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OF
COMPARATIVE ZOOLOGY,
AT TARVARD COLLEGE, CAMBRIDGE, MASS,
Founded by private subscription, tn 1861.
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QUARTERLY JOURNAL
MICROSCOPICAL SCLENCE:
EDITED BY
EDWIN LANKESTER, M.D., F.R.S., F.L.S.,
AND
GEORGE BUSK, F.R.C.8.E.,. F.R.S., F.L.S.,
VOLUME VI.
ith Allustrations on Good and Stone.
LONDON:
JOHN CHURCHILL, NEW BURLINGTON STREET.
™ 1858,
ORIGINAL COMMUNICATIONS.
Description of a New Form of Naxrp-ryvep Mepvusa (Thau- 1
mantias achroa), with Histological Details. By T. SpeNcER
Cossoxp, M.D., F.L.S., Lecturer on Botany at St. Mary’s
Hospital Medical School, London.
(Communicated to Linnean Society, March, 1857.)
On the 13th of August, 1856, after filling a marine aqua-
rium, containing about three gallons of water, I detected a
small naked-eyed Medusa swimming vigorously near the sur-
face. This minute creature was immediately made the subject
of careful study, and it turned out to be a species of Thau-
mantias new to Britam (fig. 1, Pl. 1). So far as I can ascer-
tain, it has not been described by any author abroad; I have
therefore thought it worthy of a separate notice. The water
containing the Medusa had been procured four days pre-
viously from the shore near Leith, and had been kept in an
earthen vessel hermetically closed. The animal was only
preserved alive until the 16th of the same month, in conse-
quence of injuries sustained during a prolonged and often-
repeated microscopic examination.
Referring to the various organs in detail, I allude in the
first place to the umbrella. The form and general aspect of
this structure resembles that of the more typical species, being
hemispherical, transparent, colourless, smooth, slightly elon-
gated vertically when in a state of rest, the transverse diame-
ter measuring rather more than the third of an inch, and
becoming much increased during contraction, the length of
the disc, at the same time, being proportionately lessened.
To remark particularly on such admeasurements may appear
triflimg, but it is useful as an aid to diagnosis, because the
animal bears a very marked resemblance to Thaumantias
punctata and T. Thomsoni. These, however, present a more
depressed umbrella. Again, it is similar, at first sight, to
T. convexa ; but this species has the umbrella more cylindrical,
and there are other distinguishing characters, which will be
alluded to presently. The circumferential portion of the um-
brella is frmged by twenty-four tentacula of extreme delicacy
and unusual length ; also, by eight ocelli, a circular gastro-
vascular canal, and a well-defined shelf-like veil directed
inwards. These parts will be considered separately. Under
VOL. V1. B
2 COBBOLD, ON A NAKED-EYED MEDUSA.
a quarter-inch objective, the external convex surface of the
umbrella presented a few well-defined and sparsely scattered
cellules, which were rather irregularly disposed beneath the
transparent, and, in such situations, slightly elevated, epider-
mis (fig. 2). No other indications of structure were noticed.
The ¢entacula, while relaxed and motionless, are fully three
times the length of the dise—a peculiarity serving to distin-
guish this Medusa from all other British species, their peculiar
arrangement (5 x 4+ 4) also constituting a satisfactory
mark of identification. During the gentle agitation of the
water it frequently happened that the tentacula stretched
beyond this length, the trailing filaments assuming an almost
invisible tenuity, but when violent contraction occurred, the
threads suddenly acquired the form of minute tubercles, bor-
dering the circumferential margin of the umbrella. A gradual
unfolding usually commenced immediately after the contrac-
tion—-the exciting agent bemg removed—the extension inva-
riably originating at the base of the filament, and proceeding
uniformly downwards to the extremity, until each succeeding
portion was unfurled. Incompletely extended, the tentacles
always appear clavate at the tip. Amplified 50 diameters,
they exhibit a finely granular and ringed appearance, analo-
gous to that of the prehensile labiate organs of hydroida (fig.
3) ; with an ordinary pocket-lens indications of knotting may
be seen at the extremity of the cirrhi. To the naked eye the
tentacular bulbs appear colourless and homogeneous, but under
a magnification of 300 diameters, the sub-epidermic tissues
display numerous closely packed fusiform cells, identical with
those described as lying beneath the cuticle of the umbrella
(fig. 9). They refracted light very strongly, but the exist-
ence of nuclei could not be demonstrated. At the bulb the
cells are irregularly disposed ; a little further down they begin
to assume symptoms of grouping, co-ordinate with which
bulgings appear at the margin of the thread. Lower still,
the fusiform particles acquire an mcompletely linear arrange-
ment, speedily merging into a definite series of rings or
knots, placed at regular intervals. While the cirrhus is re-
laxed the cell-groups are separated by a transparent interspace,
which is much constricted, but exceeds in length the paren-
chymatous knot. Near the extremity of the thread the cells
are more cogently developed, and being placed at a right
angle to the axis of the filament, appear to stand out from the
investing epidermis (fig. 4). At the upper part the tentacula
exhibit lateral lines in their interior, denoting the presence of
a central canal, the markings becoming more conspicuous
near the bulb (fig. 9). This last-named structure, viewed by
COBBOLD, ON A NAKED-EYED MEDUSA. 3
transmitted light, appears more opaque than the filament, m
consequence of its greater thickness, and the abundance of
those highly refracting fusiform particles already described.
The limitmg membrane of an otolitic vesicle was discernible,
but there were apparently no vibratory movements within the
cavity.
The ocelli, eight m number (2 x 4), are placed round the
circular margin of the disc, at intervals, between every third
tentacle—an arrangement somewhat peculiar. The unassisted
eye failed to detect their presence ; a very slight enlargement,
however, rendered them visible. Magnified 60 diameters,
each ocellus was seen to consist of a transparent vesicle con-
taining a round nucleus at the base, and in addition, five
bright yellow, highly refracting globules (fig. 8). The latter,
larger than the nucleus, varied in size respectively, the diffe-
rence being uniform and gradational. Under a quarter-inch
lens these variations in size were more obvious, the bulk of
the central and superior globule bemg paramount. The wall
of the sac was now seen to be double, the ocellus bemg sup-
ported by a cellular thickening of the ining membrane of the
circular gastro-vascular canal (fig. 10). When under exami-
nation, the nucleus broke up, and many of the tissues, else-
where, disintegrated, while the animal was still living in an
enfeebled condition.
The marginal vessel is about the width of the filamentary
tentacle, and to the unassisted eye its walls appear transpa-
rent and homogeneous. Two kinds of corpuscles, large and
small, are contained within the canal; of these we shall speak
more particularly when referring to the circulation.
The shelf-like veil is directed inwards at a right angle to
the axis of the disc, and, though broad and conspicuous, offers
no structural indications.
The sub-umbrella is placed rather higher than midway be-
tween the marginal ring and the convex surface of the disc.
The depth of the concavity lessened during contraction, but
not uniformly so, it bemg observed that the upper part re-
mained unaffected, to the extent of a third of its area, from
the summit downwards, the circular limit of this rigid portion
forming, as it were, a point d@appui for the development of
contractile action throughout the remainder of the membrane.
No muscular tissue, properly so called, could be detected.
The proboscidiform peduncle has all the features common
to the genus. It is about the twentieth part of an inch in
length, quadrangular, and provided with four simple or
slightly fimbriated triangular lips (fig. 5). The contained
stomachal cavity was thrown into various shapes during the
aT COBBOLD, ON A NAKED-EYED MEDUSA.
lateral and twisting contractile movements of the peduncle,
but viewed from above, while empty and im a state of rest,
the walls were symmetrically disposed in the form of a cross
(fig. 7). With the help of a pocket-lens the lips presented a
finely granular or ground-glass-like appearance, which was
due to the abundance of those minute fusiform cellules form-
ing, as we have seen, the general parenchyma of the body.
The functionally combined respiratory and nutritive sys-
tem of vessels, or gastro-vascular canals, are five in number—
four radiating and one cireumferential—as in other gymnoph-
thalmatous genera; their walls are transparent, well defined,
and rigid. The smaller kind of the contained corpuscles are
rather less in diameter than human blood-globules; while the
larger, apparently mother-cells, are nearly three times greater,
possessing nuclei of variable size, but frequently identical in
character with the lesser globules. All are transparent and
colourless, with the limiting membrane sharply marked (figs.
9, 10, 11). When the circulation was active, the corpuscles
moved in a moderately rapid and regular manner, their course
in the radiating vessels being continuous from one half of the
hemisphere to the other. In other words—two vessels carried
the particles from the marginal canal, convergingly, to the
central point of intercommunication, on the one hand, and
two conveyed the same elements from the centre, divergingly,
on the other (fig. 7). The behaviour of the corpuscles led me
to conjecture the presence of cilia within the canals, though
they were not structurally demonstrated. In regard to the
presumed continuity of the vessels with the stomach in this
genus, at the summit of the umbrella, let it suffice me to add,
that I could discover no opening or any interposed channel
of communication. The enlarged central vascular space
formed at the crossing of the radiating canals, was the only
indication of a supra-stomachal cavity ; through this space the
corpuscles rolled on uninterruptedly (fig. 11).
The reproductive glands—four in uumber, elongated or
semiclavate—are placed on the inferior surface of the sub-
umbrella, a short way distant from the margin, and in the
course of the radiating canals. Their border to the naked eye
was smooth, but under a half-inch objective the surface looked
undulating, an appearance due to the bulging of the ovarian
cells lying immediately beneath. Each gland was subdivided
by one of the radiating vessels traversing its long axis (fig. 6).
The subjacent ova at the surface severally displayed an outer
cell-wall with its included transparent albumen, a second
membrane surrounding the molecular yolk, and a third con-
stituting the germinal spot, within which were three or four
LISTER, ON INVOLUNTARY MUSCULAR FIBRE. 5
rounded particles, beautifully distinct (fig. 12). Deeper in the
organ were similar cells, smaller in size and imperfectly de-
veloped, evidently destined to supply the place of those ripe
for expulsion. The connecting tissue between and among
these ova displayed many of the ordinary parenchymatous
cellules within its substance.
To facilitate identification, I subjoin in conclusion a few
particulars gathered from Professor Forbes’s monograph, in
which Thaumantias inconspicua, T. punctata, and T. Thomsoni
differ from this species. The first has the dise wider and
more flattened, also, purplish-coloured glands and twenty ten-
tacles. The second has thirty-two tentacula, is a larger
species, with the umbrella more depressed. The third has
but sixteen tentacula, the bulbs and reproductive glands con-
taming a yellow pigment. There is no other British species
for which it can be readily mistaken. The great length of
the tentacula forms a distinctive peculiarity. I have desig-
nated this Medusa, Thaumantias achroa (&xpoos, colourless).
On the Minute Srructure of Invotuntrary Muscutar
Fisre. By Josepn Lister, Esq., F.R.C.S. Eng. and
Edin., Assistant-Surgeon to the Royal Infirmary, Edin-
burgh. Communicated by Dr. Curistison.
(From the ‘Transactions of the Royal Society of Edinburgh” Read
December ist, 1856.)
Ir has been long known that contractile tissue presents
itself in the human body in two forms, one composed of fibres
of considerable magnitude, and therefore readily visible under
a low magnifying power, and marked very characteristically
with transverse lines at short intervals, the other consisting
of fibres much more minute, of exceedingly soft and delicate
aspect, and destitute of transverse striae. The former variety
constitutes the muscles of the limbs, and of all parts whose
movements are under the dominion of the will; while the
latter forms the contractile element of organs, such as the
itestines, which are placed beyond the control of volition.
There are, however, some exceptions to this general rule, the
B §
6 LISTER, ON INVOLUNTARY MUSCULAY FIBRE,
principle of which is the heart, whose fibres are a variety of
the striped kind.
Till within a recent period the fibres of unstriped or invo-
luntary muscle were believed to be somewhat flattened bands
of uniform width and indefinite length, marked here and
there with roundish or elongated nuclei; but in the year
1847, Professor Kélliker of Wurzburg announced that the
tissue was resolvable into simpler elements, which he regarded
as elongated cells, each of somewhat flattened form, with
more or less tapering extremities, and presenting at its
central part one of the nuclei above mentioned. These
* contractile” or “ muscular fibre-cells,” as he termed them,
were placed in parallel juxtaposition in the tissue, adhering
to each other, as he supposed, by means of some viscid con-
necting substance. In the following year the same distin-
guished anatomist gave a fuller account of his discovery in
the first volume of the ‘ Zeitschrift fiir Waissenschaftliche
Zoologie,’ and described in a most elaborate manner the ap-
pearances which the tissue presented in all parts of the body
where unstriped muscle had been previously known to occur,
and also in situations, such as the iris and the skin, where
its existence had before been only matter of conjecture, but
where the characteristic form of the fibre-cells, and of their
“rod-shaped ” nuclei, had enabled him to recognise it with
precision. Confirmations of this view of the structure of
involuntary muscular fibre were afterwards received from
various quarters, one of the most important being the obser-
vation made in 1849 by Reichert, a German histologist, that
dilute nitric or muriatic acid loosens the cohesion of the fibre-
cells, and enables them to be isolated with much greater facility.
In 1852 I wrote a paper “On the Contractile Tissue of the
Tris,” published in the ‘ Microscopical Journal,’ in which I
gave an account of the involuntary muscular fibre contained
in that organ in man and some of the lower animals, stating
that the appearances I had met with corresponded exactly
with Kdélliker’s descriptions, and illustratmg my remarks
with careful sketches of several fibre-cells from the human
iris, isolated by tearing a portion of the sphincter pupille
with needles in a drop of water. In 1853, another paper by
myself appeared in the same Journal, “ On the Contractile
Tissue of the Skin,” confirming Kdlliker’s recent discovery
of the “arrectores pili,’ and describing the distribution of
those little bundles of unstriped muscle in the scalp. These
and other investigations into the involuntary muscular tissue
convinced me of the correctness of Kolliker’s observations,
and led me to regard his discovery as one of the most beau-
LISTER, ON INVOLUNTARY MUSCULAR FIBRE. 7
tiful ever made in anatomy; and this is now, I believe, the
general opinion of histologists.
Still, however, there are those who are not yet satisfied
upon this subject. In Miiller’s ‘ Archives’ for 1854, is a
paper by Dr. J. F. Mazonn of Kiew, in which the author
expresses his belief that the muscular fibre-cells of Kolliker
are created by the tearing of the tissue in preparing it, and
denies the existence of nuclei in unstriped muscle altogether ;
but he gives so very obscure an account of his own ideas re-
specting the tissue, that his objections seem to me to carry
very little weight, more especially as the appearances which
he describes require, according to his own account, several
days’ maceration of the muscle in acid for their development.
In June of the present year (1856), Professor Ellis, of Uni-
versity College, London, communicated to the Royal Society
of London a paper entitled “ Researches into the Nature of
Involuntary Muscular Fibre.’ In the abstract given in the
‘ Proceedings’ of the Society, recently issued, we are in-
formed that, “ having been unable to confirm the statements
of Professor Kolliker respecting the cell-structure of the
involuntary muscular fibre, the author was induced to under-
take a series of researches into the nature of that tissue, by
which he has been led to entertain views as to its structure
in vertebrate animals, but more especially in man, which are
at variance with those now generally received.” In the
“summary of the conclusions which the author has arrived
at,’ we find the following: “In both kinds of muscles,
voluntary and involuntary, the fibres are long, slender,
rounded cords of uniform width » Tn neither
voluntary nor involuntary muscle is the fibre of the nature
of a cell, but in both is composed of minute threads or fibrils.
Its surface- -appearance, in both kinds of muscle, allows of the
supposition that in both it is constructed in a similar way,
viz., of small particles or ‘sarcous elements,’ and that a
difference in the arrangement of these elements gives a
dotted appearance to the involuntary, and a transverse striation
to the voluntary fibres.” “On the addition of acetic acid,
fusiform or rod-shaped corpuscles make their appearance in
all muscular tissue ; these bodies, which appear to belong to
the sheath of the fibre, approach nearest in their characters
to the corpuscles belonging to the yellow or elastic fibres
which pervade various other tissues; and from the apparent
identity in nature of these corpuscles in the different textures
in which they are found, and especially in voluntary, as com-
pared with involuntary muscle, it is scarcely conceivable that
in the latter case exclusively they should be the nuclei of
oblong cells constituting the proper muscular tissue.”
VOL. VI. c
8 LISTER, ON INVOLUNTARY MUSCULAR FIBRE.
Mr. Ellis, then, agrees with Mazonn in believing that the
tapering fibre-cells of Kélliker owe their shape to tearing of
the tissue; and he regards the nuclei as mere accidental ac-
companiments of the proper muscular structure, probably
belonging to the sheath of the fibres, which, according to
him, are of rounded form and uniform width.
The distinguished position of Mr. Ellis as an anatomist
makes it very desirable that his opinion on this important
subject should be either confirmed or refuted, and the object
of the present paper is to communicate some facts which
have recently come under my observation, and which, I hope,
may prove to others as unequivocally as they have done to
myself, the truth of Kolliker’s view of this question.
In September last, being engaged in an inquiry into the
process of inflammation in the web of the frog’s foot, I was
desirous of ascertaining more precisely the structure of the
minute vessels, with a view to settling a disputed point
regarding their contractility.
Having divided the integument along the dorsal aspect of
two contiguous toes, I found that the imcluded flap could be
readily raised, so as to separate the layers of skin of which
the web consists, the principal vessels remaining attached to
the plantar layer. Having raised with a needle as many of
the vascular branches as possible, I found, on applying the
microscope, that they included arteries of extreme minute-
ness, some of them, indeed, of smaller calibre than average
capillaries. A high magnifying power showed that these
smallest arteries consisted of an external layer of longitu-
dinally arranged cellular fibres in variable quantity, an
internal exceedingly delicate membrane, and an intermediate
circular coat, which generally constituted the chief mass of
the vessel, but which proved to consist of neither more nor
less than a single layer of muscular fibre-cells, each wrapped
in a spiral manner round the internal membrane, and of
sufficient length to encircle it from about one and a half to
two and a half times. They are seen to have more or less
pointed extremities, and are provided with an oval nucleus at
their broadest part, discernible distinctly, though somewhat
dimly, without the application of acetic acid. The tubular
form of the vessels enables the observer, by proper adjust-
ment of the focus, to see the fibre-cells in section; they are
then observed to be substantial bodies, often as thick as they
are broad, though the latter dimension generally exceeds
the former. The section of the nucleus is in such cases
invariably found surrounded by that of the substance of the
fibre-cell, though occasionally placed eccentrically in it.
From the circular form of its section the nucleus appears to
LISTER, ON INVOLUNTARY MUSCULAR FIBRE, 9
be cylindrical. These fibre-cells are from z}5 inch to 735
inch in length, from 3355 inch to 3,555 inch in breadth, and
about z3!55 inch in thickness, measurements on the whole
rather greater than those given by Kolliker for the human
intestine, the chief difference being that in the frog’s arteries
they are somewhat broader and thicker.
Now, the middle coat of the small arteries is universally
admitted to be composed chiefly of involuntary muscular
fibre; but in the vessels just described it consists of nothing
whatever else than elongated, tapering bodies, corresponding
in dimensions with Kolliker’s fibre-cells, and each provided
with a single cylindrical nucleus imbedded in its substance.
Considering, then, that no tearmg of the tissue had been
practised in the preparation of the objects, but that the parts
were seen undisturbed in their natural relations, it appeared
to me that the simple observation above related settled the
point at issue conclusively.
It was, however, suggested to me by an eminent physiolo-
gist, that the various forms in which contractile tissue occurs
in the animal kingdom forbid our drawing any positive
inference regarding the structure of human involuntary
muscle from an observation made on the arteries of the frog.
Beimg anxious to avoid all cavil, and understanding that Mr.
Ellis’s researches had been directed chiefly to the hollow
viscera, I thought it best to examine the tissue in some such
organ. For this purpose I obtained a portion of the small
intestine of a freshly killed pig, selecting that animal. on
account of the close general resemblance between its: tis-
sues and those of man. The piece of gut happened'to be
tightly contracted, and on slitting it up longituglimally, the
mucous membrane, which was thrown into loége folds, was
very readily detached from the subjacent parts” E raised one
of the thick, but pale and soft fasciculi of the circular coat,
and teased it out with needles in a drop of water, reducing it
without difficulty to extremely delicate fibrils. On examining
the object with the microscope, I found that it was:composed
of mvoluntary muscular fibre, almost entirely unmixed with
other tissue, reminding me precisely of what I had seen in
the human sphincter pupille, except that the appearances
were more distinct, especially as regards the nuclei, which
were clearly apparent without the application of acetic acid.
