that it may be compared to some old-
fashioned drawer-handle represented in alto-relievo.

Rutilaria ventricosa, n. sp., Grev.—Frustules ventricose,
with short, linear extremities; nodule circular, nodulose ;
puncta radiating, decussate towards the ends. Length about
0040". (Fig. 2.)

Hab. Barbadoes deposit, from Cambridge estate; C.
Johnson, Esq., R. K. G..

A much smaller species than the preceding, and relatively
shorter, but not unlike it in general form. The nodule,
however, is quite different, being circular, with some ap-

GREVILLE, ON NEW DIATOMS. 229

pearance of being lobed or convoluted. The puncta dis-
tinctly radiate from the centre, until they reach the linear
extremities, where they decussate. The extremities vary
somewhat in breadth, and the apices are either obtuse or
subacute.

Rutilaria elliptica, n. sp., Grev.—Frustules elliptical, with
a slight contraction towards the acute apices; nodule circu-
lar, somewhat nodulose; puncta radiating, decussate at the
ends. Length about 0040". (Fig. 3.)

Hab. Barbadoes deposit, from Cambridge estate; C.
Johnson, Esq., R. K. G.

The same size as the last, buf well distinguished by its
elliptical form.

CAMPYLODISCUS.

Campylodiscus undulatus, n. sp., Grev.—Disc nearly cir-
cular, with a linear, median space, and about 25 costz on
each side, which are separated by a longitudinal furrow into
apparently two series. Diameter about 0042". Coste 4 in
7001". (Fig. 4.)

Hab. Bermuda, in mud brought up on the fluke of an
anchor ; kindly communicated by George Norman, Esq.

This species is nearly related to Campylodiscus striatus
of Ehrenberg, figured by Mr. Brightwell in the seventh
volume of the ‘ Journal of Microscopical Science,’ but is, at
the same time, abundantly distinct. It is a larger and
much finer species, with nearly double the number of costz,
and in the character of the latter differing essentially. In C.
striatus there are really two series on each side, the narrow
hyaline space between them forming an actual interruption,
while near each extremity of the median line they unite, a
short line, at least, only passing between them. In our
present species, on the contrary, the narrow hyaline space
which divides the apparent two series of coste is, in
reality, a deep furrow, round the bottom of which the costz
are carried, as is easily seen towards each end, where, as the
furrow becomes gradually shallow, the costz are plainly con-
tinuous.

GRAMMATOPHORA.

Grammatophora Moronenis, n. sp., Grev.—Septa straight ;
margin very coarsely striated; striz 11 in ‘001’. Length
0025”. . (Fig. 5.)

Hab. Deposit at Moron, in the Spanish province of Seville.

230 GREVILLE, ON NEW DIATOMS.

I have not seen the lateral view of this species, but in the
small section of the genus characterised by straight septa
the coarse striz at once distinguish it.

CoscINODISCUS.

Coscinodiscus scintillans, n. sp., Grev.—Dise with a cir-
cular umbilical space and radiating lines of small, distinct,
brilliant granules, the long ones wide apart, with 2—3 short,
very irregular intervening lines at the margin; margin
striated ; long lines of granules 4 or 5 in:001; marginal
strie 15 in 001”. Diameter 0032”. (Fig. 6.)

Hab. Barbadoes deposit, from Cambridge estate; G. M.
Rrowne, Esq.

A. very beautiful species, which I have only observed in
some slides which Mr. Browne obligingly sent for my in-
spection, the disc in question being one of the objects to
which he particularly directed my attention. The great
distance between the lines of granules which reach the centre
is the leading character; and the very irregular imtervening
lines, varying in length from a couple of granules only, to a
third of the radius, help to individualise it. The granules
are singularly brilliant.

Coscinodiscus griseus, n. sp., Grev.—Dise gray, convex,
depressed in the centre, with a somewhat indefinite umbi-
licus; granules equal, in close radiating lines ; margin pro-
minent, with a row of extremely minute puncta on its inner
boundary. Diameter about -0035”. (Fig. 7.)

Hab. Barbadoes deposit, from Cambridge estate ; in slides
communicated by C. Johnson, Esq.

I am not aware of any described species with which the
present one can be confounded. But I am under an im-
pression that one of the same colour, and in some other
respects very similar, exists in the same deposit, differing,
however, essentially in the presence of a row of marginal
tubercles. There is an umbilicus in our present species, but
it is generally more or less filled up with a little cluster of
granules. The lines are crowded in the centre, more distinct
as they approach the margin. The very minute puncta con-
nected with the latter are easily overlooked.

ASTEROLAMPRA.

Asterolampra Moronensis, n. sp., Grev.—Valve subcir-
cular ; areolated segments somewhat square at the base ; um-
bilical lines with an angular bend, radiating from a central

GREVILLE, ON NEW DIATOMS. 231

point ; median ray narrow, the rest (6) linear, slightly dilated,
and as if notched at the margin. Diameter ‘0030.” (Fig. 8.)

Hab. Deposit at Moron, in the province of Seville; G.
Norman, Esq., R. K. G.

A very distinct species belonging to the section composed
of Ehrenberg’s genus Asteromphalus, characterised by one of
the rays being much narrower than the rest, and by two of
the radiating umbilical rays being approximated. It appears
to have most affinity with 4. Darwinii in the angular bend
of the median lines, but in no other feature. In a general
sense, the valve may be called circular; but it is not strictly
so, for in the numerous specimens I have examined it is
more or less unequal at the margin; so much so occasionally,
as to have a somewhat cornered appearance. The umbilical
lines are sometimes divided near their origin, as in A. Bredis-
soniana and A. variabilis. The rays are exceedingly well
marked, by being invariably dilated at their marginal ex-
tremity, and by having the appearance of being notched, or
as if a shadow indicated a funnel-shaped termination of the
ray-tube.

TRICERATIUM.

Triceratium Robertsianum, nu. sp., Grev.—Valve with con-.
vex sides, obtuse angles, pseudo-nodules, and a wide hexa-
gonal cellulation, the external row of cellules twice the size of
the rest; those at the angles rounded and much smaller.
Distance between the angles about ‘0054”. (Fig. 9.)

Hab. Curteis Straits, Queensland ; very rare ; in a dredging
communicated by Dr. Roberts, of Sydney.

This fine species belongs to the group of which 7. Favus is
the type, and which requires to be carefully studied, as the
extent of variation in 7. Favus itself is by no means clearly
ascertained. In the rare diatom now before me there is no
ambiguity, the outer row of large cellules being of a very re-
markable character. The angles also are peculiar, the cellules
which occupy them being rounded and much smaller, a
vacant space being left immediately below the pseudo-nodule.
The cellules in the centre are about 5 in ‘001’. Those of
the marginal row scarcely 3 in ‘001”.

Triceratium prominens, n. sp., Grev.—Valve with straight
sides, obtuse angles, and very prominent pseudo-nodules ;
centre slightly inflated; granules remote, large, in radiating
lines, and increasing in size from the centre to the margin,
where the lines are 4—5 in ‘001’. Distance between the
angles 0040". (Fig. 10.)

232 GREVILLE, ON NEW DIATOMS.

Hab. Barbadoes deposit, Cambridge estate; C. Johnson,
Esq.

The granules are distinct and remote over the whole valve;
not circular, but rather slightly quadrate, mimute in the
centre, but increasing in size as they radiate to the margin,
which is striate. Pseudo-nodules vertical relatively to the
plane of the valve, obtuse, and extremely prominent.

Triceratium disciforme, n. sp., Grev.—Valve nearly circu-
lar, with no perceptible pseudo-nodules; granules (rather
cellules) very large, subquadrate, radiating, mcreasing in size
from the centre to the margin, where the lines are 5 in 001”.
Distance between the angles about ‘0035”. (PI. X, fig. 11.)

Hab. Barbadoes deposit, from Cambridge estate; C.
Johnson, Esq., R. K. G.

In this curious species the valve is so nearly circular that
the first specimen which came under my observation I took
to be a Coscinodiscus. The angles, in fact, project so very
little beyond the circular line as to be hardly perceptible,
and are only discovered by looking for them. The structure
is cellulate, but at the first glance seems coarsely granulate.

Triceratium cinnamomeum, n. sp., Grev.—Valve of a
reddish colour, with slightly concave sides and obtuse angles,
minutely punctate; puncta forming a line which projects
from each angle fully half way towards the centre, while
along the margin they are arranged in arch-like series.
Distance between the angles about ‘0030”. (Fig. 12.)

Hab. Deposit at Moron, in the province of Seville; G.
Norman, Esq., C. Johnson, Esq., R. K. G.

This little species, which is not rare in the Moron deposit,
is characterised invariably by its reddish-brown colour, and
by the line formed by two rows of puncta, which projects
inwardly from the angles. There are, besides, not unfre-
quently, three or four additional uncertain lines radiating
very irregularly from near the centre. The latter, however,
although evident enough in some examples, are scarcely per-
ceptible in others. In the centre of the valve the puncta
are not crowded. ‘Towards the margin they are 18 in -001”,
arranged in more or less arched lines, which, under a power
of 400 diameters, form a remarkable and conspicuous cha-
racter.

Triceratium inflatum, nu. sp., Grev.—Valve with very con-
vex sides and somewhat obtuse angles, and several vein-like
lines reaching from the margin about half way to the centre ;
surface with remotely scattered puncta, which become
smaller and more numerous at the margin. Distance between
the angles 0035”. (Fig. 15.)

GREVILLE, ON NEW DIATOMS. 233

Hab. Barbadoes deposit, from Cambridge estate; C.
Johnson, Esq.

I do not know any described species to which this diatom
can be referred. The central remotely scattered puncta are
rather large, while those near the margin are minute. There
is no pseudo-nodule.

Triceratium lineolatum, n. sp., Grev.—Valve with nearly
straight sides, somewhat obtuse angles, and prominent pseudo-
nodules ; surface entirely filled with minute, uniform, radiating
cellules, while 4—5 short vein-like lines project inwards
from the sides. Breadth between the angles about :0042”.
(Fig. 16.)

Hab. Barbadoes deposit, from Cambridge estate; C.
Johnson, Esq.

Quite distinct from every species in this large genus. The
vein-like lines are generally four on each side, and reach
scarcely half way to the centre. Although the structure is
minute, it is evidently cellulate under a power of 300 or
400 diameters.

Triceratium lobatum, n. sp., Grev.—Small ; valve distinctly
3-lobed, with no perceptible pseudo-nodules; lobes ovate,
having about 4 short vein-like lines on each side, and being
more or less filled up with scattered puncta. Distance be-
tween the angles about :0022”. (Fig. 13.) ,

A very beautiful and well-marked little species. The
peculiar form is constant, resembling a 3-lobed leaf, while
the short parallel limes may be compared to the veins. The
puncta are not equally visible in all specimens, being some-
times irregularly scattered and most conspicuous near the
margin; but in perfect examples the puncta (which, in fact,
constitute a regular cellulation) are equally distributed over
the valve, except im the centre, where there is a partially
blank triangular space.

Triceratium denticulatum, nu. sp., Grev.—Valve with con-
cave sides and rounded angles ; margin with numerous short,
tooth-like striz, the middle with a few minute puncta ar-
ranged in a triangular form, leaving the centre blank ; to-
wards the angles a few scattered large puncta. Distance
between the angles ‘0025”. (Fig. 14.)

Hab: Barbadoes deposit, from Cambridge estate; C.
Johnson, Esq.

In general form the frustule may be said to be slightly 3-
lobed. The marginal striz are very short and rather robust,
forming an even line, except quite at the angles, which are
left blank, but there is no pseudo-nodule.

Triceratium constans, n. sp., Grev.—Valve with straight

234 GREVILLE, ON NEW DIATOMS.

sides, obtuse angles and small circular pseudo-nodules;
whole area filled up with hexagonal cellules, about 5 in -001”
in the centre, becoming smaller towards the margin. Distance
between the angles 0040”. (Fig. 17.)

Hab. Barbadoes deposit, from Cambridge estate; C.
Johnson, Esq., J. Ralfs, Esq., R. K. G.

A neat, well-defined species. The rather small pseudo-
nodules filling up the slightly rounded angles are not promi-
nent, but somewhat resemble the processes of an Auliscus.
The cellulation becomes gradually smaller in approaching
the margin, which is narrow, well-defined, and striated.

Triceratium tumidum, u. sp., Grev.—Valve with concave
sides, very rounded angles, filled with large, oval, tumid,
minutely punctate pseudo-nodules ; surface with very remote,
large, scattered puncta. Distance between the angles -0042”.
(Fig. 18.)

Hab. Barbadoes deposit, from Cambridge estate; C.
Johnson, Esq.

Very distinct. The pseudo-nodules symmetrically rounded
and prominent.

Triceratium Normanianum, un. sp., Grev.—Valve with the
sides constricto-concave, angles dilated, widely hemispherical,
with a transverse line at about one third of the distance
between the lateral concavity and the summit; whole surface
filled with minute puncta, those of the centre radiating.
Distance between the angles about -0030”. (Fig. 19.)

Hab. Barbadoes deposit, from Cambridge estate; G. Nor-
man, Esq. ,

Unquestionably very near 7. castellatum of West, but
differing from it in the lateral concavities being far deeper
and sharper, in the lobes or angles being more widely
dilated, in the central puncta being radiate, and in the
transverse lines which separate the angles from the centre
being situated nearer the ends. It appears to be an
extremely rare species, as it has only been seen by Mr.
Norman.

Triceratium subcapitatum, n. sp., Grev.— Small; valve
with straight or slightly convex sides, and very produced,
slender, somewhat capitate angles, having a transverse line
near the apex; surface minutely punctate, the puncta radiat-
ing, with 2—3 irregularly situated spmes. Distance between
the angles about ‘0020”. (Fig. 20.)

Hab. Barbadoes deposit, from Cambridge estate; not un-
frequent.

The nearest ally of this minute species is 7. capitatum of
Ralfs. That diatom, however, is almost hyaline, the central

a

GREVILLE, ON NEW DIATOMS. 235

puncta quite obscure, while in the produced angles beneath
the capitate extremity there are a few large puncta. On
the other hand, in our present species radiating puncta
occupy the whole valve; there is also a row of marginal
puncta not to be seen in the other ; the produced angles are
narrower, and the apex much less rounded. With regard to
the spines, I have seen sometimes two, sometimes three
(doubtless the normal number), and sometimes have been
unable to detect them at all. Whether in the latter case
they had been broken off and left no trace, or whether they
are occasionally undeveloped, I am unable to say.

ENTOGONIA, nov. gen., Grev.

Frustules with the lateral view triangular, containing a
central triangular figure, having a broad border. divided by
transverse cost into punctate or cellulate compartments.

I propose this genus for the section of Triceratium of
which for some time 7. marginatum of Brightwell was the
only representative. In my Series IV, (Trans. Mie. Soc.,’
vol. ix) I added six additional species, and in Series VII a
seventh. Having now obtained four other species, I have
been led to consider whether this most remarkable group
ought not to be removed from Triceratiwm altogether. 'The
species are exclusively fossil, and confined to the Barbadoes
deposit. Their structure is quite peculiar, bemg composed of
one triangle within another, the space exterior to the inner
triangle being simply a very broad border, divided into com-
partments by transverse coste. In the angles is a more or
less complex arrangement of a pseudo-nodule, with a blank
space immediately beneath it, and often various short lines.
With regard to the species, it is impossible to say whether
the characters I have selected for the diagnosis are perma-
nent, as I am not aware of any analogy to guide me, and our
knowledge of the whole group is very limited. There
appear to be two natural sections, in which the species may
be arranged as follows

Secr. I. Central triangle blank.

Entogonia Abercrombieana, Grev.—Triceratium Abercrom-
bieanum, Grev. ‘Trans. Mic. Soc.,’ vol. ix, p. 83, Pl. X, figs.
7—9.

Entogonia inopinata, Grev.
l.c., p. 84, fig. 10.

Entogonia gratiosa, Grev.—Triceraiium gratiosum, Grev.,
1.6.5 p. 85, figs. 12, 13.

Triceratium inopinatum, Grev.,

236 GREVILLE, ON NEW DIATOMS.

Entogonia approximata, Grev.—Triceratium approximatum,
Gtev2 1) ep» S4piiel i

Entogonia variegata, Grey. — Triceratium variegatum,
Grev., l.c., p. 85, fig. 14.

Secr. II. Central triangle filled up with various markings.

Entogonia marginata (Brightw.), Grev.—Triceratium mar-
ginatum, Brightw., 1. c., p. 82, fig. 5.

Entogonia pulcherrima, Grey.—Triceratium pulcherrimum,
Grev., |. c., p. 82, fig. 6.

Entogonia amabilis, n. sp., Grev.—Valve with slightly
convex sides and somewhat obtuse angles; the border com-
partments punctate ; pseudo-nodule circular, very prominent ;
central triangle with slender radiating costz, the angles pene-
trating a circular pseudo-nodular space. Distance between
the angles about -0042”. (Fig. 21.)

Hab. Barbadoes deposit, from Cambridge estate.

This is very similar to EH. pulcherrima in the radiating
coste of the inner triangle, but the manner in which the
outer angles are filled up is totally different. Instead of the
oblong pseudo-nodule, with the lateral costee continued round
it, we have in the species before us a very prominent cir-
cular one, and no cost passing round it at all; and instead of
a pseudo-nodular blank space forming a continuation of the
oblong outline of the pseudo-nodule, without any contraction
between the two, we have a circular pseudo-nodular blank
space immediately beneath the pseudo-nodule itself.

Entogonia venulosa, n. sp., Grev.—Valve with straight
sides and obtuse angles ; the broad border divided into punc-
tate compartments by perfect and imperfect coste ; central
triangle punctate, with a few radiating and transverse costee ;

- pseudo-nodular blank space somewhat cup-shaped, and sepa-
rated from the pseudo-nodule. Distance between the angles
about :0032”. (Fig. 22.)

Hab. Barbadoes deposit, from Cambridge estate ; G. Nor-
man, Esq.

Perfectly distinct in the minutely punctate inner triangle,
which is also traversed by a few costz, those in the immedi-
ate centre radiating. It is peculiar, also, in the pseudo-
nodular blank space being separated from the pseudo-nodule
by a punctate compartment or band. The pseudo-nodule is
roundish, and fills up the angles.

Entogonia Davyana, Grev.—Triceratium Davyanum, Grev.,
l. c., vol. xi, p. 232, Pl. X, fig. 4.

Entogonia conspicua, n. sp., Grev.—Valve with straight

GIGLIOLI, ON THE GENUS CALLIDINA. 237

sides and sub-obtuse angles; compartments of the border
with large, remote cligicey central triangle with smaller,
radiating, oblong cellules ; pseudo-nodular blank spaces trans-

versely oblong ; pseudo-n nodules large, fillmg up the angles.
Distance between the angles 0025”. (Fig. 23.)

Hab. Barbadoes deposit, from Cambridge estate ; G. Nor-
man, Esq.

In this fine species we have, for the first time, the imner
triangle filled up with cellules only, there being no veins or
cost in this part whatever. These oblong cellules do not
form radiating lines, but they all occupy a radiating position.
Those of the lateral ‘compartments are more or less circular,
large, and few (5 to 7 for the most part) im each. The
pseudo-nodules are very large, fillmg up a_ considerable
angle, minutely punctate, and in juxtaposition with the large,
transversely oblong, pseudo-nodular blank spaces. ‘The
margin is striated, an exceptional character in the genus.

Entogonia punctulata, n. sp., Grev.—Valve with straight
sides and obtuse angles; inner triangle filled up with minute
radiating puncta; lateral compartments remotely punctate ;
pseudo-nodules large, rounded, having a_ hemispherical
blank space at their base. Distance between the angles
about -0030”.

Hab. Barbadoes deposit, from Cambridge estate; G. Nor-
man, Hsq., R. K. G.

This species differs so obviously from the preceding that it
is unnecessary to enter into a minute description. In gene-
ral habit it resembles some of the species of the first section,
but the punctate inner triangle and non-striated margin at
once separate it. There is a very striking appearance of a
pore at the outer extremity of each of the costee which
divide the border into compartments, a feature I have not
observed in any of the other species.

On the Genus Catiipina (Ehr.); with the Description and
Anatomy of a New Species. By Henry Gicuio.t.

Tue genus Callidina was founded in 1830 by Ehrenberg,
to receive the then only known species C. elegans, discov ered
by the Prussian zoologist himself in Berlin. This genus
belongs to the Philodinade, and its members are character

238 GIGLIOLI, ON THE GENUS CALLIDINA.
ised by the total absence of eye-spots, the smallness of their
trochal disc, and the vivacity of their movements.

I intend to describe briefly the three known species, and
to dwell more minutely on the fourth, which I discovered
last winter, and believe to be new. Before commencing I feel
it my duty to express my sincere thanks to Mr. Gosse, who
contributed not a little to lessen the difficulties I encountered
in working out the affinities of the last-mentioned species by
the generous loan of his valuable drawings and MS. observa-
tions. I shall give the species in the order they were dis-
covered and described.

Callidina elegans,* Khr.—Body spindle-shaped; trochal
disc small. The digestive canal, which is figured filled with
a dark-blue colouring matter, is a narrow, wavy tube, dilating
distally, and not occupying the whole breadth of the granular
mass which surrounds it; the mastax is very indistinctly
figured, but in the text Ehrenberg describes it as being pro-
vided with many delicate teeth. The total length of the
animal is ‘37. It was first observed in a pond near Berlin.

Callidina constricta,+ Dujard.—This species was first dis-
covered at Toulouse, in 1840. Its mastax, according to
Dujardin, presents “une rangée de petites dents paralléles.”
The trochal dise is much constricted, whence its name.

Truly the characters of this species are very similar to
those of the preceding one, the only difference being in the
length, which here is ‘5.

Callidina bidens,{ Gosse.—This species was first observed
by Mr. Gosse, in London, in 1849. He describes it as being
spindle-shaped, ;4,th of an inch in length, and possessing
only two teeth in the mastax. Mr. Gosse expresses a doubt
whether this may not be C. elegans of Ehrenberg, but the
number of teeth is quite different. It is, however, more than
hikely that Dujardin’s and Ehrenberg’s species are identical.

None of the above-described species are parasites.

Callidina parasitica, mihi.—This species may or may not
be distinct from the preceding one; I firmly believe it is. It
certainly differs from C. bidens in its parasitism; moreover,
many other minor differences exist, in the size and shape of
different organs; but as it is no easy matter in these days to
define the true characters required to constitute a species, I
shall leave it to future investigators to decide. ;

Last winter, while engaged in examining the contents of

* Ehrenberg, ‘ Infusionthierchen,’ p. 482, pl. lx, fig. 1.
tT PF. Dujardin, ‘ Infusoires,’ p. 658, pl. 17, fig. 3.
+ P. H. Gosse, ‘Ann. and Mag. of Nat. Hist,” vol. viii, 2nd series, 1551,
p- 502.

i
:
'

GIGLIOLI, ON THE GENUS CALLIDINA. 239

the digestive and perivisceral cavities of Gammarus Pulex, in
search of Gregarine, 1 first came across this species. At first
I thought that I had got hold of a second entozoic Rotifer,
and some time elapsed before I discovered my error, and
that, instead of infesting the interior, it occurs as an epizoic
parasite on the thoracic and abdominal appendages of Gam-
marus Pulex and Asellus vulgaris, inhabiting chiefly the
branchial plates. It fastens itself on the bodies of these fresh-
water Crustaceans by means of the two suckers placed at the
extremity of its last caudal segment; it often changes place,
crawling over the body of its victim in a leech-lhke manner.
I have found this species in no other situation, not even on
other freshwater animals or on aquatic plants; and though I
have examined about seven or eight hundred Gammari from
different localities, I have not found one free from these Cal-
lidmee. On Asellus they are not so constant.

The body of C. parasitica is fusiform, and may be divided
into a head, a neck composed of two false segments, a body
or trunk consisting of one segment, and a caudal termination
composed of six false jomts (Pl. XI, figs. 1, 2). The penul-
timate caudal segment terminates in a pair of moderately
large claspers ; the last one terminates in a point, and sup-
ports two soft, cylindrical, protrusible appendages, which
terminate distally mm a sucker (fig. 8). In a specimen I
measured they were -,,!,,th of an inch in length; that of the

claspers being ),,th of an inch.

The body is very transparent and colourless; no angular
prominence exists on its central part, as in C. dbidens ;* the
caudal extremity is comparatively long. C. parasitica does
not swim much, as the preceding species, but it creeps a good
deal, the proboscis and calcar being extended while the
trochal disc is retracted. Its movements are precisely like
those of a leech. It creeps in the followmg manner :—the
suckers at the extremity of the tail fix themselves, the body
is then stretched to the utmost, and its anterior portion is
fixed (how, I was unable to make out) ; the tailis now drawn
up, and the body contracted. All this goes on with great
rapidity. The outer chitinous integument of the body or
trunk is often thrown into strongly marked longitudinal
ruge; they generally appear when the creature diminishes
the width of its body.

The C. parasitica differ much in size; the largest adult
one I measured, when fully extended, was =!,th of an inch in
length and =1,th of an inch in breadth; the smallest was

* P, H. Gosse, MSS., vol. iii, 1849, p. 9.

240 GIGLIOLI, ON THE GENUS CALLIDINA.

about ,1,th of an inch in length and +3,,ths of an inch in
breadth.

Muscular system—On compressing the animal suddenly
and violently, I saw several longitudinal and some transverse
muscles (fig. 2), which were certainly not striated. Other
muscles also exist, and often the tissues under the external
integument contract within it, formimg a sinuous outline,
very likely under muscular action (fig. 1).

As in all Philodinade, the trochal disc is double, or rather
bilobed; it is small, and surrounded by a single circlet of
short cilia (fig. 2); it is rarely extended, the cilia continu-
ally vibrating, even when it is retracted. In small individuals
the trochal disc is about -;,ths of an inch across.

Digestive system.—In the middle of the trochal disc, on
the ventral side, is a ciliated, protrusible, wedge-shaped pro-
boscis, having at its extremity the oral aperture; it is not
thick and rounded, as described by Mr. Gosse in C. bidens,
and it never projects when the trochal disc is extended. The
oral aperture (fig. 3) leads into a long, narrow, buccal funnel,
richly ciliated internally (fig. 3), and dilated in the middle ;
it narrows again, and leads into the pharyngeal bulb or mas-
tax, which is highly muscular, trilobate, and armed with a
pair of moderately sized jaws, each possessing two teeth (fig.
3). A short cesophagus follows, leading into a large pyriform
stomach (fig. 3), composed distinctly (as the rest of the in-
testine seems to be) of two membranes, the inner one sup-
porting numerous cilia; it gradually narrows into the intes-
tine, which has a bend on the left if the animal is considered
in its natural position (fig. 1) ; the intestine gradually widens
into a broad cloaca or rectum, richly ciliated, which opens
externally on the left side of the dorsal aspect of the second
segment of the tail (fig. 1) in a small anus, which is slightly
-protrusible, and not ciliated; the intestine also appears not
provided with cilia. The particles of food are constantly
undergoing a revolving movement in the stomach, as also
the feecal granules in the cloaca. In a large specimen the
total length of the alimentary canal was {th of an inch; the
pharyngeal bulb was ;4,,th of an inch in length and —3,,ths
of an inch broad ; the cesophagus was ;,!,,th of an inch long ;
the stomach -3,,ths of an inch in length; and the intestine
was =,!;,th of an inch in breadth.