Several of the fibre-cells were isolated in the first specimen
I examined, each one presenting tapering extremities about
equidistant from a single elongated nucleus. The fibre-cells
were of soft and delicate aspect, generally homogeneous or
faintly granular, with sometimes a slight appearance of lon-
gitudinal strie.
~
10 LISTER, ON INVOLUNTARY MUSCULAR FIBLE.
I had now seen enough to satisfy my own mind that the
involuntary muscular fibre of the pig’s intestine was similarly
constituted with that of the human iris and the frog’s artery:
but before throwing up the investigation, I thought it right
to examine carefully some short, substantial-looking bodies
of high refractive power, which at first sight appeared, both
from their form and the aspect of their constituent material,
totally different in nature from the rest of the tissue. Hach
is seen to be of somewhat oval shape, with more or less
pointed extremities, and presents several strongly marked,
thick, transverse ridges upon its surface ; and each, without
exception, possesses a roundish nucleus whose longer diameter
lies across that of the containing mass. Yet between these
bodies and the long and delicate homogeneous fibre-cells
above described, every possible gradation could be traced.
In several cells one half was short, with closely approxi-
mated rugze, the other half long and homogeneous. Hence
it was pretty clear that the appearances in question were
due to contraction of the fibre-cells, and that the shortest
of these bodies were examples of an extreme degree of
that condition; their substantial aspect and considerable
breadth being produced by the whole material of the long
muscular elements being drawn together into so small a
compass. The rounded appearance of the nuclei was ac-
counted for by supposing either that they had themselves
contracted, or that they had been pinched up by the con-
tracting fibres, of which explanations the latter appears the
more probable.
In order to place the matter if possible beyond doubt, I
prepared two contiguous portions of the circular coat of a
contracted piece of imtestine in different ways; the one by
simply cutting off a minute portion with sharp scissors, so as
to avoid as much as possible any stretching of the tissue, the
other by purposely drawing out a fasciculus to a very consi-
derable length, and then teasing it with needles. In the
former preparation, the fibre-cells appeared all of them more
or less contracted, except in parts where the slight traction
inseparable from any mode of preparation had stretched the
pliant tissue, which in the fresh state appears to yield as
readily to any extending force as does a relaxed muscle of a
living limb. In the other object, where the tissue had been
purposely stretched, most of the fibre-cells were extended,
and possessed elongated nuclei. Here and there one would
be seen of excessive tenuity, scarcely broader at its thickest
part than the nucleus, looking, under the highest magnifying
power, like a delicate thread of spun glass. To how great a
length the fibre-cells admit of being drawn out in this way
LISTER, ON INVOLUNTARY MUSCULAR FIBRE. i}
without breaking I cannot tell. Among these extended
fibres, however, there lay, here and there, an extremely
contracted one, the result, I have no doubt, of the irrita-
tion produced by the needles upon the yet living tissue. In
order to guard against this source of fallacy, I kept a piece
of contracted gut forty-eight hours, and then examined two
contiguous parts of the circular coat in the way above
described. The muscle was much less readily extended than
in the fresh state, and I found that, where stretching of the
tissue had been avoided as much as possible, it was composed
entirely of fibre-cells marked with transverse ridges of vary-
ing thickness and proximity; a minute fibril having, under
a rather low power, the general aspect represented in fig. 17.
But I saw no distinct examples of the extreme degree of con-
traction so frequent in muscle from the same piece of intes-
tine in the fresh state. This confirmed my suspicion that
the latter had been induced by the irritation of the mode of
preparation. On the other hand, a fully stretched fasciculus
showed its fibres everywhere destitute of transverse rugze, so
that the point was now distinctly proved. Kdlliker, in his
original article in the ‘ Zeitschrift ftir Wissenschaftliche Zoo-
logie,’ figured some long fibre-cells with transverse lnes
upon them—“ knotty swellings,” as he termed them,—which
he supposed probably due to contraction, and he repeats this
hypothesis in the part of his ‘ Mikroskopische Anatomie,’
published in 1852. The proof of the correctness of this idea
is now, I believe, given for the first time.
The bearings of these observations on the main question
respecting the structure of involuntary muscular fibre are
obvious and important. In the first place, if the short, sub-
stantial bodies were mere contracted fragments of rounded
fibres of uniform width, we should expect them to be as
thick at their extremities as at the centre, instead of which
they are always more or less tapering, and often present a
very regular appearance of two cones applied to each other
by their bases. Secondly, the uniform central position of
the nuclei in the contracted fibres, proves clearly that the
former are no accidental appendages of the latter, to which
it seems difficult to refuse Kolliker’s appellation of cells.
The effect of acetic acid on the involuntary muscular
tissue is to render the fibres indistinct, but the nuclei more
apparent; and if this reagent be applied to a piece of con-
tracted muscle, many of the nuclei are seen to be of more or
less rounded form. The deviation of the nuclei from the
“rod-shape”’ has hitherto been a puzzling appearance, but is
now satisfactorily accounted for.
In examining a fasciculus that had been fully stretched,
12 LISTER, ON INVOLUNTARY MUSCULAR FIBRE.
forty-eight hours after death, I met with several good speci-
mens of isolated fibre-cells. Though these fibres are very
long, yet we have no reason to believe that anything near
the extreme degree of extension has been attained in them,
and we cannot but contemplate with amazement the extent
of contractility possessed by this tissue.
In one of the drawings is represented a portion of a fibre-
cell curled up, which has been mtroduced for the sake of the
clear. manner in which it shows the position of the nucleus
imbedded in it. Just as in the case of the fibres wrapped
round the arteries of the frog’s foot, this cell might be seen
im section by proper adjustment, and that section is observed
to be oval; proving that the fibre is not round, but somewhat
flattened. It happens that the nucleus appears at this point ;
its section is circular, and is surrounded on all sides by the
substance of the cell.
The pig’s intestine seems to be a peculiarly favorable situa-
tion for the investigation of unstriped muscle. Judging from
Kolliker’s measurements, the fibres appear to be of much
larger size there than in the same situation in the human
body. The length of the fibre-cell 3 is 3; inch. The fibre
2 is imperfect at one extremity; but, taking the double of the
distance from its pointed end to the nucleus, its length is 35
inch. These measurements are between three and four times
greater than any which Professor Kolliker has given for the
human intestine, and considerably exceed the length of the
“colossal fibre-cells ”? which he describes as occurring in the
gravid uterus. The individual fibre-cells, with their nuclei
and transverse markings, if they have any, are quite distinctly
to be seen with one of Smith and Beck’s 34, object-glasses.
But in order to examine their structure minutely, a higher
power is required: that which I use is a first-rate +,, made
several years ago by Mr. Powell, of London. The principal
HN arg of the fibre-cells from the pig’s intestine are as
under
Length of fibre-cell, 3 - yy inch.
Breadth of ditto ‘ : - 3500. 39
Length of nucleus of ditto Iood »
Breadth of ditto B000 9»
Breadth of fibre-cell, 16 ‘ - 3000 0»
Thickness of ditto . ; : : =d00 2»
Length of fibre-cell, 13 ‘ > Fea OD
Breadth of ditto : . Fede
1
Longitudinal measurement at nueleds of ditie sB00
Transverse ditto
Length of fibre-cell, 15 ual
LISTER, ON INVOLUNTARY MUSCULAR FIBRE. 13
Hence it appears that the length of the most contracted
fibre-cell is the same as that of the nucleus of an extended
one. The fibres vary somewhat in breadth, independently of
the results of contraction. Thus, one in the extended condi-
* tion which I sketched, but which is not here shown, measured
only 555 ich across. The nuclei of the uncontracted fibres
are very constantly of the same length, and are good examples
of the rod-shape to which Kolliker has directed particular
attention. They always possess one or two nucleoli, and have
often a slightly granular character; occasionally, as in fig. 21,
they present an appearance of transverse markings. One
frequently sees near the nucleus of a fibre that has been
artificially extended from the contracted state, an appearance
of a gap in the substance of the cell, forming a sort of exten-
sion of the nucleus, asif the fibre generally had been stretched
more completely than the nucleus. Mr. Ellis lays great stress
on a dotted appearance which he considers characteristic of
tavoluntary muscular fibre. I must say I agree with Kolliker
in finding the fibre-cells, for the most part, homogeneous when
extended, or faintly marked with longitudinal strie.* No
doubt dots are present in abundance; but these, so far as I
have observed them in the pig’s intestine, are distinctly exte-
rior to the fibres, though adherent to their surface; and I
suspect them to be little globules of a tenacious connecting
fluid. 'That the fibre-cells do stick very tightly together,
may be seen by drying a minute portion of the tissue, after
which they will be found shrunk, and slightly separated from
one another, but connected more or less by minute threads.
To sum up the general results to which we are led by the
facts above mentioned. It appears that in the arteries of the
frog, and in the intestine of the pig, the involuntary muscular
tissue is composed of slightly flattened elongated elements,
with tapering extremities, each provided at its central and
* The longitudinal stria above referred to, are probably due to a fine
fibrous structure in the substance of the fibre-cells. When in London, last
Christmas, I had, through the kindness of Dr. Sharpey, the opportunity of
examining a specimen of muscle from the stomach of a rabbit; which he had
prepared after Reichert’s method. The nitric acid had not only detached
the fibre-cells from one another, but also brought out very distinetly in each
muscular element the appearance of minute parallel longitudinal fibres,
which seemed to make up the entire mass of the fibre-cell except the
nucleus. Ina plate accompanying the paper on the Iris, before referred to,
I gave figures of some fibre-cells with distinct granules arranged in longi-
tudinal and transverse rows. This appearance, which, however, so far as
my experience goes, is exceptional, and is hardly sufficiently marked to de-
serve the appellation “dotted,” is probably caused by unequal contractions
in the constituent material.—April 2d, 1857.
14 RALFS, ON DIATOMACE.
thickest part with a single cylindrical nucleus imbedded in
its substance.
Professor Kélliker’s account of the tissue bemg thus com-
pletely confirmed in these two instances, and the description
here given of its appearance in the arteries of the frog’s foot
being an independent confirmation of the general doctrine,
there seems no reason any longer to doubt its truth.
It further appears, that in the pig’s intestine the muscular
elements are, on the one hand, capable of an extraordinary
degree of extension, and, on the other hand, are endowed
with a marvellous faculty of contraction, by which they may
be reduced from the condition of very long fibres to that of
almost globular masses. In the extended state they have a
soft, delicate, and usually homogeneous aspect, which becomes
altered during contraction by the supervention of highly
refractmg transverse ribs, which grow thicker and more
approximated as the process advances. Meanwhile, the “ rod-
shaped” nucleus appears to be pinched up by the contract-
ing fibre till it assumes a slightly oval form, with the longer
diameter transversely placed.
I will only further remark, that these properties of the
constituent elements of involuntary muscular fibre explain, in
a very beautiful manner, the extraordinary range of contrac-
tility which characterises the hollow viscera.
Nores on the S1uicrous Cety of Diatomacem.
By J. Rarrs, Esq.
Tur few remarks now offered to the British Association,
“upon the siliceous cell formed within the frustules of
several Diatomaceze,” have been written rather to stimulate
the researches of my fellow-students, and to elicit their
opinions, than to communicate any new facts.
I believe that in my description of Fragilaria (Himan-
tidium) pectinalis, in 1843, I was the first to indicate the
occurrence of these cells, in the following words: “ Within
the frustule there is apparently another siliceous frustule, the
lateral margins of which are rounded, having striz like the
outer frustule. In the longer frustules it is nearly elliptic,
but in the shorter ones appears as if truncated at the ends,
and in both it occupies the whole interior of the frustule,
except the corners where the puncta at the ends are situated ;
RALPS, ON DIATOMACES. 15
it is filled with a yellowish, granular mass, mixed with
numerous colourless vesicles.” Subsequently, the presence
of these internal cells has been, in two instances (Meridion
Zinckent and Himantidium Soleirolit), adopted as part of the
specific character. In this conclusion I could not concur,
because I found in the same filament such frustules inter-
spersed with others in the common state. More recently, in
Professor Smith’s beautiful work on the British Diatomaceze,
we have had his opinion respecting this condition of Meridien
circulare thus stated :
“Tn var 6. we meet with a curious modification in the
growth of the frustule, which has been regarded by some
observers as characteristic of a distinct species. re
A close examination of such frustules, especially in the living
state, has led me to the conclusion that the appearance of a
double wall of silex is owimg to the formation within the
original frustule of a second perfect cell, instead of the usual
mode of division by which the original frustule is divided
into two half-new cells. In the present case, the central
vesicle, or cytoblast, becomes enlarged without division, and
secretes on its extension two new valves, which are pushed
outwards until they lie in close approximation with the
original valves. ‘This process is not always repeated, the
usual mode of self-division again recurs, and two valves are
formed in the interior of this new cell according to the nor-
mal method. This unusual method of development is not,
however, sufficiently constant to warrant the separation of
such frustules from the species in which it occurs, perhaps
hardly sufficient to constitute a variety, as frustules in both
the ordinary and abnormal states may be met with in the
same gathering, and even in the same filament.”
As part of the above explanation seems to me inconsistent
with what I have observed, I am anxious briefly to state my
own views, and to solicit a re-examination of the phenomena
by Professor Smith himself, satisfied that it would either
induce him to modify his opinions, or by the discovery of
new facts dissipate the uncertainty which at present may
reasonably be entertained of the nature of these internal
cells.
Although it is true that “we frequently find in the same
filament cells thus formed, and others following the normal
mode of growth,” as I formerly showed, yet I cannot agree
to Professor Smith’s statement under Himantidium Soleirolii,
that “there is no doubt of its being merely an accidental
modification of cell-growth.” On the contrary, I believe it
to be a reproductive state of the species, and consequently to
have a definite and important part in their economy.
16 RALFS, ON DIATOMACES.
For several years I have attentively watched the circum-
stances connected with the formation of these ner cells in
Himantidium undulatum, by gathering specimens at short
intervals. During great part of the winter, the filaments
increase in bulk, by repeated division of the frustules, until
they form large masses, filling the ditches; at length the
inner cells make their appearance, at first sparingly, but as_
spring advances, it is difficult, in many situations, to obtain
a filament without them. I have found that when these
become abundant, the filaments cease to grow, and the entire
mass soon breaks up and disappears. The same thing hap-
pens in the other species of Himantidium, and in Meridion.
I do not find that the inner cell commences in the centre,
and pushes its valves outwards, as stated by Professor Smith.
Vere this the case, the internal matter also would necessarily
be pushed outwards by the advancing valves, and thus con-
densed between them and the walls of the frustule. On the
contrary, in the Himantidium the internal matter, before
nearly fluid, collects within the new cell, becomes dense and
more granular, and the new walls are formed round it in the
situation they are to occupy, leaving an empty space between
them and the walls of the frustule.
The alteration and condensation of the colourmg matter,
and the appearance, or at least great increase of vesicles, have
a strong resemblance to what takes place previous to the
formation of sporangia, the completion of which, as in this
case, usually preludes the death and disappearance of the mass.
As in most acknowledged sporangia, the cell thus formed
always tends to assume an oval or orbicular form. It, how-
ever, is very frequently, and perhaps generally, divided in
halves, as in the fission of the frustules, so that the oval
seems made up of two neighbouring frustules ; but this is not
the case, as may readily be ascertained by noticing the mar-
ginal puncta of the original frustule.
Do these newly constituted cells ever continue to divide,
as Professor Smith supposes? I believe not; at least I have
never seen a specimen in which the semi-elliptie portions
were separated by the interposition of other valves resembling
either themselves or those of the ordinary frustule. For my .
own part, I have been unable to trace the species after the
formation of these cells, owing to the quickly succeeding
disappearance of the mass. If, indeed, this renewed division
does occur, the resemblance to what takes place in the
sporangia of some species of Melosira would be increased.
Professor Smith, in his most interesting and valuable
account of the ‘Reproduction in the Diatomacez,’ enume-
ROPER, ON BRITISH MARINE DIATOMACESA. 17
rates four modes in which sporangia are formed. The third
is thus defined :
“The valves of a single frustule separate, the contents set
free, rapidly increase in bulk, and finally become condensed
into a single Sporangium.”
As far as regards the Melosira varians, the only one in
. this group which I have had an opportunity of noticimg, I
believe the process is essentially the same as in the examples
already described. The only difference is, that the new-
formed cell being inflated, and much larger than the original
frustule, the valves of the frustule must necessarily be either
ruptured or pushed apart by the increasing growth of the
sporangium, and the latter alternative happens.
I have seen no specimen of Mr. Brightwell’s Chetoceros
Wighamii, but from his figures I believe the goniothecia-
like bodies constitute another example of the formation of
internal cells.
I have said that I consider these internal cells sporangia,
and essentially of the same nature as the inflated ones of
Melosira varians. At the same time we should not forget
that Mr. Thwaites discovered the Himantidium pectinale in a
truly conjugated state, and that it is contrary to our experi-
ence of the economy of nature that the same result should
be obtained in the same species in two different ways.
Notes on some New Spectres and Varieties of Britisn
Marine Diatomacez. By F.C.S. Rorrr, F.L.S., F.G:S.
Tue greater part of the British fresh-water species of
Diatomaceze, from the facility with which they are obtained,
and the frequent opportunities for collecting them offered to
every observer with a microscope, have probably been already
described; but that this is not the case with the marine spe-
cies, is shown by the great additions lately made to this class
by the researches of Dr. Gregory, Mr. Brightwell, and others ;
and, as they appear to have been hitherto somewhat neglected
on our Southern coasts, I hope to draw more particular at-
tention to this abundant field of origimal observation by
pointing out the best means of obtaining the marine species,
and at the same time propose to describe a few of the more
18 ROPER, ON BRITISH MARINE DIATOMACEA.
peculiar forms that have occurred to myself within the last
two years.
The mud of tidal harbours, and the creeks and pools on the
banks of estuaries, such as occur in the Thames, Poole Har-
bour, &ec., have been the chief source of supply of our present
marine flora of this class. But a large number of the more
interesting species are only to be obtaimed by dredging or
collecting the various species of filamentous marine Algze at
the lowest spring tides. These should be gathered in consi-
derable quantity, thoroughly washed, and left for some short
time in water, so that all the Diatomacez may become de-
tached. The sediment must then be allowed to subside, a
portion of it bemg preserved for the examination of any new
or interesting forms in a living state, and the remainder
treated with acid in the usual way. The sand and any re-
mains of the Algze not dissolved by the acid may then be
removed by subsidence, on the plan recommended by my
friend Mr. Okeden, in the ‘ Microsc. Journal,’ vol. i, p. 158,
which is preferable to that of Dr. Munro, described at page
241 of the same volume, as it is impossible to prevent the
admixture of gatherings from different localities by this
process, though when that is not an object it has some
advantages.
From an examination of the species described in Professor
Smith’s ‘Synopsis,’ I find that out of 455 species included in
that work as indigenous to Great Britain, 231 are from fresh
water, 82 occur in brackish water, and 142 are marine; and
of this latter number 72 have been collected from Poole,
Pevensey, Hull, and the Thames, whilst 10 were obtained
from molluscs, and only 6 are described as dredged in deep
water. That this gives a very imperfect notion of the nume-
rous species to be found at a considerable distance from the
shore is shown by the examination of the gatherings in
which the greater part of the new species now to be described
were found.
The Caldy gathering, which was made in five to six fathoms
water, contains many rather rare and interesting forms, in-
cluding Coscinodiscus concinnus, Biddulphia Baileyii and
rhombus, EHucampia zodiacus, Nitzschia spathulata, and Melo-
sira Westii, and I have altogether met with sixty-six species
described by Professor Smith. In the Lyme Regis gathering,
from a depth of five to eight fathoms, Synedra undulata,
Amphora costata, Campylodiscus Hodgsonit and Ralfsii, Na-
vicula crabro, and Rhabdonema Adriaticum occur, and I have
already found seventy-nine species included in the ‘ Synopsis.’
In addition to the new species and varieties which I now
proceed to describe, there are numerous other forms in both
ROPER, ON BRITISH MARINE DIATOMACES. 19
these gatherings of which the characters are so doubtful that
it is impossible to determine satisfactorily their specific, or, in
some cases, even generic position. All the drawings are mag-
nified 400 diameters.
Eupodiscus tessetatus, n. s.—Cellular structure distinctly
hexagonal, with a small rounded nodule at each angle of the
hexagons. The surface of the valve slightly elevated, flat,
with a declining margin, of about one fifth of the diameter ;
pseudo-nodule single, submarginal.- Colour of dry valve
brown. Diameter :002”; diameter of cellules -000066" (fig.
i avand 6,'Pl: 111).