Now, Mr. Gosse* considers in C. bidens the whole mass
surrounding the alimentary canal, from beneath the mastax
to where the intestine dilates and forms the cloaca, as the

* MSS., vol. iii, 1849, pp. 981, fig. 88 e.

GIGLIOL1, ON THE GENUS CALLIDINA. 241

digestive tube itself; as indigo swallowed, diffused itself
throughout this mass: while I am positive that a distinct
alimentary canal exists, as I have above described ; at any
rate, such is the case in C. parasitica, in which its walls are
so tenacious that, having crushed accidentally one of these
creatures, I had the pleasure to see nearly the whole alimen-
tary canal float out free and disengaged from the granular
mass which invests it, through the ruptured integuments.

No so-called salivary or pancreatic glands exist, and the
substance surrounding the digestive tube is one homogeneous
cellulous mass, of a yellowish-green colour, and even with the
highest magnifying powers I could detect no follicules or ccecee
in its substance.

Water-vascular system.—This consists of a large, irregular,
rounded vesicle, situated on the ventral side of the cloaca
(fig. 2) ; it contracts rhythmically at regular intervals (about
30”); I could find no communication between it and the
cloaca, or any special outlet of its own. Running into it,
about its middle, are two extremely small, convoluted water-
vessels, which run up along the sides of the body. I have
traced them till under the trochal disc, in which I suppose
they terminate coecally. Even with one of Smith and Beck’s
largest first-class microscopes, with a linear power of 1300
diameters, I could make out no transverse branches or vi-
bratile bodies, though they exist, no doubt. In fig. 2 the
water-vessels are represented considerably larger in propor-
tion than they really are.

Nervous system and sense organs.—Just beneath the trochal
disc, on the left side of the ventral aspect of the buccal funnel,
I saw in several individuals a small mass, which may be the
ganglion, though I will not be sure about it. I could make
out no ramifications proceeding from it, neither could I make
out anything corresponding to the ciliated fossa.

The calcar (fig. 5) is large and well developed; it is not
cihated at its extremity (at least, with very high powers I
could detect no such thing), but trilobate, the external lobes
being more or less elongated. It is constantly protruded,
feeling around, and is, beyond a doubt, a tactile organ.
When the creature is contracted it appears on the median
line (fig. 4), and when the trochal disc or proboscis is ex-
tended it generally appears on one side (fig. 2); it is rarely
retracted as in fig. 1. No eye-spots exist in young or adult ;
and Mr. Gosse has observed that his C. bidens thrives well
in the dark, but when exposed to a strong light it soon dies ;
this is very interesting, for many other animals are in the
same predicament, and C. parasitica, living on G. Pulex and

242 GIGLIOLI, ON THE GENUS CALLIDINA.

A. vulgaris, which frequent the roots and under leaves of
aquatic plants, exists necessarily in darkness. I do not
know, however, if they perish when exposed to the light,
not having made the experiment.

Reproductive organs.—As yet I have not met with a single
male individual of this species; that is, I have not seen any
not provided with an alimentary canal. I have observed
many small ones without ovaries, but they were, doubtless,
young. This is remarkable, considering the large number I
have examined. The females have one or two ovaries, the
latter number being the commonest; they are large, irregu-
lar, oval bodies, situated one on each side of the digestive
apparatus (figs. 1, 2), and consisting of a finely granular
mass, in which may be seen, more or less distinctly, germinal
vesicles and ee (fig. 9). The length of an ovary I mea-
sured was ;6.,ths of an inch, and its: breadth —2,,ths of an
inch. I could make out no distinct oviduct. An ovum,
which could not have been long laid, measured +3 ; = 2 ti On aan
inch in its long diameter, and 5 ” ths of an inch in its short
one (fig. 6). The ova, when deposited, adhere, by their
posterior and smaller extremity (where the posterior part of
the embryo’s body is afterwards developed), to the appendages
of the crustacean on which the mother lives (fig. 7).

Development takes place very soon; the egg, after the
blastoderm is formed, assumes a somewhat pear-shaped form.
Tn the largest ovum (fig. 7) the embryo is quite formed, the
trochal disc is entire, and the ciliary action was goig on
most vigorously when I observed it; the mastax is distinct,
and part of the alimentary canal can readily be made out.
The length of the mature egg is ;,°,,ths of an inch; the
ee ~@cths of an inch. The enclosed embryo was

— s_ths of an inch in length.

I found nothing corresponding to ephippial ova.

In the neck and tail exist a number of what old authors
thought to be glands, and which were very properly termed
by Professor Huxley vacuolar thickenings.

243

Nores on RapHIvEs.
By Epwin Lanxester, M.D., F.R.S.

Tue term Raphides (from pagic, a needle) was first applied
by De Candolle to certain needle-like crystals found in the
tissues of plants. The term has since been extended by
some writers to all crystals found in plants, whilst others,
adhering to the etymology of the word, apply it only to
erystals of an acicular form. Schleiden discards the word
altogether, and perhaps it would be better to get rid of a
term which has neither accuracy nor utility to recommend
it. The discovery of crystals in plants is due to Malpighi,
who first figured crystals found in a species of Opuntia in his
‘Anatomy of Plants.’ The needle-like crystals were after-
wards described by Rafn as occurring in the milky juice of
the Euphorbiacee. Jurin found the same kind of crystals in
the leaves of Leucojum verum. Raspail was the first to
demonstrate that many of these crystals were oxalate of
lime—a fact that Scheele had demonstrated with regard to
the crystals found in the roots of the common rhubarb. The
most elaborate and complete paper on this subject was pub-
lished by Edwin Quekett, and appeared in the appendix to
the third edition of ‘ Lindley’s Introduction to Botany’ in
1839. Since that time various observers have published
observations on this subject. The late Professor John Quekett,
in a paper in the ‘ Microscopical Transactions, showed that
many of these crystals had an organic basis. Mr. Rainey, in
his ‘ Researches on the Mineral Structure of Vegetable and
Animal Cells,’ has contributed many observations on the
presence of crystalline matters in vegetable cells. In the
January number of the ‘Annals of Natural History,’
Professor Gulliver, in a paper “On the Raphides of British
Plants,” says: “It appears to me that these raphides are de-
serving of more attention than they have yet received both in
relation to the structure and economy of vegetables, and as
affording a wide, interesting, and scarcely cultivated field of re-
search for the chemical phytologist.”” These raphides, he adds,
“may also be often useful as diagnostic characters in systematic
botany when others are not available; for example, a mere
fragment of one of the Onagracez or of the Lemnaceze may
be so surely distinguished simply by its raphides from some of
its near allies in other orders, that this fact ought henceforth
to be added to the description of the orders just mentioned,
independently of its value in other respects.”” ‘Though com-

VOL. IIT.—NEW SER. s

244. DR. LANKESTER, ON RAPHIDES.

mon in some orders, it is remarkable that the raphides are
so rare where they might be most expected, that I have not
a single note of their presence in young parts of the stem,
leaves, and flowers of British Oxalidaceze, Umbelliferee,
Labiatez, Euphorbiacez, or Polygonacez, and even among
Crassulacez. No crystals were found in Sedum Telephium
and S. acre,”

There can be no doubt of the important part that mineral
substances play in the organization of both plants and
animals, but the composition of these mineral matters, es-
pecially in plants, is but imperfectly known. The method
most relied upon for ascertaining their nature has been
chemical analysis, but where this has been resorted to, after
the destruction of the tissues of the plant by exposure to heat
changes take place in the composition of the minerals, which
render this method very uncertain. Fourcroy and Vauquelin,
as long ago as 1809, showed that the greater part of the
carbonates found in the ashes of plants were formed during
the burning from other salts of vegetable acids. They proved
that almost all plants contain acetate and malate of lime
dissolved in the sap, also citrate, tartrate, and oxalate of lime,
either dissolved or in a solid form. Certain elements are
also expelled by heat, as chlorine, so that chemical analysis
alone does not give us a satisfactory explanation of the com-
position of mineral compounds in plants. The careful use
of the microscope seems to offer a more satisfactory means of
ascertaining really what the nature of these substances is. A
large number of the salts present in plants are insoluble, and
they present slender crystals in the tissues of plants, and it
is these which have been observed by the microscope and
called Raphides. Even with regard to the soluble salts,
their forms might be made out by the evaporation of the
juices in which they are contained, in the same way as has
been so successfully pursued in making out the salts of the
biood and urine. There can be no doubt that this subject
affords an inviting field for research, and would amply repay
investigation. The researches of Mr. Attfield on the nature
of the efilorescence found on medicinal extracts show what
may be done in this direction. The fact that so large a
number of these crystalline productions are composed of
chloride of potassium is very interesting, as pointing to the
_probability that the form in which potassium exists in land
plants is really that of a chloride, and that the carbonates of
potash obtained from the ashes of land plants are formed in
the same way as the carbonates of soda from the sea plants,
which contain chloride of sodium. The extent of our know-

DR. LANKESTER, ON RAPHIDES. 245

ledge of the forms in which the soluble salts of plants exist
is very limited; the recorded facts with regard to the salts
which are insoluble are much more extensive; at the same
time the number of those which have been observed is not
large.

The most common of the insoluble salts is undoubtedly the
oxalate of lime. Schleiden says it appears to be present in
every plant, but this is undoubtedly an error. The state-
ment of Professor Gulliver with regard to the absence of
raphides in certain plants contradicts this assertion; and
what is very curious in his observations, is the fact that he
has not been able to discover these crystals in the British
Oxalidaceze. The acidity of the Oxalis has been usually as-
cribed to the presence of oxalic acid; and if this be true, it
is certainly very strange and curious that the oxalate of lime
should not be found in these plants. The oxalate of lime
occurs in two principal forms. First, as large, single crys-
tals, which are either elongated prisms, or octohedrons.
They are frequently more or less rounded, or assume a dumb-
bell form, arising from their crystallizmg in contact with
organic matters, as occurs with many other forms of crys-
tals. Such rounded bodies are seen in the milky juices of
plants, and have been regarded by Schultes and others as
possessing vital properties of much importance in relation to
the growth of the plant. Secondly, in the form of groups of
crystals. In this form they are frequently developed upon an
organic basis, and have been called by Meyen and others
crystal glands. Itis to some of these compound crystals that
Weddel applied the term Cystolithes.

With regard to the form assumed by these crystals there
has been some difference of opinion. Quekett took some
pains to discover their exact form, and says, “That the four-
sided is the ultimate form of these minute crystals is ren-
dered more probable by the occurrence of rhombohedral and
rhombic prisms, without pyramids of the same composition
in the same plant, but of much greater widths; and there
can be no doubt that these latter bodies and the acicular are
two modifications of crystal of the same substance. The
most decided proof of their being four-sided is obtained by
pressing lightly on the piece of glass which covers them
whilst examined under the microscope, when those which
appear six-sided instantly appear four-sided, owing to the
square crystal resting obliquely.”

The acicular crystals, to which the name raphides have
been more particularly applied, have been often described as
having the same composition as the larger single and com-

246 DR. LANKESTER, ON RAPHIDES.

pound erystals. They are prismatic in shape, and lhe toge-
ther in bundles of from twenty to thirty im a single cell.
They are sometimes enveloped in a gummy matter, which,
on being moistened, distends and bursts the cell in which
they are contained, and the crystals escape at both ends:
such cells have been called Biforines. TE. Quekett was one of
the first to point out that these crystals consist of phosphate
of lime. He says, if heated red hot they do not dissolve in
acids with effervescence—a fact which essentially distinguishes
them from the oxalate-of-lime crystals. The acicular crys-
tals appear to be much more abundant than any other kind.
This fact is interesting in connection with the supply of
phosphate of lime to the animal kingdom, and the existence
of these acicular erystals may be made to indicate the value
of plants which possess them, as food for man and domestic
animals.

Next to the oxalate and phosphate of lime in frequency
comes carbonate of lime. It assumes a variety of forms, but
is most frequently found in that of a pure rhombohedron.
Crystals of carbonate of lime are often found with those of
oxalate of lime in the Cactaceze. I have found it in every
part of the structure and on the surface of Chara hispida.

The next salt of lime which has been described as present
in the tissues of plants is sulphate of lime. It is found m
the form of double or single octohedrons, or in a tubular
form, as octohedrons above and below, with the end of the
prism obtuse. They even occur in a twin form, like the
gypsum crystals from Montmartre. They are found, accord-
ing to Schleiden, in Musaceze and Scitaminaceze.

Quekett refers to the presence of crystals in the fruit of
the grape as differing from those im the leaves. These may
be tartrate of lime. We might also expect here bitartrate of
potass. Any of the less soluble combinations of the organic
acids with the bases magnesia, potash, and soda, might be
found with the aid of the microscope.

Although silica is not usually enumerated by writers on
raphides and crystals in plants, it must evidently be re-
garded as one of the most important of the mineral con-
stituents of plants. I find nowhere any observations on
silica in plants in the form of crystals, although Quekett,
Schleiden, and others, speak of crystals of silica as occa-
sionally found. The presence of silica seems essential to
large groups of plants. As every one knows who reads the
‘Quarterly Journal of Microscopical Science,’ the Diato-
macee are almost entirely constructed of it. It forms the
framework of the Equisetaceze. Schleiden gives the follow-

DR. LANKESTER, ON RAPHIDES. 247

ing per-centage of silica in the ashes of species of Equi-
setum :—E. limosum, 94°85, E. arveuse, 95:48, E. hyemale,
97°52. A complete mould in silica of the whole structure of
these plants may be obtained by treating them with nitric
acid. ‘The palms contain large quantities of silica in their
stems. Lumps of silica, called tabersheer, are found in the
interior of some of the palms. The ashes of Calamus ro-
tang, according to Jablons, yielded 97:20 per cent. of silica.
John Quekett, in his lectures on ‘ Histology,’ has given
illustrations of the presence of silica in the glumes and
paleze of the cereal grasses. One of the most interesting
instances of the presence of silica amongst exogenous plants
is that of the stellate spicules on the under surface of the
leaves of Deutzia scabra. 'This very exceptional case shows
that the appropriation of these mimeral substances is no
mere general function of plant structure, but that it is the
result of the special organization of the plant.

The position of raphides has been a subject of controversy.
Raspail, who wrote on them in his usual wrong-headed way,
asserted that they were never found in the interior of cells,
but always in intercellular passages. Of course this was
easily refuted, but the converse was not true, that they are
always found m cells. The fact is, they are found in both
positions, and even in the free surfaces and in the spiral
vessels of plants. They have been found by Quekett loose in
the anthers, mixed with the pollen in Hemerocallis purpurea,
Anigozanthus floridus, and other plants. Of all the parts
of plants in which crystals are found, the stems of herba-
ceous plants are the most common. They are, however, founa
in the tissues of all parts of plants. Observations are want-
ing on the presence or absence and comparative numbers
of these crystals at different pericds of the growth of plants.
Professor Gulliver says, that ‘in old, decaying, or diseased
portions of Polygonacez, and in many other orders, crystals
are frequent.” Observations on these would be interesting,
as affording indications of the mineral composition of the
living plant.

Professor Gulliver has given an account of his observations
on raphides, as they occurred in order. It would be of
value to know what crystals are found in particular orders ;
it would throw light on the functions of plants, and explain
some of their economy. Already we know that some plants
grow on chalk soils, others on clay soils, whilst some again
require phosphoric acid, and others potassium or sodium in
excess. A minute analysis of crystals by the microscope
may lead to a better system of manuring for cultivated plants

248 DR. LANKESTER, ON RAPHIDES.

than any that have yet been suggested from the misleading
analyses of the ashes of plants.

The following are the orders and plants, as far as I can
find, in which raphides and erystals have been found :

CRYPTOGAMIA.

Atex.—Nostoc Muscorum, Conferva crystallifera. Cheeto-
phora, Hydrurus, Polysperma, and Spirogyra.

Cuarace®.—Chara hispida.

EquiseTacr&®.—Silica in the walls of cells of several species
of Equisetum.

ENDOGEN &.

Littacez.—Species of Aloe. Scilla maritima. Bulbs of
onion. Endymion nutans, in all parts of the plant (Gulliver.)

BRroMELIACER.—Agave Americana.

Aracex.—Calla Aithiopica, Caladium esculentum, Dieffen-
bachia Seguina.—Professor Gulliver says that he finds
raphides throughout the plant in Arum maculatum.

Iripacex.—In Iris pseudacorus, long prismatic crystals in
leaves (Gulliver).

TypHacex.—In Sparganium ramosum and S. simplex, in the
perianth, fruit, stem, and leaves.

Lemnaceaz.—Raphides most abundant in Lemna trisulca
and L. minor, but comparatively scanty in L. polyrhiza and
L. gibba. In L. minor abundantly, associated with starch
granules (Gulliver).

Cyprrace®.—Meyen and other observers have found
raphides abundant in Papyrus Antiquorum.

Mvsaczex.—Crystals of sulphate of lime have been found
in M. Paradisaica and other species of Musa, also in the order
Sc1TaMINER.

Oxcuipacea#.—In Epidendrum elongatum (Lindley), and in
Orchis Morio, O. mascula, O. maculata, and Habenaria chlo-
rantha (Gulliver).

ExoGENn&. .

Cactace®.—All the forms of oxalate of lime have been re-
corded in this order. Quekett especially mentions Opuntia |
crassa, and Lindley Cactus Peruvianus.

OnaGrace&#.—Gulliver says that true raphides occur in
such abundance in this order as to be quite characteristic,
especially in the netted-veined group. He adds that they
occur in all parts of these plants, so that a minute fragment
of any of them will serve to distinguish them from Lythracez

DR. LANKESTER, ON RAPHIDES. 249

and Haloragacee. In the latter order Schleiden says they
have been found in Myriophyllum, in the cells and in the
glands of the air-passages.

CaryorHyLLace&®.—The only species in which they have
been found by Gulliver is the Selene Armeria.

Oropancuace®.—Schleiden says that crystals of carbonate
of lime are found in Lathrea.

Saxirracaces®.—Crystals have been observed as excretions
in the edges of the leaves in Sazifraga Aizoon and S. longifolia.

Nycracinacem®.—Lindley mentions the existence of ra-
phides in great abundance under the cuticle of the Mirabilis
Jalapa.

Lrecumrnos#.—But few instances are recorded of crystals
in this large order. Professor Bailey 1s quoted by Balfour
as having found them in great abundance in Locust bark.

CapriroLiachz.— Meyen found an abundance of crystals
in the bark of Viburnum Lantana.

Tinracp&.—Quekett says he has observed two kinds of
crystals in the bark of the lime (Tilia Europea).

Evrnorsrace®.—In the milky juice of these plants crystals
are recorded as occurring, by several observers. Quekett says
he has found them in eascarilla bark.

Viraceaz.—The bark, leaves, stipules, and fruit of the
common grape contain crystals of more than: one sort
(Quekett).

Potyconacrm.—The various species of Rheum contain
oxalate of lime, more especially in their roots.

JuGLANDACEX.—Flattened prisms in hiccory bark (Carya
alba, J. Quekett).

Gatiacea®.—Gulliver found raphides in the ovary, corolla,
leaves, and other parts of Sherardia, Asperula, and six spe-
cies of Galium. ‘They are common in the corolla aud young
fruit, but scanty in other parts of Galiwm Mollugo.

Composita. — Professor Gulliver says of this order,
“* Raphides are less common in this order than other crystals,
and I have only found them in the ovary or fruit. They
were seen in Corymbifera, Cynarocephalie, and Cichoracez.
In Pulicaria dysenterica single oblong crystals, with angular-
pointed ends; in Senecio Jacobea and S. aquaticus, short, aci-
cular crystals ; in Arctium intermedium and two other species,
cubical crystals, —..th of an inch diameter; in Centaurea
nigra, single and double crystals, shaped like those of Pulicaria ;
in Carduus lanceolatus, C. palustris, and C. acaulis, some acicu-
lar forms, and a greater number like those of Pulicaria and
Centaurea; in Hypocheris radicata, Apargia auiumnalis, and
Crepis virens, minuter square or cubical crystals.”

250 DR. LANKESTER, ON RAPHIDES.

Urticace®.—In the milky juice of Ficus elastica; in the
tissues of Parietaria officinalis (Henfrey). Single crystals in
the bark of the common elm (Ulmus campestris, J. Quekett).

Pomacem.—Bark of the common apple-tree (Pyrus Malus,
J. Quekett).

Ev.macnacex.—Pith of Hleagnus angustifolia (J. Quekett).

Conrrer®.—E. Quekett mentions crystals in the bark of
Araucaria imbricata.

Crncuonace®.—In the barks of the various species of
Cinchona (E. Quekett).

PuytoLaceacE®.—Phytolacea decandra.

Cycapacrm.—Compound crystals in the stems (Schleiden).

Dioscornace®.—Raphides plentiful in the stem and leaves,
and still more in the perianth and stamens of Tamus com-
munis, Gulliver.

I have given the above summary as far as the materials
within my reach will enable me. I know it is very imper-
fect, but I believe, with Professor Gulliver, that the subject
is deserving of more attention than it has yet received, and
offers a capital field of investigation for the microscope.
Mr. Gulliver has set a good example in detailing the facts
which he has recorded in the life-history of our common
plants. The biography of our indigenous plants has yet to
be written, microscope in hand, and it is not till the minute
details of the cell-life of each plant has been recorded, that we
shall be in a position to arrive at the laws which govern the
life of the vegetable kingdom.

Before concluding, I would add a remark or two on the
uses of raphides. Link first propounded the notion that
the raphides were an abnormal condition, and resembled
calculi in animals, and Edwin Quekett regarded them as acci-
dental deposits. He succeeded, in fact, in forming artificially
oxalate-of-lime crystals in rice-paper, by immersing it first in
oxalate of ammonia and then in lime-water. This experiment,
indeed, showed that the formation of these crystals might be
the result of chemical laws, but it did not show that the
chemical force was not counteracted by other forces connected
with special conditions of the plant. Professor Gulliver’s
observations with regard to the Lemnas are especially inter-
esting, as showing that plants closely connected in structure,
and living under the same external circumstances, neverthe-
less produced these crystals in very different quantities.
The persistence of the same crystals in the same plants
clearly indicates that there is a relation between these bodies
and the life of the plant.

Some physiologists regard the raphides as representatives

DR. DUFFIN, ON PROTOPLASM. 201

of a skeleton in the animal kingdom, and I recollect, in
1837, Professor Grant, in his lectures at University College,
drawing a comparison between raphides and the siliceous
spicules of the sponges. When we consider the functions of
the siliceous deposits in so large a number of plants, I think
there can be little doubt that, in many cases, these mineral
deposits perform the same functions in the plant as in the
animal. At the same time, just as we find a large number
of mineral compounds in plants which do not subserve the
purposes of a skeleton, so in plants many of these mineral
substances probably perform this and even more important
functions in the life of plants.

What these are it is for careful observation to point out.
It is not sufficient that we know that certain mineral com-
pounds are necessary for the life of plants, but what we
require to know is how particular mineral compounds are
necessary to the life of plants, and the nature of the vital
processes which are thus affected by these agents.

Some Account of Protoptasm, and the part it plays in the
Actions of Livinc Brernes. By A. B. Durrin, M.D.,
Assistant-Physician to King’s College Hospital.

Ir will not be seriously contested that, of the constituents
of the cell, the so-called “ protoplasm” is deserving of particu-
lar attention, from its lability to change, its activity, and the
marked manner in which it participates in the vital pheno-
mena of living structures. Since the publication of H. v.
Mohl’s remarkable work, the botanists have long arrived at
the conclusion that, not only the formation of the cell-mem-
brane, but also the inner nutritional changes of the cell itself,
primarily depend upon the protoplasma.

As early as 1861* Max Schultze insisted upon the neces-
sity of a modification of the views generally entertained re-
specting the relation of the cell-membrane to the cell-con-
tents, and to the so-called intercellular substance of animal
structure, and he argued in favour of a higher position for
that part of the cell which corresponds to the protoplasm of
Mohl. He at the same period pomted out how materially a
careful study of the phenomena presented by the pseudo-
podia extended by the various Rhizopoda might assist in

* “Ueber Muskelkorperchen,” Reichert u. Du Bois Reymond’s ‘Archiv,’
1861

252 DR. DUFFIN, ON PROTOFPLASM.

elucidating the life of the essential cell elements. Unger*
had been already struck with the close similarity of the
mobile phenomena of the Polythalamize with those of the pro-
cesses of protoplasm stretched across the cavity of many
vegetable cells. Although he had not personally investigated
the former, he became convinced, from Schultze’s deserip-
tion, that a resemblance amounting to identity existed be-
tween their movements and the protoplasm streams of many
vegetable cells. Shortly prior to the appearance of Unger’s
work, Pringsheim,+ in opposition to the theory of the pri-
mordial utricle then prevalent, insisted that everything that
lay within the cell-membrane of a living vegetable cell
might have a complex disposition, but consisted essentially
of nothing but protoplasma and cell fluid. He admitted that
in the cortical layer of the protoplasma a distinct arrange-
ment into layers often occurred, and these he distinguished
as the cutaneous and granular layers of the protoplasma, but
he denied that the primordial utricle could be differentiated
as a membrane from the subjacent protoplasm. If in animal
cells, partly from their relatively smaller size and partly from
their greater average wealth in protoplasma, it is more rarely
possible to make a sharp demarcation between a cortical layer
of protoplasm and a cell-fluid, there nevertheless exists a dif-
ference in the constitution of the former, such that a cutane-
ous layer, destitute of or scantily supplied with granules,
encloses the remaining more granular material. The white
blood-cell may serve as an example. This is, however, very
different from a proper membrane.

To pass on to some account of the movements presented
by the pseudopodia of the Foraminifera. Max Schultze { de-
scribes them as threads of a transparent material rich in
granules, presenting a high degree of variability in their shape
and length. They pursue a diverging course, divide at acute
angles, and unite to form a kind of network. They are con-
stantly in motion, lengthening, shortening, subdividing,
uniting. They are also the seats of an inner activity which
affects even those fibres that are subject to none of the above-
named changes. This inner activity is the so-called granule
movement. It isa gliding, a flowing of the granules contained
in the substance of the filaments. With a greater or less
velocity they travel either to the periphery or to the root of
the thread, often, even in the thinnest threads, in both direc-
tions simultaneously. When granules happen to meet, they

* © Anatomie u. Physiologie d. Pflanzen,’ p. 280, 1855.
+ ‘Untersuchungen tiber d. Bau u. d. Bildung d. Pflanzenzelle,’ 1854.

{ ‘Das Protoplasma der Rhizopoden und der Pflanzenzellen’ von Max
Schultze, 1863.