Marine. Caldy, Pembrokeshire, Rev. J.Guillemard; Hum-
ber, Mr. Norman.
I received the first specimens of this very pretty species in
a gathering obtained by the Rev. J. Guillemard, by washing
a collection of small Algze, from the shore of Caldy Island,
near Tenby, and have since met with it im some slides sent by
Mr. Norman from dredgings in the Humber. It belongs to
the same class as H. crassus, fulvus, and Ralfsii ; which differ
from HE. argus, the typical species, m having merely one
circular spot or pseudo-nodule near the margin, and not dis-
tinct processes, as in that species. The cellular structure is
very peculiar, and unlike any other Diatom that I am ac-
quainted with, excepting coscinodiscus concinnus, each angle
of the hexagons bemg marked with a small dot or boss, as
shown in fig. 1 0, requirmg a magnifying power of 800 to
1000 diameters to bring out distinctly. The valves, when
seen with a low power, have so much the appearance of a
small piece of mosaic that I have named it ¢esselatus.
This species differs from EH. radiatus, the only form with
hexagonal cells, placed, I thik doubtfully, in this genus by
Professor Smith, in the peculiar arrangement of its cellules,
and in wanting the elevated processes and spines, which would
rather lead me to place that species with the Biddulphias
than in its present position.*
* Professor Smith, at p. 47 of the second volume of the ‘Synopsis,’
alluding to this species, states that it differs from Biddulphia ‘in the orbi-
cular outline of the valve, and in the processes being rather projections
from the disc than produced angles.” I have, however, specimens of B.
turgida, which are very nearly orbicular, and I cannot agree that the pro-
cesses simply rise from the surface of the disc, as shown in t. lxii, f. 255,
of the ‘Synopsis,’ but are projections rising gradually from the centre of the
valve, with cellular structure continnous nearly to their apices, exactly as in
B. rhombus, many specimens of which are also nearly orbicular. In addi-
tion, the processes in Eupodiscus are all similar in structure, whilst in Z.
radiatus we have two cellular projections, and two spines, as in B. Baileyit,
and generally in B. aurita.
20 ROPER, ON BRITISH MARINE DIATOMACE.
From a careful examination of the figures in Ehrenberg’s
‘ Microgeologie,’ I consider this species may be synonymous
with his Coscinodiscus limbatus, t. xx, f. 29, or Cos. fimbriatus,
t. xxii, f. 2, but there is no pseudo- nodule given in the figures,
and without authentic specimens it is impossible to refer it
with any certainty to either of these species.
Coscinodiscus concinnus.—‘ Synopsis,’ vol. 1, p. 85.
Marine. Caldy, Pembrokeshire, Rev. J. Guillemard ;
Humber, Mr. Norman (fig. 12).
This interesting species, discovered by Professor Smith,
and described in the Appendix to vol. 11 of the ‘ Synopsis,’
occurs with tolerable frequency in the Caldy gathermg, and
I have received remarkably fine specimens, through the
kindness of Mr. Norman, from dredgimgs in the Humber.
Although not a new form, it has not yet been figured, and as
the large size of the specimens enables me to add some further
points to those already given by Professor Smith of the
peculiarities of its structure, I may be excused for cluding
it in these notes.
The description given in the ‘Synopsis’ is as follows:
“ Cellules arranged im radiating lines, equal except im centre
of valve, where there occur three to eight larger cellules ;
cellules 24 im 001"; diameter :0025" to -0056."” This is
perfectly correct as far as it goes, except as to size, my
specimens ranging from ‘004 to -013”, or nearly double
the size of Professor Smith’s. But the larger specimens
show plainly a point that is not easily discernible in those
under ‘O04 in diameter, namely, a submargmal row of
minute spines varying from ya4yoth to zo!)pth of an inch apart,
according to the size of the disc, and from each of which
there is a radiating line almost to the centre of the valve.
The celiules themselves are hexagonal and formed on the
same peculiar plan as already described im Eupodiscus
tesselatus, and shown im fig. 1 8 The large irregularly
formed cells in the centre havi ing hkewise dots at their a angles.
The valve is very convex ; so much so in the larger specimens,
that when the central cells are in focus with a high power,
the circumference is almost invisible. It differs in this
respect from Cose. per, foratus, to which it is most nearly
allied, that species having much the form of a lmette watch-
elass, flat im the centre, with a narrow sloping margin. The
cellules are also much smaller in C. concinnus.
With these new facts the following description might be
given of the species: “Valves very convex, with minute
hex xagonal cellules arranged in radiating lines, divided at
ROPER, ON BRITISH MARINE DIATOMACE. 21
short intervals by rays, extending from a band of submarginal
spines almost to the centre, where there occur from three to
eight irregularly shaped larger cellules.” Cellules 10 to 26
in 001”; diameter 0025” to :018”.
I figure a small specimen as the structure is precisely
similar, and cellules vary little in size from those in the
largest valves, those with 10 to 20 in :001 being rather rare,
and I have only found them of this size in the specimens
from the Humber.
Coscinodiscus labyrinthus, un. s.—Cellules hexagonal, minute,
arranged in quincunx in large irregular hexagonal spaces,
divided by lines of confluent cellules or dots; valves not
spinous at the margin, but with a ring of minute submar-
ginal papille. Diameter :0018" to 00247” ; diameter of hexa-
gonal spaces ‘00027" to -00038”; cellules 15 in ‘001" (fig. 2 a
and 8).
Marine. Caldy, Pembrokeshire, Rev. J. Guillemard.
I have only met with four specimens of this peculiar species
in the slides I have examined from the Caldy gathering, but
the arrangement of the cellules is so different from any yet
figured, that it may fairly be entitled to rank as a new
species. It has somewhat the aspect, under a low power, of
a finely marked specimen of C. eccentricus, but differs in the
absence of the spmous margin, and in the peculiar arrange-
ment of the cellules, which have somewhat the appearance of
whorls or coils of dots, as shown in fig. 2 5, the surface of
the valve being thus divided into large and irregularly shaped
hexagonal spaces, without any clearly defined margin. C.
eccentricus occurs abundantly in this gathermg; but neither
in this nor in any other locality in which I have met with it,
has there been any tendency to a similar arrangement of the
cellular markings.
Coscinodiscus (?) stellaris, n. s.—Cellular markings very
minute, with five or six larger cells or dots arranged as a star,
in the centre; surface slightly convex; margin not spinous ’
colour of dry valve, brown. Diameter -00252” (fig. 3).
Marine. Caldy, Pembrokeshire, Rev. J. Guillemard.
The detached frustules and single valves of this species are
abundant in the Caldy gathermg. The markings on the
surface of the disk are exceedingly fine, and have much the
appearance of the transverse striz on Pleurosigma angulatum,
even when seen with an 4-objective and oblique light. The
star-like arrangement of cells or dots is found in the centre
of both valves, and is readily distinguished with a magnifying
power of 200 diameters. The strize are so inconspicuous, and
22 ROPER, ON BRITISH MARINE DIATOMACES.
valve so hyaline, when mounted in balsam, that it has probably
hitherto escaped notice, from being considered a detached
ring or connecting membrane of C. radiatus or eccentricus.
I was at first inclined to refer this species to Podosira, but
the slight convexity of the valve, and the absence of the appa-
rent perforation at the apex characteristic of that genus, are,
T consider, sufficient to preclude its bemg so classed. The
frustules being always separate and never in filaments, distin-
guish it from Melosira, and the want of any process or
pseudo-nodule separate it from Eupodiscus It differs from
the finest-marked specimens of Coscinodiscus eccentricus 1m
the absence of the eccentric limes and spinous margin, and
from all other species of that genus in not having distinct
cellular markings.
Coscinodiscus (?) ovalis,n.s.— Valves oval, with finely dotted
striz radiating from the centre to the circumference ; of a dull
slate colour when dry, and light brown in balsam. Length
00158" to :0023" ; breadth -00128” to :00149” (fig. 4).
Marine. Caldy, Pembrokeshire, and dredged off Tenby,
Rev. J. Guillemard.
The valves of this species occur abundantly in the Caldy
gathering, and in the washings of Vesicularia dredged in five
fathoms off Tenby. Professor Smith informs me that he does
not see any satisfactory evidence for referring this species to
the Diatomacee ; and although I differ from so high an au-
thority with great reluctance, I still record it, though with
some doubts as to its generic position, in the hopes that the
attention of observers in other localities may be directed to
it, in order to clear up the doubtful poimts in its structure.
That it belongs to the Diatomacez I think admits of little
doubt ; the frustules are siliceous, composed of two valves
very slightly convex, and occur abundantly in gatherings,
almost confined to various species of marme Diatoms. The
radiating strize on the surface of both valves are delicate, and
require a magnifying power of 400 diameters to make them
out satisfactorily; but the arrangement of the dots or
cellules is very similar to that of many other species of the
class.
The general outline of the valves agrees with that of some
species of Cocconeis, but the absence of a median line and
central nodule separate them from that genus. It is very
probable that it may be entitled to rank as a distinct genus ;
but as I have not had any opportunity of examining it in a
living state, I place it provisionally in Coscinodiscus, to
which, in general structure, it appears most closely allied.
ROPER, ON BRITISH MARINE DIATOMACES. 23
I have met with a few specimens of the same form in a
gathering of M. De Brébisson’s, containing Nitzschia palpe-
bralis, &c., from Normandy, kindly sent me by Professor Smith.
Actinocyclus triradiatus, nu. s.—Valve with three rays, the
surface covered with minute puncta or dots, with faint lines
connecting them ; the rays formed by slight elevations, with
a more closely dotted structure. Diameter -003" to ‘004 (fig.
5 a and 0).
Brackish water. Near Caermarthen.
This species occurs occasionally in clay, obtamed by my
friend, Mr. Okeden, from a brick-yard near Caermarthen, de-
posited probably by the tidal estuary that runs up to that
town. The general structure of the valve differs from all the
described species of this genus, having no distinct margins to
the segments, or any pseudo-nodule in the centre of the valve.
I consider, however, that it must be referred to Actinocyclus
without hesitation, and should have adopted Ehrenberg’s
name of Ternarius, but, from the figure in the ‘Microgeologie,’
that species appears to have distinct cells, and the rays are
similar to those in A. undulatus, and not elevations, or pro-
bably thickened cell-walls, as in this species. The peculiar
arrangement of the dots is shown in the enlarged fig. 5 6.
Nitzschia virgata, n. s—F. V. quadrangular, linear; S.V.
hnear-lanceolate, slightly arcuate, with produced and rather
obtuse extremities; striz distinct, dilated at intervals into
prominent ridges on the inner margin. Length :00405” to
70053"; strie 26 in 001”. (Fig. 6: a, side view; 0, front
view.)
Marine. Dredged off Tenby, Rev. J. Guillemard.
The outline of this species differs but slightly from that of
Nitzschia amphioxys, w.s.; but that is decidedly a fresh-water
species ; its extremities are more acutely lanceolate, and the
valve more arcuate ; the striz also terminate in puncta or
dots, stead of dilating into distinct bands, asin this species,
which was dredged in five fathoms, at about five miles from
the shore, and may be considered purely marine. The strongly
curved inner margin, and slightly recurved obtuse extremities,
as well as the peculiar thickened striz, separate it from
N. vivax.
The dark bands appear to arise from a thickening of the
strie at irregular intervals, varying from the third to the
first in succession, and extend on an average about one third
of the breadth of the valve, being shorter at the centre
VOL. VI. D
24 ROPER, ON BRITISH MARINE DIATOMACE,
and extremities, and rather above that length m the inter-
mediate space.
Amphora sulcata, Bréb.—Valves oblong, with truncate
extremities; the entire surface covered with longitudinal
bands, formed of short transverse strie. Length -00266” ;
breadth -001”; striz 14 and 20 in ‘001” (fig. 7).
Marine. Caldy, Pembrokeshire, Rev. J. Guillemard.
This species differs from any figured in vol. i. of the
‘Synopsis,’ and though it approaches in structure some of the
peculiar forms described by Professor Gregory m vol. v. of
the ‘ Microsc. Journal,’ I cannot refer it satisfactorily to either
of the species he has figured. M. De Brébisson, in his
‘Memoir on the Marine Diatomacez of Cherbourg,’ gives a
figure and description of Amphora sulcata, which appears
only to differ in being rather more elliptical than the present
species. I have therefore adopted his appellation, rather than
make a further addition to our long list of native species. It
appears to be rare, as I have only at present met with a
single specimen.
It differs from A. costata in the absence of the distinct
longitudinal coste and moniliform puncta, and from the
extremities being truncate and not produced as in that
species ; and from A. affinis, to which the outline of the valve
more nearly approaches, by the peculiar structure of its longi-
tudinal bands.
Amphora membranacea (fig. 8 a and b).
Brackish water. Pembroke Harbour. Barking Creek.
This species occurs abundantly in the mud from Pembroke
Harbour, but does not appear to be common in many other
localities, and I meet with it but rarely in the Thames and its
tributaries. I merely give a figure, as that in vol. i. of the
‘Synopsis’ appears to be taken from a frustule shortly after
self-division, and gives an erroneous impression of the full-
grown valve. The longitudinal striz are so marked a feature,
and the breadth between the central nodules so much greater
than in the specimen figured by Professor Smith, that the
form now given might readily be mistaken for a distinct
species. Fig. 8 a@ may be considered as fairly representing
the state in which 4. membranacea usually occurs. Fig. 8 6
is a frustule in process of self-division.
Cocconeis scutellum, var. y (fig. 9).
Marine. Lyme Regis.
I figure this species as a variety of C. scutellum, as at
ROPER, ON BRITISH MARINE DIATOMACE. 25
present I have only met with it in one marine gathering, in
which, however, it is not uncommon. The valve is oval, with
the nodule dilated into a stauros, and differs from C. scu-
tellum, var. (3, in the fineness of the dotted striz, and peculiar
ocelli or semi-oval markings cutting off a portion, on each
side of the valve. Professor Smith informs me that in his
opinion they belong to the connecting membrane, but they
appear to be rather. a thickening on the inner surface of the
cell-wall. This species of Cocconeis is 80 very variable in size
and appearance, that without having specimens with the
same peculiar structure from several localities, I think it
better to consider it as a variety, though more extended
observation may prove that it should be classed as a distinct
species.
Navicula liber, var. 3.—Valve oblong, contracted towards
the rounded extremities ; striz faint, parallel, not reaching the
central line. Length -0033" ; breadth -OOL” (fig. 10).
Marine. Caldy, Pembrokeshire, Rev. J. Guillemard.
Professor Smith having, in vol. ii of the ‘ Synopsis,’
Liha Ehrenberg’s Nav. amphigomphus as a cuneate variety of
N. firma. 1 refer this species with little hesitation as a
somewhat similar variation to the nearly allied marine form
N. liber, from which it appears to differ only m having
bluntly cuneate extremities, and rather larger space between
the termination of the strize and the median line. . It is pro-
bably synonymous with Ehrenberg’s N. dilatata of the
‘Microgeologie,’ t. u, f. 10.
Pleurosigma transversale, var. 3.—V alve elliptical, lanceolate,
with acute extremities, and very slightly curved median line ;
strice aoa Length -0032" to ‘004 ; breadth -0009” to -001”
(ig. 11).
Marme. Caldy, Pembrokeshire, and dredged off Tenby,
Rev. J. Guillemard.
The typical species of P. transversale is by no means
uncommon in both the gatherings above alluded to, whilst
the variety here figured is rather rare. The general outline
and structure of the valve is, however, so similar to that
species, that having only at present met with it in these
gatherings from Tenby Bay, I figure it merely as a variety,
though more extended observation may prove it to be a
distinct species. The vaives are much broader in proportion
to the length than in the typical species, the extremities are
acute instead of obtuse, and the median line nearly straight
instead of having a considerable curvature. The striation
also is finer and more difficult to resolve, than in that species.
26
TRANSLATIONS.
On the OssiricaTion of the PrrmorpIAL CARTILAGE.
By A. Baur, of Tubingen.
(Abstracted from Miiller’s ‘ Archiv,’ 1857, No. 4, p. 347.)
A mricroscopicaL analysis of the changes which take place
in the ossification of cartilage has two questions to resolve :
First, in what way does the peculiar structure of osseous
substance arise from the so widely different structure of car-
tilage? and, secondly, im this process, im what relation do
the elements of the cartilage stand towards those of the
bone? The latter question especially, since it has become
known that bone may be formed without any pre-existing
cartilage, has acquired redoubled interest.
The origin of all osseous substance, not previously car-
tilage, must be referred to the ossification of a blastema,
which, according to most observers, is to be regarded as of
the same nature as that of connective tissue; it consists,
that is to say, of a matrix as yet indistinctly fibrillated, in
which are scattered simple rounded cells, identical with the
primary formative cells of connective tissue—the future con-
nective tissue corpuscles. It is easily perceived that the
ossification of this blastema is effected simply by the deposi-
tion of calcareous matter in its intercellular substance, owing
to which it gradually, and without any distinct lne of limi-
tation, assumes the character of the osseous basal substance,
whilst the cells shoot out into the irregular bone-corpuscles.
In this case, it is certain that no intermediation of cartilagi-
nous elements takes place ; nor can any indication of a pre-
vious opacity dependent upon calcareous particles be re-
marked. The process, therefore, can only be described as a
direct ossification of the connective tissue.
The process of ossification in cartilage is more complex.
In this case, a simple transformation of the substance does
not take place, but simultaneously with it a total change of
structure, in consequence of which it becomes difficult to
trace the histological alterations. The most favorable objects
for examination are, perhaps, thin transverse sections made
in various directions through the ossifying border of the dia-
physis of a foetal long-bone, in as fresh a condition as possible.
BAUR, ON OSSIFICATION OF CARTILAGE. 27
The processes, which have in part been long well known,
which are here seen to precede the ossification, are as fol-
lows: The cartilage-cells,.which were previously uniformly
dispersed, assume a definite order, corresponding to the sub-
sequent bony structure; in the cartilages of the long bones
they dispose themselves in rows, which, in a transverse sec-
tion, appear like rounded groups. At the same time the
individual cells increase in size, their contents, at first opaque
and granular, become transparent, and exhibit a large vesi-
cular nucleated nucleus. This enlargement of the cartilage-
cells is effected at the expense of the matrix, which is even-
tually so much diminished in proportionate bulk, that the
separate rows of cells are separated only by a thin layer of .
intercellular substance, whilst the cells in each row are
themselves in absolute contact. A deposition of earthy
elements, in the form of an opaque, coarse- or fine-grained
material, now takes place on the walls of these cartilaginous
cavities or canals. This deposit of earthy matter “forms
apparently the distinction between cartilage and bone, but
the microscopical characters of bone are still wanting—the
bone-corpuscles, that is to say, and a homogeneous matrix.
The cartilage-cells as yet lie unchanged in the cartilaginous
capsules incrusted with calcareous matter, and whose opacity,
even, renders the tracing of their further metamorphosis
difficult. This, however, in the next place, consists in the
circumstance that each cartilage-cell becomes the seat of an
endogenous cell-formation ; for in place of a single vesicular
nucleus, which may already be regarded as a secondary cell,
several ‘vesicles of the same kind make their appearance,
which fill the parent-cell, and after its disappearance become
free. It is this brood of cells thus corresponding to the
nucleus of the cartilage-cells, which constitute the contents
of the calcified cartilaginous cavities, and become the start-
ing point of all the subsequent changes. The fact, that in the
ossification of cartilage an endogenous cell-formation takes
place in the cartilage-cells—a process which is to be essen-
tially distinguished from the multiplication of cartilage-cells
by division, ‘such as is noticed in the growth of the cartilage
before the commencement of ossification—has hitherto been
adduced by all observers only in connection with the forma-
tion of the medullary constituents of the bone, its import-
ance as regards the origin of the bone itself not having been
recognised. For whilst, in fact, part of this new generation
of cells is transformed into blood-vessels, fat-cells, or indif-
ferent medulla-cells, the peripheral cells, in apposition with
the calcified cartilaginous capsules, are always surrounded
28 BAUR, ON OSSIFICATION OF CARTILAGE.
with a layer of soft, streaked interstitial substance, which
lines the interior of the cartilage-cavities. Of true bone-
substance, no trace was, up to this stage, to be perceived.
This is not formed until this time by the direct ossification
of this blastema, that is to say, by the transformation of its
cells into bone-corpuscles, and of its intercellular substance
into a homogeneous, not granular, osseous matrix. Whence
it is evident that the first bone-substance must make its
appearance in the form of a tube imclosing these calcified
cartilage-cavities, and which in a transverse section presents
the appearance of a ring beset with a single series of bone-
cells. This osseous cylinder now becomes thickened from
within outwards, by the successive ossification of new layers
of blastema, deposited m a similar manner to the first, so
that each cartilage-canal is gradually more or less completely
filled up with a system of concentric osseous lamelle. The
uniform concentrically lamellated structure of the long bones,
which ever exists, is thus explained by the circumstance, that
in the interior of each medullary canaliculus, a successive
formation of ossifying lamin takes place from the centre
outwardly, exactly in the same way as in the formation of
the cortical substance from the periosteum, it takes place
from the periphery.
From what has been said, it is apparent that the individual
tubuli of newly formed bone-substance must at first be sur-
rounded by calcified cartilage-substance, and be separated
from each other. It is now generally admitted, as in fact
appearances render probable, that the calcified matrix of car-
tilage itself is gradually transformed into homogeneous bone-
substance, either by the coalescence of the separate calca-
reous particles into a homogeneous substance, or that these
particles, being only a provisional calcareous deposit, are
previously absorbed. Upon this point it may now be re-
marked, that the granular earthy deposit at any rate dis-
appears, but with it also the organic substance to which it
belonged ; and that thus the already commenced resorption
of the cartilaginous matrix continues also after the com-
mencement of the deposition of calcareous matter, in order
to make way for the new bone-substance. This may be
proved by direct observation. If a portion of cartilage
undergoing ossification be treated with dilute hydrochloric
acid, and transverse sections be made at the proper place,
parallel with the border of the ossification, on using a due mag-
nifying power, the ring, consisting of a single layer, of yellow-
ish, strongly refractive bone-cartilage, beset with opaque
bone-cells, will be seen, sharply defined, and in strong con-
BAUR, ON OSSIFICATION OF CARTILAGE. 29
trast with the wholly colourless cartilaginous matrix sur-
rounding it, and which has regained its transparency owing
to the solution of the calcareous particles, a clear proof that,
in this case, the two tissues are not in a Condition of con-
tmuous transition, but simply in juxtaposition. Further on,
the separate, occasionally thickened and laminated osseous
rings are seen to become more and more closely approxi-
mated, until, the mtervening layer of cartilage having en-
tirely disappeared, they come into immediate contact. Thence
it follows that the matrix of the primordial cartilage takes no
part in the formation of the bone-substance, but that, on
the contrary, notwithstanding the calcification, it undergoes
absorption. This result, derived from observ ation, has been
long rendered probable by the chemical ElnGene of these
tissues, seeing that the diversity in chemical constitution
between bone-cartilage and the hyaline cartilage-substance
was opposed to the notion that the latter remained im a per-
sistent form in bone. In explanation, therefore, of the pro-
cess of ossification, we must assume either a chemical change
or a molecular replacement of the one substance by the other.
But from what has been stated, it is proved that this replace-
ment is not one of a merely chemical, molecular nature, but
histological. The organic basis of bone is no more anatomi-
eally than it is chemically identical with the matrix of hya-
line cartilage. The latter is incapable of true ossification ;
its calcification’ is a process accompanying ossification, it is
true, but one of an essentially different nature.
The osseous substance which makes its appearance in car-
tilage is a new formation in the cartilage-cavities, but it does
not commence at once as such, its formation being preceded
by that of a blastema, consisting of simple cells, and a soft
intercellular substance. Now this blastema corresponds in
every respect with the ossifying layer of the periosteum, and,
like that, with immature connective tissue, and it should,
therefore, be described as of the nature of connective tissue.
Its ossification takes place by the calcification of the persis-
tently homogeneous intercellular substance, and the transfor-’
mation of its cells mto bone-corpuscles.
Thus, in cartilage also, ossification is preceded by a forma-
tion of connective tissue—in this case effected through the
cartilage-cells. Connective tissue is thus the only foundation
of the formation of bone. We thus have a histogenetic
demonstration of the chemical correspondence of the so-
termed bone-cartilage with the collagenous tissues, and, in
general, established the hitherto overlooked unity in the
genesis of the osseous tissue, inasmuch as the formation of
30 BAUR, ON OSSIFICATION OF CARTILAGE,
the primary and secondary bone-substance is referred to one
and the same process.
The share taken by the cartilage-cells in the process of
ossification, consists im this, that they are the parents of
those cells which afterward surround the ossifying connective
substance, and sprout out in a radiate manner to form the
bone-corpuscles. Thus the cells of the primordial cartilage
are never, as such, transformed into bone-colls. The num-
ber, size, and arrangement of the two, are consequently by
no means the same; it should rather be said, that all the
bone-corpuscles of a lamellar system correspond to a single
row of cartilage-cells in the bone. The bone-corpuscles do
not make their appearance until after the cartilage cells have
been destroyed in the production of secondary cells, so that
any transition from one into the other will be sought for in
vain.
In sections, on the other hand, taken from slowly and
imperfectly ossifying cartilage, appearances are not unfre-
quently met with, showing the occurrence within the still
visible contours of a cartilage-cell of only one, or of a few
closely packed bone corpuscles. In this case, the production
of secondary cells had been limited to a few, or of only one.
The surrounding of the endogenous cells with ossifying con-
nective tissue, took place while still within the parent cell;
true bone-substance, therefore, is limited to the cireumfer-
ence of the cartilage-cell, whilst the latter itself is surrounded
by calcified (or, im rachitic boxes, by perfectly hyaline) car-
tilage-substance. Appearances of this kind have given rise
to the supposition, that the bone-corpuscles correspond to
the nuclei of the cartilage-cells, or to the cells themselves,
thickened by imternal deposit. This view, however, in the
case of the ossification of fcetal cartilage, leaves us im the
lurch, whilst the results here obtained permit us to arrive, m
general, at a satisfactory explanation. The process of ossi-
fication of the primordial cartilage has shown, on the one
side, that the bone-substance is not only chemically identical
with that of connective tissue, but can only be referred, his-
togenetically, to the elements of that tissue; and, on the
other, that the tissue of hyaline cartilage is incapable of direct
ossification, smee it can be shown that neither its substance
nor its cells, as such, remain in the synonymous elements of
the bone. The proposition that a formation of bone is pos-
sible out of cartilage, in the same way as it is out of con-
nective tissue, by the deposition of calcareous salts in its
matrix-substance, and the transformation of its morphologi-
cal elements into bone-corpuscles, is thus contradicted, and,
KOLLIKER, ON MUSCULAR FIBRE. 31
at the same time, is the doctrine of the identity of cartilage
with bone and connective tissue, deprived of one of its most
important supports.
K6.i1KeR on the Structure of Muscutar Fisre
(‘Zeitsch. f. Wiss. Zool.,’ vol. viii, p. 311.)
KOLuikeEr states in his recent examination of muscle, made
with reference to certain observations by Leydig on the same
subject, he has found that in recent muscular fibre, besides
the contractile parts and the nuc/ez, an interstitial substance
exists presenting peculiar morphological characters, and
which would appear, in all probability, to play an important
part in the physiological and pathological processes in muscle.
If a portion of recent frog’s muscle be examined carefully,
and with good glasses, in an indifferent medium, two con-
stituents in the muscular fibre will be perceived :
1. The contractile, transversely or longitudinally striped
substance, and—
2. Very pale rounded corpuscles imbedded in the con-
tractile substance, and disposed in long linear tracts. These
granular tracts exist throughout the entire thickness of the
fibre, on the surface as well as more deeply, and are so nu-
merous as apparently to constitute no inconsiderable element
of the muscular fibre. They are most readily seen in the
longitudinally striped fibres ; but even in these it is not easy
to determine the true position of the particles, although it
would seem from the appearances presented that the tracts
are not continuous through the entire length of the muscle,
but are subdivided into longer or shorter portions. In the
transversely striped fibre, these molecules are rendered
more evident on the addition of water.
Kolliker notices also the formation of vacuolar spaces in
the interior of muscular fibre, under the influence of dilute
saline solutions—as for instance of sulphate of soda of 83—7
per cent. ‘These vacuoles, which contain a clear fluid, are dis-
posed in longitudinal series, apparently occupying the spaces
in which the above-described granular tracts are disposed.
SS KOLILIKER, ON MUSCULAR FIBRE.
After other observations tending to disprove the existence
of the minute canals supposed by Leydig to exist in muscular
fibre, Kolliker says, “ with respect to the interstitial granu-
lar tracts in the muscular fibre of the frog, that one thing
in particular should be remarked,—that the opaque fat-
granules, which are frequently noticed in frog’s muscle, origi-
nate in a metamorphosis of the pale granules above described.
These molecules, in chemical constitution, appear to differ
but little from the contractile substance—they are merely
of rather more difficult solution in caustic alkali, and more
soluble in acetic acid.
This interstitial granular substance would appear to exist
in the muscular substance, perhaps, of all animals. It is
particularly well developed in the muscles of insects, naked
amphibia, the sturgeon, &c.; in the latter instance, however,
the molecules in their normal condition were observed only
in the pale-coloured muscles. In the reddish subcutaneous
muscles they appeared to be replaced by series of fat-mole-
cules, of far larger size, especially near the tendons, and
giving the muscle a more peculiar character than is presented
even in the muscles affected with the highest degree of fatty
degeneration.
In the mammalia and in man the interstitial granules are
very delicate and pale; and they are distinctly recognisable
only when in a state of fatty degeneration, in which state
they exhibit, in a transverse section, an appearance like that
seen in the muscles of the frog.
As regards the physiological import of the interstitial
granular substance, Kolliker throws out as a probable hypo-
thesis, that the granular tracts in question originate directly
in the disintegration of the fibrils, and represent the normal
molecular change of the muscular substance. He admits,
nevertheless, that this explanation is attended with many
difficulties, and that other suppositions may be entertamed
with apparently nearly equal justice.
He sums up the results of his inquiries into the ultimate
structure of muscle as follows :
1. All muscular fibres contain a large number of well-
marked, vesicular nuclei with nucleoli, which are either
parietal and affixed to the sarcolemma (human), or uni-
formly dispersed throughout the contractile substance (Am-
phibia), or even, as in certain embryos, disposed in series in
the centre of the primitive fasciculus (some muscular fibres
of Amphibia.)
2. Inthe case of the contractile substance of the muscular
fibres, it appears to him, as regards the higher animals, most
SCHLOSSBERGER, ON CRYSTALS IN CATERPILLARS. 33
im accordance with nature to assume that they are composed
of fibrils, the transverse segments of which may be recog-
nised in the Amphibia as minute, closely approximated
points.
3 No amorphous connective substance between the fibrille
can be shown to exist by the microscope; but, on the other
hand, there exists between them, at greater or less distances,
an interstitial substance of peculiar morphological character,
represented by serially disposed, pale granules.
4. These granules, which exhibit considerable power of
resistance towards caustic alkalies and acetic acid, are seen
in longitudinal views of recent unchanged musular fibre, or
in fibre which has been treated with caustic alkali, in their
natural relations; whilst, under treatment with acetic acid,
they appear like delicate streaks not unlike nucleated fibres.
In transverse sections of muscle, they always present the
appearance of a closer or wider punctation.
5. The well-known fat-granules of muscular fibre are
manifestly genetically connected with the granular streaks ;
and, in fact, the fat-granules in the pale muscles may often
be at once perceived to originate in the pale granules.
6. The lacunar system described by Leydig has no ex-
istence. The larger lacune of Leydig are the altered nuclei
of the muscular fibres, the smaller the changed interstitial
substance.
7. The physiological imports of the interstitial granules is
at present anything but clear. Many considerations would
show the probability of their beimg connected with. the
normal molecular changes in the muscles, but at the same
time other suppositions are conceivable.
On the Crystats contained in the Ma.pPicHIaN Vesseis of
Carrrpittars. By J. Scuiosspercer, of Tubingen.
(From Miiller’s ‘ Archiv,’ 1857, p. 61.)
In the Malpighian vessels of a caterpillar (Hichenspinne-
raupe) the microscope showed the contents to consist of
numerous, brilliant, and colourless crystalline corpuscles, of
34 SCHLOSSBERGER ON CRYSTALS IN CATERPILLARS,
very various sizes, although the largest were scarcely equal to
the quadratoctahedra of oxalate of lime which occur in human
urine. Most of these minute crystals were isolated; but
here and there might also be remarked crystalline masses, in
which the individual crystals were united by an amorphous
or membranous connective material. The isolated corpuscles
never presented more than one surface to view, which was for
the most part quadratic, though in some cases having an
oblong form. No octahedra could be observed.
They were insoluble in water, alcohol, and ether, as well
as in acetic acid, even after long standing or the application
of heat. Treated with nitric acid, and subsequently moistened
with ammonia, they exhibited no trace of the murexid colour.
Dilute nitric or hydrochloric acids dissolved the greater part
of them without effervescence ; the solution threw down a
copious precipitate on the addition of ammonia, which was
insoluble in acetic acid. When covered with sulphuric acid
gas bubbles were evolved, and bundles of crystals of selenite
shot out. When heated on platina-foil they turned brown
without fusing, andtheneffervesced with acids.
From the foregomg no doubt could be entertained that the
granules consisted essentially of ovalate of lime, and it is
certainly not without interest to find im the urme of man
and of insects, in the latter of which the presence of uric
acid had already been demonstrated, a second constituent
common to both, and probably a derivative of that acid, viz.,
oxalic acid.
When the crystals placed on the stage of the microscope
were brought into contact with mineral acids they exhibited
a very peculiar condition. A dark line appeared passing
transversely across the entire face and dividing it into two
halves, and frequently a second would be seen perpendicular
to the former, so that the surface would be divided into four
areas. Ultimately they also melted down from the borders,
but frequently were only partially dissolved, an extremely
minute granule or very thin plate, evidently of organic ma-
terial, being left. When the crystals were cautiously heated,
and then submitted to the microscope, many could be seen
retaining their original form, but deprived of their brilliancy
and transparency, and tinged of a yellowish colour. It must
be left undetermined whether the bodies now described are
to be regarded as true crystals or not rather as a sort of
secondary crystals or incrustations. With respect to this,
the author refers to the fact that m crystals of carbonate of
lime formed in the animal body (as, for instance, otolites),
for the most part, when dissolved, also leave a residue of or-
SCHLOSSBERGER, ON CRYSTALS IN CATERPILLARS. 35
ganic matter; not unfrequently, also, they are distinguished
from mineral calc-spar by their curved surfaces.
Whether the crystals in the Malpighian vessels of the
caterpillar of Sphinx convolvuli, described by H. Meckel
(Mull. ‘ Arch.,’ 1846, p. 44), and those noticed by Leydig in
the renal canals of Bombyx rubi and Talus (Mull. ‘ Arch.,’
1845, p. 466), are chemically identical with those above
noticed, cannot be determined, since neither author has com-
municated any chemical details. The former describes the
crystals in Sphynx convolvuli as quadrate pyramids, sometimes
white, and sometimes constituted of two white and an inter-
mediate red layer. The crystals noticed by Leydig were
octahedrous, whence it is very probable that these also con-
sisted of oxalate of lime.
REVIEWS.
A Monograph of the Fresh-water Polyzoa. By Guo. J.
Auman, M.D., F.R.S., &c., Regius Professor of Natural
History in the University of Edimburgh.
To the well-known and invaluable series of Monographs
by Alder and Hancock, Forbes, Baird, and Darwin, published
under the auspices of the Ray Society, we have to announce
the addition of the long-expected work of Professor Allman,
on the ‘ Fresh-water Polyzoa, including all the known species,
both British and Foreign.’
In this splendid addition to their publications, the Ray
Society, as in the former, has done excellent service to natural
history ; for whether we regard the intrmsic interest of the
subject itself, the complete and exhaustive way in which it has
been treated, or the beauty and fidelity of the illustrations,
Professor Allman’s Monograph may well take rank among
the most important contributions to zoological science that
have appeared for many years.
In the preface we are informed, if that were necessary,
that the work contains the result of many years’ careful
study, and that in its preparation no trouble has been spared
to render it as complete as possible, the subjects of which it
treats having been considered under every point of view of
which they seemed susceptible—zoographically, zootomically,
homologically, and historically. All the figures, we further-
more learn, upon the eleven lithographic plates, have been
drawn from nature, and contain careful representations of
of every species seen by the author, and in every case a
figure is given of the species, both coloured and in its natu-
ral size and magnified.
As the number of known species of “ Fresh-water Polyzoa”
is very small—not amounting to more than twenty-one,
twelve of which belong to one genus,—it is obvious, that had
the work been limited to a mere zoographical description of
them, its bulk would have been very inconsiderable. But of
the 119 pages of which it consists, 75 are occupied with con-
siderations involving the Polyzoa in general, though more
especially directed to those which are peculiar to fresh water.
It is needless to insist upon the greatly-increased value given
to the work from this large portion of its contents, for, as
remarked by Professor Allman, “ the Polyzoa constitute an
exceedingly natural group, and possess great uniformity of
ALLMAN, ON POLYZOA. 37
structure ; and as the fresh-water species afford fine typical
examples of the class, a work devoted to the anatomy of
these will apply in all essential points to that of the entire
class, while such points of structure as are peculiar to the
fresh-water forms will only tend to illustrate and explain the
structure of the marine ones; so that the present Mono-
graph, in its anatomical relations, may be fairly regarded as
a general treatise on polyzoal organization.”
After a full discussion of the anatomy, physiology, and
homologies of the Polyzoa in general, the author proceeds
to the zoographical part of his subject, including the history
and biblography of the Fresh-water Polyzoa—their habits,
geographical range, and classification. To which succeed
the diagnoses, synonymy, and natural history of the genera
and species; thus completely exhausting the subject, and
bringing our knowledge of it, in most essential particulars,
up to the present moment.
The classification of the Polyzoa adopted by Professor
Allman will be apparent in the following tabular view of their
orders and sub-orders :
Orders. Sub-orders.
Lophophore bilateral ; (Arms of lophophore free or
mouth with an epistome. | obsolete. j Lornorea.
PHYLACTOLASMATA | Arms of lophophore united at } Prices mien
the extremities. ;
Polypide only partially re-] UrnaTeLira
tractile P (fresh-water).
PALUDICELLEA
tile ; evagination of tenta- (fresh-water).
Polypide completely vente}
cular sheath imperfect.
Polypide completely retrac-
tile ; evagination perfect ; | CycLostoMaTA
orifice of cell destitute of { (marine).
GYMNOLAMATA. . moveable appendage.
Polypide completely retrac-
tile; evagination perfect ; |
a circle of sete attached to Crenostomata
the invertible portion, and { (marine).4
acting as an operculum in |
the retracted state. 2
tile; evagination perfect ;
orifice of the cell with a
moveable lip.
CHEILOSTOMATA
(marine).
Polypide completely at
38 ALLMAN, ON POLYZOA.
An arrangement which appears to us to be very natural and
convenient. The definitions, however, of the marine gymno-
leematous sub-orders do not include certain characters perhaps
fully as important as those here given. The Cyclostomata are
distinguished from the Cheilostomata, as much by the ter-
minal position of the orifice of the cell, as by its bemg unfur-
nished with a moveable lip or operculum; and from the
Ctenostomata, not more by the absence of the fringed or
setose margin to the orifice of the cell, than by the cir-
cumstance that in them the cells arise by gemmation one
from the other, as do those of the Cheilostomata, whilst in the
Ctenostomata, or, as perhaps they might move appropriately
be termed, the Crossostomata, the cells arise each separately
from a common tubular stem, with whose cavity that of
the cell communicates. The sub-terminal position of the
orifice of the cell appears to be an essential characteristic
of the important and numerous group of the Cheilo-
stoma.
The terminology employed by Professor Allman in the
description of the Polyzoa, differing from that heretofore
used, which has been very confused and unsatisfactory,
demands attention, inasmuch as, with perhaps the exception
of one term, it seems to us highly desirable that it should be
generally adopted. The retractile portion or zooid, he terms
“ nolypide ;” to the common dermal system of a colony—
often erroneously termed ‘ polypary” and “ polypidom”’—he
apples the term “ coencecium ;” this part consists almost
universally of two perfectly distinct tunics — the outer
of which is the “ ectocyst,’ whilst the internal is termed
“endocyst.” The sort of disc or stage, which surrounds
the mouth and bears the tentacula, is called the ‘“ lopho-
phore,’ whilst the “epistome” is a peculiar valve-like
organ which arches over the mouth in most of the fresh-
water genera. The “ perigastric space” is the space included
between the walls of the endocyst and the alimentary canal.
The canecium is composed of the little chambers, or “cells,”
in which the polypides are lodged, whilst that part of the ced/
through which they protrude is the “ orifice.”