DR. DUFFIN, ON PROTOPLASM. 253

either pass each other or move round each other till, after a
short interval, each pursues its original course, or the one
carries the other away with it. They often stop in the midst
of their career, and then return, but the majority reach the
extreme ends of the threads, and only then change their
direction. All the granules of a thread do not move with the
same velocity, but the one may overtake the other. Where
several threads coalesce, the granules may be observed to
pass from the one to the other. As such spots move, ex-
tensive collections of the material composing the filaments
may be found, and from these fresh independent processes
may originate. Many of the granules run evidently quite
on the surface of the threads, over which they may be dis-
tinctly seen to project. In addition to the small granules,
large collections of material resembling spindle-shaped swell-
ings or lateral intumescences may occasionally be seen
moving in the same manner as the granules. Even extra-
neous bodies which may chance to adhere to the filament
may participate in this movement.

That this remarkable movement of granules should be
brought into some relation with the contractility of the sub-
stance of the pseudopodia has never been questioned, since
we have no other expression wherewith to designate the
inner cause of independent animal movement than contract-
ility. As it is evident that the granules have no active faculty
of locomotion, but obey the impulses of the basic material,
this last must of necessity be considered as in a state of
flowing motion.

That a filament may lengthen, large masses of substance
must change their place, and this can often be watched in
the larger advancing nodules. If this great change in posi-
tion be admitted for larger portions of the substance of the
pseudopedia, it is obvious that such a change of locality cannot
be denied for smaller portions of it. Thus, the expression
flowimg movement of the basic substance is to be explained,
which, at the same time, gives some indication of the peculiar
consistence of these contractile pseudopodia which so closely
resembles that of a fluid.

Reichert* has objected that in the substance of pseudo-
podia of the Polythalamiz no granules exist, but that they
are an optical delusion, derived from waves on the surface of
the filaments, being mistaken for granules in their substance.
Against this, Max Schultze argues: 1. The sharp definition
and decided lustre of the bodies in question do not speak im
favour of their being only parts of the substance of the

* ¢ Monatsberichte d. Akad. d. Wiss. zu Berlin,’ pp. 406—426, 1862.

254. DR. DUFFIN, ON PROTOPLASM.

filaments, as Reichert himself admits—that this has little
more refracting power than the surrounding water. Granules
which project literally from a thread pass into luminous points
when the tube is lengthened beyond that position m which
the movements are best observed. 2. With a high power it
will be seen that many of the granules circulatmg im the
threads of the Milolides have an oval or staff-like shape, and
although the majority of them have their long axis parallel
to that of the thread, they not unfrequently lhe at right
angles to some, only to roll over as they move onwards. In
short, these bodies often rotate, and this proves their corpus-
cular nature. 3. Reichert argues that the granular appear-
ance vanishes whenever the threads are extended im a quies-
cent state, but Schultze notices the extreme rarity of this
phenomenon, and asserts that, however thin the filaments,
seldom more than a second passes without a granule coursing
along it from some neighbouring thread. These extended
fibres in a quiescent state are just those that show the most
vivid play of the granule circulation. Frequently a few
granules may be seen to rest for a short while, as at the so-
called bridges, when these chance to stand at right angles
to the filaments they happen to unite. By artificial means
the granules may be brought to rest over considerable tracts
without, as Reichert supposes, any disappearance of them.
If a drop of distilled water be placed at the margin of the
glass covering an animal with its pseudopodia extended, the
movement of the granules becomes sluggish, and ultimately
stops without any other change bemg noticed in the filament ;
the granules are as distinct and numerous as before; the
basic substance appears totally unchanged. Should the in-
fluence of the distilled water be continued, small vacuoles
appear in the substance of the filament, enlarge, spread, and
‘acquire a frothy appearance, till the whole is destroyed by
the mereasing phenomena of imbibition. Similar results
may be obtained from solutions of iodine, weak acids, or
alkalies, and the electric current. The objection that the
phenomena of coagulation disturb the observation is met by
the following experiment. If an animal with extended
pseudopodia be crushed so that its capsule bursts and the
contents are extruded in dense masses, the extended threads,
wherever they are not mechanically incommoded, lie un-
changed, and retain their characteristic movements for a
while. Although their connection with the body of the
animal has been in many cases severed, the circulation of
the granules persists. But it becomes more and more tardy,
the filaments contract more and more to dense networks or

DR. DUFFIN, ON PROTOPLASM. 2090

extended aggregations, whence a few fresh threads may issue,
but im these the movement of the granules ultimately ceases.
Nevertheless the granules in the substance of the threads are
as distinct as before, till the diffusmg influence of the water
gradually dissolves the whole.

In order to give a clear insight into the consistence of the
substance of the pseudopodia, Schultze places a Miliolide in
the object-holder, with its pseudopodia extended. He then
notices that all the filaments that are lengthening rapidly
and in a straight line are rounded at their extremities so as
to form nodular swellings, either globular, heart-shaped, or
cylindrical. This terminal swelling is granular, like the rest
of the filament, and the granules are, like itself, in a constant
tremulous movement. The nodule advances as if feeling its
way, inclining hither and thither, and fresh granules continue
to flow in from the base of the thread, whilst others retire
along it. If the filament has advanced some way without
encountering any obstacle, it curves round, often at a tolerably
right angle, and moves now in the new direction as if aware
where to find other radiating pseudopodia. ‘The instant it
touches a neighbour, the nodular end breaks up like a vesicle
full of fluid, and mingles its contents with those of the fila-
ment it has encountered. When a broad filament meets a
narrow one it will coalesce with it, but pursue its original
course for a while, as if undisturbed. It is frequently to be
observed that just as one is expecting approaching fibres to
coalesce, they pass close to each other in different planes.
The coalescence does not ensue even on direct contact.
Consequently either an act of volition must assist, or an
obstruction has to be overcome, as when two drops of oil
will only flow together on being pricked with aneedle. That
volition comes into play is evident, since the filaments of
different individuals never unite, but retreat from each other
as from a determined foe. The passage of a granule from
one filament to another may be considered as conclusive
of their coalescence. It is very interesting to feed these
animals on carmine. The granules adhere to and circulate
within the pseudopodia, and the more minute the particles the
more rapid the motion. Some glide towards the peripheral
end of the filament; the majority are received into the in-
terior of the creature. One granule of carmine overtakes
the other, and if two meet, the one carries the other with it.
Schultze has even known masses of carmine produced by the
adhesion of many small ones to be dragged away, although
ten times the diameter of the threads. Even those threads
in which a centripetal stream is most marked, not only do

256 DR. DUFFIN, ON PROTOPLASM.

not shorten, but either retain their dimensions, or continue
to elongate. Similarly the centrifugal current persists in a
retracting filament. These experiments show the very slight.
consistence of the surface of the pseudopodia, that the move-
ment of the granules may be compared to a current, and
further they afford us a means of ascertaining what part of
the animal is destined for the reception and digestion of
nourishment.

The consistence of the pseudopodia is, however, lable to
considerable variations in different kinds of Rhizopods. The
relation is the same as in the protoplasm of different cells or
of the different parts of a cell. Among the Gromide the ex-
tremes are best observed in G. oviformis and G. Dujardinii.*
The latter is characterised by the completely hyaline cha-
racter of the threads it emits. They are very torpid in their
movements—so rigid and firm, as to show no tendency to
flow together even on contact. They present no movement of
their substance that can be compared with the granule
motion, still there is no evidence of their being composed of
loosely-aggregated threads. In G. oviformis, on the con-
trary, the whole mass of the pseudopodia is uniformly gra-
nular and difiluent. Many of the Miliolides occupy a position
intermediate to the two varieties of Gromia. But even in
the same animal firmer and more fluid hyaline and granular
substance may occur together in the pseudopodia. Just as
in many Ameebas a hyaline cortex encloses the granular in-
terior, and the two constitute the Ameeba, so there are pseu-
dopodia the axis of which is a hyaline, and, it would seem,
firm thread, on the surface of which the granular, softer ma-
terial moves about. This is the case with Actinophrys
Kichhorni. The pseudopodia have so little movement that
they look hke hard spines; still they consist of a contractile
material. Curves and coils are occasionally met with on them,
and they possess the faculty of retraction, but all changes of
shape occur very slowly. They are also endowed with the
granule movement, but this is restricted to the cortical sub-
stance. All the radiating filaments arise by means of their
hyaline axis from the interior of the body of the animal, but
the movable granular cortex comes distinctly from the
cutaneous layer of the Actinophrys. It is further remark-
able that several axial filaments, arising close together, but
from distinct points on the medullary substance, may be
apposed so as to constitute a common fibre. This union
generally occurs during their course through the cortical

* ¢Ueber d. Organismus d. Polythalamiw,’ taf. i and taf. vil.

DR. DUFFIN, ON PROTOPLASM. 2bi

substance, but may only ensue when they have quitted the
body of the animal. The lines of contact do not always
totally disappear. These compound radii are always enclosed
by a common sheath of the soft granular mass. Should the
axes only unite outside the body, the soft coverings of each
will coalesce, whilst the finer hyaline axes run side by side,
without becoming agglomerated. Thus Actinophrys Eichhornit
appears to contain in its pseudopodia both those substances
that are found separately in Gromia oviformis and Dujardinit.
The application of artificial means further illustrates the
structure of the pseudopodia of Actinophrys. If moderate
pressure be exerted on the animal so as to flatten it, the
pseudopodia will be slowly drawn back. The granular cortex
melts together to little, spindle-shaped nodules, and the pre-
viously smooth fibre appears varicose. The fibre continues
to retreat, and may become curved. Whenever one of the
spindle-shaped aggregations of the cortical substance touches
the surface of the animal, it flows in with a sudden jerk, as
when one drop of fat is merged into another. This is quite
decisive for the glutmous character of the material im ques-
tion, and proves that a special membrane does not exist on
the surface of the pseudopodia. Similar changes take place
on the addition of very dilute acids and alkalies, solutions of
strychnia and veratria, and under the influence of the mag-
neto-electromotor. ‘The influence of an elevated temperature
closely resembles that of the agents just alludedto. Between
35° and 38° C. the contraction of the pseudopodia begins.
The soft granular cortical substance becomes aggregated into
spindle-shaped masses on the surface of the axial thread.
The pseudopodia retreat altogether, and the animal might be
considered dead were it not for the slow progress of a few
granules in the interior, and that no haziness of the sub-
stance takes place. Schultze found Actinophrys Hichhornit
to remain alive till 42° C.

It is remarkable with reference to Kiihne’s* investigations
on the rigor mortis produced by heat, that even among in-
vertebrate animals great varieties exist as to the period of its
occurrence. Thus Vorticellz begin to die at 41° C.; Difflu-
gia, Actinophrys, and Ameeba (radiosa, Ehrenb.), remain
alive till 42° C. Anguilline, Turbellarize, Naiads, Rotiferze,
and Ostracodes, are in active life at 48° C.; and a few sam-
ples even till 45° C. If we trace the pseudopodia of Actino-
phrys Eichhornii to their roots on the surface of the darker
nucleus, they will be observed to lose themselves in the walls

* «Ueber die chemische Reizung d. Muskeln und Nerven,” Miller’s
‘Archiv,’ p. 315, 1860.

258 DR. DUFFIN, ON PROTOPLASM.

of the smaller alveoli. Schultze, in his attempts to trace
these radicles more accurately, encountered a number of cell-
like bodies in the cortex of the nucleus. These were particu-
larly distinct if the animal had been killed by a temperature
of 42° C. <A high power, then, shows that these bodies lie
scattered in the cortex of the darker medullary substance.
Their number may amount to forty and upwards. They are
globular formations, with very delicate walls, and with coagu-
lable, albuminous contents, and usually with numerous small,
apparently homogeneous nuclei. They are in no way con-
nected with the roots of the pseudopodia.

Such being the chief characters presented by the pseudo-
podia of the Rhizopods, Schultze compared them with the
phenomena of motion that are to be observed in vegetable
protoplasm, thus carrying out the idea of Unger, which has
been already alluded to. The objects which admit of the
most direct comparison with the pseudopodia of the Polytha-
lamize are the threads of protoplasm that traverse the cell-
cavity of Tradescantia, Viola, Cucurbita, and Hydrocaris
leaf-cells. Several filaments of varying thickness pass from
various parts of the protoplasm, and particularly from that
portion which surrounds the nucleus, across the cell in dif-
ferent directions. They consist clearly of a basic substance,
containing highly refracting granules. These latter run in
the interior, or as on the surface of the filaments, either only
in one direction, or in both, on one and the same thread.
On the broadest filaments this double direction of the stream
is almost constantly seen, and it may even be noticed in
threads that are only just perceptible. When granules meet
they may either pass each other, or the one may carry the
other off—a proof that two separate filaments do not consti-
tute the cause of the double direction of the stream. On the
same thread a rapidly moving granule may overtake its more
sluggish neighbour. The threads often bifurcate, and when
a granule reaches the point of division, it may oscillate before
selecting its further course. ‘The shape and direction of the
filaments are liable to constant change.

Bridges are formed and run upwards or downwards be-
tween the fibres, shorten as the latter approach, vanish as they
coalesce, till a broad stream flows where previously there had
been only separate filaments. Occasionally longer spindle-
shaped masses pass along, with the same or a somewhat
diminised velocity as the granules. The results obtained by
the influence of various reagents (as distilled water, dilute
acids and alkalies, the electric current, &c.) have so close an
affinity to those obtained with the pseudopodia as to amount

DR. DUFFIN, ON PROTOPLASM. 209

to a repetition of what has been already stated. The follow-
ing experiment will show how sensitive the protoplasm is to
certain reagents :—The staminal hairs of Tradescantia Vir-
ginica, just prior to complete development, contain many
small starch granules in their protoplasm; these become
violet blue on the addition of iodine. If, whilst the move-
meut is active, a little extremely dilute iodine solution be
added, all activity of the protoplasm will rapidly be arrested,
even before the starch granules give any indication of a blue
colour, or the protoplasm or cell-wall change their tint. In
exposing these cells to the electrical current, it is found that
about the same force of stream is requisite to arrest the move-
ment of the granules as was noted for the pseudopodia.
Curiously enough, those hair-cells through whose long axis
the current was passed, died more rapidly than those whose
long axis lay at right angles to it. The influence of the
current on the movement of the granules was restricted to
a retardation of it which precedes incipient decomposition.
This must, of course, not be confounded with the changes in
the arrangement of the protoplasm as described by Briicke,*
when speaking of the hairs of Urtica urens :—‘‘ To follow the
influence of the electric stream in its separate stages it is
best at first to close the circuit only for one or two seconds,
so that the hair only receives a short series of shocks. The
earliest change which is then observed generally consists in
the appearance of a greater or less mass of threads which
project from the body of the cell into the intracellular fluid.

. . Occasionally they shoot forth lke rockets from the
body of the cell, as soon as the circuit of the magneto-elec-
tromoter is closed . . . At their extr emity they often bear
a greater or smaller intumescence, and they are engaged in
a constant tremulous or oscillating movement of varying
intensity.”

Both Heidenheim and Schultze have seen the threads of
Tradescantia become varicose under the influence of the
electric current. A temperature of 30°—40° C. increased
the rapidity of the granular movement, and it was found that
the velocity of that in the pseudopodia of the Miholides
precisely coincided with the highest obtained from the pro-
toplasm of vegetable cells. The temperature which was fatal
to Tradescantia, Urtica urens and Vallisneria spiralis, proved
to be 48°C. Already at 38° C., however, the movements
began to slacken.

The difficulty of bringing the movements of the granules

* “Das Verhalten d. sogenannten Protoplasmastréme in der Brennhaaren
von Urtica Urens,” etc., ‘ Kais. Akad. d. Wiss.,’ Bd. xlvi, June 20, 1862.

VOL. III.—NEW SER. iF

260 DR. DUFFIN, ON PROTOPLASM.

into harmony with those of other contractile bodies is obvi-
ously very great. The former is evidently associated with a
change of locality, not only of the granules but of their im-
mediate neighbourhood, for it is only possible thus to interpret
the arrival of the substance of the pseudopodia at places that
it did not previously occupy, and the complex changes in the
arrangement of the protoplasma. This Briicke also admits
for the hairs of Urtica urens, but he distinguishes two kinds
of movement in their protoplasm ; a slow, creeping or draw-
ing movement, upon which the changes in the arrangement
of the protoplasm depend, and a more rapid flowing which is
observed in the movements of the numerous granules. Whilst
the former is directly referable to contraction of the proto-
plasm, the latter depends upon a granular fluid enclosed by
the contractile plasma, and from which it derives its moye-
ment. Thus, Briicke would draw a distinction between the
cortical and medullary portion of the protoplasma. As the
movement of the granules can be accounted for in the same
manner as those of the pseudopodia of the Polythalamiz,
Schultze sees no reason for admitting this differentiation.
Before closing this analysis we would make a few remarks
upon the fresh light thrown by these observations on the move-
ment of granules generally. Beale* describes the mucus-
corpuscles as “composed of soft semi-transparent matter
which exhibits delicate spherical particles, varying in size in
every part. These particles are in constant motion. Ina
few moments an oscillation of the particles is observed at
some portion of the circumference of the mass. Then one
or more bulgings occur, and parts of the surface become
quite uneven by the formation of a number of little processes
which move from the general mass and often assume the
form of little spherules, which still remain attached by narrow
' pedicles to the general mass. Occasionally two or more
processes coalesce, and a rmg may be momentarily produced
at some part of the circumference. From the first protrusions
smaller protrusions very often occur, and these gradually
become spherical, but remain attached by a narrow stem, and
in a few seconds, perhaps, again become absorbed into the
general mass.” The different forms assumed by the same
mucus particle during one minute are represented in Pl. IX,
fig. 15, in Vol. XI of the ‘ Transactions of the Microscopical
Society.’ Beale further states that the transparent moving
matter is itself composed of very minute, spherical particles,
and describes the movements of the larger spherical particles
which make their way from the general mass into the new
* « British Medical Journal,’ Nos. 115—117, 1863.

DR. DUFFIN, ON PROTOPLASM. 261

processes or bulgings that are formed. The phenomena
described in the mucus-corpuscle and young epithelial cells
closely resemble those observed in the pseudopodia of the
Polythalamiz. The active movements of the molecules con-
tained in the salivary corpuscles, the various shapes assumed
by these corpuscles, either spontaneously or under the in-
fluence of various reagents, and particularly the fact that
magnetism is capable of arresting all this activity, have been
fully described by Briicke.* The same author also describes
the molecular movements of the white blood-corpuscles and
of pus: “The granules which they extended evinced for a
considerable time the same movements as the granules of the
salivary corpuscles.”

One very important auction to which these observations
gives rise relates to their bearmg on the cell theory. It is
evident that no proper membrane invests either the pseudo-
podia of the Polythalamiz, or the salivary or mucus-corpuscles.
Briicket denies a membrane to the white blood-corpuscles
and to pus, and has contested every argument that has been
adduced in favour of its existence in the red blood disc.
Beale takes the same view. Dr. Dalton has also contested
the existence of this membrane. Brettauer and Steinacht
have shown that membrane does not invest the whole of a
particle of cylindrical epithelium, but only casts a conical
mantle about the same. Dr. Beale$ has insisted upon the
difficulties attending the acceptance of a proper membrane
for the hepatic, renal, and other cells, and further states, that
as in Guinea-pig’s blood, each single corpuscle becomes one
tetrahedral crystal, it is impossible that there can be a proper
membrane to the red blood disc. He also very truly re-
marks that in young cells generally no cell-wall whatever
exists ; it is, therefore, impossible to regard the cell-wall as an
essential structure. Thus grave doubts are thrown on the
propriety of including the investing membrane in the defini-
tion of a cell. Schultze || does not hesitate to define the cell
as a mass of protoplasm enclosing a nucleus, and he regards
the formation of a chemically differentiated membrane on the
surface as a retrogression.

Beale has considerably extended this definition, and in-

ae “Die Elementar-organismen,” ‘ Kais. Akad. d. Wiss.,’ Bd. xliv, Oct.,
1861.

+ Ibid.

+ Briicke, ibid.

§ ‘On the Structure and Growth of the Tissues,’ a Course of Lectures
delivered at the Royal College of Physicians, 1861.

|| ** Ueber Muskelpérperchen, ” Reichert u. Du Bois Raymond’s ‘ Archiv,’
1861.

262 DR. DUFFIN, ON PROTOPLASM.

cludes, under the term ‘‘ formed material,”’ not only all mem-
branes and intercellular substance, but also those various
precipitates, as starch, oil, &c., that may come to oecupy the
interior of the cell. His “ germinal matter” seems to corre-
spond generally with Schultze’s definition of protoplasm. It
is the sole seat of those movements that have been described.
Both Schultze and Briicke are much troubled how to regard
either the origin or the function of the nucleus. The latter
even says* “the constancy of its appearance is subject to
essential limitations if, as cannot be avoided, the cells of Cryp-
togams are also considered, and it be not assumed that
the nucleus must be present even where it is invisible.”
Schultze, on the other hand, includes the nucleus in his
definition of a cell. Neither tells us in what light to regard
the nucleolus when it exists, and we often find, particularly
in the vegetable kingdom, that the protoplasm itself would
admit a further separation of parts. If we understand Beale
aright, the difference between nucleolus, nucleus, and pro-
toplasm, is only one of degree, the former being younger and
more “ vitally” active “ germinal matter” than the latter, but
all presenting this important contrast to all formed material,
that under the influence of an appropriate pabulum, they are
capable of indefinite multiplication. Beale therefore regards
all living structures as consisting of matter in two essentially
different states, that which és living and that which has hved,
and the first passes into the last, the transition bemg some-
times so gradual that, by the action of carmine, many zones
may be demonstrated, the outer not being coloured at all,
while the inner ones are very intensely coloured.+ That in
order to find the most active centres we must even look for
particles, far smaller than the nucleolus, is most probable.
It is as difficult to conceive an ultimate living centre as to
“conceive the universality of space. The formed material,
on the other hand, whether in the shape of cell-membrane or
intercellular substance, is practically but the altered germinal
matter, and although endowed with most important func-
tions, restricts the growth of the germinal matter within cer-
tain limits, and it cannot, like germinal matter, produce new
matter like itself. All pabulum must pass through the formed
material before it can reach the germinal matter within, and
therefore it follows that the rate of growth of the germinal
matter is determined by the permeability of the formed mate-
rial. He thus explains alterations in the rate of growth
* «Tie Elementar-organismen,’ op. cit.

+ ‘The Structure of the Tissues ;’ see also a paper in the ‘ Archives of
Medicine,’ vol. ii.

DR. DUFFIN, ON PROTOPLASM. 263

without employing the doctrine of irritation. Instead of
saying that the activity of a living structure is increased by
an “‘irritant”’ or “ excitant,” he would say simply that the
living matter grows faster, because the access of pabulum to
it is facilitated, in consequence of rupture of the formed ma-
terial which surrounds it, or by this formed material being
rendered more permeable to nutrient fluids.*

The more active the growth of a tissue the smaller is the
amount of formed material it contains. If we look to the
cells of the yelk-bag, we find every grade of germinal matter,
nucleolus, nucleus, protoplasm, varying in consistence at dif-
ferent depths, but we have no proof that these are surrounded
by any proper membrane whatever. The protoplasm is held
together by its own consistence, and the appearance of “ cells”
or separate masses is due to its having travelled outwards,
or to its tendency to divide and subdivide.

We will, in conclusion, endeavour in a few words to show
still more distinctly the difference between the views brought
forward in this paper and those of Dr. Beale. This observer
insists + that physical and chemical changes take place in
“formed material,” but that vital actions occur in the “ ger-
minal matter” alone. All that is necessary to his “ cell” is
—(1) matter that is active and living, or ‘ germinal matter ;”
and (2) matter that is formed and has lived, but is now pas-
sive, “ formed material.” Neither “nucleolus,” ‘ nucleus,”
“cell-wall,” “cell-contents,” are essentials. The “protoplasm”
in the Rhizopoda, &c., according to Beale, consists of parti-
cles of liwing, active, germinal matter, imbedded in inactive
formed material, which was itself once germinal matter. In
using the term “ vital action,” Beale admits the existence of
a force or power peculiar to living beings. He would refer
the movements of protoplasm to the vital power of the living
particles entering into its composition. In all forms of ger-
minal matter, Beale finds particles so minute that they are
only just visible under a power of 3000 diameters, and he
believes that living particles exist which are too minute to be
seen by any power yet made. Beale therefore refers the move-
ments seen in protoplasm to the living particles themselves,
and not to a fluid or basic matter in which they are sus-
pended; the latter, which usually exists in inappreciable
quantity, exhibits motion, but its movements are secondary,
and the impulse is communicated to it from the living par-
ticles.

* See a paper in the ‘ Lancet,’ April, 1863.

+ See papers read before the British Association for the Advancement of
Science, 1861 and 1862; also ‘ Archives of Medicine,’ vols. ii and iii.

264 DR. DUFFIN, ON FPROTOPLASM.

Beale maintains that the germinal matter in every cell
possesses the power of active movement; and in individual
masses this movement takes place in a direction from cen-
tres. To it all processes of cell multiplication are referred.
Beale considers that each spherical particle of living or ger-
minal matter is itself composed of smaller spherules. In any
spherule new centres of growth may arise. A piece of ger-
minal matter may be detached from the parent mass, the
“jucleus” remaining behind intact, but a new nucleus may
arise as a new centre in the detached portion, and a nucleolus
may arise in the nucleus, and so on. Formation is, accord-
ing to this observer, the conversion of germinal matter into
formed material, in which process the matter loses its vital
power, but acquires new properties and a definite composi-
tion. Formed matter was once germinal matter, and this
was once pabulum. The pabulum having become “ living
matter,’ moves outwards, as spherical particles, from the
centre where the change occurred, like the particles of living
matter which existed before. What appears to be a fluid, ex-
hibiting certain streams or currents, really consists, according
to him, of a number of minute spherical particles of living
matter, every one of which possesses the power of movement.
These living particles can be seen very readily with the 25th
of Messrs. Powell and Lealand in the Vallisneria and Trades-
cantia. The larger bodies, consisting of formed material,
such as starch-granules, chlorophyl, &c., are forced on in
the currents produced by the movements occurring in the
particles of living or germinal matter. All movements ob-
served in “ germinal matter” are regarded by Beale as depen-
dent upon the peculiar “vital”? endowments of the ultimate
living particles of which it is composed.

TRANSLATIONS.

On the genus Lucernaria, O, F. Miitier.*
(Pl. XII.)

Tue genus Lucernaria, which flourishes more peculiarly in
the northern seas where it is represented by several species,
has hitherto received less attention from zoologists than it
has from systematic writers, and notwithstanding the various
places it has occupied in systems of classification.

Recently it appeared to have found a resting place among
the polyps, but at present it has been compelled to abandon
this for one among the Acalephe. As regards the anatomy
of these curious creatures, we possess no important informa-
tion beyond that furnished in the admirable description by
Sars,t the figures by Milne-Edwards,{ and the comparison
between their structure and that of the Anthozoa drawn by
Frey and Leuckart.§

As the genus had for a long time greatly excited my
interest, from its constituting a distinctly transitional form
between the Anthozoa and Acalephz, I gladly seized the
opportunity of studyimg its anatomical structure afforded me
at St. Vaast-la-Hogue, not far from Cherbourg, where I
obtained two species, viz., L. octoradiata, Lam., and L. cam-
panulata, Lamx., which were abundant on Zostera thrown up
on the rocky shore from the deeper water.

In the following pages I propose to consider, first, the
structure of Lucernaria, and afterwards, its systematic
position.

§ 1—The Structure.
In this section I shall first describe Lucernaria generally ;

* « Untersuchungen iiber niedere Seethiere.’ Von Wilhelm Keferstein,
M.D. _ (‘Zeitsch. f. wiss. Zool.,’ xii, p. 1, 1862.)

+ ‘ Fauna littor. Norvegie,’ ltes Heft, 1846.

£ Cuvier, ‘ Regne animal. Zoophytes,’ pl. Ixui, fig. 1, 1849.

§ ‘Beitrage z. Kenntn. wirbell. Thiere,’ 1847.

266 ON THE GENUS LUCERNARIA.

and afterwards, in due order, the Bell, the Stem, the Ten-
tacles, the marginal Papille, the Stomach, the Gastro-
vascular system, and, lastly, the Generative organs.

1. General description.—A Lucernaria (Pl. XII) may be
compared in form to a goblet or a funnel with double walls; at
the commencement of the stem the inner wall (s) is attached
to the outer at four points or angles, so that between these
points four passages into the cavity between the walls origi-
nate, the stem itself being prolonged only from the outer wall.
At the bottom of the funnel, where the inner wall begins to
divide at the four pomts, is a cylindrical elevation—the
mouth (0) resembling the short clapper of a bell turned
upwards, and which fills in this manner the narrow part of
the funnel, and usually hides from view the four angles and
passages into the inner cavity.

In order to form a general idea of the structure, it will
be useful here to compare the different parts of the animal
with those of other well-known forms, and thus to abandon
any objective description, and to include in the structural
details some insight into the nature of the various parts.

Sars, and Frey and Leuckart have remarked that the body
of a Lucernaria may be compared to the disc of a Medusa.
Four thin partition-walls (7), which spring from the before-
mentioned points of the inner wall, divide the cavity between
the two walls into four compartments, which communicate
with one another round the margin of the cup (7’). The body
of the Lucernaria so far corresponds with the dise of a Me-
dusa, which presents four large radial vessels (which, in that
case, may be better termed gastric pouches) and an annular
vessel coursing round the margin. These gastric pouches
open into a wide aperture between the points (above men-
tioned) of the inner wall into the cavity of the stomach, and it
is clear that whilst the outer wall (@) of the body of a Lucer-
naria corresponds to the gelatinous disc of the Medusa, the
inner wall (s) represents its natatory organ. In Lucernaria,
where the radial vessels are so disproportionately large, the
natatory organ is connected to the gelatinous disc only in
four narrow tracts, while in the Medusa the reverse is the
case, and the radial vessels run between the natatory organ
and the gelatinous disc in the form of slender channels.

Bearing in mind that the development of the Medusz
originates in a bud formed by the intro- and extroversions of
two formative membranes, we shall readily perceive that
Lucernaria represents an aborted Medusa. In the Medusa-
bud the radial vessels are not at first separated from each

ON THE GENUS LUCERNARIA. 267

other, but the embryonic vascular system exists, it may be
said, in the form of a subdivided conical or hemispherical
space between the natatory organ and disc; the natatory
and gelatinous portions of the umbrella afterwards grow to-
gether along four radial tracts, so that four wide pouches are
formed, constituting the vascular system, and which commu-
nicate with each other only at the border. Now, in Lucer-
naria the gastro-vascular system remains in this condition,
whilst in the Medusa it is more and more defined as
the connection between the natatory and gelatinous portions
of the disc becomes more and more intimate and extensive,
until at last they are separate only along the hnes of the
slender radial vessels and in the annular vessel, which latter,
however, frequently disappears also.

But notwithstanding that we are thus compelled to regard
Lucernaria as an aborted Medusa remaining in the condition
of a bud, still we cannot concur in the opinion, lately ex-
pressed by Agassiz, that Lucernaria resembles most the stro-
bila form of Medusa; for the scyphistoma, and afterwards
the strobila, represents a polyp in which the development
has been arrested at a much lower stage than it is in Lucer-
naria, since in these forms no distinct natatory sac exists,
and, consequently, also, no rudiments of a vascular system
are apparent.

The resemblance of Lucernaria to an undeveloped Medusa
is also very plainly shown besides in the mode of formation of
the gastro-vascular system, in the position of the marginal ten-
ticles, and of the reproductive organs. The marginal tentacles
(4) spring, as do those of many Medusz, from the edge of
the disc, and are assembled into groups where the radial
vessels join the circular vessel, and may be considered in
both cases merely as pr olongations of the gastro-vascular sys-
tem. The bell is, commonly, deeply notched between the
groups of tentacles, which thence appear to be placed upon
arm-like prolongations of the bell; and in some species there
is a marginal papilla (p) in the interbrachial space, which,
from its structure, must be regarded as equivalent to a tens
tacles” The 9 generative organs (g) are commonly found in
Lucernaria, as in many Medusz, on the wall of the radial
vessels ; but whilst in the latter they quite cover the slender
vessel on the side of the natatory sac (of which vessel they
appear to represent a nodular or elongated outgrowth), in
Lucernaria, where the radial vessels are so exceedingly broad,
they only appear as radiating, band-like thickenings of the
wall of the natatory sac, which develops two such generative
bands in the space of each gastric pouch.

268 ON THE GENUS LUCERNARIA.

Just as in a Medusa-bud, the bell of Lucernaria is sup-
ported by a stem, which, as the natatory sac does not extend
into it, consists of only one of the two formative membranes,
whose existence can be demonstrated throughout the Aca-
lephe. The Lucernaria attaches itself to various marine
plants (in the two species examined by me this was always
Zostera) by the cecal end of this stem, and floats freely in
the water, mostly downwards, more rarely upwards or in any
other posture.

In Lucernaria, consequently, the same disposition of the
organs obtains as that which is characteristic of the Medusee ;
and in the following description, therefore, the same terms
may be employed in speaking of the different parts as are
commonly employed in the anatomy of the Medusz.

2. Bell.—The bell consists of the gelatinous disc, constitut-
ing the outer wall of the cup, and of the natatory sac, which
forms its inner wall.

The gelatinous disc (G) is covered outside by the outer
formative membrane (a), and inside by the inner formative
membrane (2), between which is a thick layer of gelatinous
substance (z), which, as in the lower Medusz and Siphono-
phoree, is quite destitute of cellular elements, appearing to be
constituted solely of fine, close fibrille, passing for the most
part straight from one membrane to the other, and which
may be regarded as mere thickenings in the structure of
the gelatinous substance. A similar fibrillation occurs very
generally in the gelatinous substance of the Meduse and
Siphonophorz, and is also apparent in the problematical
gelatinous substance in the body of the Helmichthyde.
Both membranes, as in all cases, are composed of a tissue
of closely contiguous cells.

‘ At the margin of the cup (fig. 3) the two membranes curve
inwards and are continuous with the natatory sae (s), the
intermediate gelatinous substance no longer existing between
them, and the two membranes, consequently, coming into im-
mediate contact. It is true that the two cellular membranes
cannot be demonstrated throughout the whole extent of the
natatory sac, which appears to consist only of a single layer
of cells, supporting on its inner aspect a ciliated cuticle, but
at the line of junction of the gelatinous dise with the natatory
sac, as well as at the point of attachment of the generative
organs and the oral tube (fig. 4), they may both be distinctly
traced, and in the latter situation they are most distinctly
seen to be separated again by the gelatinous substance.

At the bottom of the cup the natatory sac is divided into four

ON THE GENUS LUCERNARIA. 269

regular angles or points (s), the apices of which are attached to
the gelatinous disc. This attachment is continued im a line
(7) almost to the margin of the goblet, and, by the four
lines of connection produced in this manner between the
gelatinous disc and the natatory sac, the imternal cavity is
divided into four spaces (k)—radial vessels—which only com-
municate with each other round the margin of the cup. These
bands of connection are much broader in L. octoradiata than
in L. campanulata, being in the latter almost linear, while
they may rather be termed bands in the former. They always
run opposite the sides of the more or less quadrangular oral
tube, and at the point of each angle of the swimming sac,
they meet the strap-shaped: generative organs. In those
species, also, in which the dise is divided imto four arms, as
in L. guadricornis, these lines of connection lie in the middle
of each arm, and, consequently, if the groups of tentacles
placed within the space of one expanded radial canal are to
be regarded as belonging to one and the same set, in the
case of these four armed cups, the two groups at the extre-
mity of each arm do not belong to the same set, but are
constituted of contiguous groups belonging to two distinct
arms.

The connection of the gelatinous dise with the natatory
sac, and the lines of junction of the two, may be most easily
seen in a transverse section, made either in a radial direc-
tion through both walls (fig.3), or mm a circular one around
the cup (fig. 2).

In the outer membrane of the gelatinous disc, as well as
in that of the natatory sac, numerous thread-ceils are
lodged, which, as is always the case, are produced in the
cells of the membrane. On the outer surface of the disc
they form spots of about 0°-1—0-2 mm. in diameter, in which
the outer membrane is somewhat tuberculated, and contains
the oval thread-cells (0-011 mm. long), which are arranged
side by side, like palisades, together with yellowish pigment-
granules, which give a reddish colour to the whole surface.

These coloured collections of thread-cells do not often
occur on the surface of the natatory sac, but in this situation
they are lodged in great numbers in follicles of the outer
membrane (fig. 14). These form the round, white, or, in
L. campanulata, often turquoise-blue spots (2), visible to the
naked eye, and already mentioned by Lamoureux, and which
abound especially round the margin of the cup and along
the course of the generative organs. These follicles are
simple depressions of the outer membrane, 0°18 — 0°22 mm.
in diameter, which consequently project into the internal

270 ON THE GENUS LUCERNARIA.

cavity —the radial canals—and their orifice (#) is surrounded,
on the exterior, by a thickened border, and has scarcely any
visible canal.

The thread-cells are formed in the parietal cells of these
follicles, and falling then into the cavity, which they quite fill,
they can be squeezed out of the mouth. These follicles have
thus, in all respects, the typical structure of a gland, and on
that account claim a special interest.

The thread-cells in these receptacles, like those in the yellow
spots on the outside of the Lucernaria, where similar recepta-
cles are of but very rare occurrence, are of an oval form, and
0-011 mm. long; when shot out, the apparently spiral thread is
seen to be placed upon a hollow peduncle, 0°01 mm. long, and
furnished on the exterior with reflexed setze. The capsule is
then only 0-008 mm. long, and almost globular (fig. 15).

3. Stem.—The bell narrows suddenly into the cylindrical
stem, the end of which is closed and expanded in a disc-like
manner to form the usual adhesive organ of the animal,
and which serves the same purpose as the foot of the Actinia.

The stem is a direct continuation of the gelatinous dise,
for as the natatory sac is divided into four points at the bot-
tom of the cup, and is also at these points attached to the
disc, the stem contains no continuation of that organ, and
its wall, like that of the disc, consists of the outer and
inner formative membrane and the intermediate gelatinous
substance. ;

In a transverse section of the stem, which can easily be
made in L. campanulata, in which it contains no muscles,
and is scarcely at all contractile (figs. 10, 11), the wall is
seen to project on the interior into four longitudinal ridges,
which are so placed as to meet above the angles of the
natatory sac, as has been described by most writers. On the
under side of the foot they present the appearance of four
spots, and in the lower part of the stem of L. octoradiata—in
which, however, on acccount of its great contractility, | have
never been able to obtain a satisfactory view—they appear
to be so much developed as to meet and join in the axis, so
as to subdivide the simple cavity into four tubes, separated
from one another, but communicating above (fig. 13, h).

In the centre of the under side of the foot there is a de-
pression, which appears to have been first described by
Lamarck as a cecal pit (figs. 11, 12, &), projecting into
the gelatinous substance. In L. campanulata, where the
stem is non-contractile, these relations can be easily studied.
In a foot-dise 0°44 mm. im diameter this pit was 0°074 mm.

ON THE GENUS LUCERNARITA. Day |

deep, and it may with certainty be affirmed that it is only
an inversion of the outer membrane, which, indeed, extends
so far as to penetrate through the gelatinous substance, and
to form a little projection in the bottom of the cavity of the
stem, where, though not in the rest of the stem, the inner and
outer membranes are in contact. Consequently, as, however,
Lamarck has already justly remarked (a, a, 0), there is, in
this situation, no orifice communicating with the cavity of
the body, such as exists, for instance, in Hydra.

4. Tentacles—In all Lucernarie the tentacles are placed
in eight tufts round the margin of the bell, which is notched
between them. In this way the tentacles come to be placed
on arm-like projections, which in some species attain a con-
siderable length, and give the bell the appearance of being
deeply cleft. These arms are not always equidistant, for those
which arise nearest to the partition between two radial
canals are placed nearer to one another than those which
arise in the extent of a radial canal. In this manner the
arms form four regular groups, and the two arms of each of
these groups, as may be easily surmised, do not belong to
one radial canal, but to two contiguous ones; and the two
arms which arise on the border opposite a radial canal sup-
port two of such groups. The nearer the two arms in one of
these groups are approximated, the less deeply is the margin
of the bell between them notched; the notch, on the other
hand, being deeper in proportion to the degree of separation
between the groups.

Whilst in L. octoradiata and campanuiata the arms are
scarcely perceptibly associated in pairs, and arise at almost
regular distances apart, it is quite the reverse in L. quadri-
cornis, in which we have apparently four long arms divided at
the end. The tentacles (figs. 6, 7), which form a sort of rigid,
divergent tuft on the extremity of the arm, are, as in all the
Acalephz, prolongations of the vascular system, and conse-
quently are constituted of both the outer and inner mem-
branes. This condition is easily observed in young tentacles,
in which the gelatinous substance may often be seen between
the two membranes. But in older ones, on the contrary, the
in nermembrane is changed, towards the interior, into a dense
cellular tissue, in which the central canal scarcely remains
open, whilst on its outer side it is transformed into muscular
fibres, which run in a longitudinal direction, and form a
cylindrical layer, from which the tentacle derives its contrac-
tility.

The tentacles, of which I counted 25 to 27 in L. octora-

272 ON THE GENUS LUCERNARIA.

diata and campanulata, have capitate extremities, and in
this part the central cavity is enlarged, and the outer mem-
brane manifestly thickened. In L. octoradiata these heads
are quite round, and have a diameter 0°15 mm. on tentacles
which are about 15 mm. long. In L. campanulata, on the
contrary, they are discoid, and often have an acetabular depres-
sion in the centre; their diameter reaches 0-4 mm. in tenta-
cles of 1'6 mm. length, so that they are here proportionally
of a much more considerable size than in those of the former
species.

In L. campanulata the fine tentacles situated on the under
side of an arm (figs. 4, 5) are of peculiar construction. They
are, for instance, very short, and the base expands into
a round, boss-like projection (4), 0°4 mm. in length, which is
a thickening of the outer membrane, and is filled with thread-
cells as fully as the button-like end itself. These five bosses
are very regularly arranged ; the lowest and central one is the
largest, whilst the two on either side regularly diminish in size.
Milne-Edwards did not recognise their place on the base of
the small tentacles, and describes them as vesicles, and
probably as representing organs of secretion.

The outer membrane of the button of the tentacle and of
these boss-like thickenings contains a layer of dense, pali-
sade-like, scimitar-shaped thread-cells, which in L. campa-
nulata are 0'015 mm. long and 0:005 mm. wide, and between
these some larger oval ones are irregularly distributed, having
in the same species a length of 0:017 mm. and a width of
0007 mm. These knobs contain, besides the thread-cells,
granules of yellow pigment, which give them a yellow colour,
often very bright.

The animal can exert preheusile movements with its
tentacles, and L. campanulata, by means of its disc-like knobs,
can attach itself as with suctorial acetabula.

5. Marginal papille.—In some species peculiar papille
occur, regularly placed on the margin of the bell between
the arms. These were first mentioned by O. Fabricius in
his L. auricula, and I have examined them myself in L.
octoradiata, in which species they have been described by
all earlier observers. :

These papille (fig. 1 and 3, p) consist of protrusions of the
two membranes with the intermediate gelatinous substance,
and in essential structure resemble the tentacles. They are
not placed precisely on the margin of the bell, but rather
under it, so that they appear lke protrusions of the gela-
tinous disc. ‘They have a large internal cavity, which com-

ON THE GENUS LUCERNARIA. 2738

municates by a wide opening with the vascular system
and they have usually a round or oval form. Now and
then they assume quite a tentacular form, and then have a
projection (p’) at the end, which is filled with thread-cells,
and they may be so elongated as to present exactly the as-
pect of isolated tentacles.

I have never found muscular fibres in the papille as in the
tentacles; the muscular fibres of the margin of the bell (m”)
reach to them without entering into them, but the papille
are in spite of this very contractile, and act like extremely
strong acetabula. When the foot is loosened from its point
of attachment, the Lucernaria can still hold itself fast by
these acetabular papille, till it has again found a secure
resting-place, and individuals are often met with adhering
to Zostera-stems by both the foot and marginal papille,
especially when in danger of beimg torn away by the force of
the ebbing tide.

The marginal papille are wanting in L. campanulata, but
the knobs of the tentacles are in this case acetabular, and
can be employed in a similar manner for the purposes of
adhesion and fixation.

6. Stomach.—At the bottom of the bell (fig. 4) the
natatory sac (S), as has been already described, is divided
into four triangular points (s), and which are attached by their
extremities to the gelatinous disc. In this way four inter-
spaces (e), which may be compared to bow windows, are
formed in the natatory sac, and which lead from the cavity
of the stomach into the radial canals. Above the situation
where the natatory sac is subdivided into the four points is
an annular thickening or elevation, which constitutes the
prismatic oral tube (0), and which, as in Meduse, is probably
a process of the natatory sac. A large quantity of gelatinous
substance is developed between its two membranes, and its
free margin is divided into four lobes, answering to its four
sides, though these are often indistinct; and again, in most
cases, subdivided into numerous minute lobules, and corru-
gated.

In the stomach we have consequently to consider, first,
the true gastric cavity which lies between the four points of
the swimming sac, and terminates below at the commence-
ment of the stem, at the pomt where the inner wall of that
part is thickened into a circular ridge, by which its cavity
appears, in most cases, to be separated from that of the
stomach ; and secondly, the oral tube, which is very movable,
and can be entirely folded upon itself. Lamouroux describes

274 ON THE GENUS LUCERNARIA.

some solid discoid bodies in the wall of this oral tube in L.
campanulata, which serve for the crushing of the food, but
I have not been able to find these myself.

In this stomach the digestion of the nutriment, consisting,
as all observers agree, of small crustaceze and molluscs, is
effected. I have never noticed any trace of food in the stem,
or radial canals, although Sars has found some in the latter
situation.

Numerous vermiform internal oral tentacles are set in a row
on the margins of each point of the natatory sac, and which
commonly project into the cavity of the stomach, where they
move about in a serpentine manner. In the Meduse these
internal oral tentacles are very large, and one cannot help
ascribing to them some function in the digestive process.
It can be demonstrated with certainty in Lucernaria, as Fritz
Miiller has already described in Meduse, that these tentacles
are solid within, and consist of the gelatinous substance,
covered by the outer formative membrane, and we cannot,
therefore, agree with Gegenbaur, who, in Meduse, nor with
Frey and Leuckart, who say that in Lucernaria these tentacles
are hollow. Many oval thread-cells are imbedded in this
membrane, and it is everywhere furnished with cilia, which
exist also throughout the whole gastric cavity.

These internal oral tentacles have a peculiar structure in
L. campanulata (figs. 16, 17), the outer membrane being
much thickened throughout two thirds of the circumference,
and forming nodular projections on the internal aspect. This
larger portion of the tentacles contains no thread-cells,
which occur only in the narrow tracts, where the outer mem-
brane is of its usual thickness, and has a smooth surface
towards the interior.

7. The gastro-vascular system.—As parts of the gastro-
vascular system in Lucernaria must be reckoned the cavity
of the stem, and that between the gelatinous disc and the
natatory sac in the sides of the bell. I cannot positively
assert whether these cavities are shut off from that of the
stomach at the time of digestion, but it seems, nevertheless,
very probable, and when food is found in them it may be
assumed to have entered there by accident.

The whole gastro-vascular system is clothed imside with
delicate cilia (fig. 9), springing from the cuticle by which the
cellular layer of the inner membrane is covered.

The cavity between the double walls of the bell is divided
by the four lines of connection between the outer and inner
membranes (7) into four spaces (rR) answering to the four

4

ON THE GENUS LUCERNARIA. 279

radial canals which communicate with each other at the
border of the bell, up to which the lines of connection do
not quite reach, and thus leave, as it were, an annular passage.
In L. octoradiata these lines of connection are very regularly
arranged. They always extend from the middle of one of
the sides to the oral tube, in the direction of the longitudinal
ridges of the stem, and the openings which represent the
annular vessel are but small; in L. campanulata, on the con-
trary, where the lines of connection can scarcely be detected
from the outside, though their existence can be proved by
the introduction of a probe, they are often not absolutely radial
in direction, and the annular vessel is of considerable and irre-
gular width. When the arms of the bell are united into four
groups, a similar line of connection always divides one of
these groups or arms of the first order into two secondary
arms, as I have already noticed. Frey and Leuckart describe
eight such pouch-like radial canals in LZ. guadricornis, but
Milne-Edwards has already remarked that this must be a
mistake, as in that species, as well as in all the others hitherto
examined, only four partition-walls and radial canals exist.

In the gastro-vascular system J have constantly found a
clear granular fluid, which is kept in motion by the cilia,
and the cavity 1s very much crowded in places by the before -
described nematophorous follicles, the muscles, and the
generative organs.

8. Muscular system.—The very distinctly marked muscular
system in Lucernaria is easily recognised ; it is composed of
bundles of fibres running in definite directions, beyond which
I have remarked no further structure.

In the stem of LZ. octoradiata (fig. 13) there are found in the
above-described longitudinal ridges (/), but lying free in the
gelatinous substance, four cylindrical or flat bundles of muscular
fibres (m), which arise below from the pedal disc, and suddenly
terminate at the apices of the four points of the natatory sac.
It is to these muscles that is due the great contractility of
the stem in this species. In L. campanulata these muscles
are entirely wanting; and in accordance with this the stem
exhibits very little or no contractile power, so that sections in
any direction can as easily be made in it as im the stalk of a
plant.

Two sets of muscular fibres can be distinguished in the
bell, a radial and a circular, but these belong, as in all Me-
dusze, to the natatory sac alone.

The radial muscular bands (m’) are eight in number, one
running in the centre of each arm. At the apex of each

VOL, I1].—NEW SER. U

276 ON THE GENUS LUCERNARIA.

point of the natatory sac, therefore, two of these cords meet,
run close to its border, and proceed quite to the end of the
arms, where they become somewhat broader, and perhaps
pass partially into the muscular system of the tentacles.
These muscular bands are placed on the surface of the nata-
tory sac, looking towards the cavity, and form ridge-like
thickenings, upon which the generative organs are developed.

The circular muscular bands (m’) on the margin of the
natatory sac are limited entirely to the border, where it turns
outwards, to become continuous with the gelatinous disc.
They extend from one arm to another, terminating at the
summits, and perhaps giving off some fibres to the tentacles,
the muscular system of which has been already described.
The marginal papille arise in close contiguity with this set
of circumferential muscles, but they receive no fibres from
it, notwithstanding which, however, as before said, they are
highly contractile.

9. The generative organs.—The sexes m Lucernaria, as in
all the Meduse,* are separate, and the generative organs are
placed in the course of the radial canal, as in the whole family
of the Thaumantiadz. In the wall of each of the wide radial
canals are two ridges, projecting into the cavity and running
entirely across it. These ridges extend from the end of the
arms, into which the margin of the bell is divided, to the
angles of the natatory sac. Their position cannot better be
described than by saying that they run on or near the above-
described radial muscular bands.

These ridge-like generative organs are very apparent, and
both O. Fabricius as well as Lamouroux describe them as
intestinal tubes radiating from the stomach; F. Rathke was
_ the first to suggest that they were generative organs.

More accurately considered, the generative ridges in L.
octoradiata consist of contiguous spherical processes of the
internal membrane of the natatory sac, within which (pro-
bably from a growth of the outer formative membrane, as in
the Meduse and Siphonophore) the generative products are
developed. Whilst in the Meduse these processes or thick-
enings of the walls of the radial canal project externally, in
Iucernaria they are placed on the inner aspect. The inner
membrane, where it covers the generative organs, especially
in the female, contains much brown pigment, and by this,
as well as by the whitish colour of the testicular follicles
when mature, the female can easily be distinguished from

* As an exception to this, vid. Strethill Wright, ‘On Hermaphrodite Re-
production in Chrysaora hyoscella,” in ‘ Ann. Nat. Hist.,’ vii (1861), p. 357.

ON THE GENUS LUCERNARIA. 277

the male, even by the naked eye. The ovisacs are densely
filled with ova, of about 0°037 mm. in size; the yolk is red-
dish and coarsely granular, and often completely conceals
the germinal vesicle and germinal spot, which are respectively
0:015 mm. and 0:004mm. in size. Thespermatic tubes have,
when immature, a tuberculated aspect, from the large granu-
lar sperm-cells with which they are filled; when the product
is mature, the tube presents a perfectly smooth appearance,
and it then contains innumerable highly mobile spermatozoa *
(fig. 18), which survive a long time in water, and have a nail-
like head, 0:004—0-005 mm. in length, to the broader end of
which is attached the long, thick, and rigid caudal portion.

Among the numerous specimens of L. octoradiata which
I have examined, there were as many male as female, which
could not be distinguished by their form or size, but were
readily detected by the colour of the generative organs, as
before mentioned. Out of about twenty specimens collected
of L. campanulata there were no females, all being males.

In the latter species the generative organs differ, in some
respects, in their appearance from those of L. octoradiata.
The spermatic tubes (which alone, from the circumstance
above related, I was able to examine) form, not spherical, but
merely lobular projections, and whilst in L. octoradiata in
the middle portion of the sexual organ there are always two
spherical sacs lying close together, this is not the case in
L. campanulata, in which the entire organ appears to be con-
stituted of a single ligulate, lobed cord. ;

I had no opportunity of observing either the fertilisation
or development, although the specimens lived for a week in
my glasses.

§ 2.—On the Systematic Place of Lucernaria.

In this section I will first trace the genus Lucernaria
through the classifications of various systematists, and then
endeavour to determine under which order of animals it may
be most correctly placed; and lastly, give a synopsis of all
the species at present known.

1. Historical review.—The genus Lucernaria was disco-
vered and established by Otto Fr. Miiller, and about the
same time it was met with in Greenland by O. Fabricius.
This Greenland species was also first published by O. Miiller,
though he did not recognise its affinity with his new genus,
but placed it, though somewhat doubtingly indeed, amongst
the Holothurie ; Milne-Edwards is therefore incorrect in

278 ON THE GENUS LUCERNARIA.

citing Fabricius as the author of the genus. Fabricius him-
self afterwards described his Greenland species accurately
under the generic name given to it by his friend, and Gmelin
placed the new and very anomalous-looking genus with the
Actinie, Holothurie, Medusze, and Asteroide, under the
Linnean order Vermes: Mollusca.