With reference to these terms, we would observe, that the
term polyzoary, or in Latin, polyzoarum, which we have
elsewhere employed, appears to us to be more likely
to receive popular acceptation than the more recondite
word, cenecium. 'The terms “ ectocyst” and “ endocyst,”
though strictly applicable and highly appropriate nearly
throughout the Polyzoa, must, when employed in the descrip-
tion of the Ctenostomata, be somewhat strained when used to
ALLMAN, ON POLYZOA. 39
signify the outer and inner membranes of which the tubular
portion of the polyzoary is composed. With respect to the
composition of these membranes, a full description is given
of the structure of the endocyst, which may be observed most
favourably in Lophopus crystallinus. In this species it is com-
posed of large, irregularly-shaped cells, filled with a colourless
and transparent fluid. The mode of formation of these cells
may be satisfactorily followed.
It would seem, from some appearances noticed by Pro-
fessor Allman, that the endocyst is pervaded by a system of
canals of extreme delicacy, which constitute an irregular
network in its substance; a curious and important fact, if
confirmed by further observation.
The ectocyst appears m every case to be absolutely struc-
tureless, and the presence of cellulose could never be detected
in it. The reactions of the pergamentaceous ectocysts of
Plumatella are in favour of this tissue being composed of
chitine. The “ ectocyst,’ therefore, it 1s observed, of the
Polyzoa would seem to differ—at any rate, chemically—from
the test of the Tunicata.
In the account of the digestive system, an elaborate
account is given of the histological structure of the alimen-
tary canal, which is somewhat complex. Hermaphrodite flowers.
B. Animals by Zooids. B. In Animals.
J. Isozooids. 1. Gynozooids.
Gems, or buds. Females.
2. Allozooids. Fi) Oe
* Nurses ” (Steenstrup). 2. A nay suit
** Avamozooids”’ (Huxley). oy
“Virgin Aphides”’? (Owen). 3. Androgynozooids.
“ Agamic eggs” (Lubbock), Hermaphrodites.
“Drone bees” (Siebold).
PROCEEDINGS OF SOCIETIES. 81
On certain Pathological Characters of the Blood-corpuscles.
By Mr. J. B. Hennessy.
He stated the results of his microscopical observations on,
first, healthy blood, and on, secondly, inflamed blood. The
result to which he directed particular attention was, that in
infiamed blood the corpuscles were smaller and darker than
in healthy blood. In corroboration of his views, he quoted
the remarks of M. Donne, of Mr. Wharton Jones, Mr.
Gulliver, and many others, upon this change of size. Mr.
Hennessy founded a theory of inflammation through increase
of temperature, the occurrence of the buffy coat and the
other phenomena being satisfactorily explained.
On the importance of introducing a New and Uniform Standard
of Micrometric Measurement. By Professor Lyons.
He alluded to the great difficulties experienced by observers
in enumerating, rendering, and even remembering the various
kinds of measures now in use in these countries and on the
Continent, portions of the English, Irish, and French inch
and line, and decimal parts of the French millimetre. The
high figure in the denominator and the number of decimal
plans were exceedingly cumbrous. He (Dr. Lyons) would
propose that some definite micrometric integer should be
assumed, being a determinate part of unity. He proposed
that this measure should be denominated a microline. He
did not mean definitely to bind himself to the adoption of
any standard, but would propose provisionally that the one
ten-thousandth part of the English inch should be assumed
and denominated the standard microline pro tem. He would,
however, have his hearers bear in mind the present tendency
of scientific men towards a decimal system. For his own
part he would prefer the French decimal scale.
Observations on the Flow of the Lacteal Fluid in the Me-
sentery of the Mouse. By Josrry Lister, Esq., F.R.C.S.
Eng. and Edin., Assistant-Surgeon to the Royal Infirmary
of Edinburgh.
Tuer experiments of which a short account will be given in
the present communication, were performed in the summer
of 1853, but have not been hitherto published. The objects
for which they were undertaken were, in the first place, to
observe the character of the flow of the chyle through the
lacteals, a thing which, as far as I know, had never been
satisfactorily done; and in the second place, to throw some
light if possible upon the debated question whether or not the
82 PROCEEDINGS OF SOCIETIES.
lacteals possess the power of absorbing solid matter in the
form of granules visible to the human eye.
In the experiments made for the former purpose, a mouse
having been put under the influence of chloroform about two
hours after partaking of a full meal of bread and milk, the
abdominal cavity was laid open by a median longitudinal
incision, and the animal having been placed on its side upon
a plate of glass, a coil of intestine was drawn out gently,
sufficiently far to admit of the microscope being applied to
the mesentery, which was kept moistened with water of about
100° F. Under a ;4,-inch object-glass the lacteals were readily
recognised as beautiful transparent beaded cords; the beads
corresponding to the situations of the valves which were
observed to be standing open while the chyle-corpuscles moved
along through the tubes with a perfectly equable flow, at a
rate of about a quarter of that at which the blood passes
through the capillaries. There was nothing like rhythmical
contraction to be observed in the vessels, and it was evident
that the source of the movement of the fluid was some cause
in constant and steady operation. Chyle-corpuscles, appa-
rently fully formed, to judge from their size, were observed
constantly passing along, even in parts very near to the intes-
tine, the scene of absorption showing the rapidity with which
those corpuscles are elaborated. These observations were
repeated several times.
The other set of experiments were conducted in the same
manner, except that some insoluble coloured granular mate-
rial, such as indigo, carmine, or flower of sulphur, was mixed
with the bread and milk. The animals partook freely of the
mixture, which also passed on into the intestines, yet none of
the colouring particles were ever to be seen in the lacteals by
aid of the microscope, although had they been present in the
granular form in the chyle they would have been certainly
detected, being quite different in appearance from the normal
constituents of the fluid. It may be imagined that the colour-
ing substances exercised a poisoning influence and paralysed
the function of absorption. There was, however, no appear-
ance of any such thing, the chyle presenting the same cha-
racters both as to its constitution and rate of flow, as when
simple bread and milk had been alone administered.
These facts, though not perhaps absolutely conclusive,
appear to throw great doubt upon the interpretation which
has been given of alleged cases of absorption of indigo and
some other granular substances, and render it probable that
the lacteals are incapable of admitting visible solid particles
through their parictes.
ORIGINAL COMMUNICATIONS.
Investication of a Stmete Rute for Finpine the Numer of
Entrre Hexaconat Facets contained in a Given Crrcre.
By H. M.
I. Tue area of a hexagonal facet (the diameter bisecting
3
the sides bemg = 6) = ss 6? = & X *866025.
II. The area of a circle whose diameter = N6d is N26?
x 7854.
Ilt. Then the number of areas in the circle, each equal
N28? x -7854 eee
to that of a facet, 1s §2 x 866025 == IN? x 90691 = N?2 x 9
oe 2 :
or 7 oN nearly
———
——<———
2 EX
= \
VOL, VI. H
84 ON HEXAGONAL FACETS 1N A CIRCLE.
IV. But this does not represent the number of entire facets
in the circle, for many of these facets will be cut through by
the circle, and the fractional parts must be rejected (by the
question). We must therefore seek a more accurate method
of calculation.
V. Take now, as Casr I, that of N an odd number, the
centre of the circle containing the facets, comciding with the
centre of one of the facets.
It is evident from fig. 1 that hexagonal facets must be
arranged on any surface, plane or curved, in the following
order :
Ist. A facet in the centre.
2d. Six facets round this central one.
3d. Twelve round those.
Ath. Eighteen round the last ; and so on, increasing by six
in each term of the series.
Hence the whole number of facets in the hexagonal ar-
rangement, whose diameter N = 2n + 1, may be thus found.
Let H be the number required, then H, = 3x.» +1+1.
EXAMPLE.
N = 35
2n = 34
n=17
~. H,=51 x 18+1=919.
Case II.
VI. If N be even, the centre of a circumscribing circle
will fall in the bisection (A) of a side of a facet (fig. 2).
Here, therefore, we must find, by the rule for Case I, the
number of the facets in the half hexagon whose centre is the
centre of the facet next to A (observing that if n be the
number of facets in AB, n—1 will be the number of terms
in the arithmetical series), twice the number so found will be
the number in the whole hexagonal arrangement, less by the
row of facets on the diameter AC(= 2n).
“. Hy, =3n.n—1+2n +1.
It has now been shown how to find the exact number of
ON HEXAGONAL FACETS IN A CIRCLE. 85
hexagonal facets in a given hexagonal arrangement of the
same.
This is a necessary step towards finding the number of
such facets contained in a circle described about this hexago-
nal group.
VII. We know indeed that the number required must be
(by § II) less than N? x ‘9 (=C) and not less than H, or H,
(or H).
The question therefore is,—Can we find a proportion of the
difference C — H, which being subtracted from C, would give
a remainder equal to the number required ?
Now proportion, in the case of N = 164, is found, viz., by
actually calculating all the ordimates in the segment of the
circle beyond each side of the hexagonal figure, erected, on
the versed sine, at intervals equal to the diameter of a facet,
and then finding the number of facets that may be arranged
between each pair of ordinates in succession to be so nearly
L C — H) that we may well be contented with this approzi-
4 y p
mate rule for finding the number (8) of entire hexagonal facets
contained in the given circle, viz.,
1 9 1y9 7
=C — -(C—H) = — N?—-4 —N?— Her.
ah (Cc H) rie era J
86 ON HEXAGONAL FACETS IN A CIRCLE.
ExaMPLe 1.
N = 164
9
—N?= 24206
10 :
H = 20091
9
C=—N?—H = 4115
io 1
(c-H) (aN De are
1
.-S=C a (C — H) =24206 — 1028 = 23178.
S as found by § (VII) = 23228.
Error == 50.
EXAMPLE 2.
N=" 10
C= /90
ise
4|19
il
2 Ek
{(¢—)
S=H+4=75.
Which number will be found correct by mspection of fig. 2.
EXAMPLE 3.
ee Oe eos
n = 34
38n = 102
H =8n.n+1+1= 8571
1
C—H = 4284 — 8571 = 718... 7(C — H) = 178
gy “(C — H) = 4284 — 178 = 4106 =S.
87
On Ruasponema, and a New ALuiep GrENvs.
By G. A. Warxer-Arnort, LL.D.
Tue late Professor Smith was justly entitled to be placed
at the head of those whose attention was directed to the
Diatomacez. Possessed of excellent instruments, and of a
mind clear and discriminating as to what the limits of a
genus or species were, he was alone qualified, if he had ob-
tained access to authentic perfect specimens, to correct the
unavoidable errors of Kutzing, or extract what is valuable
from the chaotic writings of Ehrenberg; the latter of whom,
by his figures of numerous forms of which he had only seen
very imperfect specimens, unaccompanied by precise, suffi-
cient diagnostical characters, has done more to cumber the
science with a load of useless names than can be rectified
for many years to come.
So long as Smith survived, I preferred committing my
notes to him to dispose of as he thought proper, his senti-
ments being in accordance with my own,—that it is better
not to publish a new species, or give it a name, than to do
so from scanty or imperfect materials which leave both genus
and species doubtful. Even now I have some hesitation in
writing on the subject, as my views are diametrically opposed
to those who consider it necessary to give names to forms
which, to the eye, appear distinct, but which have not struc-
tural differences sufficient for a specific character; and this
alone entitles them to be acknowledged or referred to by
others.
In the following I shall endeavour to make the characters
as clear as possible.
Smith has first correctly defined and explained the struc-
ture of Rhabdonema. Each frustule of this genus has two
valves or ends, which are alike, and marked with moniliform
strie; these valves are separated by several annuli, which
are cellulate; the annuli project into the interior septa,
which are open in the middle. These septa are sometimes
projected from the whole imner surface of the annulus;
sometimes from one half only, and consequently do not then
pass beyond the central aperture: the first are called oppo-
site, the last alternate, septa; in either case, each septum is
supposed to terminate at the middle; they may be entire, or
with openings when they are said to be perforate.
As many merely consult figures, it is necessary that I
request my readers to keep the above in recollection ; or, if they
possess Smith’s second volume of the ‘ Synopsis of British
88 WALKER-ARNOTT, ON RHABDONEMA.
Diatomacez,’ to peruse what he says, otherwise my present
observations may not be understood. It will be also neces-
sary to bear in mind that, in some other genera, as Achnanthes,
where there is a dissimilarity between the two valves of the
frustule, the one next the point of attachment is termed the
inferior valve, the other the superior. These terms I shall
have occasion to employ.
Having received lately from Professor Harvey, of Dublin,
some Algze of the group called Corallinacee, from New
Zealand, I washed these thoroughly, in case of any diatoms
being mixed with the sand and mud that accumulate about
such, and obtained a few only; but two interesting and
closely allied forms presented themselves, along with several
of Kutzing’s species of Grammatophora, &c. Both had a
resemblance to what I have found m the coarse or sandy
portions of Ichaboe guano (imported about two years ago),
and of which I distributed some slides under the fanciful
but only provisional name of Gephyria, as I had not then
sufficient materials to clear up its affinities. Of the two
from New Zealand, one exhibited a side view which some-
what resembled a species of Swrirella ; the second was elliptic-
linear (as if one had compressed a ring), and apparently
pierced with numerous pentagonal holes in a double row.
These markings sometimes extended to the end of the valve,
sometimes stopped half way from the middle. There were
also two forms of front views, which it was difficult to con-
nect with the side view peculiar to it.
On afterwards examining the Corallines, I detected a small
specimen of Ballia callitricha, and creeping on Corallina offici-
nalis a little piece of Polyzonia Harveyana; on both of these
I observed a diatom which resembled closely the genus Rhab-
donema, but of which the thread was composed of not more
than three frustules ; this, however, might have arisen from the
remainder being broken off, although my present impression
is that such an appearance was not accidental. From the
scantiness of the materials I succeeded in obtaiming only a
very small preparation of each; and although I kept them
separate, still, in consequence of the previous washing along
with the Corallines, a few frustules in both instances had
been deposited on, or caught by the Alga, on which the
other was parasitical. At first, then, I had some doubts if
these two were distinct, as, in both, the valves were furnished
with coste; but the front views exhibited a different ap-
pearance, from the septa in the one being rudimentary,
while in the other those nearest the valves were marked
similarly to these, and scarcely distinguishable from them.
WALKER-ARNOTT, ON RHABDONEMA. 89
Doubts may arise whether what I have described as costz
on the valve, are not strongly developed septa projected by
the adjacent annulus and seen through the valve; and this
hypothesis would increase the affinity of the first and third
species to the second one. But a careful examination of the
first species to be described, where observations can be more
easily made than on the other two, leads to a contrary
opinion: Ist, the striz are never seen on the valve except
between the costz; on the lower valve they terminate where
the costz terminate: 2d, I have not been able to detach a
single valve so as to exhibit striz without the cost, or septa
without striez. The two formations are thus dependent on
each other, and the one is indissolubly united to the other;
whereas in Rhabdonema and Grammatophora the septa can
be separated, leaving the striated valve by itself.
In all the three species the valve varies considerably in
form; so that had I not obtained them in a tolerably
separate state, I should have been puzzled whether to
combine all imto one, or to constitute of them many more
species than I have proposed. Indeed, when species of the
same genus are much mixed and only known from deposits
or dredgings, it is quite impossible to draw any satisfactory
conclusions.
Perhaps it might have been sufficient to unite the species
I have to notice to Rhabdonema ; but the valves are not only
furnished with costz, but these costz are differently ar-
ranged on the two valves; whereas in all true species of
Rhabdonema, the two valves are precisely similar to each
other, and without coste. If the two genera be combined,
the character must be enlarged, and then it will be no easy
matter to exclude by it other genera which all agree are dis-
tinct. I have therefore thought it preferable to separate the
new one under the name of
EUPLEURIA.
Filaments compressed or arcuate, continuous, attached.
Frustules annulate, indefinite; annuli plane, cellulete or striate
on their circumference; septa opposite or alternate, rudi-
mentary or perforate. Valves ovate, elliptical, or arcuate,
with one median and several lateral costs; inferior with the
coste and striz disappearing below the extremities of the
valve, superior with them reaching to the extremity: striz
moniliform, oblique.
1. Eu. pulchella ; annuli as broad as the flat valves, cellu-
late ; septa all rudimentary.
Hab. New Zealand, on Polyzonia Harveyana.
90 WALKER-ARNOTT, ON RHABDONEMA.
Annuli numerous, about 11 in ‘001, with about 15 cells in
‘001. Septa apparently wanting, but from the external ap-
pearance of the frustule, they seem to exist, although in a
very rudimentary state, and to be alternate; they have con-
sequently no perforations. Valves the breadth of the annuli,
flat, usually more or less ovate and acuminate, sometimes
linear-oblong. Strize only between the costz, oblique, about
30 in ‘001, easily seen with a quarter-inch object-glass.
2. Eu. ocellata; annuli as broad as the nearly flat valves,
finely striate ; the septa contiguous to the valves, perforate.
Hab. New Zealand, on Ballia callitricha.
Annuli numerous, about 13 in ‘001, with about 40 striz
in ‘001. Septa opposite, those nearest the valves composed of
coste similar to what are seen on the valves, but with the
interstices open ; the rays on the front view (formed by the
subjacent septa) diverging from the lower valve, and con-
verging from the upper one, indicate that these openings
enlarge, while the septa themselves become narrower and
fainter as they approach the middle of the frustule, where
they are evanescent or rudimentary. All the annuli do not
project the septa simultaneously ; those next the valves do so
first, the last projected being the most remote: a frustule,
therefore, may present itself which has only the annulus
next the valve provided with septa, and one solitary example
occurred where even then they had not been formed or were
wanting; when this takes place, the species can scarcely be
distinguished from the followmg one, except by the flatness
of the valve, the coarser striz on the annuli, and the breadth
of the annuli as compared with the valve. Valves nearly flat,
not perceptibly broader than the annuli, elliptic linear or
sometimes slightly lunate, rounded at each extremity. The
striz are so faint that I have not been able to observe
them satisfactorily.
Mixed with this, and parasitical along with it, are seve-
ral frustules of what at first sight resembles a minute
Himantidium ; but 1 have not yet ascertained its side view,
and as its genus is as yet doubtful, it is unnecessary to allude
to it further.
3. Eu. incurvata ; annuli conspicuously narrower than the
very convex valves, delicately striate ; septa entire.
Hab. West coast of Africa (among guano from Ichaboe,
1855).*
* T would not have introduced this species had I not seen many front as
well as side views of it, as it is seldom that any certain conclusion can be
obtained from deposits, dredgings, or guanoes. As an instance of a mis-
take occurring in that way, I may allude to Pleurosigma compactum, Grev.,
WALKER-ARNOTT, ON RHABDONEMA. 91
Annuli few, about 5 in ‘001, with about 50 striz in ‘001.
Septa apparently opposite and rudimentary, or if present are
not marked by coste or perforations. Valves very convex,
arcuate, or somewhat linear and lunate, considerably broader
than the annuli, the entire frustule presenting the appear-
ance of a little bridge (Gephyria) with a low parapet on each
side. Striz oblique, only between the costz, very much
fainter than in Hu. pulchella, but not seemingly much more
numerous (from 36 to 40 in :001), although requiring careful
illumination and an object-glass of high power (3-inch) to
exhibit them.
In all these the median line or costa is not quite straight, but
shghtly bent in a zigzag manner, the lateral ones being gene-
rally alternate and proceeding from the angles of the median
one. In the inferior valve the median line projects slightly
beyond the lateral ones, and there usually forms a little
knob.
I have not attempted to measure the distances of the strize
or annuli with accuracy; the numbers I have assigned are
therefore more to be considered as relative, and probably are
very different from what others may determine them to be.
I shall now give the generic character of Rhabdonema
slightly restricted from what is given by Smith, with abridged
characters of all the known species.
RuABpONEMA, Kutz.
Filaments compressed, continuous, attached, or stipitate.
Frustules annulate, indefinite ; annuli plane, cellulate on their
circumference ; septa opposite or alternate. Valves similar,
which is a genuine species of Amphiprora. This was first found copiously
in the living state, and properly understood by Mr. Ralfs, of Penzance; and
as the specific name given by Dr. Greville is quite inapplicable to an AmpAi-
prora, \ have no hesitation in changing it to 4. Ralfsic.
A. Ralfsii; F. V. narrow, elliptical, deeply constricted; V. twisted
equally from end to end; striz about 53 in ‘001.—A. didyma, Sm. Brit.