For a long time the new genus could find no systematic
. place, until, owing to the increased knowledge acquired of
the zoophytic division of animals, fresh points of comparison
for this remarkable form were perceived. Even at this early
period we meet with the two views, which have pre-
vailed up to the present day, respecting the position of
Lucernaria ; according to one—that of Lamarck—the genus
belongs to the Medusoid class, whilst according to the other,
adopted by Cuvier, it was deemed to be more appropriately
placed near the Actinie.

Lamarck placed the genus with the Siphonophorz and
Ctenophora, in his division of “ radiaires molasses” that is
to say, of anormal Radiata, though recognising, nevertheless,
its affinity with the “ radiares médusaires,” a view in which
F. Dujardin, in the second edition of Lamarck’s work, is dis-
posed strongly to agree, although he leaves the genus in
the place assigned to it by Lamarck.

In opposition to his great colleague at the Jardin des
Plantes, Cuvier held that the genus Lucernaria must be ap-
proximated to the Actinie, as Lamouroux had before said,
and formed out of it, together with Actinia and Zoanthus, his
first order, Acaléphes fives, in the class Acalephe. Latreille
was of the same opinion, and established an order of Radiata
—the Helianthoidea—of equivalent value to the Acalephz
and polypes, and including Lucernaria and Actinia.

The systematic place indicated by Cuvier met with univer-
sal assent ; and by nearly all writers, as Schweigger, Blainville,
Ehrenberg, Johnston, Van der Hoeven, Dana, Troschel,
Burmeister, &c., Lucernaria was considered to be closely
allied to Actinia, and both genera share the same fate in
further systematic arrangements, although some writers, as
Ehrenberg, Allman, Van der Hoeven, and Burmeister, re-
cognising its relations to the Meduse, have doubted the cor-
rectness of placing it amongst the Actinie.

Lucernaria was first removed from its place near Actiniz
when its structure became better known through the re-
searches of Sars, Frey and Leuckart, and Milne-Edwards, and
Leuckart placed it among the polypes, in a second order—
the Carycozoa, of equal value to the ANTHOzOa.

It would seem that Milne-Edwards and Jules Haime, quite

_

ON THE GENUS LUCERNARIA. 279

independently of Leuckart, decided upon separating Lucer-
naria entirely from the Actiniz, and divided their sub-class
Corallaria into three orders—Zoantharia, Aleyonaria, and
Podactinaria, the last consisting only of the genus Lucer-
naria. Milne- Edwards afterw ards, came still nearer to
Leuckart’s view, when he admitted only two sub-classes—
“ Cnidaires” and “ Podactinaires’’-—into his class Corallia,
and, as unhesitatingly as Leuckart, regarded the single genus
Lucernaria as equivalent to the whole of the Anthozoa.

As Cuvier’s views at first had gained general acceptance,
so those of Leuckart and Milne- Edwards were now adopted
by several authors, as Troschel, Bronn, &c., who recognised
the genus Lucernaria as the type of a distinct division among
the polyps, whilst Gegenbaur, strangely enough, placed it
im the order Octactiniz, in which, however, no previous sys-
tematist had ventured to put it.

Having thus pomted out the two places occupied in suc-
cession by Lucernaria mm systematic works, in one of which
we find it associated with Actinia, and in ‘the other to con-
stitute a division of the Corallide, we come to the third and
last phase in its systematic fate, in which we are carried back
almost to Lamarck’s view, and brought to recognise its affinity
with the Medusidee.

Lucernaria owes its new position to Huxley, by whom the
entire division of the Meduside is denominated Lucernaride ;
in this view he is fully supported by Reay Greene and
Allman, the latter recognising in Lucernaria a still closer
affinity with the naked- eyed” than with the covered-eyed
Medusze. Agassiz also places Lucernaria in a similar place
among the hydroid polypes, and remarks upon its similarity
more especially with a young Medusa; but in my opinion he
goes too far, when he compares it most : nearly to the Strobila-
form. This opinion with respect to the position of Lucer-
naria with respect to the Meduse has hitherto met with little
assent, and in no systematic work has this much-vexed genus
been placed in this, as it appears to me, true place. Schlegel,
in his ‘ Manual of Zoology,’ approaches nearest to its proper
position in placing Lucernaria amongst the hydroid polypes.

2. Systematic place.—From the description above given of
the structure of Lucernaria, it has been made clear how, in all
essential parts, this apparently so abnormal a genus corre-
sponds with the Meduse, and that a correct notion of its
form and the disposition of its organs may be arrived at when
it is regarded as a fixed and pedunculate Medusa-bud, in
which the stomach has been formed, and is open at the end,

280 ON THE GENUS LUCERNARIA.

but in which the radial canals still retain a very great width,
and are separated from each other only by narrow dissepi-
ments; which bud remains in this stage of development,
reaches maturity, and develops sexual organs along the course
of the radial canals.

With respect to its Medusoid resemblance, I could here
only repeat what has been laid down in many places in the
former sections, and will merely add that, in the points where
Lucernaria approaches the Meduse, it differs in the essential
parts from the Actinioid animals. In it, for mstance, we do
find neither the stomach hanging in the visceral cavity,
nor the reproductive organs seated on the free margins of the
septa, both points characteristic of the Anthozoa. Nor have
I been able to discern anything in its structure decidedly
polypoid, as stated by Leuckart, who, according to his as
yet unpublished researches, expresses a decided opinion in
favour of the affinity between his Calycozoa and the polyps.

The class Ceelenterata, which has everywhere met with the
warmest acceptation, and against which Agassiz alone has ex-
pressly declared himself, I would subdivide, as has also been
done by Leuckart and others, into three sub-classes—Antho-
zoa, Ctenophora, and Acalephe.

These three divisions may be distinguished by the structure
of the stomach; in Anthozoa it is suspended freely in the
cavity of the body, which is divided into chambers by radial
septa; in the Ctenophora, in which the construction of
the stomach bears most resemblance to that of the Anthozoa,
a canal system always exists, which conveys the products
of digestion throughout the body, and in Acalephe the
stomach either hangs freely down or is excavated in the sub-
stance of the body itself. The Ctenophora, which are usually,
-since Escholtz, placed amongst the Acalephze, are so essen-
tially separated from them by the microscopical structure of
their parts, and have so much resemblance to the Anthozoa,
that it is more proper to consider them as a group of the
Celenterata, equivalent to the Acalephz and Anthozoa.

Under the Acalephe I arrange, in the first place, the
Meduse, with the hydroid polyps which have been properly
grouped together as Hydrasmeduse ; and, as a second order,
the Siphonophore. To the Hydrasmeduse, at first sight,
belong very different creatures :—1, minute polyps, which
spht up into Medusz by the transverse division of their
upper part; 2, large polypidoms, some of which throw off
Medusa-like buds, while the propagation of others is carried
on by ova; and 3 and lastly, Meduse, which have almost always
originated as buds on polypes, though they are frequently

OT yee ot Oe ee ee

ON THE GENUS LUCERNARIA. 281

also developed directly from ova. All these forms, however,
are closely allied, as the numerous transitions between them
show; and however great may be the importance set by
nature in the higher-animals, on the processes of reproduc-
tion and development, this seems to be by no meaus the case
in the order of creatures we are considering ; and however
regularly the different stages of ovum, polyp, and Medusa,
may, in one form, be gone through, in another this regularity
is entirely wanting, and the animal often remains at the
polyp stage, and whilst in it becomes capable of repro-
duction; often also it entirely omits the polyp stage, and
emerges at once from the ovum in the form of a Medusa.
But all these diversities, as has been said, afford no ground
for systematic divisions, and since we find the Medusoid
generation to be subdivided into two forms, which were dis-
tinguished as far back as by Escholtz, and have been named
by Gegenbaur, the Acraspeda and Craspedota, so also can the
Hydrasmeduse in the same manner be divided into sub-
orders, to which the Lucernariadz are to be associated as a
third.

When we thus assign Lucernaria as a sub-order to the
order of the multiform Hydrasmeduse, all that is extra-
ordinary in its structure by degrees disappears. Since in this
order we find numerous Medusz originating immediately
from the ovum, and others which first bud out into a poly-
pidom, it is readily conceivable that there may also exist
forms exactly as in Lucernaria, iu which the Medusa remains
at the commencement of its development, but is capable, in
this conditiou, of reaching sexual maturity.

83. The genus Lucernaria and its species—Having thus
considered the structure and systematic position of Lucer-
naria, we may define the genus as follows:

Lucernaria, O. F. Miller, 1776.

An animal presenting the general structure of a Medusa,
having the form of a pedunculated bell. The peduncle dilated
at the base into a discoid expansion, by which the animal at-
taches itself. The margin of the bell produced into eight more
or less projecting arms, furnished with numerous tentacles,
and which arms are often arranged in four pairs. Four wide
radial canals, separated only by thin dissepiments, and com-
municating with each other at the border of the bell. Mouth
elongated into a quadrilateral oral tube. Internal tentacles
in the stomach. Sexual organs situated in eight tracts in

232 ON THE GENUS LUCERNARIA.

the walls of the natatory sac, corresponding to the eight
arms.

The genus is probably confined to the northern seas; and
in Europe the Channel, and in America Fundy Bay,
appear to be its southern limit. Quoy and Gaimard, it is
true, mention it as occurring at Toulon, but very vaguely,
and later observers have never met with Lucernaria in the
Mediterranean.

The species of the genus have hitherto remained in consi-
derable confusion, arising chiefly from the circumstance that
that first observed by O. Fabricius has been regarded as
identical with the one since described by J. Rathke under the
same name. But this is now well known not to be the case,
as I have satisfied myself, and as had previously heen stated
by Steenstrup and Sars.

1. Lucernaria quadricornis.
L. quadricornis, O. F. Miller; Gmelin; Lamouroux ;
Sars ; v. Carus, Milne-Edwards.
L. fascicularis, Fleming; Lamouroux; Ehrenb. ;
Johnston; Frey and Leuckart.

Char, Bell depressed, shorter than the stem. The elon-
gated arms united into pairs, separated only at their extremi-
ties, and each furnished with numerous (about 100) tentacles.
Reaches 70 mm. in size.

Hab. This, which is the largest of the known species,
occurs throughout the coasts of Norway, in the Cattegat and
Sound, also in North and South Greenland; on the east
coast of North America; Faroe and Shetland Islands.

Sars once noticed, among numerous specimens of L. quad-
ricornis, one with a marginal papilla between the four arms;
whether this may prove a new species, Dr. Keferstein does
not venture to decide.

2. L. auricula, O. Fabricius.
L. auricula, Gmelin; Sars; Steenstrup.

Bell deep, infundibuliform, subcylindrical, with eight small,

equidistant arms, between which are eight very minute mar-
ginal papille. Stem as long as or longer than the bell.
Length 40 mm.

This species has till quite recently been confounded with
others. Lamarck, Blainville, and Sars place it with L. quad-
ricornis, whilst J. Rathke, Montagu, Johnston, and Milne-
Edwards associate it with L. octoradiata.

;

)

ON THE GENUS LUCERNARIA. 283

Its distinction was first recognised by Steenstrup, and
afterwards by Sars.
Hab. Coasts of Norway; Greenland; Britain, &c.

3. L. octoradiata, Lamarck.
L. octoradiata, Lamarck; Steenstrup; Sars.
L. auricula, J. Rathke; Montagu; Sars; Johnston;
Milne- Edwards.

Bell rather deeply infundibuliform, with eight short, equi-
distant arms. Hight large marginal papille between the
arms. Stem equal in length to the depth of the bell.
Length 30 mm. :

This species has hitherto been confounded with L. auricula,
O. Fabric. ; for although Lamarck, who gave it the name of
octoradiata, regarded L. auricula, Fabr., as synonymous
with L. guadricornis, Miull., subsequent writers considered
his L. octoradiata as a synonym of L. auricula, Fabr.
Steenstrup was the first to clear away this great confusion.

Hab. Norway; British Channel, both sides; Holland ;
South Greenland, and the Faroe I[slands.

4. L. campanulata, Lamouroux.

L. auricula, Montagu; Milne-Edwards.

LL. campanulata, Lamouroux; Johnston; Milne-
Edwards.

L. octoradiata, Lamarck.

LL. convolvulus, Johnston.

L. tnauriculata, Owen.
pe Jules Haimes.

Bell rather deep, infundibuliform, with eight equidistant,
long arms. Stem scarcely as long as the bell is high, and
not containing any muscles. Length 45 mm.

Hab. Shores of the British Channel and south of England,
to which it appears to be confined.

This species, though accurately described by Lamouroux,
has been often confounded with L. octoradiata.

5. L. cyathiformis, Sars.
L. cyathiformis, Sars.
Depastrum cyathiforme, Gosse.
Carduella cyathiformis, Allman.
Calcinaria cyathiformis, Milne-Edwards.

Bell cup-shaped, expanded at the margin. Border circular,

284. ON THE GENUS LUCERNARIA.

not divided into eight arms, furnished throughout with ten-
tacles, which are, however, assembled into eight equidistant
groups. Stem equal in length to the height of the bell.
Sexual organs arranged together in pairs, not reaching to
the border of the cup. Length 15 mm.

From this species, which was originally described by Sars,
have been made the genera Depastrum, Gosse, Carduella,
Allman, and Calcinaria, Miine-Edwards, but it is here left
under Lucernaria, where it was originally placed by Sars, as
Dr. Keferstein is unable to find any essential distinction be-
tween it and the other species of the genus.

Hab. The coasts of Norway and England.

Closely allied to it is the following species :

6. L. stellifrons, Gosse (sp.).
Depastrum stellifrons, Gosse ; Allman.
‘3 cyathiforme, Gosse.

Bell cyathiform, constricted below the opening. Border
octangular; arms 0, but the tentacles are placed in eight
equidistant groups, between the angles of the border. Sexual
organs reaching the border. Stem as long as the bell.
Length a few millimétres.

This species was found by Gosse on the English coast, but
he confounded it with L. cyathiformis, and formed out of the
two his genus Depastrum. Soon afterwards, however, he
distinguished it from JL. cyathiformis, and named the new
species D. stellifrons. By Allman it was regarded as so
distinct as to induce him to make it the type of the genus
Depastrum, in contradistinction to Carduella, for which he
took L. cyathiformis as the type.

Remarks.

1. It may be mentioned that Professor Reay Greene is in-
clined to unite L. quadricornis, octoradiata, and campanulata,
with a single species, which he names L. typica, stating that
he has met with an intermediate form connecting these
three species. But it appears to the author, as it does to
Leuckart, to be not improbable that this intermediate form
is L. auricula, Fabr., which is readily and essentially distin-
guishable from the others, with respect to whose independence
the author agrees with Leuckart and Percival Wright in
considering that there can be no doubt.

2. Although Fabricius, under the name of Lwucernaria

EEE a

MECZNIKOW, ON THE VORTICELLA-STEM. 285

phrygia, describes an animal which, according to his descrip-
tion, has little similarity with Lucernaria, and of which he
himself remarks—“ De hujus genere etiamnum dubitans,
pro tempore Lucernaris associavi, in multis tamen hydris
affinem,” but which, nevertheless, has been included in many
works under Lucernaria. Blainville, it is true, remarks that
it cannot belong to the genus Lucernaria, but adding that it
cannot even be placed under the type of his Actinozoa. He
consequently makes of it a distinct genus, Candelabrum,
which he places among the Sipunculide.

Steenstrup, who, as has been stated, first made out from
the manuscripts of O. Fabricius his ZL. auricula, has at last
pointed out the true place of ZL. phrygia. According to him,
it is a colony of hydroid polypes, most nearly resembling the
genus Acaulis of Stimpson.

Researcues on the Nature of the VortIcELLA-STEM.
By Exias Meczntxow.*

THE question respecting the anatomical and chemical
structure of the lowest organisms possesses at the present
time a special interest from its relation to the discussions re-
garding the cell-theory, which have of late been carried on
so warmly. In order to throw some light upon this ques-
tion, the author, under the guidance of Professor Sezelkow,
undertook a series of researches respecting the behaviour of
some of the Infusoria towards various physical and chemical
reagents. These researches, however, being incomplete, he
has in the present paper confined himself to a portion of
them to which he had devoted more particular attention, viz.,
on the stem of Vorticella.

With regard to the nature of this organ, two principal
views have been for a long time entertained. According to
one of these, first enunciated by Ehrenberg,+ the central
streak in Vorticella is a muscle. Dujardin,{ on the other
hand, denied the muscular nature of this part. Both views
have found advocates. In favour of the former of them, we
have Eckhardt, Czermak, Leydig, Claparéde, Lachmann, and
Kithne. Eckhardt? confirms Ehrenberg’s view, and, more-

* ¢ Archiv. Anat.,’ 1863, p. 180.

t ‘Die Infusionsthierchen,’ &c., 1838, pp. 274, 279.

+ ‘Hist. Nat. des Infusoires,’ 1841, pp. 49, 50, and 547.
§ ‘ Archiv f. Naturgeschicte, 1846, i, pp. 217, 218.

286 MECZNIKOW, ON THE VORTICELLA-STEM.

over, points out a special connection between the shortening
and extension of the stem and the motions of the ciliary
apparatus, which is retracted on the shortening, and protruded
on the extension of the stem. Czermak* showed that the
streak itself was spiral, and that the shortening, of the stem
was effected by it. Leydig + even describes transverse lines
on the central streak of the Vorticelle—an appearance which
is regarded by him as a strong proof against the theory of
unicellular organisms. Claparéde and Lachmannt{ fully
agree with Czermak, and assert, besides, that the central
streak when retracted is lost sight of in the hinder part of
the body.

Among the opponents of this view may be named Dujardin,
Ecker, and Stein. The first thinks that the movements of
the stem do not depend upon the enclosed band, but upon
the external membrane ; but this was completely and correctly
disproved by Eckhardt. Ecker thus expresses himself re-
specting the nature of the stem: “ The contractile substance
of the body is continued into the stem, the form of which
part it consequently follows, but this band-like portion is
nevertheless not a muscle.” Stein,§ however, is the most
determined opponent of Hhrenberg’s view. This observer
denies the existence of transverse lines on the central band,
which were first described by Gleichen and afterwards by
Ehrenberg. Besides this, Stem subjected the Vorticelle to
the action of various substances, and found that the central
band exhibited the same reactions towards them as the in-
ternal parenchyma of the body itself; he thence concludes
that the stem is not identical with muscular tissue.

This was the state of the question before the publication
of Kiuhne’s || researches, by which this author was led to the
same conclusion as Ehrenberg and his followers. Kiihne
compared the effects of various physical and chemical re-
agents on the muscles of the frog and on the stem of Vorticelle,
and found them to be essentially the same in both cases.

The author having instituted some researches according to
Kiihne’s method, is desirous of communicating them, inas-
much as the results at which he has arrived differ widely
from those of Kiihne.

1. Klectricity.—The phenomena observed were as follows :

‘Zeitsch. f. wiss. Zool.,’ iv, p. 438.
‘Lehrb. d. Histologie, 1857, p. 183.
‘ Zeitsch. f. wiss. Zool.,’ i, p. 236 (uote).
§ ‘Die Infusionsthiere,’ 1854, pp. 78—S80; and ‘Der Organismus der
Tnfusionetineeee 1859, p. 54.
| ‘ Myologische Untersuchungen,’ 1860, p. 213—229.

itt ¥

—?_ ae oT ae

MECZNIKOW, ON THE VORTICELLA-STEM. 287

A weak induction-current has no effect on the Vorticelle ;*
but when the force of the current is increased up to a certain
point, its passage through the preparation caused the instan-
taneous contraction of all the stems; but even when the
current was maintained for some time, this position was not
long retained. The animalcule soon stretched itself out
again, and began its movements afresh. The force of the
current may now be increased considerably without any
change in the phenomena. But if a very powerful current
is applied, the Vorticellie, it is true, roll themselves up, but
they die almost immediately, as is shown by the circumstance
that on the breaking of the current the animalcules remain
perfectly still; and if the same strong current is kept up for
any length of time, the Vorticelle break up, as Kiihne very
truly states. It is to be remarked, moreover, that whilst
under the influence of the galvanic current, the anterior
ciliary apparatus always remains retracted, as stated by
Kiuhne.

2. Rhodankalium, a substance which, as is well known,
produces powerful EMESIS and sudden rigidity in muscle,
does not, from what the author has observed, even in a
tolerably ‘concentrated solution (0°3 grm. to 5 ce. water), pro-
duce any effect whatever on the movement of the stem of
Vorticella; nor are weaker solutions (0°38 grm. Rhodanka-
lim to 10, 15, 20 cub. cent. water) any more efficacious. It is

certainly very interesting to observe the length of time the
Vorticellze can live in these solutions, since all other Infu-
soria observed by the author, even the lowest (Monas), die
very speedily in them. But the Vorticelle, even after their
body has become quite deformed and angular by the action
of the solution, nevertheless still continue to move. This
observation was several times repeated by the author, and
always with the same result, although it is in direct contra-
diction to Kiihne’s assertion, that the stem of Vorticelle

contracts and becomes rigid in a solution of Rhodankalium.

3. Veratrine.—It is usually stated that Veratrine is in-
soluble in either cold or hot water, but this is not correct.
The author boiled, five times in succession, the same quan-
tity of Veratrine in distilled water, and the filtrate on each
occasion assumed a carmine-red colour on the addition of
concentrated sulphuric acid.

It is well known that Veratrine is a very powerful muscular
poison, inducing very speedy contractions and rigidity. A

* The species employed in all the experiments were /. convadlaria, Khr.,
and /. microstoma.

288 MECZNIKOW, ON THE VORTICELLA-STEM.

frog, into which a filtered, very bitter decoction of Veratrine
had been injected, soon died. Nothing of the kind takes
place when Infusoria are exposed to the same solution,
and numerous experiments have satisfied the author that
this poisonous agent has no effect whatever upon the life of
Infusoria. The stem of Vorticellz moves just as actively in
a solution of Veratrine as before its immersion, and the
whole behaviour of the animal presents nothing abnormal.
Kuhne describes the action of this poison quite otherwise.
He states that the Vorticelle are killed by it, and that the
stem contracts and becomes rigid—statements which the
author has been wholly unable to confirm.

4.. Hydrochloric acid.—According to Kihne, a solution of
this acid containing ;1,th part induces speedy contractions
and rigidity in the stem, succeeded by its solution. But
this statement the author is not able to confirm any more
than he is the preceding. In his experiments he employed
a solution of the same strength as that used by Kiihne, and
observed the following results :—At first the stem is moved
with some rapidity ; but the movement gradually becomes
slower and slower, and at last ceases altogether. The same
phenomena are manifested also when much stronger solutions
are employed (3 drops in 5—10 cub. cent. of water).

5. Common salt——Concentrated solutions of this salt im-
mediately kill all Infusoria; weaker ones act less energetically,
the Infusoria dying more slowly. A solution containing half
part of salt per cent. had no effect whatever upon the stem.

6. Chromic acid.—According to Kiihne, this acid causes
muscle to contract. In the stem of Vorticelle, a solution
containing two parts in the hundred causes sudden contrac-
tion, and extension never again takes place, although the
body of the Vorticella continues to live. This contraction,
however, cannot be attributed to the property possessed by
chromic acid of coagulating albumen, since other substances
possessing the same property (alcohol, acetate of lead) have
not the same effect.

7. Bile.—The sudden application of bile kills and dissolves
all Infusoria; whilst a slower one allows them to die more
slowly. But bile has no irritant effect upon the stem of
Vorticella, although in the frog’s muscle its application is
followed by contraction and shrivelling up.* Diluted bile
has no effect whatever on the movements of the stem.

8. Sulphate of copper.—Solutions of this salt of any strength
cause the most powerful contraction in muscle; but im the
stem of Vorticella even concentrated solutions lave no effect.

* Kine, op. cit., p. 24.

ae = Ot ee

MECZNIKOW, ON THE VORTICELLA-STEM. 289

The stem, in fact, even when the body of the Vorticella is
wholly contracted and wrinkled, still exhibits movements.

9. Caustic potass.—The sudden application of a solution of
potass containing not more than one part in a hundred
instantly kills all Infusoria; its more gradual application is
followed by less rapid decease. It has no effect whatever on
the stem of Vorticella, although in muscle it produces con-
tractions.

10. Curara.—With respect to this substance the author
fully confirms, from long-continued observation of his own,
Kihne’s statement that it has no effect on the stem of Vor-
ticelle. This fact appears the more interesting when we find
that the poison is not without influence upon the body of the
animal, as may be seen in the circumstance that the anterior
ciliary apparatus always remains retracted under it.

When the action of the various reagents employed by the
author is considered, it must be allowed, he says, that, at any
rate, we have no right at once to identify the mobile element
in the Vorticella-stem with a muscle, as many have done;
and this view is the further supported by the fact that the
stem presents no property of double refraction im polarized
light, as repeated observations have shown. He, more-
over, takes the opportunity of remarking that he was as unable
as was Kiihne to confirm Leydig’s statement respecting the
transverse striation of the stem. ‘‘When it is examined,” he
says, ‘‘ with a power of 1000 diameters (Ocular No. 4; and
system No. 9, & immersion, of Hartnack) no doubt can be
entertained as to its homogeneity and as to the non-existence
of transverse striation.”

REVIEWS.

Porutar Puystotocy.—l. A Manual of Animal Physiology,
for the use of Non-medical Students. By Joun Suwa,
M.D. London: Churchill.—2. 4 Manual of Popular
Physiology; being an attempt to explain the Science of
Life in Intellectual Language. By Henry Lawson, M.D.
London: Hardwicke.

Tue publication of two manuals almost simultaneously,
devoted to the subject of physiology and for the instruction
of unprofessional persons, is certainly a:subject for congratu-
lation. Of all the departments of human knowledge which
the recent progress of natural science has systematised and
made available for the practical use of mankind, physiology
is undoubtedly the most important. It deals with the facts
and laws of life—than a knowledge of which there is nothing
more important to man. Just as he has gained a knowledge
of the conditions that influence his life, has he become more
civilised, more healthy, more moral, and more religious. In
utter ignorance of the laws of life no man can live. The
facts with which he becomes instinctively acquainted serve
him, in his barbarous and civilised state, to maintain his
existence and even increase his race; but it is in those con-
ditions of society where men are taught those laws of life
which are the result of sufficient investigation, that we can
alone anticipate the healthiest existence and the highest
moral and religious development. It has been only within
the present century that physiology, by embracing the sta-
tistics of life and death in large communities of men, and
tracing minutely, with the aid of the microscope, the minute
details of the changes which go on in the system to produce
these grand results, has been in a position to claim the atten-
tion of man. It now comes forth with an authority which
ought to compel its principles to be listened to and its pre-
cepts to be taught to all who have an interest in health and
life. We would here especially suggest to those who are en-

SHEA AND LAWSON, ON POPULAR PHYSIOLOGY. 291

gaged in microscopic investigations into the nature of those
changes which go on in the tissues of the body, that they
should make the knowledge they thus gain as practical as
possible. Let them not be satisfied with the beauty or the
interest of minute vital changes, but let them strive to con-
nect them with the great laws of life by which the population
of the world is maintained and human health and happiness
secured. Microscopical research is not an end, and the mi-
croscope is only an instrument to help the eye to investigate
the more minute phenomena of matter, in whatever form it
presents itself. Of all the practical directions in which a
fondness for microscopic rescarch may be made available
for the benefit of the individual who makes it, and for the
circle in which he moves, is that of striving to understand the
laws which regulate the healthful existence of his own body.
The man who acquires any kind of knowledge at the expense
of health has made a poor exchange, and the highest use to
which human knowledge can be applied is to gain good health
and length of days. As introductions to a knowledge of the
great laws of life which are already known, we can recommend
the manuals named above They differ in matter and style,
but they have the same object in view. Dr. Shea’s is a plain,
straightforward account of the phenomena of life, and is the
result of much reading and reflection; Dr. Lawson is much
more discursive, does not hesitate to introduce his own views
of phenomena, and endeavours to amuse whilst he instructs.
If we were asked for what class of readers they are adapted,
we should say that Dr. Shea’s manual was best adapted for
a class, whilst Dr. Lawson’s would be found more available
for private reading and self-instruction. “ve will, however,
endeavour to give our readers an idea of these useful little
books by extracts from those portions of the books which
treat of microscopical subjects. We first give an extract
from Dr. Shea’s account of the blood.