Diat., t. 15, f. 125? (excl. the name and char.)—Plewr. compactum, Grev.,
M. J. V., t. 3, f. 9 (mame and char. erroneous).
Hab. Penzance; J. Ralfs. Cumbrae; R. Hennedy. Dredged also in
various places in the Clyde by Mr. Hennedy and Rev. Mr. Miles.
The figure given by Sinith is equally characteristic of this species, and
of what Dr. Gregory calls 4. Lepidoptera; but if the number of strie, 72
in 001, be not an error of the press for 52, it can be neither. Dr. Gre-
ville describes the strize as “ obscure,” which they are under a bad object-
glass; but they are as conspicuous and as few in ‘001 as in Pleur. istuarit,
which usually in this country accompanies it, both in the normal and dis-
torted shells; the latter of which has both ends bent in the same direction,
a structure that occurs in some other species of that genius,
92 WALKER-ARNOTT, ON RIABDONEMA.
elliptical, ecostate, with a median line, striate. Stric trans-
verse, moniliform.
Sect. I. Septa entire.
1. Rh. arcuatum, Kutz. ; septa opposite; striz not reaching
to the end of the valves.
Hab. Shores of Europe, Africa, and North America.
To this belongs Tessel/a catena of Ehrenberg.
2. Rh. minutum, Kutz.; septa alternate; strize reaching to
the extremities of the valves.
Hab. Shores of Europe and North America.
To this belongs Tessella catena of Ralfs.
Secr. II. Septa alternate, with perforations along the middle
between the margin and central aperture.
3. Rh. Adriaticum, Kutz.; septa with one oval perforation.
Hab. Shores of Europe, North America, Asia Minor,
Mauritius, and Ceylon.
Probably more diffused than any other species. To it
belongs Tessella catena of Bailey.
4. Rh. mirificum, W. Sm.; septa with several (3 to 12)
irregular perforations.
Hab. Shores of Ceylon and Mauritius.
In this species the openings in the septa are irregular in
form, and reach from the upper to the lower margin of the
annulus ; while the portions of the septa that separate these
are narrow, and resemble bars which are either straight
across or slightly oblique. When two such septa cohere, the
perforations seem to extend from the one end to the other,
and are then in no instance, as far as I have seen, fewer than
seven, including the central opening, but usually are much
more numerous (20 to 25).
In my preliminary remarks I have alluded to Achnanthes.
I may here take this opportunity of stating that A. brevipes
of Kutzing, which has a rather short stipes and valves with
acute extremities, has been found lately (November, 1857),
by Mr. Okeden, at Neyland, in South Wales. This is re-
ferred by Smith to A. longipes, on account of the presence of
costz on the valves, along with moniliform striz: to this
there is no valid objection; but, in that case, it ought to be
noticed as a well-marked variety, and the word “ obtuse,” in
reference to the valves, deleted from the specific character,
as by no means applicable to this form of the species. Mr.
Okeden has also found (March, 1857) at Neyland the A.
parvula of Kutzing! a species which must be removed from
BRIGHTWELL, ON RHIZOSOLENIA. 93
the section in which Kutzing has placed it (from using an
inferior microscope), as the striz are very conspicuous with a
good lens, being as few as 33 or 34 in ‘001. It differs from
the true A. brevipes of Agardh, by the elliptic-oblong obtuse
valves ; from A. subsessilis by the usually numerous frustules
and the distinct and somewhat elongated stipes; and from
both by the much finer striz.
Remarks on the Genus “ RuizosoLventa” of EHRENBERG.
By Tuomas Bricutwe.t, Esq., F.L.S., Norwich.
Amone the remarkable forms lately detected in Ascidie
and Noctiluce, specimens have been found of some which
appear to belong to the genus Rhizosolenia, of Ehrenberg.
Having had, in this case, as in that of Chetoceros, an op-
portunity of examining the species in a tolerably perfect
state, we hope to be able to exhibit the true character of
several more of those fragmentary and unsatisfactory forms
which Ehrenberg, mm his various works, and particularly his
‘ Microgeologie,’ has, as we conceive, too hastily and inju-
riously to science, erected into genera and species.
The characters given by him of the genus Rhizosolenia
are “lorica tubular, with one extremity rounded and closed,
while the other is attenuate and multifid, as if termimatimg
in little roots.” He describes five species, some of which
do not at all agree with the above characters; and the late
Professor Bailey added a sixth under the name of R. hebe-
tata. The greater part of these supposed species are, as we
believe, only fragments of the silicious organisms we are
about to describe, or of kindred species, and to enable the
reader to judge of the correctness of our views, we have
given copies of several of Ehrenberg’s published figures, as
well as figures of all our newly-discovered perfect forms.
Ehrenberg’s five species are*
1. Rh. Americana, from Virginian earth. Of this he
gives no less than eleven figures, most of them certainly not
belonging to this genus.
* These species (and a sixth clearly not belonging to it) are described in
Kutzing’s ‘Species Algarum,’ p. 24, where the references to Ehrenberg’s
works or papers, in which they first appeared, are to be found.
D4: BRIGHTWELL, ON RHIZOSOLENIA.
2. Rh. pileolus. A doubtful species.
3. Rh. campana, Bermuda. No figure is given of this; but
from the description it appears to be a terminal section of a
Rhizosolenia.
4, Rh. calyptra, South Sea. This is clearly the calyptri-
form terminal process of a Rhizosolenia, very like our Rh.
styliformis.
5. Rh. ornithoglossa. The terminal process of the same
species. Of Bailey’s Rh. hebetata we were favoured with
specimens by the late lamented professor. It is clearly dis-
tinct from any of the above, and from any of our species. —
We present the following as a synopsis of the species
which have come under our observation.
RHIZOSOLENIA.
Filamentous, frustules subcylindrical, greatly elongated,
silicious, marked by transverse lines, extremities calyptri-
form, pointed with a bristle.
Species.
1. Rh. styhiformis——Frustules from six to twenty times
longer than broad ; transverse lines obvious ; terminal process
at the base spathulate and bifid; straw colour to chestnut
brown.
“Found in the stomach of an Ascidia taken from oyster
shells, dredged twenty or thirty miles from the Yorkshire
coast, at a place a little to the north of the Humber, known
as the ‘Silver Pit?” (Mr. Norman, of Hull, in ‘ Annals
Nat. Hist.,’? vol. xx, p. 158). In Noctiluce, Gorleston,
Suffolk. (Col. Baddeley.) In guano, Callao, often in
little bundles of fragments. In Salpe. (Dr. Wallick).
The base of the calyptriform process is carried out into a
spatula-formed elongation, bifid at the end; the lines of the
bifid division run upward on either side, with a stout nerve,
to nearly the apex of the cone. Boiled in acid, the frustules
break up, and the calyptriform processes in an isolated but
perfect state, and detached imperfect rings are only to be
found. (Pl. V, fig. 5.)
2. Rh. imbricata.—Frustules four to seven times longer
than broad, punctated; terminal process subulate, entire;
pale straw colour.
In Ascidiz with the former. (Mr. Norman.) In Nocti-
lucee. (Col. Baddeley.)
The direction of the transverse lines and puncta give this
species an imbricated appearance. (Pl. V. fig. 6.)
BRIGHTWELL, ON RHIZOSOLENIA. 95
3. Rh. setigera.— Frustule five to fifteen times longer than
broad ; transverse lines obscure ; terminal bristle as long as
the frustule ; colourless, of glassy transparency.
In Ascidize with the two former species. (Mr. Norman.)
In Noctiluce. (Col. Baddeley.) In Salpz. (Dr. Wallick.)
This species is distinguished by its extreme delicacy, and
by the great length of the terminal bristle. (Pl. V, fig. 7).
4. Rh. alata—Terminal process alate, recurved, blunt;
colour chestnut brown.
In Ascidize with Rh. styliformis. (Mr. Norman.)
This delicate little species, which bears some resemblance to
a pipe fish, and might have been called “ sygnathoides ” differs
frout all the others by its blunt, turned-up nose, and its small
but conspicuous appendages to the terminal process (Pl. V,
fig. 8).
In most of the above species, self-division has been ob-
served. It takes place in or near the centre of the frustule,
and has the same indefinite character as in Rhabdonema and
Striatella. The rings of the Rhizosoleniz appear equivalent
to the annuli in these genera, but, instead of being perfect
and united by flat surfaces, they are united at acute angles,
and carry out the frustule to an almost indefinite length.
The process of self-division is therefore truly diatomaceous.
Two new calyptriform valves are gradually formed within a
connecting membrane, as is seen in our PI. V, figs. 6, 7, a, 6.
These eventually separate, when the old frustule becomes
two, each division having a new calyptriform end.
In the genus Isthmia, the frustules of which are trapezoi-
dal, one valve having a produced angle, we see some resem-
blance to the Rhizosoleniew, and this would be much
increased by supposing an Isthmia carried out to ten times
its normal length, and self-division taking place in the
centre, as seen in the central fig. in pl. xlvii, ‘ Smith’s
Brit. Diatom.’
In specimens of Rh. setigera a motion has been observed
resembling that of many of the Diatomacez, the frustule
proceeding forward in a jerking, tremulous manner, and then
retrograding.
Large numbers of Rhizosolenia have been detected in the
stomachs of Salpze, and they have also been observed floating
free in the ocean in warm latitudes, their appearance being
that of little confervoid flakes of exquisite delicacy, but of a
sufficient aggregation of filaments to be seen by the naked
eye. The mass appeared (probably from the endochrome)
of a faint, evanescent, ochraceous colour.
96
FiustreLta HispipaA and its DrvreLopMEeNnT. By Prver
Reprern, M.D. Lond., Lecturer on Anatomy and Phy-
siology, and on Histology, in the University and King’s
College, Aberdeen.
(Read before the Natural History Section of the British Association, at
Dublin, in August, 1857.)
Tue Flustrella hispida of Dr. Gray is the Flustra hispida
of Fleming, and the Plustra carnosa of Dalyell and Johnston.
It seems to have been overlooked by Mr. Gosse, in his ‘ Marine
Zoology,’ and to have attracted much less attention than it
deserves, when its beauty and general distribution are con-
sidered.
I have found it abundant on the rocky coast of Kincardine-
shire, for eleven miles south from Aberdeen; on the Irish
coast at Howth, Dalkey, and Bray, in the Bay of Dublin,
and at Wicklow; also in North Wales, at Llandudno. It
usually grows on the fronds of /ucus serratus, but in the im-
mediate vicinity of Aberdeen, it is excessively rare on that
Fucus, but abundant on Chondrus mamiilosus. It forms
round or oblong, brown, hairy patches, about a line thick,
which extend completely round narrow fronds, but are con-
fined to one side of broad ones. It is mvariably encrusting.
The extent of the coeneecium rarely exceeds an inch on the
Kincardineshire specimens, but it extends for three or four
inches on those gathered in Dublin Bay and North Wales. It
occurs on the Fucus, together with the Alcyonidium hexa-
gonum (Hinks) and the Cyclowm papillosum (Hassall) ; on the
specimens of Chondrus the Flustrella occurs with Alcyonidium
hirsutum.
The ccoencecium is thick in the centre ; thin, and composed
of the last-formed individuals at the edges. The cells radiate
from the centre, and they are imbricated in various degrees
in different parts, the whole length of the cell, or merely its
summit, being visible on the surface. The arrangement of
the cells is variable, but generally alternating. When
allowed to dry on the plant, the ccencecium presents the
appearance of a wrinkled, hairy membrane; when it is sliced
from the plant, and dissected with needles, a large quantity
of viscid matter escapes from its cells.
The wall of each cell is set with rigid, reddish-brown,
pointed and slightly curved hairs, very numerous, and, for
the most part, occupying the whole circumference in the
Kincardineshire specimens, but very few in number, and set
REDFERN, ON FLUSTRELLA HISPIDA. 97
in a semicircle over the summit of the cells, in the specimens
from Dublin, Wicklow, and North Wales.
In the Kincardineshire specimens, the young cells have
five to seven or nine hairs in a semicircle over their summits,
and two or three only on each side. The older cells have
hairs distributed uniformly over their whole circumference,
their lateral septa often presenting eight to twelve or more
hairs with their roots closely packed together, one half
haying their points directed over the cell to the right of the
group, the other half having theirs turned over that to its
left. One of the lateral hairs on each side often reaches
across the cell at the lower margin of its aperture, but no
hair of any kind grows in any other position than those above
indicated.*
In the specimens from the Irish and Welsh coasts, the
summit of the cell has often no more than three hairs upon
it, the usual number being five to seven; the sides and base
of the cells are often entirely devoid of hairs, the lateral
septa occasionally presenting a patch of two or three. So
far as I am able to judge from the examination of a large
number of specimens, there is always a wide difference in the
number of hairs on the Kincardineshire specimens and those
gathered further south, this difference being the more re-
markable, because an inverse ratio maintains between the
number of hairs and the extent of the coencecium in the two
series of specimens. JI am anxious that the attention of
naturalists should be directed to this occurrence, because it is
possible that the functions of the hairs may be determined
by observations of the number and character of the hairs of
the same species, growing under different circumstances.
The aperture of the cell is somewhat quadrangular—dis-
tinctly so during the protrusion of the polypide. The charac-
ters of the cells, their hair sand apertures, are shown in Pl.
IV, figs. 1, 2, 3, and 3 dis.+
The polypide, when healthy, is easily removed from the
cell with its digestive viscera entire, as in fig. 4. The number
of tentacles I found to be twenty-eight in all but one of a
large number of instances, in which I counted them with
* Tn old and mech imbricated specimens the hairs on the sides and base
of the cells are best shown by slicing the ccencecium from the plant, and
dissecting the cells asunder by needles. By this method the polypide may
also be easily removed from its cell in so perfect a state that it will live for
many hours, showing the effects of ciliary motion more beautifully perhaps
than in any other instance whatever. : hed. ;
+ The subsequent observations were all made on Kincardineshire speci-
mens.
98 REDFERN, ON FLUSTRELLA HISPIDA.
great care, by the aid of the camera lucida; in the single
instance there were twenty-seven. Each tentacle is hollow,
covered by a thick layer of ciliated epithelium, easily de-
tached. It is quite remarkable how rapidly these epithelial
cells become distended and destroyed when fresh water is
added; and as this is the case also with the cells of other
parts of the animal, it is not surprising that fresh water
instantly destroys it. Fig. 5 represents a portion of a
tentacle with its epithelium in the natural state; fig. 6
the tentacle divested of its epithelial covering ; and fig. 7
shows the action of fresh water upon the epithelial cells.
The pharynx and cesophagus are lined throughout by
ciliated and columnar epithelium. The stomach is separated
from the oesophagus by a distinct and complete valve which
never allows the alimentary matters to regurgitate. The
cesophageal portion of the organ is cylindriform, the body is
greatly dilated having a pouch-like dilatation on its great
curvature, and being gradually narrowed towards the pyloric
aperture, where the stomach can be shut off from the intes-
tine, apparently by a contraction of its muscular wall (py-
loric valve). Over the whole of the stomach, the epithelial
cells contain a nucleus and deep-red, granular contents.
Those of the cul-de-sac, and in the great curvature, and those
at the pyloric end, are ciliated; but no cilia are observable
in the other parts, nor in any portion of the intestine. The
action of the cilia of the stomach is remarkably beautiful
when viewed under the microscope, and produces a rapid
rotatory motion of the contents of the cul-de-sac, or of the
pyloric end, in the axis of these parts respectively.
To the stomach succeeds a dilated portion of the intestine,
where the alimentary matters are retained for some time, and
converted into elongated consistent pellets. The wall of this
portion of the canal has an epithelium, the cells of which
contain deep-red granules like those in the stomach-cells,
but much fewer in number. Beyond this the intestine is
considerably contracted, and its wall becomes so thin that it
is often torn during the dissection, in tearing away the tu-
bular sheath of the tentacles, formed of the soft, protrusible
portion of the cell. Through this membrane the anus opens
externally. I have never noticed the discharge of alimentary
matters, except at the moment of protrusion of the tentacles,
when the pellet to be discharged escapes from within the
crown of tentacles, and commonly falls through between two
of them to the exterior.
Muscular system.—The retractor muscular fibres are best
seen, im situ, in preparations which have been preserved in
REDFERN, ON FLUSTRELLA HISPIDA. 99
spirit, in which they are remarkably distinct. The insertion
of the great retractor into the lophophore, the pharynx, and
cesophagus, is beautifully seen in the animal removed from
its cell by dissection, as in fig. 4.
The great retractor muscle consists of a long ecylindriform
bundle of fibres, stretching from the deepest part of the cell
over the stomach, to reach the cesophagus, pharynx, and
lophophore, into which the fibres are inserted. Another
bundle of much shorter fibres extends from the side of the
cell, near its bottom, to the cul-de-sac of the stomach, into
which it appears to be inserted, drawing this part of the
organ downwards and towards one side when in action, and
thus assisting i folding the parts of the alimentary canal
upon each other, that they may be easily accommodated in the
interior of the cell. Yet neither these fibres nor any of
those of the great retractor muscle remain attached to
the stomach of the polypide withdrawn from its cell. I
have examined the perfect stomach thus removed in at
least twenty instances, and in none have I seen a single
fibre attached to the wall of the stomach, whilst, in every
case, the torn pharyngeal fibres remain connected with
it. Four or five distinct bundles of muscular fibre stretch
from the interior of the cell, at different points, to the
polypide; passing transversely to the axis of the cell.
Other bundles of at least two different muscles extend from
the upper part of the interior of the cell to the mvaginated
portion, which forms the sheath of the tentacles during the
retraction of the polypide. The longer of these bundles is so
much relaxed durig complete retraction, that it is bent upon
itself.
During retraction, the csophageal end of the stomach is
rapidly drawn down to the bottom of the cell on one side,
the cul-de-sac of the organ to the bottom on the other side ;
the pyloric end of the stomach is folded upon the upper cur-
vature, the pyloric orifice being brought very close to the
cesophageal; the intestine is bent upon the pyloric end
until the two lie parallel; and the tentacles are folded in a
somewhat spiral manner, close to the intestine which lies by
their side. Thus the cesophageal and pyloric ends of the
stomach, and the dilated commencement of the intestine, are
folded and lie parallel to each other directly across the axis
of the cell, in the state of retraction, whilst they lie with their
axes parallel to that of the cell, in the state of protrusion of
the polypide. The act of retraction is sudden and rapidly
completed, like that of voluntary muscles in general; the
act of protrusion is performed very slowly, as if the tenta-
VOL. VI. I
100 REDFERN, ON FLUSTRELLA HISPIDA.
cles were gradually distended with fluid, and the body slowly
pressed out of the cavity of the cell.
By dissection, ova or statoblasts are obtained in great
numbers, presenting the appearances represented in figs. 8
and 10, and consisting of an outer envelope, contaming a
number of clear and highly refractive nucleated cells, and an
opaque, reddish, spherical mass, composed of cells with red
granular contents. When some of the contents of these
bodies have escaped, their structure is much more easily ex-
amined, as in fig. 9. None of those figured possessed cilia.
The cilia belong to a membrane, which is placed outside the
two capsules figured, and separated from the outer of these
by a finely granular mass. Only one of these bodies was
observed to have cilia, amongst twenty or thirty carefully ex-
amined to determine their presence or absence.
Development.—My reasons for believing that the animal
whose development has been examined is the same as the one
just described are :—lst, that it grew on the wall of an
aquarium, in which there were numbers of specimens of
Flustrella growing on Chondrus mamillosus, and, so far as
I could judge, no other which could be mistaken for it ;
2d, that on the cell of the second polypide hairs grew of
a similar character to those shown in figs. 1, 2, and 3; 3d,
the character of the tentacular crown, and the number of
the tentacles, as far as it could be determined in a bad posi-
tion for counting them, and the appearance of the digestive
organs, were exactly such as occurred in the creature figured
from 1 to 10.
On the 3d of July, 1857, I first observed a solitary poly-
pide in its cell, on the wall of an aquarium. It was appa-
rently in perfect health, alternately protruding and with-
drawing its beautiful, bell-shaped crown of tentacles. The
elegance of the form of the bell, and the number of its
tentacles, led me to compare it with the specimens growing
on Chondrus in the same vessel, and the result was, that I
could find no difference between them. On this occasion I
did not notice any projection of the wall of the cell for the
formation of a gemma.
On the 4th of July, a definite projection of the wall was
observed (fig. 11) ; two days later the projection had imcreased
in size considerably, and it presented externally a protruded
portion of the wall of the original cell, and in its interior a
striation slightly radiating towards the surface, the striz
being produced of rows of highly refractive globules (fig. 21.)
On the evening of this second day, the body of the polypide
was. visible, as a small cone, at the deepest part of the
REDFERN, ON FLUSTRELLA HISPIDA. 101
striated mass, and on the third day it had become much
more distinct, whilst the gemma appeared to be encroaching
on the old cell, and the striated mass had approached the
surface (fig. 13). Witha view of facilitating the examination,
a small mirror, the framework of which had been recently
coated with gold size, was introduced into the aquarium.
Shortly afterwards, the tentacles of the polypide (fig. 11)
were observed to be bent at various angles, and to hang
loosely, as if they had been broken, resuming thei natural
appearance at intervals. The polypide protruded itself but
rarely, and never recovered its healthy characters, dying four
days subsequently. I believe that it was injured by the
gold size.
On the fourth day of the formation of the gemma, it pre-
sented a yellowish striated band at its deepest part, appa-
rently the first trace of its retractor muscle. On the same
day, traces of the formation of three other gemmee were seen,
as in fig. 14, but their development was speedily arrested, and
they were not again observed.
On the seventh day, the new polypide presented the form
of a bent tube, the striation near the surface remained, and
between it and the bent canal, representing the body of the
animal, there was a clear space faintly separated into bands
by indistinct striz (fig. 15). These ultimately became the
tentacles. On this day, four distinct and blunt hairs were
observed to have formed on the wall of the cell of the new
polypide.
On the eleventh day, the gemma had considerably in-
creased in size, and presented a nipple-like membranous
prominence. The polypide was observed shrinking in its
cell on the application of a bright light. The hairs, which
were blunt at their ends on the seventh day, had become
pointed. The perigastric space was quite distinct. The re-
fractive globules, producing the striation near the surface
had gradually diminished in number, and formed a thin
layer between the tentacles and the surface. This state was
figured on the twelfth day, as in fig. 16.
On the thirteenth day, the apex of the cell had become
much thinner, and presented the appearances represented in
the drawings (figs. 17 and 18), sketched by the aid of the
camera lucida, when the polypide was retracted and protruded.
The tentacles were much longer and more distinct, the rows
of highly refractive globules between the tentacles and the
surface were greatly diminished in number and size, and the
perigastric space was clearer. The condition of the polypide
at this timeis so graphically described by the Rev. T. Hincks,
102 REDFERN, ON FLUSTRELLA HISPIDA. |
in a paper in the eighth volume of the‘ Annals and Magazine of
Natural History,’ that I can add nothing to his account of it.
I regret that I was not aware of the existence of this paper
until after my opportunity of observing the creature had
passed away. Mr. Hincks says :—“ Imperceptibly the body
of the polype shapes itself within the mass. The tentacles .
are first visible.* Soon violent convulsive movements are
seen within. The front part of the cell is frequently pushed
out with much apparent force, so as to form a neck of con-
siderable length, and then suddenly retracted. There is no
appearance of an opening at this time. The tentacles become
very restless, and bend themselves about as if trying their
powers, and impatient of confinement. Gradually the parts
become more defined ; the elongation and retraction of the
fore part of the cell contimue, and, at length, the polype
breaks from its captivity.”
On the fifteenth day, the polypide protruded fully, and its.
tentacles expanded freely. The wall of its cell was beauti-
fully transparent, and admitted a full examination of the
viscera, now receiving the alimentary matters. On the
seventeenth day, the drawings 19 and 20 were made. In the
state of protrusion, the lophophore and anus were carried
outwards, and the alimentary canal stretched, owing to the
stomach being drawn but little away from the bottom of the
cell, whilst the other parts were shifted extensively. Ciliary
motion was distinct on all the parts on which it is observed
on the adult polypide. In the state of retraction, the qua-
drangular state of the aperture of the cell was distinctly ob-
served ; the tentacles were folded somewhat spirally upon
each other; the cesophageal end of the stomach was drawn
down to the bottom and side of the cell, and the pyloric end
folded over it, the pyloric orifice being carried towards the
same side, together with the dilated commencement of the
intestine, which was laid parallel to the pyloric end of the
stomach, and directly across the direction of the cell.
Some appearance of the formation of a gemma occurred on
the wall of this second cell, as in fig. 20, but it became no
further developed, and the second polypide itself was found
dead on the twenty-seventh day of its existence, to my very
great regret.
* When I first saw the striated mass beneath the surface of the gemma
I supposed that it was the early stage of the formation of the tentacles, but
I subsequently found that they formed beneath it, and that they were not
distinct until after the body of the polypide had assumed the decided form
of a bent tube.
103
TRANSLATIONS.
Abstract of Remarks on the Marernat Bontzs of the Mepus2.
j By Professor C. GEGENBAUR.
(Miiller’s ‘Archiv,’ 1856, p. 230.)
“ Tuxse bodies,” the author observes, “ afford better syste-
matic characters for the classification of these animals than
can be derived from the form of their bodies or the relations.
of their tentacles.”
He describes:—A. Marginal corpuscles of the lower
Medusz.
This class includes the forms termed by Forbes “ naked-
eyed,” embracing the Aiquoride, Alginide, &c., all probably
medusoid forms of polypes. In these Medusze two kinds of
marginal bodies are met with. Both are placed at the border
of the disc, and are either in intimate relation with the base
of the tentacles, or constitute small eminences between those
organs,—in one case supported on long peduncles. One form
presents the appearance of vesicles containing earthy con-
cretions, whilst the other represents merely a deposit of
colouring matter, sometimes enclosing a refractive body.
a. Vesicular marginal bodies.
These are found, first, in all the Geryonidz and Aiginide—
probably also in the Auquoride ; and secondly in some of the
medusoid forms at present included under the genus
Thaumaniias.
Tn all the true Oceanide, as well as in the Thaumantiadze—
both of which families appear to be characterised by the
presence of pigment-spots at the base of the tentacles—no
trace of vesicular marginal bodies is found to exist.
The vesicles are of a rounded, elliptical or elongated shape,
and always have thin walls, apparently continuous with the
integument of the Medusa, and enclosing the cavity on all
sides. Internally this wall is ined with an epithelium, com-
posed of smooth polygonal cells, which are not visible, how-
ever, except upon the addition of acetic acid. The vesicle
contains one or several spherical or oval, motionless concre-
tions, surrounded with a transparent fluid. The concretions,
to judge from the effect upon them of acetic acid, consist in
part of carbonate of lime; and after this is dissolved, an
104 GEGENBAUR, ON MEDUS.
organic residue is left retaining the original form of the
concretion. Gegenbaur has never observed crystalline forms
or crystals.
The number of these marginal vesicles is constant in the
Geryonide, and also in the minute medusoid forms resembling
Thaumantias, and which should probably form a distinct
family from the true Thaumantiade. In the Auginidze their
number is very variable, and in this group the maximum in
this respect is probably reached, viz., about 60; though even
in this family exceptions exist.
The position of these bodies always indicates an intimate
relation to the gastro-vascular system, although the cavity of
the vesicles does not, as might be supposed, communicate
with the interior of the gastric canals. This relation is
especially evident in the Cuninide, in which the marginal
vesicles are always sittiated at the extremities of the gastric
sac, and never in the interspaces.
In the Geryonide a marginal vesicle is seated at the base
of each tentacle. In some species of the family Aiginide
the vesicle is seated in a depression at the summit of a conical
eminence, composed of distinct cells, each of which, in a form
allied to gina, supports a long descending ciliwm.
Gegenbaur has never witnessed ciliary movement within
the vesicles, nor in fact motion of any kind, except what
might be referred to endosmotic action. In this he agrees,
he says, with all his predecessors, except Kolliker, who
describes in a species of Oceania the existence of cilia in the
marginal bodies,—an observation the correctness of which
Gegenbaur does not doubt, but supposes it to refer to Oceania
marsupialis (Carybdea marsupialis, Peron), whose marginal
bodies present very remarkable peculiarities, which he after-
wards discusses.
If the rather large marginal vesicles of Geryonia be ex-
amined, it will at once be seen that the concretion is not free
in the vesicle, but connected to the wall by means of a short
peduncle, from which, in fact, a delicate membrane extends
over and encloses the concretion entirely. Repeated obser-
vation will occasionally detect a much thicker investment,
within which, besides the concretion, are contained minute
molecules, and an oval or rounded corpuscle, resembling a
nucleus. In fact, there is nothing opposed to the notion that
the concretion is formed in the secreting cavity of a parietal
cell which projects into the interior of the vesicle, m the
same way that other concretions are formed in the lower
animals, as for instance the renal concretions of the Gastero-
poda, &e.
GEGENBAUR, ON MEDUSZ. 105
If this be the true state of things, there can be no question
as to the non-existence of motion in the concretions, and in
great measure the analogy fails, which would place the
marginal bodies of the Meduse in the same category with
the auditory organs of the Acephala and Cephalopoda.
6. Pigment-spots (ocelli).
Coloured spots on the base of the tentacles occur only in
the Oceanidz and Thaumantiad, both of which families
(certainly the former) are medusoid forms of polypes. Con-
sequently, except in Oceania turrita, coloured spots and mar-
ginal vesicles are not found to coexist.
The spots themselves consist of dense agglomerations of
yellow, red, brownish-red, or black pigment-cells, placed upon
a more or less prominent elevation on the base of the
tentacle. Except in Tiaropsis, their number corresponds
with that of the tentacles.
In Lizzia, Bougainvillea,—Oceanide, with the tentacles
disposed in groups,—the ocelli are always situated on the
under side of the tentacles in the form of a crescent.
In Cladonema and the allied Eleutheria of Quatrefages, a
spherical, highly refractive corpuscle is lodged in the midst
of the pigment. In Eleutheria this body is of considerable
size, and projects above the surface.
B. Marginal bodies of the higher Meduse.
In the lower Meduse we have seen the two forms of
marginal bodies existing in distinct families, but in the
higher or steganophthalmatous group we see indications of
the union of the two into a single organ.
In the simplest form of these bodies, as in Pelagia and
Cassiopeia, they constitute vesicles of an oval form, somewhat
acuminate at the free end, and wider at the opposite, sup-
ported on a short stem in the incision and between the lobes
of the disc. Immediately above the notch in which the
marginal body is lodged, runs a canal communicating with
the contiguous prolongation of the gastric cavity. The canal
at this point is slightly dilated and furnished with distinct
walls. It enters the stem of the marginal body, running
downwards in it for more than one third of its length, ulti-
mately curving round nearly at a right angle with the longi-
tudinal axis of the marginal vesicle.
The marginal body itself encloses an oval cavity also
surrounded by a well-defined layer of tissue. The curved
canal of the peduncle opens into this space, which would, in
fact, represent a sudden dilatation of it. Thus, in the
106 GEGENBAUR, ON MEDUS&.
higher Medusze, there is a communication between the
marginal vesicle and the gastro-vascular system, a fact dis-
puted by Kélliker. The interior of the vesicle, like that of
the canal, of which it is, as it were, a derivation, is lned
with a very delicate ciliary investment, by means of which a
constant circulation of the contained fluid is maintained.
Kolliker and others have described an opening on the upper
side of each marginal vesicle, through which the ampulla
above described would communicate with the surrounding
medium; but Gegenbaur denies altogether the existence of
any openings of the kind.
At the free end of the marginal body, and constituting
nearly its whole apex, is placed an oval sacculus, 0°14’ long
by 0:09’ broad, closely filled with prismatic crystals, and
which probably represents the most important physiological
portion of the organ. The membrane of this sacculus is
indeed thin, though possessing a certain resistance. At the
sides and distal end it is enclosed by the walls of the marginal
body itself, which are here somewhat thinned, whilst the
part corresponding to the ampulla is covered with the ciliary
lining of the latter. There is no communication between the
ampulla and the crystalline sacculus. Gegenbaur has never
perceived any movement in the crystals, and denies the
existence of cilia in the sacculus containing them. The
crystals themselves are six-sided prisms, obliquely truncated
at each end; in length and number they vary very much.
The longest measure 0:02'". They appear to be insoluble in
acetic acid.
Gegenbaur then proceeds to describe the unusual forms of
marginal bodies which exist in species termed by him
Ephyropsis,* and probably belonging to the genus Nausitho,
of Kolliker,+ and in Carybdea marsupialis, in both of which
Meduse, moreover, the ocelli contain sperical, refractive
bodies.
After discussing the question concerning the function of
these bodies, Gegenbaur inclines to the opinion, that the
coloured spots, especially when furnished with a spherical
refractive corpuscle, are of the nature of visual organs, whilst
he throws out the supposition that the other kind may be
excretory. Relying chiefly upon the absence of motility in
the concretions or crystals, and of cilia in the cavities in
which these bodies are lodged, he attempts to show the im-
probability of their being auditory organs.
* “Comptes rendus,’ t. xxxviii.
+ ‘Zeits. f. Wiss. Zool.,’ Bd. iv, p. 323.
107
Mopes of Dretrerminine, by the Use of the Microscorz, the
Rerracrive Inpex of Fiurps.
(Freely translated from the Dutch of Professor Hartine, of Utrecht.
By Wixtiam Rosertson, M.D., F.R.C.P.E. See ‘ Het Mikroskoop,’
Tweede Deel, b. 200.)
A KNOWLEDGE of the laws which the rays of light observe
in their course through refracting media enables us, with the
help of the microscope, to determine the index of refraction
of certain substances, to which, on account either of their
small quantity or of their insufficient transparency except
when in layers of extreme thinness, the ordinary methods are
inapplicable.
I. Sir David Brewster’s Method.
It is many years since Brewster first used the microscope
for this purpose. His mode of procedure is described in his
‘ Treatise on Philosophical Instruments,’ Edinb., 1813, p. 240.
He uses a compound microscope, the object-glass of which is
a biconvex lens, with sides of equal curvature, and of consi-
derable focal length. This lens is firmly fixed in the lower
extremity of a brass ring, which is to be filled with the fluid
whose refractive power is the subject of examination. The
upper opening of the brass ring is then to be closed by laying
on it a circular glass plate with parallel surfaces. The con-
tained fluid now forms a plano-concave lens, the concavity of
which rests on the upper side of the biconvex glass lens.
The object-glass is thus converted into a plano-convex com-
pound lens, resembling an achromatic combination of flint-
and crown-glass, but with this difference, that in the former
the convex surface is directed downwards and the flat surface
upwards.
When the biconvex is thus converted into a plano-convex
lens, its focal length becomes of course considerably aug-
mented ; and in like manner the distance at which an object
must be placed in order to be clearly seen through the mi-
croscope becomes greater.
That the eye may in the course of a series of observations
be as nearly as possible in the same state of accommodation,
Brewster recommends the use of an eye-piece with a wire
or glass fibre crossing its field, to form a distinct image on
the retina at the commencement of each observation, and
108 ON THE REFRACTIVE INDEX OF FLUIDS.
thus secure the uniform exercise of the same amount of
accommodating power.
For the calculation of the index of refraction we must have
the following data:
lst. The radius of curvature of the biconvex lens = 7.
2d. The distance between the biconvex lens and the object,
when the latter is best seen, and air only is interpo.ag
between the lens and its covering-plate. This distance =
3d. The distance between the biconvex lens and theob. ~
when the latter is best seen, and the space between lens!&¢ts
glass covering-plate is filled with the substance under ex and
nation. This distance = 6.
If now we make the required index of refraction =n, we
have the following equation :
eee pee (C— or !
ab
This formula has been communicated to me by my colleague,
Van Rees, and I have substituted it for that given by
Brewster, in which the index of refraction of the biconvex
lens is assumed as known, which, however, can be the case
only when such a lens has been made for this express purpose
of glass whose index of refraction is ascertained before grind-
ing.
The advantages of Brewster’s method are, that it is not
only applicable to fluid bodies, but to such as are so soft as
to admit of being pressed into the lenticular form, even when
their degree of transparency is but feeble—a case for which
we can provide by causing the light to traverse a thinner
layer of the substance under examination. Different bodies,
such as wax, pitch, opium, &c., which are in mass absolutely
opaque, become, when pressed into a thin layer, transparent
enough to admit of the determination of their indices of
refraction by this method.
The disadvantages of the procedure are the following. In
the first place it requires the adaptation to the microscope of
a special apparatus, consisting of an object-piece constructed
for the purpose, and of a very accurate micrometric movement
for measuring the distance at which the object is seen sharply
defined. In the second place, the radius of curvature of the
biconvex lens must be exactly known—one of the most diffi-
cult of requirements in the case of microscopic lenses.
Iinally, in the third place, the question arises—‘ from what
point is the distance of the object to be measured ?”
Brewster seems to have used the lowest point of the lens as
his ‘‘ point de départ ”?—but this is not correct, for the true
ON THE REFRACTIVE INDEX OF FLUIDS. 109
point, the optical centre, is in the compound lens, and at a
depth varying with the thickness of the layer and refracting
power of the fluid which constitutes a part of the plano-con-
vex lens. Henceit is hardly possible to measure the distance
of the object with the degree of accuracy required for the
subsequent calculation.
Il. Harting’s Method.
The following method may be followed with any micro-
scope and without the addition of special apparatus ; and
although comparatively limited in its application, which is _
restricted to certain fluids, it affords indications of extreme
exactitude when due attention is paid to the manipulation.
It is free from the above-mentioned disadvantages of
Brewster’s method, and has the further recommendation that
a very small quantity of fluid is required for each observation,
even a few milligrammes amply sufficing for the determination
of the index of refraction.
This method is founded upon the different dimensions of
images of the same object placed at like distances from air-
bells of like size in fluids of different refractive power. That
this difference in the size of the images is rather considerable,
the following examples will show:
Water . n=1:336 Diameter of image = 1000
Sulph. acid . > L416 ah 3 =e fo
Canada balsam ,, 1°504 95 es == 5o2
To enable us to calculate the index of refraction, it is
necessary that there should be—
Ist. A thin layer of the fluid between two plates of glass
with parallel surfaces ; also some air-bells in the fluid to act
as dispersing lenses and form images of objects situated
beneath them. To prepare the fluid for the observation, let
a drop be placed on a thin glass plate, and some air-bells
formed by blowing air into the fluid through a small glass
tube drawn out very fine in the blowpipe flame. ll.
In my investigations, I prefer a fixed distance of 100 milli-
metres, on account of the convenience of this round number
in calculation. The construction of most microscopes also
renders this aconvenient distance. Between the distance and
the diameter of the object a certain ratio should be observed.
If the latter be more than one fifth of the former a correction
of the final result becomes necessary, for in consequence of
the excessive obliquity of the rays proceeding from the
margins of the object, the difference between their angles of
incidence and of refraction becomes too sensible to be neg-
lected.
4th. The microscope being so arranged that the object is
brought distinctly into view, the diameter of the air-bell and
of the image of the object below it are to be successively
measured; and in doing so it will be of course necessary to
alter the focus of the instrument slightly, the margins of the
air-bell and the image lying in different planes.
As the accuracy of the result in great measure depends
upon these two measurements, it 1s scarcely possible to bestow
too much care in taking them. For the methods to be
followed in this stage of the observation, I refer to the
chapter on Micrometry.* I must not neglect to add that
these measurements should be made by reflected light—if
transmitted light be used, the influence of diffraction causes
the results to be somewhat too small. It is also advisable
that the strip of metal used as an object should be of a white
colour.
It is essential that the successive measurements of air-bell
and image should be made rapidly, both in order to obviate
the influence of changes of temperature, and because the
gradual absorption of air by most fluids, and especially by
* In the ‘Monthly Journal of Medical Science,’ May, 1852, p. 453, a
very full abstract of this chapter will be found. The most exact methods
are those in which the screw-micrometer eye-piece or the plan of “ double
vision” are used. (T.)
ON THE REFRACTIVE INDEX OF FLUIDS. lil
those of organic origin, causes the diameter of the air-bell
after a certain time to become notably diminished. We
must not therefore rest satisfied with a smgle measurement,
but take each set of dimensions again and again, and use in
the final calculation the mean results of all.
Let us now suppose :
Distance between object and air-bell
Diameter of the object
Diameter of image >
Diameter of the air-bell
I fl Wl
a
b.
c.
d
The index of refraction will then be obtained by means
of the following formula, for which I am indebted to my col-
league, Van Rees:
i b—c)d
= = + Ae ee
4ac
But as c may be regarded as infinitely small when com-
pared with 4,
1 1 bd
as Vv; * Fae
The use of this formula enables us to deduce the refractive
index with certainty to the third decimal place, but only
when the above-mentioned conditions are attended to, and
the final mean of several measurements is used as the basis
of calculation. When a thicker object-plate, and especially
when a larger object is used, there arises the necessity for
different corrections, which cannot be neglected, and which
render the computation troublesome and its result less
exact.