“ Bioop-corpuscLes.—T wo varieties of corpuscles exist, red and
white. As seen under the microscope, they are flattened cells, of a cir-
cular form, the red presenting either a bright or dark central spot, as
they are brought in and out of focus.

“* Red corpuscles are present in large numbers in the blood; their dia-
meter varies from 3;th to z,th of an inch, and their thickness is about
tomoth of an inch. When examined singly they appear almost colour-
less, and it is only when viewed in numbers that they exhibit the florid
colour.

“White corpuscles are much less numerous than the red, not more than
one white to fifty coloured being present in human blood. As a rule,
their diameter is greater than that of the red corpuscles, and may be
estimated at 535th of an inch. The form and appearance of the cor-
puscles, both red and white, varies greatly, according to the character of

VOL. III.—-NEW SER. x

292 SHEA AND LAWSON, ON POPULAR PHYSIOLOGY.

the liquid in which they float. The colour uf the blood may even be
altered by a change of form in the corpuscles. Thus it is probable that
the difference in colour of arterial and venous blood depends on an
altered form of the corpuscles contained. When subject to the action
of water, corpuscles swell, become convex, or even round, and may at
length burst.

“With regard to the structure of red blood-corpuscles, they may be
considered to be cells, provided with an elastic cell-wall, enclosing appa-
rently homogeneous contents impregnated with red colouring matter,
called hematine. The white corpuscles, however, seem to contain gra-
nular matter, the cell-wall being scarcely ever visible unless the cor-
puscles are treated with water or diluted acid, when the cell becomes
distended, and the wall separated from the enclosed matter.

“If the minute vessels in the web of a frog’s foot are examined, both
varieties of blood-corpuscles will be seen hurrying along in the current
of the blood, the red moving rapidly in the centre of the stream, the
white passing more slowly along the sides of the vessels.

«The functions served by the blood-cells have not been determined,
nor has it been ascertained how or where they are formed. The most
probable source of their origin is, that they are formed from the chyle
and lymph corpuscles poured into the blood from the thoracic duct; as in
the general current of the blood, corpuscles in intermediate stages of
development are always found, and indeed, occasionally the fluid in the
thoracic duct has a red tinge, supposed to be due to the commencing
development of hematine in the interior of the chyle-corpuscles. Doubt-
less the blood-cells are continually undergoing decay, whilst others are
being generated to supply their place; and most likely they are derived
in the manner just noticed, for they are proved not to be developed by
fission of the pre-existing corpuscles.

“Chemically, the blood may be regarded as an alkaline fluid, com-
posed principally of water, containing a certain amount of solid matter.
Amongst the more important components of the solid matter, haematine
may be mentioned. It is stated to contain iron, and is found mixed with
globuline, the compound being termed eruor.

Chemical Composition of the Blood.

CWater ... 0.7000 20.78 See ee eee 795
Hematine... 8
Blood 4 (Corpuscles ... Globulin ... 140
Tron ee i

(Solid matter ...... J Wibrine \J/0:.0.)332g533s, nese 2

A Meme + obs Bee 40

Bay We St aN eee 2

| anes. Be ae Sock ance §

| Extractive ‘matter ............ a

~
i=)
So
oO

“The difference between venous and arterial blood, as regards colour,
has been already noticed; but other differences exist; thus, in the arte-
rial fluid there is less albumen and more fibrine than in the venous.
Moreover, the specific gravity is lower, the amount of red corpuscles

eg and probably, the proportion of oxygen larger in the arterial
ood.

SHEA AND LAWSON, ON POPULAR PHYSIOLOGY. 293

“ The quantity of blood in the body.—The precise determination of this
point is difficult. It has been found that if numerous vessels in the body
of an animal are opened, and the blood permitted to pour from them, a

Piles or rouleaus of red corpus-
cles, exhibiting a peculiar ten-
dency that these corpuscles pos- Blood-corpuscles: a and 4, the two different
sess of running together and ad- t appearances of red corpuscles.
hering by their broad surfaces.

large quantity can be collected. In this manner it has been estimated
that the weight of the blood is to that of the body:

As 1] to 12 in an ox.
» 1 to 18 ina horse.
», 1 to 16 ina dog.

These data can only be an approximation to the truth; for however
freely the vessels are opened and the blood permitted to flow, still a large
quantity must remain in the body. Nor can such an experiment be
made on the human subject, except, indeed, in cases of execution. It is
stated that as much as 24 lbs. of blood were taken from a decapitated
female. Applying the results of experiments on other animals to the
human body, it appears that the amount of blood contained may be
estimated at 18 lbs. to 20 lbs.”

We now give an extract from Dr. Lawson’s account of the
cilia :

“ The larger bronchial tubes are lined on the inside by a beautiful deli-
cate down, soft as velvet, of which I have just placed a portion under
the microscope ; and what a pretty sight is presented—a field of corn in
miniature! This down is formed by an almost infinite number of ex-
tremely minute, hair-like filaments, resting on club-shaped projections,

Fig. 40.—A portion of the lining membrane of the
Windpipe, showing the Cilia. a, the club-shaped cells;
b, particles of matter; c, the Cilia—The arrows indicate
the direction of the currents.

d perpetually moving in one direction, giving exactly that appearance
to the eye which is produced by a meadow swayed in gentle undulating
curves by the action of the wind (vide fig. 40). I now drop a small

294 DR. CHAMBERS, ON MUCUS AND PUS.

quantity of a solution of potash upon the specimen, and I have a “ dis-
solving view ” produced, for the elegant little filaments (cilia) have van-
ished.

Surely, these exquisite organisms are not without a purpose! There
must be sowe office which they fulfil.

“Oh, happy living things! No tongue
Their beauty might declare :
A spring of love gushed from my heart,
And I blessed them unaware.”

The cilia always move in one direction, and in the bronchial tubes this
is toward the windpipe—upwards. Hence all particles of dust, all sorts
of materials in a finely powdered state, which may be accidentally sucked
in during respiration, are prevented descending into and accumulating
in the air-cells by the influence of these cilia. A small, almost atomic,
portion of road dust we often draw into the lungs on a blustry summer’s
day, but it effects no injury, for it hardly has got in before the cilia “ take
it in hand,” and it is sent back again from one to the other till it has
reached the mouth.

“Were it not for this grand provision, all the millers and stonecutters
would be exterminated in a very short period. Even as it is, they do
meet their death sooner than other folk, because of the inability of the
cilia to prevent all the particles entering. A more energetic atom than
usual will elude their vigilance and slip down occasionally, and this being
oft repeated, the collected matter sets inflammation and other morbid
processes agoing, which end in the extinction of life. The bronchial
tubes and windpipe are composed of a kind of gristle or cartilage, mixed
with tissue of sinewy description; and in addition to these there are a
few fibres of muscular tissue (flesh). These muscular filaments can
hardly be seen, but a very ingenious experiment has shown us their
existence. Muscle always contracts when galvanized, and therefore if a
galvanic shock causes the lung tissue to contract, it probably contains
muscle. An English physiologist having dissected out the lung and
bronchial tubes of an animal, placed the entire organ so that the opening
of the windpipe was opposite the flame of a candle; next he applied the
wires of the galvanic battery to the lung, and he heard the air rush out,
and saw the candle extinguished.”

With these extracts we must conclude our notice of these
manuals, commending them to the notice of all who are
anxious to acquire or spread a knowledge of the first prin-
ciples of physiology.

Three Lectures on the Formation of Mucus and Pus, being
the Lumleian Lectures of the Royal College of Physicians.
By Dr. T. K. Cuamsers.

Tue Lumleian lectures have this year been delivered by
Dr. Chambers, the subject chosen being the formation of
mucus and pus. The use of the microscope is of course
essential in researches such as those which Dr. Chambers

DR. CHAMBERS, ON MUCUS AND PUS. 295

details, and we therefore give a brief abstract of the lectures
taken from the report of our contemporary, the Lancet. “ A
physiological fellow of our college,” says Dr. Chambers,
“was in the habit of regarding his patients as so many
‘mucous membranes.’”? The term was no exaggeration, for
to the medical man the mucous membrane is all-important.
Most of the drugs administered to his patients act on it,
and all are introduced through it. The business of mucous
membrane is to offer a passage for oxygen, water, fat, albu-
men, and other nutrimentary substances, and to defend the
less easily renewed tissues beneath it, from the deleterious
action of external agents. These functions are performed best
when it is bedewed with a moderate watery exhalation, and
not with mucus. It must not be supposed that the secretion
of mucus is the special function of a mucous membrane ;
in fact, the membrane is most active when there is least
mucus. The secretion which usually moistens its surface,
possesses nothing of that stringy adherent character by
which we recognise mucus. It is transparent and watery,
and contains the epithelial scales shed from the surface.
Shed epithelia are found also in mucus, but not as a peculiar
characteristic. Its most obvious characteristic is the pre-
sence of transparent viscid bodies of an oval form, and with
one or more nuclei in their interior; the fluid in which
these are placed seems to be that whence the peculiar con-
sistence and adhesiveness of the mucus is derived. This seems
to be the case, since oval globules similar to those of mucus
constitute the bulk also of pus, which has entirely distinct
attributes and properties. Professor Henle’s view with
regard to these globules seems very plausible. He considers
them as young epithelia, prematurely moulted from the
body. The condition which produces them is an arrest of
development. The peculiar structure of epidermal tissue is
well known, consisting of cells flattened externally by pressure,
and rounder, looser, and more globular as they approach the
inner surface. This is the structure of both the scarf-skin
and mucous membrane; the former covering the whole
external superficies of the body, the latter acting as a pro-
tection for the surfaces of the various internal viscera and
canals. The “ mucous globules,’ of which mention has been
made, appear to be the young epithelial cells, and may be
seen by removing the external layer of scales more advanced
in development. They are exactly identical with the inner
strata of the epidermis, the rete mucosum of Malpigh. Dr.
Chambers gives a very minute account of the development of
these epithelial cells. He says:

296 DR. CHAMBERS, ON MUCUS AND PUS.

“The appearance they have is that of all matter when it first puts
on life. ‘The telescope and the microscope equally reveal to us these
nebule as the earliest indication of vitality, drawing the surrounding
chaos towards a central point, then exhibiting that central point as a
kernel or nucleus. And then this kernel becomes the parent of new
centres, individual and separate, and these again starting places of new
action. The dawn of vitality is exhibited in the coalescence of molecules
of organic matter so as to form nuclei, which, under favorable cirecum-
stances, develop either separate cells or tissues.

“Up to this point each focus of life seems to be a separate individual.
It takes in nourishment by its innate power from without; it increases
in size and alters in shape. And this alteration in shape seems prin-
cipally to take place from within. It is not merely an aggregation out-
side of new molecules, but a plastic change of internal appearance. Nay,
more—it possesses the faculty of giving birth to an individual, and so to
a succession of individuals, like itself. No better evidence of automatic
existence can probably be given.

“ These phenomena can be seen without much difficulty in the globules
of mucus. That which answers best is what we often expectorate in
little semi-transparent gelatinous lumps from the bronchi in the morning
after exposure to night air. This must not be mixed with water or
be allowed to cool, but kept at the temperature of the body, and put
immediately under a lens of as high a power as you can command. Dr.
Beale showed me the phenomena first under a 24th, but I have seen
them very well under an 8th inch in an old-fashioned Powel’s microscope.
Keep your eye fixed on one nuclear mass, and you will often see a
gradual change in its appearance. First a clearer nucleus appears in it ;
then, as you gaze, two, three, or more smaller nuclei. Then the fine
granular speck into its sides coalesce into a nucleus. Then you see that
it has a bulge in its side, and that a nucleus forms a bud, and then has
a constricted neck or stalk. And then, perhaps, if you are lucky enough
to get the mucus in motion without losing sight of your object, the bud
may float off as a separate globule. Or the whole globule may divide into
two each with a separate nucleus.

e
o
20,0000,%

°
°
o
@,

“ A temperature below that of the body seems to check this develop-
ment, but you may often keep it on by means of a spirit-lamp. The
globules in which I have seen it take place are those from the trachea,
from the os uteri, and from warm freshly-passed urine in cases of in-
flamed bladder.

“When the fluid has got dried up by the heat thus constantly applied,
you may in some degree restore its activity by moistening it with a
viscid animal fluid, such as saliva. The greater part, indeed, is broken
up into molecules, and these show no disposition to unite into globules,
but among them will remain some globules unbroken, and these will
again form new nuclei, and bud as they did at first.”

DR. CHAMBERS, ON MUCUS AND PUS. 297

“Each of the globules appears to be a centre of life, mto
which nourishment passes from the outside, and enables them
to increase in number.” ‘“ Mucus,” says the lecturer, ‘‘ may
be regarded as a parasite, receiving from the body its nutri-
ment indeed, but not its form nor its claim to vitality.”

.The similar globules forming the bulk of pus are, when in
freshly secreted matter of all shapes and sizes irregular,
budding, with or without nuclei; but in that which has been
secreted some time, the globules are nearly all of one size,
even, and spherical. This seems to indicate a general change
of form by time—a certain completion of creation in that
which has been the longest formed. The growth of these
globules is not, m Dr. Chambers’ opinion, comparable with
that of ordinary cells ; for some of the buds spoken of are
not derivatives from the central nuclei, but new starting
points of growth. He, therefore, considers the globules
themselves as nuclei, or rather composed of nuclear matter.
Dr. Beale has shown that when tissues are steeped in a
solution of carmine, the nuclei or young growing matter in
them are the only parts which receive a per manent. stain.
Now, the entire mass of the mucous globules receives a
permanent stain from carmine, and they appear, therefore,
to be equivalent to the nuclear matter of ordinary cells.
The question now arises as to how these mucous globules make
their way to to the surface of the membrane, where they are
found. They are developed beneath the epithelium, whereas,
when we find them, they are quite uncovered. Dr. Buhl,
of Munich, has shown that they undergo a modification, and
pass through the epithelium. He has seen them in transitu.
Dr. Chambers suggests that these bodies may want the
solidity they appear to possess, and yet have a definite shape
and form, and considers it at least an open question, whether
both epithelial scales and elementary globules may not
possess rather the properties we attribute to fluids. The
observations of Henle, Rindfleisch, and others, Dr. Chambers
remarks, ‘seem to show that the pus or mucus globule on
mucous membranes is the material of young or “renovated
epithelial cells, arrested in its development ‘at the earliest
dawn of life, before it has assumed the form of a cell, when
it is as unlike its destined final form: as an egg is to a
chicken. They seem to show that in this state it may be
thrown directly off by the epithelium being broken, or it
may pass into the substance of the epithelium. In either
ease it does not part with the low degree of life it has ac-
quired ; but neither does it acquire a higher degree; it goes
on propagating, but nothing more.” Bubl’s observations

298 DR. CHAMBERS, ON MUCUS AND PUS.

differ from those of Rindfleisch in this particular. Buhl
contends that the epithelial cells increase by simple division.
Rindfleisch asserts that he has watched a process going on
analogous to that of yelk division. It appears that both
may be right.

In his third lecture, Dr. Chambers treats of the chemical
nature of pus compared with that of mucus, and enters into
some details as to the production of pus under inflammation,
and the various external agents which may affect the mucous
membrane. He also makes some very able remarks upon
the manner in which various drugs act beneficially in certain
diseases through the mucous membrane. Some of Dr.
Chambers’ speculations are certainly wild, and he frequently
clokes a very simple and obvious fact under a multitude of
words ; nor have the lectures the merit of much originality,
being more a summary of what. has been done on the sub-
ject than anything else: but, on the whole, they are well
worth the attention of physiologists and pathologists, and
will prove a useful addition to the English literature of the
subject,

re

NOTES AND CORRESPONDENCE.

Sunlight Illumination of Diatoms.—Dr. Maddox (whose skill
and success in obtaining micro-photographs is well known)
remarks, in a letter to me, dated 28th July, “I have seen in
the photograph what I never saw in the object with the most
careful illumination.”” Some years ago, in one of my com-
munications to the Society, “On obtaining Photographs of
Microscopic Objects,” I mentioned the very peculiar distinct-
ness with which markings on test-objects were shown on the
screen, and expressed my opinion that the photographs might
aid in determining their structure. Dr. Maddox’s remark
having revived this impression, I placed my microscope in
strong sunlight—illuminated the object with the concave
mirror and an achromatic condenser of large aperture. As
a consequence, the illumination was so intense that no object
could be looked at directly through the microscope, as the
eye would not endure the hght for an instant. To look for
markings was precisely hke attempting to discern spots on
the sun’s disc through a telescope without the protection of
sun-glasses; but by taking the red and green glasses off my
sextant (which, combined, gave a pleasant neutral tint to the
sun), and laying them on the caps of the eye-pieces, the light
was toned down to just the right pitch, and the markings on
all the most difficult tests were easily and quickly brought out
with remarkable distinctness. In objects of extreme difficulty
the parabolic dispenser may be employed, directing the sun-
light with the plane mirror. With the achromatic condenser
and direct sunlight, the sap circulation in Anacharis is beau-
tifully shown.

I feel that some apology is due for the smallness of this
announcement, but as many who use the most costly micro-
scopes and apparatus appear to use them principally for the
purpose of displaying the markings on the most difficult tests,
to these anything should be welcome that will aid in stimn-
lating or coaxing an expression into the reluctant aspect of

300 MEMORANDA.

their favorite objects, and who can easily contrive arrange-
ments for holding glasses of various shades and colours.

In.many instances, with artificial illumination, the best
effect would be obtained by throwing the most intense light
possible on the object; but in this case the light fatigues the
eye and destroys its sensitiveness. It is then usual either to
lower the achromatic condenser, or to employ a lamp with a
blue shade; but by placing a light moderator of coloured
glasses over the eye-piece, the object may be examined with
the strongest light obtainable—F. H. Wrnuam.

On Coloured Illumination—Since Mr. Wenham called my
attention, a few days past, to the employment of strong
sunlight passed through an achromatic condenser, behind
the object, and coloured glasses over the eye-piece, in
the examination of various objects, the markings of which
under the ordinary method of illumination are somewhat in-
distinct, I have made a few trials with such colours as were
to hand. ‘They were not of a sufficiently extended character
to enable me to say in what particular class of objects the
method may be found most useful, therefore these remarks
may prove of very little value.

The external contour of many pale objects appeared more
defined; in insect structures the internal parts were more
distinct, with bolder shades giving contrast relief to the
other parts. It appeared requisite to seek the coloured glass
most useful to-appropriate, what I would call, the false light,
otherwise in many objects it did not offer anything striking.
The coloured glasses tried were light orange, medium or
rather blue, intense green, intense neutral tint, and carbuncle
red. They werevariously arranged. The first two, used together,
gave a very pleasant tint to the field, but I do not think they
were of sufficient intensity to permit of long employment
without fatigue to the eye. Many of the diatoms gave their
interstructural lines very distinctly. Intense green alone had
a fine effect in Aulacodiscus, Arachnoidiscus, Heliopelta,
cotton-fibre of Zostera, &c. Deep neutral tint appeared
useful in the examination of the paler kinds of Acari, the
orange colour gave to the deeper coloured Acari a depth in
their structural parts. The carbuncle red scarcely permitted
any structures to be seen. The same glasses placed behind
the condenser, also behind the object, were not equal in
effect to when placed over the eye-piece. The neutral tint,
however, seemed to throw up some structures with more defi-

MEMORANDA. 301

nition when behind the slide. Over the prism in the camera
lucida, the image of many objects appeared very strongly ;
the pencil indistinct. The more or less translucent structures,
as the feet and claws of Acari, had considerable boldness,
and the foreshortening in the claws was more marked. Pos-
sibly many of these variations may be due to the nature of
the glass employed in the slide and objective, also of the
medium in which the object was mounted, and might there-
fore relate to these as well as to the objects themselves.

Having much used sunlight concentrated by a prism and
condenser in photomicrography, I consider the use of coloured
glasses over the eye-piece with sunlight will render service in
cases of doubtful structure. Sunlight with the parabola was
employed by the Rev. Mr. Osborne in his examination of
Closterium Lunula, ‘Mic. Journ.” No. VIII. Mr. Jabez
Hogg, in the third edition of his work on the ‘ Use of the
Microscope,’ says in examining the same object: ‘ Strong
dayhght should be transmitted through coloured glasses pro-
posed by Mr. Rainey, and adapted to 41-inch condenser, using
4 objective.” I expect an equal if not a better effect would be
found by using sunlight and coloured glasses over the eye-
piece, as suggested by Mr. Wenham. I was not able to suc-
cessfully use the parabola for producing photograph nega-
tives.—R. Mappox.

Method of Dry-mounting Entomological and other Objects.—
Have ready a number of rings punched from thin gutta
percha, supported on lead, folded in thin paper, to prevent
“jagged” edges. Place the specimen on the slide, then the
ring, the specimen being in the centre; then place a round
cover on the ring, taking care to centre it to the round
opening. Steady the cover by means of a needle, and apply
a gentle heat beneath the shde. The gutta percha will be-
come transparent, and a gentle circular pressure applied by
the needle will cause both glasses to adhere. Allow the
slide to cool, and afterwards remove the superfluous gutta
percha with a penknife. The edge of the cover must then
be cemented with varnish, applied in very small quantity at
first. A second coating will complete the preparation.—
Tuomas SuHarMan Ratpeu, Melbourne, Australia.

PROCEEDINGS OF SOCIETIES.

Roya Soctety.

May 7, 1863.

On the Structure of the so-called Apotar, Unipouar, and
Brrorar NeERVE-cELLS of the Frog. By Lions, Beats,
M.B., F.R.S., F.R.C.P., Professor of Physiology and of
General and Morbid anatomy in King’s College, London,
and Physician to King’s College Hospital.

( Abstract.)

Tue author adverts to the opinion generally received with
regard to the existence of apolar, unipolar, bipolar, and
multipolar nerve-cells, and observes that if cells having such
very different relations to the nerve-fibres they are supposed
to influence, as apolar, unipolar, and multipolar cells, do
actually exist, as many different kinds of action must be
admitted. For it is hardly likely that a nerve-cell uncon-
nected with any fibre can affect the fibres at a distance from
it im the same way as a cell acts upon fibres which are in
structural continuity with it. Neither is it probable that a
cell with but one fibre proceeding from it can constitute an
organ which acts upon the same principle as the cell from
which two or more fibres proceed. If no fibre, or but one
fibre proceeds from certain cells, the formation of complete
nervous circuits, at least in these instances, is impossible ;
and if it be admitted that circuits do not exist in every case,
a strong argument is advanced against the existence of such
complete circuits as a necessary or fundamental condition of
a complete nervous apparatus. But if it can be shown, on
the other hand, as the author maintains is the case, that all
the supposed apolar and unipolar cells have at least two
fibres proceeding from them, the fact must be accepted in

°
PROCEEDINGS OF SOCIETIES. 303

favour of the view that such complete circuits may exist,
while the fact that the fibres connected with many cells have
been seen to proceed in opposite directions some distance
after leaving the cell, is a very strong argument in favour of
such general inference, and at the same time an explanation
of many arrangements which are observed constantly in
connection with nerve-fibres in various tissues.

Many observers have described apolar and unipolar cells
in ganglia in different parts of the frog. The author, on the
other hand, has failed to discover any apolar or unipolar cells
in this or in any other animal, and considers that the apparent
absence of fibres, and the presence of one fibre only in con-
nection with a cell, result from the defective modes of
preparation generally employed. He maintains that every
nerve-cell, central or peripheral, has at least two fibres
proceeding from it.* In many cases he has demonstrated
that these fibres pursue opposite directions, and he considers
that such an arrangement is general, and therefore necessary.
The author considers himself justified in drawing the follow-
ing conclusions from observations he has made during the
last three years :

lst. That in all cases nerve-fibres are in bodily connection
with the cell or cells which influence them, and this from the
earliest period of their formation.

2nd. That there are no apolar cells, and no unipolar cells,
in any part of any nervous system.

3rd. That every nerve-cell, central or peripheral, has at
least two fibres im connection with it.

Though the present inquiry is limited to the structure of
the particular cells connected with the ganglia in different
parts of the frog, the author has studied the arrangement of
nerve-cells and nerve-fibres in nervous centres, as well as at
their peripheral distribution, in many different animals.

* The word “cell” is only used in a general sense, as being shorter and
more convenient than ‘‘ elementary part.” It consists merely of, lst, mat-
ter in a living, active state (germinal matter), and 2nd, matter resulting from
changes occurring in this (formed material). In Pl. XIII, what is ordi-
narily termed “nucleus” and “nucleolus” of the nerve-fibre consists of
germinal or living matter, while the matter at the lower part of the cell and
the nerve-fibres are formed material. A nerve-fibre cannot produce a new
nerve-fibre, but the “nucleus” or germinal matter of a nerve-fibre can pro-
duce new nerve-fibre. The formed matter never produces matter like itself.
Germinal matter can produce matter like itself, and from this formed mate-
rial may result.

504 PROCEEDINGS OF SOCIETIES.

1. General description of the ganglion-cells connected with the
sympathetic and other nerves of the frog.

The general form of these cells is oval or spherical ; but
the most perfectly formed ganglion-cell is more or less pear
or balloon-shaped im its general outline, and by its narrow
extremity is continuous with nerve-fibres which may be
followed into trunks.

The figure represents a well-formed ganglion-cell from a
ganglion close to one of the large lumbar nerves of the little
green tree frog (Hyla arborea). The substance of the cell
consists of a more or less granular material, which by the
slow action of acetic acid becomes decomposed, oil-globules
being gradually set free. Near the fundus or rounded end
is seen the very large circular nucleus with its nucleolus.
In some of these cells, at about the central part or a little
higher, are a number of oval nuclei, some of which are in
connection with fibres. The matter of which the mass of the
cell consists gradually diminishes in diameter, and contracts
so as to form a fibre, in which a nucleus is often seen. At
the circumference of the cell, about its middle, the material
seems gradually to assume the form of fibres, which contain
numerous nuclei, and these pass around the first fibre in a
spiral manner. Thus in the fully formed cell a fibre comes
from the centre of the cell (straight fibre), and one or more
fibres (spiral fibres) proceed from its surface. These points
are represented in fig. 16, Pl. IX, Vol. XI, ‘Transactions of
Microscopical Society.’ *

2. On the formation of ganglion-cells in the fully
formed frog.

The subject is arranged under the three following heads,
but as it would not be intelligible without figures, it will not
be given in abstract. The development of these cells and
many other structures may be studied in the fully formed
animal as well as in the embryo.

a. Ganglion-cells developed from a nucleated granular
mass like that which forms the early condition of all tissues.

b. Ganglion-cells formed by the division or splittmg up of
a mass like a single ganglion-cell.

c. Ganglion-cells formed by changes occurring in what
appears to be the nucleus of a nerve-fibre.

* The specimen from which this drawing was taken has been seen by
many observers.

PROCEEDINGS OF SOCIETIES. 305

3. Further changes in the ganglion-cell after its formation.

Under this head the movement of the cell from the point
where its growth commenced is described. It is shown that
the two fibres, which at first seem to come from opposite
extremities of the cell, lie parallel to each other. They
increase in length, and subsequently one is seen to be twisted
round the other, as shown in the figure. Sometimes the
fibres below the point where the spiral arrangement exists
run parallel for a long distance, but at length pursue oppo-
site directions. The author considers that the formation of
the ganglion-cell commenced at the poimt where the fibres
diverge, and that subsequently the cell moved away,—the
parallel fibres, which at length become straight and spiral,
being gradually formed or drawn out as it were from the
cell.

4. Of the spiral fibre of the fully formed ganghon-cell.

The spiral fibre or fibres can be shown to be continuous
with the material of which the body of the cell is composed,
as well as the straight fibre, but the former are connected
with its surface, while the latter proceeds from the deeper
and more central part of its substance.

There are many nuclei in connection with the spiral fibre,
and several nuclei of the same character imbedded in the
substance of the mass of which the cell is composed. ‘These
latter nuclei seem to be connected with an earlier condition
of the matter which becomes, when more condensed, spiral
fibre. A great difference is observed with regard to the
extent of the spiral fibre in cells of different ages. In the
youngest cells the fibres near the cell are both parallel to
each other, but as the cell grows one is seen to be coiled
round the other ; and the number of coils increase as the cell
advances in age, while the matter of which the fundus of the
cell is composed gradually becomes less—apparently in con-
sequence of undergoing conversion into fibres. Nuclei are
found in the course of the straight fibre, as well as in connec-
tion with the spiral fibre. Nuclei have been demonstrated
in connection with the dark-bordered fibres near their origin
and near their distribution in all tissues.

Next follows a discussion “on the essential nature of the
changes occurring during the formation of all nerve-cells, and
on the formation of spiral fibres,” but this is not adapted for

306 PROCEEDINGS OF SOCIETIES.

an abstract. The term “nucleus” is only employed in a
general sense. The author believes that the “nucleus,”
“nucleolus,” and centres within the latter (“nucleolul’’)
merely represent centres of different ages. He considers
that the matter of the nucleus becomes gradually transformed
into the formed matter around it, and generally that these
bodies are merely centres which arise in pre-existing centres.
He maintains that from the outer formed matter connected
with the fibres new nerve-cells could not be produced, while
he holds that from the nuclei, nucleoli, and contained centres,
entirely new and complete cells could be evolved. So he
considers that the difference in the properties and powers of
the formed matter on the one hand, and the nuclei and
nucleoli on the other, depends upon these two kinds of matter
having arrived at different stages of existence. That whichis
formed cannot form new formed matter, nor appropriate
nutrient material; but the lving germinal matter of the
nucleus can be resolved into formed matter, and it can
appropriate inanimate pabulum, and confer upon it the
same wonderful (vital) powers which it possesses itself, and
which were communicated to it from pre-existing germinal
matter.

7. Of the fibres in the nerve-trunks continuous with the straight
and spiral fibres of the ganglion-cells.

The conclusions upon this important question are as
follows :—

1st. That in some instances very fine fibres, not more than
the =,2,,th of an English inch in diameter, are alone
continuous with both straight and spiral fibres of the gan-
glion-cells.

2nd. That a dark-bordered fibre may be traced to the
ganglion-cell as the straight fibre, while the spiral fibres are
continued on as very fine fibres.

3rd. That the spiral fibres may be continued onwards as a
dark-bordered fibre which may even be wider, at least for
some distance, than the fibre continued from the straight
fibre.

Ath. That both straight and spiral fibres may be con-
tinuous with dark-bordered fibres.

It is therefore quite certain that the spiral fibre is not con-
nective tissue, although the author considers it probable that
many German observers may adopt this view until they have
an opportunity of seeing the fibres themselves.

PROCEEDINGS OF SOCIETIES. 307

8. Of the ganglion-cells of the heart.

The author’s conclusions are quite opposed to those of
Kolliker, who states that all the cells are wnipolar, and that
the fibre always passes in a peripheral direction, also that the
transcurrent fibres of the vagus have no connection with
these cells. The author, on the contrary, affirms that the
cells have at least two fibres coming from them, that some of
the fibres pass towards the heart, and others towards the
brain. He regards it as very probable that many at least of
these ganglion-cells are connected with fibres of the vagus.
Kolhiker has also stated (1860) that many apolar cells could
be seen in the heart, ganglia, and in the bladder. The author
has been able to demonstrate fibres in connection with so
many cells which appeared devoid of fibres, that he considers
himself justified in denying the existence of apolar and uni-
polar cells altogether.

Next follow some observations on “ the ganglion-cells and
nerves of arteries ;” ‘‘on the connection of the ganglion-cells
with each other ;” and the paper concludes with a description
of the so-called “capsule” of the ganglion-cell, and a dis-
cussion on the nature and formation of the connective tissue
and its corpuscles in the immediate neighbourhood of nerve-
fibres.

The paper is illustrated with forty-seven drawings of the
specimens, magnified from 700 to 1700 linear; and the
author states that many of the specimens will probably retain
the appearances he has copied for several months. All the
preparations have been made in the same manner. An
outline of the process has been already given in the author’s
previous communications, but the author is aware that it may
be some time before the correctness of his conclusions is
generally admitted, i consequence of the difficulty of pre-
paring demonstrative specimens.

VOL. 11I1.—NEW SER. x

308 PROCEEDINGS OF SOCIETIES.

June 5th, 1863.

FurtTHER OxSERVATIONS in favour of the view that NeRve-
FIBRES never end in VotuntaryY Muscrze. By Lioner
S. Beatz, M.B., F.R.S., Fellow of the Royal College of
Physicians, Professor of Physiology and of General and
Morbid Anatomy in King’s College, London; Physician
to King’s College Hospital, &c.

(Plate XIII.)

Frew anatomical inquiries of late years have excited more
interest than the present one. Since my paper published in
the ‘ Philosophical Transactions’ for the year 1860, several
memoirs have appeared in Germany. In my paper just pub-
lished in the last volume of the ‘ Transactions,’ I have replied
to the statements of Kihne and Kolliker, but I had not suc-
ceeded in actually tracing the very fine nucleated fibres I
had demonstrated from one undoubted nerve-trunk to
another. As a demonstration, therefore, my conclusions
were defective, though the only explanation to be offered of
facts I had observed was that included in the view I pro-
pounded in my first paper. The question between my oppo-
nents and myself upon this matter is not one of interpreta-
tion, but a question of simple fact. I assert that the fine
nerve-fibres can be followed much further than the point
where Kihne and Kolliker maintain the ends or terminations
are situated, if the specimen be so prepared as to prevent
destruction of these most delicate fibres, and the refractive
power of the medium be such as to enable us to see them.

I propose to present to the Royal Society next session a
‘paper in which I shall demonstrate the truth of the con-
clusions I have arrived at; but as my specimens are already
prepared, and during the last few months several drawings
have been made, I hasten to give a short statement of facts,
in order that those who have been led to conclusions opposed
to my own may have an opportunity of studying the very
same muscle.

The great width and refractive power of the large elemen-
tary fibres of the pectoral of the common frog render it
impossible to follow for any great distance amongst them
nerve-fibres of the ;,4,,th of an inch = -000187” in dia-
meter; and I have therefore long been searching for a very
thin voluntary muscle, with fine fibres, which, like the
bladder of the frog, could be examined without the necessity

PROCEEDINGS OF SOCIETIES. 359

of making thin sections, and thereby deranging the relation
of all the finest and most delicate structures. Such a muscle
I have found in the extensive mylo-hyoid of the little green
tree-frog (Hyla arborea.) The elementary fibres of this
muscle are scarcely more than the ;.,!,,th of an inch = -0036”
in diameter; and as there are but two layers, the fibres of
which are at right angles to each other, all the structures in
the muscle can be demonstrated most beautifully. The very
long thin muscular fibres are not too close for exact obser-
vation. The vessels can be readily injected.*

These specimens have been prepared upon the same plan
as others, and are preserved in glycerine, which enables me
to press the thin muscle and separate the fibres further from
each other, while the finest fibres of the nerves are prevented,
by the viscid medium, from breaking or from being so com-
pressed amongst the other tissues as to be destroyed or ren-
dered invisible. The muscle must be prepared when quite
fresh, otherwise the fine nucleated fibres are completely dis-
integrated. The capillaries were injected as in the. other
cases.}

In this thin muscle, networks formed by bundles of dark-
bordered fibres, consisting of from two to five or six, may be
very easily shown, and with high powers (700 to 3000 dia-
meters) the very fine nucleated fibres resulting from the
division and subdivision of these in a dichotomous { manner,
can be readily demonstrated.

In this thin muscle I have often followed individual fine
nucleated nerve-fibres, now over, now under muscular fibres,
sometimes crossing transversely, sometimes obliquely, and
sometimes running for a certain distance parallel to the fine
muscular fibre. The drawing accompanying this paper ren-
ders further description unnecessary. I shall enter into full
detail in my communication next session; but as the summer

* The very thin and wide intercostal muscles of the Chameleon, after
having been soaked in glycerine, may be separated into two layers, external
and internal intercostals, in each of which the finest ramificatious of the
nerve-fibres may be followed, and their relation to the sarcolemma demon-
strated. The long elementary fibres of the thin tubular part of the tongue
of the same animal are also favorable for this investigation; but tle Chame-
Jeon is only to be obtained occasionally, and the muscle of the green tree-
frog, above referred to, possesses many advantages.

+ As the details of the mode of -preparing these specimens would occupy
many pages, I must defer entering into this part of the question; and it is
useless to give the outline, as success depends entirely on minutie.

{ The dichotomous division is most common; but sometimes three, four,
or even five branches result from the division of one fibre, as is well known
to be the case in the common frog.

310 PROCEEDINGS OF SOCIETIES.

is the period to obtain specimens of the Hyla, I am anxious
my fellow-labourers in Germany should at once be acquainted
with the advantages of the thin muscle alluded to; and I
cannot too strongly recommend this beautiful little frog,
which they have the advantage of procuring more readily
than Englishmen, for microscopical investigation. All the
tissues are beautifully distinct, and I challenge those who
are interested in these questions to discuss them with me,
selecting the tissues of this animal for special study.

British AssocrATION FOR THE ADVANCEMENT OF
SCIENCE.

NewcastL_e was unfortunate in the choice of its time for
the annual meeting of this Association. It was in the midst
of the holidays, when people have chosen their tours and
resting places, and cannot be disturbed. The consequence
has been that, although Newcastle did its best, the outside
public were fewer in number and repute than usual. We
have looked over the reports of the proceedings, but cannot
find any matter that would interest our readers; not that
there were not subjects brought before the section that
would have interested them, but that it is impossible that
scientific accounts of these meetings should be published.
When the ‘Atheneum’ employed a scientific reporter in
each section, its reports were complete, and could be relied
on, but now that it merely reprints the journals of the Asso-
ciation and copies newspaper reports, its accounts are of less
value. We have often thought it would be worth while for
‘the Council to publish an authorised report of the proceedings
at the time, each section naming its own reporter and editor.
The newspaper reports are admirably done, but it is too much
to expect that ordinary reporters could competently supply
those technical details which constitute the real value to
scientific men of the contributions read at the section.
Through the kindness of the author we are enabled to give
the following abstract of a paper on “ Life in the Atmo-
sphere,” read at the Physiological Section on Saturday,
August 29th, by James Samuelson, Esq.

The author commenced by saying that no subject in
natural history, excepting the allied one, the origin of spe-
cies, had of late excited greater interest than the origin of
the lowest types of living beings on the globe, which had led

PROCEEDINGS OF SOCIETIES. 311

to investigation, the indirect effect of which had been to
throw fresh light on the anatomy and life-history of the
mysterious forms of which the subject treats. It was with
the latter view, chiefly, that the author laid before the Asso-
ciation the results of his recent experiments on Atmospheric
Micrography.

First, however, he passed briefly in review the leading
facts connected with the ‘ Spontaneous Generation”’ contro-
versy, referrmg to the opinions held by the advocates and
opponents of the doctrine.

These views have at various times been published in the
‘ Microscopical Journal,’ and the author quoted the leading
expressions of Professor Pouchet, of Rouen, Messrs. Jolly
and Musset, &c., in favour of, and those of Pasteur in oppo-
sition to, the doctrine, referring his readers to the various
portions of this Journal in which they appeared for a full ac-
count of the controversy. He also touched upon the experi-
ments of Wyman, of Boston, who has recently entered the
lists as the advocate of heterogenesis, and of his own, which,
irrespective of those he has published, were rather adverse to
the doctrine than otherwise. As our readers will think,
however, Mr. Samuelson’s experiments to be now described
present features totally opposed to what ought to be expected
if the doctrine of heterogenesis were true, for he found in
distilled water, containing the dust of various countries,
many of the chief infusorial animalcul usually supposed by
the advocates of ‘ heterogenesis’ to be spontaneously pro-
duced in infusions of decaying organic matters.

Let us briefly recapitulate the chief results of these experi-
ments. In 1862, im conjunetion with Dr. Balbiani, of Paris
(the author of a very accurate and interesting work, recently
published, ‘On the Reproductive Organs of Infusoria’), he
exposed certain infusions in Paris and Liverpool, and in both
places and in all the infusions the same forms were found
amongst dissimilar ones. Some of these were traced to the
dust on the windows of the operators, and in one case Mr.
Samuelson found in pure distilled water, after it had been
exposed to the atmosphere for a few days, the same form
(Cercomonas acuminata, Dujardin) as he had found in his in-
fusions, in dust taken from the high road, and in the cata-
logue of infusoria forwarded by Dr. Balbiani, as having been
present in /is infusions.

Encouraged by these results, the author obtained dust by
shaking rugs imported from the following countries, namely,
Melbourne, Japan, Alexandria, Tunis, Trieste, and Peru, and
these different kinds of dust he kept until June, 18638, and

312 PROCEEDINGS OF SOCIETIES.

then sifted them through muslin on the surface of distilled
water, each kind having, of course, its appropriate vessel of
water. He also exposed pure distilled water in a three-
partitioned box covered with lids of blue, red, and yellow
lass.

7 The results of these experiments he read before the
Academy of Sciences in July, and in the same month he re-
peated them, which were concluded just before the meeting
of the Association.

The following are the results obtained from this double set
of experiments :

In the case of the distilled water, exposed under co-
loured-glass lids (partially open), the glass intercepted the
dust, and there was hardly any sign of life. When the dust
was washed into the distilled water, a hght deposit settled at
the bottom of the vessels, and on examination under a low
power the subsequent day, the author found mineral particles
imbedded in a gelatinous film. (He examined the deposit
without removing it from the vessel, by pouring off the water
and placing the glass vessel itself under his instrument.)
This film, under a higher power, was resolved into a mass of
minute, fixed monads, possessing a tremulous motion. The
next day a re-examination showed that these monads had be-
come active, and peopled the water.

So much for the distilled water only. Now as regards the
various kinds of dust.

In that of Egypt, Japan, Melbourne, and Trieste, life was
the most abundant, and the development of the different
forms was very rapid. ‘These consisted of Protophytes, Rhi-
zopoda, and true Infusoria.

In most of the vessels he first observed the forms known as
Monads and Vibrions; and from these he traced the develop-
“ment, first of one, and then of another species of Infusoria.
In the dust of Egypt he found anew Ameeba, whose motions
were very rapid, and the pseudopodia of w hich he compared,
both as regards their shape and mode of formation, to the
soap-bubbles blown by children with a pipe. He described
the normal globular form of this Ameeba, its gradual changes
until its pseudopodia were in full action, its conjugation, and
some other phenomena in its life-history.

In the same dust, and in this only, he clearly traced the
development of Protococcus viridis, which was, at last,
present in such numbers as to tinge the water green.

In Egypt, Melbourne, and Trieste, he found Cercomonas
acuminata (Dujardin), which his colleague and he had found
in the dust of Paris and Liverpool; and in Egypt he followed

a

PROCEEDINGS OF SOCIETIES. 313

the development of an entirely new form, from a long
“vibrion.” He thus describes this new type: “It was an
annulated vermiform animalcule, the ring being quite distinct,
and each one furnished with cilia. The whole series of cilia
extending along the body acted in concert, imparting to the
animalcule a motion precisely resembling Nais amongst fresh
water, and Nereis amongst marine annelides.

Beyond the distinct flashing of the cilia (of which he could
not count the number on each ring), a cirelet on the anterior
segment, and what appeared to be a canal running through
the whole length of the body, neither organs nor members
could be traced. Hach ring had, however, a distinct existence,
for they were cast off from time to time, and moved about
freely. The animalcule grew by the subdivision of its
ring, and became divided by their separation. It moved
freely backwards or forwards, and often when divided into
two parts, which remained attached to one another, an in-
dependent ciliary action was noticeable on each, but not such
as to interfere with the movements of the whole.

He further described how its annulated structure was
gradually converted to a smooth surface; and some other
pbonees which he observed. Its length varied from 74, to
>i, Inch; and he regarded it as a larval form, or series of
forms, bearing the same relation to some other (unknown)
Infusorium as the Strobila larva does to some of the
Meduse.

In the dust of Japan he followed the development of a
monad, first into what appeared to be a minute paramecium,
then into Lowxodes cucullulus (Dujardin), and finally into
Colpoda cucullus (Dujardin), and his experiments are quite
confirmatory of the supposition that many Infusoria now
classed as distinct types are really one and the same species
in different stages of development.

He also found, as stated by Dr Wallich, that certain
Ameebee (A. radiosa) are only another stage of others that
have been described as distinct types, just as in the case of
the Infusoria. Our space will not admit of our transcribing
more of these experiments, the recital of which was profusely
illustrated with diagrammatic plates, but we helieve our
readers will agree with us that they open out an entirely new
field for microscopists, and deal a heavy blow at the doctrine
of heterogenesis as at present understood. Mr. Samuelson’s
conclusions are in one sense rather amusing.

In drawing attention to the tenacity of life possessed by
the germs which were revived under his eye, he says that, in his
case, they survived the heat of a tropical sun and the warmth

olA PROCEEDINGS OF SOCIETIES.

of his room; but in that of Dr. Pouchet (the leading partisan
of spontaneous generation), who obtaimed his dust from the
interior of the pyramids of Egypt, “they retained their life
2000 years, and then survived an oil bath of 400° of heat.
We cannot close these observations without referrmg to
a useful practical application of these experiments, suggested
by the author, and approved by the President of the Section,
Professor Rolleston, and by many gentlemen who were
present at the delivery of the lecture, namely—the exami-
nation of the air of hospital wards, in order to trace, if pos-

sible, the existence of germs likely to cause epidemic disease. .

Mr. Samuelson claimed no originality for this suggestion,
for he said that Dr. Pouchet had spoken of such an investi-
gation, but he believed that, with the peculiar views enter-
tained by the French naturalist, he could hardly be expected
to go to his work with an unprejudiced mind, and with a
chance of practical good resulting. He, therefore, recom-
mended our hospital surgeons to make the test. In this view
Professor Rolleston quite concurred, and several valuable
hints were thrown out as to the best means of conducting
the investigation.

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JOURNAL OF MICROSCOPICAL SCIENCE.

DESCRIPTION OF PLATE I,

Illustrating Mr. J. Lockhart Clarke’s paper on the Develop-
ment of Striped Muscular Fibre in Man, Mammalia, and
Birds.

Fig.

18.—Muscular and nerve-fibres from the trunk of a human feetus of six

weeks: @ are two fibres from the thigh in process of formation,
magnified 670 diameters. In the lower one two oval nuclei are
united by granular processes proceeding from one of their ends;
similar processes extend from their other ends; along one side
of the nuclei and processes a thick fibre or lateral band is laid
down ; in the upper fibre a border is formed on both sides, but. is
much finer on one side. 4 Is anotlhier fibre from the same region,
magnified 900 diameters ; it is in different states of development
at different parts, and is an object of great interest. On one side
of the nucleus, at c, there are two distinct but smooth borders,and
between these the surface of the fibre, as well as of the nucleus,
shows indications of longitudinal, but simple or unresolved,
fibrilla. On the opposite side of the nucleus, at d, the lower
border or band, as well as one of the fibrillee on the surface, has
already become resolved into sarcous elements, but the wpper bor-
der, except near the nucleus, has not yet been laid down, and the
eage of the fibre is somewhat ragged, with granular blastema,
which may be also seen between and beneath the fibrille and
sarcous elements deposited upon it. e Are four delicate nerve-
fibres from the same region of the same fcetus.

19.—Muscular fibres and free nuclei from the leg of a human feetus of two
months, magnified 420 diameters.

20.—Fibres from the same, magnified 670 diameters: a is a striated fibre,
consisting of at least two fibrillee; along one of its sides a nucleus
and a layer of blastema have been laid, upon which new fibrille ~
are to be laid down. & Is another fibre, in which the two fibrille
composing it are more distinctly seen; nuclei with granular pro-
cesses are seen along its edge; at ¢ part of the lateral bands have
become resolved into sarcous elements.

21.—Represents muscular fibres and free nuclei from the ventricles of
the heart of a human fetus ? inch long, magnified 420 dia-
meters: a, free nuclei of different kinds; 4, nuclei zz situ, with
granular processes and fibres; ¢, different kinds of fibres; d, a
fibrilla with fine branches resolved into sarcous elements ; e, fibres
collected into a bundle; at / the striations are seen.

PLATE I—(continued).

Fig.

22.—Muscular fibres from the back and leg of a human feetus, between the
second and third month: @,a fibre in which the investing sarcous-
substance has been formed more thickly on one side than on others.
By this unequal growth the nuclei are left near the surface at dif-
ferent parts of the fibre. 4. A fibre undergoing contraction, and
becoming more cylindrical and of more uniform structure ; on one
of its sides are two nuclei joined by granular process, for the de-
velopment of a new fibre; magnified 420 diameters. «¢, d, ef.
Smaller fibres from the thigh, magnified 670 diameters; at e the
transverse striz are very strongly marked; in the others are seen
numerous large and dark granules. g Is a larger fibre from the
same locality, magnified 670 diameters. 4. A small fibre from the
same, in the first stage of formation; two nuclei are joined end-
wise by a delicate granular substance, and give off tapering pro-
longations of the same delicate substance from their opposite
ends ; along one side of the wholea band or fibre has been formed ;
magnified 420 diameters. 7. Another fibre from the same; at its
lower part the lateral band or investing substanee has increased
in thickness, so that the axis is nearly obliterated, and the fibre is
of nearly uniform structure; the striations are also strongly
marked. 7. Two other fibres lying side by side; the larger has
thick, lateral bands, divided into fine transverse strize, with a dis-
tinct axis, which resembles the other younger fibre at its side; by
altering the focus the whole surface of the fibre was found to be
striated, as in the large fibre (g) in this figure, so that the axis is
invested by a tube of striated substance.

23.—Muscular fibres from a human fcetus of four months.

24.—Nucleated fibres of the tendon of a muscle of an arm of a human feetus
two months: 4, as they are arranged am sifu; a, separated, and
more highly magnified.

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JOURNAL OF MICROSCOPICAL SCIENCE.

DESCRIPTION OF PLATES II AND III,

Illustrating Dr. H. Lawson’s paper on the General Anatomy,
Histology, and Physiology of Limax maximus (M.-Tand.).

PLATE IL.
Fig.

1,—Complete reproductive system of a fully formed specimen. 0, ovary;
ov, oviduct; A, albumengland ; v, uterus; 1, testis; v, vagina;
ve, vas deferens and penis; s, sperm-sac; D, duct of ditto; 5,
egg-sac; C, cloacal glands.

2.—Vertical section of cloaca, showing peculiar music-note-like glands.

3.—Cluster of ovarian lobules, as seen under compressorium.

4.—Compound, leaf-shaped follicle of testis, much enlarged.

5.—Sectional plan, of relations of heart, lungs, and viscera. 4H, heart;
Pg, pericardial gland; p, pericardium; ss, shell-sac; 1, lung;
§ 7, sub-thoracic visceral chamber; F, foot.

6.—Diagram of circulation. u, heart; a, aorta; vi, visceral chamber ;
LY, great lateral vein and branches; 1, lung; P, pericardial gland ;
s, sinus, which plays the part of auricle.

PLATE III.

1.—Entire digestive apparatus of a fully-developed individual. u, head;
s, salivary gland; G, gullet; st, stomach; 1, liver; 1, intestine ;
R, rectum.

2.—A lobule of the liver, highly magnified, showing gradual conversion of
the duct into the fibrous septa.

3.—Lobules of salivary gland, with circular contained endoplasts.

4,—Strata of muscular tissue from gullet, x 250, exhibiting intermingled
elastic fibres.

5.—Roughened or spinous membrane of tongue. L, single spine seen
laterally.

6.—Semi-schematic, vertico-longitudinal section of head. 0, oral orifice ;
T, tongue; P, pharynx; G, gullet.

7.—Ganglionic endoplasts, much increased.

8.—Whole nervous system, enormously enlarged. a, first circle; B,
second; C, third; PP, great pedal nerves ; Ph, pharyngeal ganglia ;
Sg, supra-cesophageal, and 1 g, infra-cesophageal, ganglia.

9,—Diagrammatic view of the relations of tentacular muscles. st, supe-
rior tentacle; rt, inferior ditto; ot, organ of taste (?); B, basal
muscle; p, posterior ditto; a, anterior ditto; s, half of second
pair of nerves; F, half of first ditto.

JOURNAL OF MICROSCOPICAL SCIENCE.

DESCRIPTION OF PLATES IV, V, & VI,

Illustrating Dr. T. Strethill Wright’s paper on British
Zoophytes. —

PLATE IV.

Aiquorea vitrina.
Fig.
1.—Planula, directly after leaving the ovary.
2.—Same, a week old.
3.—Same, after having fixed itself to the tank and developed its sclero-
derm. (Planula now become a polypary.)
4.—Polypary putting forth a polyp-bud.
5.—Same, with young polyp.
6.—Empty polyp-cell.
Atractylis arenosa.

7.—Polyp-stalk, with two opposite ovaries, the scleroderm covered by
transparent colletoderm.

8.—Ovary, with colletoderm and scleroderm removed, showing layer of ova
packed between endoderm and ectoderm.

9.—Advanced stage of ovary: a, ruptured scleroderm; 4, ectoderm; ec,
endoderm; d, secreted cap of “colline.”

10.—Ovary ruptured, ova extruded into the cap of colline or zest. (The

letters correspond to those of fig. 9.)

PLATE V.

Vorticlava Proteus.
1.—V. Proteus contracted.
2, 3, 4, 5.—Same, in different states of extension and form.
6.—Diagram of the tissues of the polyp of V. Proteus: a, colletoderm at-
tached to subtentacular ridge, 4; c, ectoderm; d, endoderm.

Acharadria larynz.
7.—Polypary, with two polyps.
8.—Immature polyp.
Laomedea decipiens.
9.—Empty cell, showing the double appearance of its border.

PLATE VI.

Trichydra pudica.
1.—Polyp extended, showing the lax habit of the body and tentacles.
2.—Polyp withdrawing itself when disturbed.
3.—Young polyp, with only four tentacles.
4.—Polyp within its tube.
5.—Empty tube.
6.—Supposed Medusoid of Zrichydra pudica.

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JOURNAL OF MICROSCOPICAL SCIENCE.

DESCRIPTION OF PLATE VII,

Illustrating E. Ray Lankester’s paper on our Present Know-
ledge of the Gregarinide.
Fig.
a eee Aphrodite, mihi, from the intestine of Aphrodite aculeata.
Length x inch.
2.—Proboscis of WM. Aphrodite. a, External membrane; 4, internal
membrane.
3.—Variety of UM. Aphrodite. Length x inch.
4.—Monocystis Serpule, mihi, from Serpula contortuplicata. Length
tote inch.
5.—WM. Serpulae, with prolongation of membrane. Length yy inch.
6.—Two individuals of M. Serpule, closely attached, as in Stein’s genus
Zygocystis. Length 785 inch.
7.—Young individual of WZ. Serpule. Length 725 inch.
8.—Vesicle of I. Aphrodite.
9.—Vesicle of M. Serpule.
10, 11. 12.—Varieties of Gregarina Blattarum. Length 4 inch.
13.—Vesicle of G. Blattarum.
14.—Probable young (?) of G. Blattarum.
15,16.—M, Sabelle, from Sabella (Amphitrite) infundibula. Length
Tao inch.
17.—Encysted G.’Blattarum.
18, 19.—G@. Blattarum attached one to another.
20.—G. Biattarum, showing striated internal tunic.
21, 22, 23, 24.—Stages in encystation of Mozocystis Lumbricit. Diameter
of cyst yop Inch.
25.—Ordinary form of Monocystis Zumbrici. Length x85 inch.
26.—W. Lumbrici, variety with fringed envelope. Length 35 inch.
27.—Smaller form of same. Length +3; inch.
28.—M. peer with envelope composed of conical cells, si; inch in
ength.
29, 30, 31.—Pseudo-Navicule after their escape from the cyst, in various
stages of change. Length yo5 inch.
32, 33.—Pseudo-Navicule, Psorosperms, or spindelzells, from cyst of M.
LIumbrict. Length p55 inch.
34.—Nematode of Lumbricus escaping from the egg.
35.—Corpuscle from testis of If. Lumbrici, probably young of Monocystis.
Diameter yoy5 inch.
36.—Ameebiform corpuscle from the perivisceral fluid of Lumbricus.
Diameter 75 inch.
37.—M. Lumbrici, with fringed envelope. Length 35 inch.
38.—M. Lumbrici, containing nucleated granules. Length % inch.

JOURNAL OF MICROSCOPICAL SCIENCE.

DESCRIPTION OF PLATE VIII,

A. Illustrating Dr. Rorie’s paper on the Nervous System of
Lumbricus terrestris.
Fig.
1.—Ganglion from ventral chain of worm.
2.—Nerve-cells of sub-cesophageal ganglion.
3.—Ditto of supra-cesophageal ganglion.
4.—Ditto of one of the ganglia of Mytilus.

B. Illustrating Prof. Max. Schultze’s paper on the Structure
of the Valve in the Diatomacee.
Fig.
1 (1).—A siliceous vesicle produced by the slow decomposition of fluo-
silicic acid gas in a moist atmosphere. X 300 diam.
2.—Section of a vesicle, showing the elevations on the surface.

3 (4).—A diagrammatic figure to represent the laminated structure of the
elevations of the wall of the vesicle.

4 (5).—The moniliform arrangement of the siliceous particles of which the
wall of the vesicle is constituted.

5 (12).—A portion of the surface of a siliceous pellicle, with acuminate
elevations, hexagonal at the base.

6 (14).—To show the mode in which, by an alteration of the focus, the
appearance of the elevations alters, owing to their laminated
structure.

6a (14a).—A side view of the same.
7 (15).—The surface of a thin pellicle, not quite in focus.
8 (16).—The surface of a pellicle, strongly resembling that of a diatom.

9 (17).—The same, viewed on the side, and showing the dots to correspond
to elevations.

10 (19).—The surface of a pellicle covered with irregular-sized elevations.

11 (21).—The appearance of Pleurosigma angulatum photographed through
one of Hartnack’s immersion-lenses, No. 10.

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JOURNAL OF MICROSCOPICAL SCIENCE.

DESCRIPTION OF PLATES IX & X,

Illustrating Dr. Greville’s paper on New Diatoms.

Series X.
Fig.
1.—Rutilaria Epsilon, front view.
2" 55; ventricosa, 5,
a— 5 elliptica, a

4.— Campylodiscus undulatus.
5.—Grammatophora Moronensis.
6.—Coscinodiscus scintillans.
7.— Pp griseus.
8.—Asterolampra Moronensis.
9.—Triceratium Robertsianum.

10.— a prominens.
11.— 5 disciforme.
12.— 35 clunumomeun.
13.— x lobatum.
14.— $5 denticulatum.
15.— 3 inflatum.
16.— ze lineolatum.
17.— a constans.
18.— = tumidum.
19.— oo Normanianum.
20.— » subcapitatum.
21.—Entogonia amabilis.
22.— a3 venulosa.
23.— 4 conspicua.
24,— 3 punctulata.

All the figures are x 400 diameters.

CORRIGENDUM.—SERIES IX.

I have committed an error in referring the diatom I have called Aulaco-
discus ? paradoxus to that genus. It is certainly an Omphalopelta. The
large, distinct granules, resembling so closely those of various Awlacodisci,
and the sort of line leading to the processes (not brought out by the
engraver) led me at first to doubt its true position.

JOURNAL OF MICROSCOPICAL SCIENCE.

DESCRIPTION OF PLATE XI,

Illustrating Henry Giglioli’s paper on the genus Callidina
(Ehren.), with a Description and Anatomy of a New
Species.

The letters have the same signification :

a, Trochal dise; 4, mouth; c, pharynx; d, mastax; e, esophagus; f, sto-
mach ; g, intestine ; 4, cloaca; 7, anus; , ovary ; /, cellular mass sur-
rounding the intestine; JZ, contractile vesicle; m, water-vessels;
n, calear; 0, ganglion (?); p, vacuolar thickenings; Q, head; &, body;
S, tail; ¢, claspers; w, suckers.

Fig. ‘

1.—Dorsal aspect of C. parasitica, with.the trochal disc retracted.

2.—Ventral aspect of C. parasitica, the trochal dise being expanded.

3.—Alimentary canal of C. parasitica, greatly magnified.

4.—C. parasitica attached by its suckers to part of an appendage of G.
pulex ; it is retracted, and shows the corrugations of the integu-
ment.

5.—Calcar, much enlarged.

6.—Ovum, recently deposited.

7.—Camera-lucida drawing of two ova attached to part of a thoracic
appendage of G. pulex ; they are magnified 210 diameters.

8.—Caudal appendages (from a camera-lucida drawing), highly magnified.

9.—Portion of ovary, greatly magnified, showing the germinal vesicles and
spots.

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JOURNAL OF MICROSCOPICAL SCIENCE.

DESCRIPTION OF PLATE XII,

Illustrating Dr. Keferstein’s paper on the genus Lucernaria.
he
Fig.
1.—Lucernaria octoradiata, Liam.
st. The stem.
¢. Tentacles.
p. Marginal papille.
p. Collection of thread-cells.
n. Collections of thread-cells in natatory-sac.
o. Oral tube.
r. Four lines of connection between the outer and inner mem-
branes of the disc.
7, The marginal space by which the different radial cavities com-
municate.
g. Reproductive organs.
m. Longitudinal muscles in the stem.
m'. Radial muscles in the natatory sac.
m’, Circular ditto.
2.—Transverse section of the bell of Z. octoradiata, carried parallel to the
border.
c. Gelatinous disc: a, external, 7, internal, formative membranes ;
z, intermediate substance, with numerous fine fibrille.
s. Natatory sae: g, sexual organs; 7, lines of connection between
the outer and inner membranes.
R. Radial canals.

3.—Radial section of the bell of L. octoradiata through the middle of a
radial canal (rn). Letters as before.

“4.—L. campanulata, Lamx., divided by a radial section at about half the
height of the bell.

o. Oral tube.

v. Stomach.

s. Point of attachment of the angle or point of the natatory sac to

the gelatinous disc.

st. Stem not cut across.

e. Orifices between the points, opening into the radial canals.

f. Internal oral tentacles.

t. Tentacles.

b. Tubercular swelling at the base of the fine tentacles placed

nearest to the arm.

Other letters as before. The reproductive organs on the right
side have been removed, so as to bring the radial muscular bands
clearly into view.

5.—One of the tentacles with a swollen base, viewed laterally.
6.—Tentacle of L. octoradiata.

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7.— a L. campanulata.
8.—Thread-cells from the capitulum of the tentacles of L. campanulata.

PLATE XII (continued).
Fig.
9.—Inner membrane lining the natatory sac of Z. octoradiata. x 260
diameters.
10.—Transverse section of the stem of Z. campanulata: a, outer, 7, inner,
cellular coat; z, transversely striated intermediate substance ; /, the
four internal ridges.
11.—Longitudinal section of the same, carried in the direction a 8 of the
foregoing figure ; &, cecal hollow in the pedal dise. Other letters as
before.
12.—Longitudinal section through ,the foot, in order to display the czcal
hollow more plainly. Letters as before.
13.—Transverse section through the stem of L. octoradiata.
4. The four longitudinal channels which replace the central cavity.
14.—Glandular inversion of the wall of the natatory sac (s) of Z. campanu-
lata, indicated at xz in fig. 4; z, orifice by which the thread-cells can
be expressed.
15.—Thread cells: a, with extended filaments still enclosed in the parent
cell. x 260 diameters.
16.—Internal oral tentacles of L. campanulata.
17.—Transverse section of the same, showing the extent of the glandular,
thickened part of its wall.

18.—Zoosperms of L, octoradiata,

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Distribution of finest nucleated-Nerve Fibres to the Hlementary Muscular Fibres of
the Mylo-hyoid Muscle of the little Green Tree Frog (Hyla Arborea). Drawn on the |
block by the Author, from a specimen magnified 1700 diameters (the first twenty-fifth |
made by Messrs Powell & Lealand). The diameter of each muscular fibre corresponds to |
that of a human red blood-corpuscle. .

SCALE. of an English Inch yew x 1700 diameters.

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JOURNAL OF MICROSCOPICAL SCIENCE.

DESCRIPTION OF PLATE XIII,

Illustrating Lionel S. Beale’s paper in the “ Proceedings ” on
Further Observations in favour of the View that Nerve-
fibres never end in Voluntary Muscle.

Distribution of finest nucleated nervefibres to the very narrow elementary
muscular fibres of the mylo-hyoid of the little green tree-frog (Hyla arborea),
magnified 1700 diameters. Drawn on the block by the author.

The elementary muscular fibres are marked g, 4, 7, &. & Isa very young
one, slightly stretched; ¢ is a fully formed muscular fibre; A, another
stretched in its central part. The nuclei of these fibres exhibit some differ-
ences in size and form. Nucleoli are distinct in all, and in the fibre marked
g the nuclei, which were coloured by carmine, exhibit three different in-
tensities of colour—the dark central spot, “nucleolus,” being most in-
tensely coloured, as indicated by the shading in the drawing.

a Is a nerve-fibre which was followed over more than twenty elementary
muscular fibres from a dark-bordered fibre. One of the subdivisions of this
fibre is seen at f, where it again runs with a very fine dark-bordered fibre
(0). ‘The dark-bordered fibre (0) was some distance higher up in the speci-
men, but its place has been altered in order to avoid the necessity for a still
larger drawing. Above 4 a nucleus of a very fine nerve-fibre is seen. Such
nuclei lie upon the surface of the muscular fibres, external to the sarco-
lemma. The nucleus often appears as if it were within the sarcolemma (c),
but the fibres proceeding from each extremity render such a position impos-
sible. The relation of these nerve-nuclei to the sarcolemma is seen at / in
profile. ‘The nuclei, as wellas the fibres for a certain distance, often adhere
to the sarcolemma very firmly ; but in the thin mylo-hyoid muscle the course
of the fibres over or under, but always ea¢erzal, to the muscular fibres, may
be readily traced if the muscular fibres be separated slightly from each other,
as represented in the drawing.

At d fine nerve-fibres accompanying the fine fibre continued from the
dark-bordered fibre, as described in the ‘ Philosophical Transactions’ for
1862, are represented. Such fibres are also seen at e and f.

m,n, and o. Dark-bordered fibres, with nuclei near their distribution.
m Would probably pass over sixty or seventy muscular fibres, and z over
perhaps twenty, before it divided into fibres as fine as those seen at J, e, f; 7.

p. A very fine capillary vessel with a nerve-fibre running close to it.

q. A bundle composed of six very fine nerve-libres near their distribution,
These fibres exhibit a very distinctly beaded appearance, which is also ob-
served in many other fine fibres in different parts of the specimen.

Traces of connective tissue are seen in all parts near the fine nerve-fibres
and around the muscular fibres. Here and there some very fine connective-
tissue-fibres, which were not altered by acetic acid, are represented. ‘These
represent the remains of fine nerve-fibres, which existed in a state of func-
tional activity at an earlier period.

The drawing, with the exception of the position of the nerve-fibre (0)
above mentioned, is an actual copy from nature. ‘The relative position of
the muscular fibres, the form and general character of the so-called nuclei,
and the position and size of the nerve-fibres and their nuclei, have been care-
fully preserved.

1 have traced the very fine nerve-fibres in so many instances from one
trunk to another ramifying at a very considerable distance, that I cannot
believe any true terminations or ends exist.

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PN DEX TOS JOURNAL.

VOL. Ii, NEW SERIES.

A.

Acharadria larynx, T.8. W., n. g.
and sp., 50.
Amehidium parasiticum, 74.
Ameeboid bodies, J. B. Hicks on
vegetable, 137.
Aiquorea vitrina, T. S. Wright on
reproduction in, 45.
Asterolampra Moronensis, 230.
Atractylis arenosa, T. Strethill
Wright on reproduc-
. tion of, 47.
Pa miniuta, T.8. W., 48.

B.

Basidiolum fimbriatum, 74.

Beale, Lionel, ‘On the Anatomy of
Nerve-fibres and Cells,’ &c., ab-
stract and remarks on, by G. V.
Ciaccio, 97.

3 on nerve-fibres in
voluntary muscle, 308.

i on the structure of
nerve-cells in frogs, 302.

Biforines, 246.

Blake, James, on infusoria in mov-
ing sand, 204.

Blood-corpuscles, W. Roberts on
the action of tannin and magenta
upon the, 170.

British Association for the Advance-
ment of Science, 310.

Brothers, Mr., on the cilia of Meli-
certa ringens, 213.

Busk, G., note on Dr. Wallich’s
“microscopic jaw,” 38.

C.

Callidina, on the genus, by Henry
Giglioli, 237.

Callidina bidens, 238.

» constricta, 238.

» - elegans, 237.

» parasitica, 238.
Campylodiscus undulatus, 229.
Carpenter, W., ‘The Microscope,’

&e., notice of, 72.

Carter, H. J., note on the colouring
matter of the Red Sea, 179.

Chambers, Dr. T. K., “On Mucus
and Pus,” in ‘Lumleian Lectures,’
notice of, 294.

Ciaccio, G. V., remarks on Dr.
Beale’s ‘ Observations on the Ana-
tomy of Nerve-fibres and Cells,
and on the ultimate distribution
of Nerve-fibres,’ 97.

Clarke, J. Lockhart, on the develop-
ment of striped muscular fibre in
man, mammalia, and birds, 1].

Clava nodosa, T. S. W., n. sp., 49.

Cohn, F., on the contractile fila-
ments of the Cynarez, 186.

Colouring matter of flowers, note
on the seat of, 78.

Comatula rosacea, Prof. Wyville-
Thomson on the embryogeny
of, 221.

Coscinodiscus griseus, 230.

ue seintillans, 230.

Crustacea, note on the occurrence
of parasitic sacs on, 73.

Curtis, Fred., on the improvement
of the compound microscope, 204. .

Cynareee, F. Cohn on the contractile
filaments of the, 186.

Cystolithes, 245.

D.

Dale, J. G., on the preparation of
crystallized films of picrate of
aniline, 210.

316

Davies, Thomas, the photography
of magnified objects by polarized
light, 201.

Davison, J., cell for viewing Euto-
mostraca, 137.

it on Kelner’s orthoscopic
eye-piece, 79.

Desmidee, Indian, notes on, by
Julian Hobson, 168.

Diatomaces, Max Schultze on the
structure of the valve in the, 120.

35 Charles Stodder on the
structure of the valve of the, 214.

Diatoms, descriptions of new and

rare, by Dr. R. K. Greville, 227.

note on the terms used
in the description of, 73.
Docidium, 169.

55 pristida, n. sp., 169.
Dry-mounting entomological objects,
by T. 8S. Ralph, 301.
Dufiin, A. B., M.D., some account
of protoplasm, and the part it
plays, 25].

E.

Eberth, Prof., on a new parasite in
tle muscles of the frog, 205.
Echinorhynchus, Rud, Leuckart on
the development of, 56.
Entogonia, n. g., Grev., 235.
5 Abercrombieanan.sp., 235.
$3 amabilis, n. sp., 236.
3 approximata, n. sp., 236.
% conspicud, N. Sp., 236.
» Davyana, n. sp., 236.
» gratiosa, n. sp., 235.
ae marginata, Nn. sp., 236.
ry, tnopinata, n. sp., 235.
», pulcherrima,n. sp., 236.
» punctulata,n. sp., 237.
os variegata,n. sp., 236.
venulosa, Nn. Sp., 236.
Entomostraca, Ji. Davison on a cell
for viewing, 137
Eolide, T. 8. Wright on the urti-
cating filaments of the, 52.
Hye-piece, Kelner’s orthoscopic, J.
Davison on, 79.

EF.

Flowers, on the seat of the colour-
ing matter in, 78.
Focal length of objectives, KR.

INDEX TO JOURNAL.

Nicholls, note on a plan for find-
ing, 75.

Foraminifera found in the Montreal
deposit, list of the, 211.

G.

Gammarus Pulex, 240.

Giglioli, Henry, on the genus Calli-
dina, with description of a new
species, 237.

Grammatophora Moronenis, 229.

Gregarinide, E. Ray Lankester on
our present knowledge of the, 83.

Greville, Dr. R. K., on new and rare
diatoms, 227.

Guyon, Geo., ona simple trough for
zoophytes, 201.

iH

Hendry, W., on the nerve-cells of
the spinal cord in the ox, 41.

Hicks, J. Braxton, note on vegeta-
ble amceboid bodies, 137.

Hobson, Julian, notes on Indian
Desmidez, 168.

Hoffmeister, W., ‘On the Germina-
nation, &c., of the Higher Cryp-
togamia,’ review of, 66.

iy rydractinia echinata, T. S. Wright
on the development of Pyenogon-
larvee within the polyps of, 51.

Hull Micro-philosophical Society,
report of the, 218.

I.

Illumination, coloured, by Dr. Mad-
dox, 300.

Infusoria, experiments on the forma-
tion of, in boiled solutions of or-
ganic matter, by Jefiries Wyman,

)

: » se) hee
= in moving sand, 204.
J.

“Jaw, microscopic,” G. Busk on

Dr. Wallich’s, 38.
K.

Keferstein, Prof., Sagitta, notice of,
134.

INDEX TO JOURNAL.

IL.

Lankester, Edwin, M.D., notes on
Raphides, 243.

Lankester, E. Ray, on our present
knowledge of the Gregarinide,
with descriptions of three new
species, 83.

Laomedea decipiens, T. 8. W., n. sp.,
49.

Lawson, Henry, M.D., ‘Manual of
Physiology,’ notice of, 290.

on the ‘general ana--

tomy, histology, and» physiology
of Limax maximus, 10.

Leuckart, Rud., on the development
of Echinorhynchus, 56

‘Life in the Atmosphere,’ by James
Samuelson, 310.

Light, some remarks, on by B. S.
Proctor, 151.

Limax maximus, H. Iaawson on the
general anatomy, histolegy, and
physiology of, 10.

Lucernaria, on ‘the genus, by O. F.
Miller, 265.

Tucernaria auricula, 282.

campanulata, 265, 283.

cyathiformis, 283.

octoradiata, 265, 283.

quadricorxis, 282.

stellifrons, 284.

Lumbricus ter restris, J. Rorie on the
anatomy of the nervous system in,
106.

Lynde, J. G., on the action of ma-
genta upon vegetable tissue, 146.

M.

Maddox, R. V., on coloured illumi- |

nation, 300.

Magenta, J. G. Lynde on the action |

of, upon vegetable tissue, 146.
agenta and tannin, action of, upon
blood-corpuscles, 170.

Manchester Literary and Philo-
sophical Society, Microscopical
section, proceedings of, Oct. 20th,

1862, 80.
= Nov. 17th, 1862, 82.
i Dee. 15th, ,, 141.

Jan. 19th, 1863, 143.

f Feb. 16th, ,, 145.
“ Mar. 16th, ,, 210.
Ss Apr. 20th, ,, 213.

317

Mecznikow, Elias, on the nature of
the Vorticella-stems, 285.

Melicerta ringens, on the cilia of, 213.

Micrasterias, 169.

3 Mahabuleshwarensis,

n. sp., Hobs., 169.

Microscope, F. Curtis on the im-

provement of the compound, 204.

Microscopical Society of London,

proceedings of, Oct. 8th, 1862, 80.

é 35 Nov. 12th, ,, 80.

55 Dec. 10th, ., SO.

Jan. 14th, 1868,146.

» anniversary, Feb. 11th,
1863, 140.

e Mar. Ist, 1863, 141.

= Ape. sth, ., 206:
= May 138th, ,, 207.
- June LOth, ,, 207.

list of presentations
to the, 208.

Micro-stereographs, F. H. Wenham
on the production of, 77.

Mucus and pus, by Dr. T. K. Cham-
bers, 294.

Miller, O. F., on the genus Lucer-
nara, 265.

Muscular fibre in man, mammalia,
and birds, J. Lockhart Clarke on
the development of, 1.

N.

Nematoda, A. Schneider on the
nervous system of the, 197.

Nerve-cells of the cord, W. Hendry,
on the, 41.

Nerve-cells of the frog, on the struc-
ture of, by Lionel Beale, M.B.,
302.

Nerve-fibres and cells, L. Beale on
the anatomy of, 97.

Nerve-fibres in muscles, by Lionel
Beale, M.B., 308.

Nevill, Mr., list of Foraminifera
shells found in the Montreal de-
posit, 211.

Nichols, R., plan for finding the
focal length of objectives, 75.

Nitzschia Epsilon, 227.

O.
Objects, microscopic, note by B. 8.

Proctor on a simple mounting
for any, 74.

318
P.

Pagenstecher, H. A., on the anatomy
of Sagitta, 192.

Parasites in the blood of the edible
turtle, note on, 73.

Photography of magnified objects by
polarized hight, 201.

Picrate of aniline, on the prepara-
tion of crystallized films of, 210.
Polarized light, on the photography

of magnified objects by, 201.

‘ Popular Physiology,’ 290.

Proctor, B. §., note on a simple
mounting for any microscopic ob-
jects, 74.

Ps some remarks upon
light, 151.

Protoplasm, some account of, by
A. B. Duffin, M.D., 251.

Pyenogon-larve within the polyps
of Hydractinia echinata, T. SB.
Wright on the development. of,
51.

Lis

Ralph, T.8., on dry-mounting ob-
jects, 301.

Raphides, notes on, by Edwin Lan-
kester, M.D., 243.

Red Sea, H. J. Carter on the colour-
ing matter of the, 179.

Roberts, W.., on peculiar appearances

- exhibited by blood-corpuscles
under the influence of solutions
of magenta and tannin, 170.

Rorie, James, on the anatomy of |
the nervous system in Lumbricus |

terrestris, 106.

Royal Society proceedings of, May |

7th, 302.
June 5th, 308.
Rutilaria elliptica, 0. Sp., Grev., 229.
» Epsilon, un. sp., Grev., 228.
Me ventricosa,n.sp., Grev., 228.

S.

Sagitta, Prof. Keferstein on, notice
of, 134.
» H. A. Pagenstecher, notes
on the anatomy of, 192.

|

| Samuelson,

INDEX TO JOURNAL.

James, on life in the
atmosphere, 310.

Schneider, Anton., on the nervous’
system of the Nematoda, 197.
Schultze, Max, on the structure of

the valve in the Diatomacez, as
compared with certain siliceous
pellicles produced artificially, 120.
Shea, John, M.D., ‘ Manual of Phy-
siology,’ notice of, 290.
Southampton Microscopical Society,
annual soirée of the, 148.
Stodder, Charles, on the structure
of the valve of the Diatomacee,
214.
Sunlight illumination of diatoms,

a is

Tannin and magenta, action of, upon
blood- corpuscles, 170.

| Thomson, Wyville, Prof., on the em-

bryogeny of Comatula rosacea, 221.

Triceratium cinnamomeum, U. Sp.
Grev., 282.
bs constans, n. sp., Grev.,
233.
a denticulatum, N. Sp.»
Grey., 233.
= disciforme, v. sp., Grev.,
232.
3 influtum, n. sp., Grev.,
232.
s. lineolatum, n. sp., Grev.,
32.
= lobatum, n. sp., Grev.,
233

Normanianum, n.
Grev., 234.
prominens, 1. sp., Grev.,

231.

SP.»

x ‘ Robertsianum, n. sp.
Grev., 231.

- subcapitatum, 0. Sp.
Grev., 234. ;

es tumidum, n. sp., Grev.,
234.

Trichodesmium LEhrenbergit, n. sp.,
Grev., 180.

Trychydra pudica, T. 5S. W., un. sp.,
50.

Turtle, note respecting parasites
found in the blood of the edible,
73.

INDEX TO JOURNAL.

U:
Urticating filaments of the Eolide,
T. S. Wright on the, 52.
Ni.
Vorticlaca proteus, T. S. W., n. sp.,
50.
Vorticella-stem, on the nature of, by
Elias Meczuikow, 285.
W.

Wenham, F. H., on the production
of micro- stereogr aphs, 77.

Pe on sunlight illumi- |

nation of diatoms, 300.

319

_ West Kent Natural History and Mi-

croscopical Society, report of, for
1862, 223.
rules of the, 224.
Wright, ike Strethill, observations on
British zoophytes, 45.
on the urticating
filaments of the Kolide, 52.
Wyman, Jeffries, experiments on
the formation of infusoria in boiled
solutions of organic matter, &.,
109.

Z.

Zoophytes, British, T. Strethill
Wright, observations on, 45.
G. Guyon on a simple
trough for, 201.

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