If, as in the arrangement which I have recommended,
a =100, b= 20, or, in general, if 4 3 then,
n=5 a: Vite 20
Some results obtained by this method may be here sub-
joined, in order that the reader may form an estimate of the
degree of accuracy of which it is susceptible.*
* The first two examples taken from Harting are all that we give
here. (T.)
112 ON THE REFRACTIVE INDEX OF FLUIDS.
1. Aqueous Humour from Cow’s Eye.
By measurement No. l - m=1°3495
” » ify \eapaleaam
» 13494
», 1°3496
3, 1°38465
OE )
By mean ..,. + *osto-gf=-djoaen
Extreme difference of measures . . = 0:0039
Probable error of mean = 0:0005
2. Vitreous Humour of same Eye.
By measurement No.1] . n=13412
5B) » 2 »” 13421
” » O 5B) 13474
” be ig Fite, Wes
»” »” 5 ” 1°3426
By mi¢an:) © 92) Sy sed Sy a date
Extreme difference of measures . . = 0:0062
Probable errorofmean. . . . . == 00-0007
III. Moser’s Method.
An account of this method is contained in the ‘ Reper-
torium der Physik,’ v, p. 395. Moser uses an object-piece
of long focus, taken from a common reading-microscope, and
fixed at one end of a tube of at least fourteen inches in
length, to the other extremity of which an eye-piece is
adapted. The refractive index of a transparent plate with
parallel surfaces, or of a layer of fluid, is then found by the
]
following formula: x=? (1 —*), When an object is
brought into focus, and the refractive medium then inter-
posed, the tube must be lengthened, or rather the object-
glass withdrawn to a certain distance, in order that a distinct
view of the object may be obtained. The difference between
these two focal distances is then called 2, the thickness of
the interposed refractive medium is termed 7, and the index
of refraction = 7.
IV. Bertin’s Method.
This method was communicated to the French Academy,
through Regnault, in April, 1849, and a full account of it
ON THE REFRACTIVE INDEX OF FLUIDS. Lis
was published by Bertin himself in the ‘Ann. de Chimie et
de Physique,’ 1849, xxvi, p. 288. To determine the refrac-
tive index of a plate of glass, he proceeds as follows. A
micrometer is used as an object, and its amplifications ob-
served—first, as it lies on the glass plate; second, as it lies
beneath it; and, third, as it rests on the stage without the
interposition of the plate. In the course of these observa-
tions the olject-piece must remain a fixed point, and the
necessary motion be given to the eye-piece only. The suc-
cessive amplifications, in the above order, are termed G, y, g,
and the formula for finding the index of refraction is
ene od
meet Gly
When the plate is very thick, it is better to compare it with
another whose index is already known. Then,
( -) i 1
Saleh Sse eee
This method, like all the others which we have had occasion
to describe, is also applicable to fluids. It is said, that its
possible error cannot exceed 1 in the second place of deci-
mals.
®_
|
aaa
py
|
Sle
ea
S 1
|
be
Note.—Of the comparative value of these four methods
I have had no opportunity of judging; but on applying
the second to the determination of the refractive power of
water, turpentine, castor oil, and other fluids, I have found
its results very uniform and satisfactory. (Trans.)
114
REVIEWS.
Archives of Medicine. Edited by Lionrt Bears, M.B.
London: Churchill.
Tis is the first number of a new medical periodical, but
how often it is to appear the editor does not inform us. ‘The
object of the editor is to publish papers of a more thoroughly
scientific character than are usually found in medical perio-
dical literature, and to have these papers freely illustrated.
The subjects on which he wishes to receive papers are as
follows :
1. Practical clinical observations.
2. Original researches in Physiology and Pathology.
3. Chemical and Microscopical examination of the solids
and fluids of the body.
4. Descriptions of scientific processes.
5. Condensed reports of researches published elsewhere.
The distinguishing features of this first number are the
papers devoted to chemical and microscopical research and
the accompanying lithographic plates. Of course microsco-
pical examination is only one means pursued in the investiga-
tion of healthy or diseased structures, and in most of the
papers in this first number we have observations recorded by
the use of the microscope. As an example of the papers we
republish one by the editor.
“On the Manner in which the Drawings illustrating the Papers have been
made, and of obtaining Lithographs from Microscopical Drawings.
“JT have always felt it very desirable that the description of scientific
observations should be curtailed as far as is consistent with accuracy and
perspicuity in the statement of the results, and it is my desire, as far as
possible, to see drawings take the place of long and necessarily tedious
descriptions of observations. Instead of alluding to the dimensions of an
object in the text, the reader will be referred to the scales appended to every
plate, and with the aid of very little trouble, the diameter of every object
depicted may be readily ascertained. For all ordinary purposes it is only
necessary to compare roughly the size of the drawing with the scale magni-
fied in the same degree as the specimen itself, but in those instances where
great accuracy is important, a pair of compasses nay be used.
“In comparing the representation of the same object delineated by different
observers, it will be often found that great confusion has been produced in
BEALE, ON OBTAINING LITHOGRAPHS. 115
consequence of the magnifying power of the object-glass not having been
accurately ascertained, and an object said to be magnified in the same degree
by two authorities is not unfrequeutly represented much larger by one than
by the other. This arises from the magnifying power of the glasses not
having been accurately ascertained.
“1 cannot too strongly recommend all microscopic observers to ascertain
for themselves the magnifying power of every object-glass, aud to prepare, in
the manuer presently to be described, @ scale of measurement by which the
dimensions of every object can be at once ascertained.
“The inconvenience of not being acquainted with the number of diameters
which any object represented in a drawing is magnified, has been often felt ;
for without this it is impossible to judge of its real size. And, on the other
hand, the annoyance of reading a long description of minute objects, differ-
ing slightly in size from one another, the dimensions of which have been
accurately noted, is very great; while no corresponding advantage is de-
rived from such minute measurements. The text becomes occupied with a
multitude of figures of but little interest to the reader. At the same time,
it is very desirable that the careful observations of different persons should
be readily comparable with each other. Elaborate researches are not un-
frequently deprived of much of their value in consequence of measurements
having been carelessly taken, or the magnifying power of the glasses
wrongly expressed.
“The plan of appending to every microscopical drawing a scale magnified
in the same degree as the object represented, supersedes the necessity of
giving measurements in the text, while it is free from any of the objections
above referred to. I propose to describe briefly a very exact, and at the
same time a very simple, method of applying scales to microscopical drawings.
All the drawings illustrating the editor’s papers may be measured by the
scales at the bottom of the page, and he strongly recommends all contri-
butors to follow the same plan.
“To carry out this it is necessary to ascertain the magnifying power of
every object-glass, and to be provided with a stage micrometer divided into
LO0ths and 1000ths of an inch.
“ Mode of ascertaining the magnifying power of the object-glass.*—A glass
micrometer divided into 100ths of -an mch is placed in the focus of the ob-
ject-glass of the microscope, which is arranged horizontally. The neutral
tint glass-reflector is fitted to the extremity of the eye-piece, and the light
carefully arranged so as to render the micrometer lines distinctly visible.
Care must, however, be taken that the distance from the object-glass to the
reflector is the same as from the latter to the paper beneath it, upon which
the magnified micrometer lines may now be traced. A four- or six-inch
scale accurately divided into 10ths of an inch is now applied to the magnified
LOOths of an inch, and the magnifying power of the glass is at once ascer-
tained. Suppose each magnified 100th of an inch covers 1 inch, the mag-
nifying power will be 100 diameters, if an inch and 3 tenths 130 diameters,
if 4 tenths of an inch 40 diameters, and so on, each 10th of an inch corre-
sponding to a magnifying power of ten times.
“Tf we wish to ascertain the magnifying power of one of the higher object-
glasses, a micrometer divided into 1000ths of an inch should be employed
instead of the one just alluded to. In»this last case, each tenth of an inch
* «This mode of measuring is alluded to in several works on the micro-
scope, but the editor considers it sufficiently important to repeat here,
especially as the drawings illustrating papers published in the ‘ Archives’
have been copied in this manner.”
VO Vil. K
116 BEALE, ON OBTAINING LITHOGRAPHS.
upon the scale corresponds to a magnifying power of one hundred, instead
of ten diameters. Any fractional parts can be readily estimated if we have
a very accurately divided scale. This process must be repeated for every
object-glass, as well as for each different eye-piece employed with the several
objectives.
“1 ascertain the Diameter of an Object.—If an object be substituted for
the micrometer, and its outline carefully traced upon paper, its dimensions
may of course be easily ascertained by comparison with the micrometer lines,
The magnified power used being the same in both cases.
“Tn order to apply this plan to microscopical drawings generally, the fol-
lowing seems to be the simplest method of proceeding, and saves mucli
trouble. Scales are carefully drawn upou gummed paper; the magnifying
power, and the micrometer employed, being written against them as repre-
sented in the plates. If a number are drawn together one of the rows can
be cut off and appended to the paper upon which the drawing, magnified of
course to the same degree, has been made. This is the plan | have followed
in all the drawings which illustrate my observations, and the scales have
been copied in the lithographs. All magnifying glasses of the same focus
do not magnify in precisely the same degree, so that it is necessary for every
observer to ascertain for himself the magnifying power of his lenses, and he
may construct little tables in the manner I have described.
“In order to make an accurate microscopical drawing, the image of the
object is carefully traced on paper with the aid of the glass-reflector, and
afterwards finished by the aid of the eye alone. In order to obtain the size
accurately, care must be taken that the distance between the reflector and
the paper is the same as that between the former and the object-glass. The
drawing having been finished, one of the scales made as above described may
be gummed on in one corner of the paper.
“Of Drawing Objects in the Microscope, from which it is intended to take
Lithographs.—The lithographs illustrating the papers in the present number
have been made by copying the image, with the aid of the reflector, on trans-
fer-paper, with lithographic ink or chalk.*
“The drawing on the transfer-paper being complete, is transferred to a
finely grained lithographic stone and properly fixed; impressions may then
be taken off.’
All the papers in this number have greater or less merit,
and we can cordially recommend Dr. Beale’s ‘ Archives’ to
the patronage of our medical readers.
* “The best transfer-paper for this purpose is made of India paper. The
ink and chalk can be purchased at any lithographer’s. Fluid lithographic
ink answers very well, and was used in making the drawings.”
t “The drawings have all been carefully copied from the objects them-
selves on transfer-paper in my house, and then transferred to the stone.
The transfers have been made and the impressions printed off by Messrs.
Harrison and Sons, of St. Martin’s Lane, and it is only right that I should
thank those gentlemen for the trouble and interest they have taken, and for
the kindness which they and their workmen have always shown in carrying
out this plan of producing the drawings, as well as other suggestions which .
have been rade.”
CARPENTER, ON ZOOLOGY. 117
The Microscope: its History, Construction, and Application.
By Jasez Hoee. Third Edition. London: Routledge.
Wuewn Mr. Hogg’s work first appeared, we predicted for
it a large sale, on account of its excellent illustrations and
low price. He tells us, in his preface to this, the third
edition, that two editions, of five thousand each, have been
sold, thus fulfillimg our prophecy. We know, also, that other
works have been equally successful, affording a gratifying
proot of the extended interest taken in microscopic researches.
In this third edition, Mr. Hogg has taken the opportunity
of adding much new matter, and bringing up the information
it contains to the time of publication.
Zoology ; being a systematic account of the General Structure,
Habits, Instincts, and Uses of the principal families of the
Animal Kingdom. By W. B. Carpenter, M.D. Vol. I.
A new Edition, edited by W. S. Datuas. London:
Bohn.
WE call attention to this new and cheap edition of Dr.
Carpenter’s work on Zoology. It is now published in Mr.
Bohn’s series of standard scientific works, and has been
brought up to the present requirements of the science of
zoology by the aid of Mr. Dallas, whose scientific labours as
a zoologist are well known.
118
PROCEEDINGS OF SOCIETIES.
Microscoricau Society, October 21st, 1857.
Grorce Suapsort, Esq., President, in the chair.
A paper was read by Dr. Donkin, “On the Marine Diato-
mace of Northumberland, with a description of twenty new
species. (‘Trans.,’ p. 12.)
Another paper, by T. 8S. Ralph, Esq., “On a Mode of Iila-
minating Objects,” was read.
November 11th, 1857.
Grorce SuHapzott, Esq., President, in the chair.
H. W. Lobb, Esq.; Samuel Mason, Esq.; John May,
Esq.; Thomas Spencer, Esq.; and G. Y. Sharpe, Esq., were
balloted for, and duly elected members of the Society.
A paper, by T. 8. Ralph, Esq., “On a Mode of Perforating
Glass Slides for Mounting Objects, and on various methods
of Mounting Objects in them,” was read. (‘Trans.,’ p. 34.)
Mr. R. J. Farrants made the following remarks :
‘“‘The author of the paper just read has noticed the want of
a-medium in which moist specimens could be mounted and
preserved, the requisite properties being that it should ‘ vis-
cify, and be readily miscible with glycerme and with water.
This want is, in part at least, supplied by the gelatine me-
dium of Mr. H. Deane, the formula for which was given in
the third volume of the ‘Transactions’ of this Society, but
which the author seems to have overlooked. This medium is
rendered fluid by heat, the necessity for which in many cases
precludes its use. In its stead I have for some time used a
mixture of gum and glycerine, which I find suitable im all
cases where the gelatine medium is proper, while it may also
be used for mounting some other delicate structures for
which the gelatine would be unsuitable. Gum in solution
was, some years ago, extensively tried as a medium for
mounting microscopic objects; but its tendency to crack
when dry (by which it frequently happened that the object
immersed in it was spoiled) was found to be an imsuperable
objection to its use, and it was, I believe, entirely super-
seded by Canada balsam. Now the tendency of the gum
to crack on drying, may be altogether prevented by the
PROCKEDINGS OF SOCIETIES. 119
addition of glycerine to the solution: the proportions I have
used are equal parts of gum, distilled water, and glycerine ;
to prevent the growth of minute alge or fungi in the
mixture I have added a little arsenic. The following is
the formula I would recommend: Boil together, in a Flo-
rence flask or porcelain capsule, 3 grains of arsenious acid
and 2 fluid ounces of distilled water ; when cold filter through
paper. ‘Take of this arsenical solution 1 fluid ounce, of pure
glycerine 1 fluid ounce, of pure gum acacia 1 ounce (Troy).
The gum should be dissolved without heat; a fortnight or
longer will be required for its complete solution: in the
mean time the mixture should be occasionally stirred with
a glass rod ; it will be well not»to shake the bottle so as to
froth the mixture, for air introduced is retained with great
tenacity, and many days elapse before it entirely disappears.
If due care be taken in selecting pieces of gum transparent,
bright, and free from impurities, the mixture will not need
filtering ; if, however, foreign matters have accidentally
gained admission, the best substance through which to strain
the mixture is fine cambric, through which a considerable
quantity of clean, cold water has been made to flow, so as to
wash away any dust or loose fibres of the fabric which might
find their way mto the mixture. This is an almost saturated
solution of gum; it has nearly the consistence and appear-
ance of fresh, pale Canada balsam, and is to be used in the
same way, but without heat. The portion of the liquid
which extends beyond the thin glass cover, soon dries (the
water rapidly evaporating), the residue being a tough elastic
compound of gum and glycerine, strongly adhering to the
glass, and with no tendency to crack. The superfluity may
be cut away with a knife, and any remaining smear be.re-
moved by a piece of soft rag moistened with clean cold
water. The specimen may be left in this state like an ordi-
nary ‘ balsam-mounted’ object; or the edges of the thin
glass cover may be coated with any of the cements commonly
used for that purpose, or (which I prefer) a piece of tinfoil,
with a hole of appropriate size, may be placed over the cover
and be cemented to the slide with a solution of Canada balsam
in ether. The most delicate structures are well shown and
preserved in this medium—such as thin sections of recent
vegetables, starch corpuscles, mycelium, and sporules of fungi;
cells, vegetable or animal; the thm, delicate membrane of
small hydatid cysts, &e. Pathological specimens, so difficult to
keep unchanged for more than a short time, have been better
preserved in this medium than in any other with which I am
acquainted ; cancer cells, for example, have been kept unal-
120 PROCEEDINGS OF SOCIETIES.
tered in their optical characters for a period of two years :
beyond this my experience does not extend. I imdeed have
no reason for supposing that specimens which have remained
so long unchanged should not continue well preserved ; fur-
ther experience will, however, afford the surest means of
determining the sufficiency of the medium as a preservative.
Some recent and moist structures, animal and vegetable,
admit of bemg mounted in Canada balsam without being
previously dried ; the advantage of this is, that the parts of
an object are not distorted, as must, to a greater or less ex-
tent, always happen when a specimen is completely desic
cated. The manner of proceeding is as follows: Take the
specimen from the water or other liquid in which it has been
prepared, let it drain a little, and then immerse it in rectified
spirits of wine; after a short time (varying from one or two
to ten or fifteen minutes, according to the size and thickness
of the specimen), remove it from the alcohol, and, after
draining, place it in methylic alcohol, otherwise known as
pyroxilic spirit, pyro-acetic spirit, &c. After allowing it to
remain a few minutes in this liquid, it may be removed,
drained, and immersed in spirits of turpentine, on being
taken from which, after a few minutes, it may be placed in
balsam, and be proceeded with in the usual manner; the
balsam ought to be sufficiently fluid not to need the employ-
ment of heat. It is recommended to pass the specimen
from common to methylic alcohol, and thence to spirits of
turpentine, because the turpentine mixes more readily with
the latter than with the former; observe, however, that
the spirit referred to is TRuE methylic alcohol, or pyroxilic
spirit, not what is commonly known as methylated spirit, which
is common alcohol contaminated with wood-naphtha, &c.
Injected preparations are well preserved and displayed in
this way: there is no displacement or distortion of parts, and
while the vessels are shown in their true position and rela-
tions, the object is more securely and permanently preserved
than if mounted in a cell with liquid in the ordinary manner ;
for, notwithstanding the greatest care cells will leak, and
there are I believe few collections which after a lapse of four
or five years will not contain cells into which air has passed,
and from which a corresponding quantity of the original
liquid has escaped. It has been said that this way of
mounting objects in Canada balsam is neither original nor
new, and in order that merit may be given where, it is
said, merit is justly due, reference has been made to some
beautiful preparations of the nerves, &c., by Dr. Andrew
Clark, put up in this way a year and a half or two years ago.
PROCEEDINGS OF SOCIETIES. 121
I reply that I do not claim any merit either for originality
in proposing, or for priority in using this plan, which indeed
is likely enough to have occurred to many persons who have
been much occupied in preparing and mounting objects for
the microscope; as, however, I thought it not unlikely that
this method might be unknown to some persons present, and
judged also that the place and the occasion were proper, I
ventured to mention it. Perhaps I may be allowed to add
that I have specimens of injections prepared and mounted in
this way as long ago as 1850, and though at first I had
recourse to this method but rarely, being uncertain about its
permanence, | have now for several years mounted ‘ injec-
tions’ almost exclusively in this way, either in cells or
without them, as the thickness of the specimen required. I
have also a pretty extensive series of sections of the roots,
woods, and barks of the Materia Medica, prepared and
mounted in this way, with the advantage of well-secured ob-
jects, without falsification of the optical characters of the
. structures.”
Mr. Wenham said—“ Having had considerable expe-
rience in working glass, for optical purposes, I may state,
that I frequently make use of hard steel with turpentine for
rapidly reducing to form pieces of glass chucked in the lathe.
I take a three-square saw-file, and grind away one of the
faces as it loses its keenness and becomes worn; this con-
stantly leaves two sharp serrated edges, which are applied to
the revolving piece of glass, ‘ overhand’ or in the way that
a spoke-shave is used, supporting the file on the T rest,
which is raised nearly level with the top of the work.
I also employ turpentine for drilling glass. If the drill is
made of the hardest cast steel, and hardened by quenching
in dilute sulphuric acid, without being afterwards tempered,
I can drill an eighth-inch hole through a plate of glass one
inch thick in about one minute. The dmill should be
sharpened on both sides, so as to cut either backwards or
forwards, and is best worked by the Archimedean drill-stock.
Most glass is somewhat softer than hardened steel, but if
the attempt be made to drill glass dry, a very intense heat is
generated on the cutting edge, which destroys the temper
and softens a very minute superficial film of the steel, which
is then rubbed away, leaving a round edge unsuitable for
cutting. The turpentine does not act in any peculiar way
upon the glass itself, but its extreme fluidity and penetrating
quality enables it to bathe the end of the drill during its
rapid rotation, and by thus keeping it cool its hardness is
maintained. For glass-turning I prefer old turpentine, as
128 PROCEEDINGS OF SOCIETIES.
it does not evaporate quite so readily. There is another
point that I may notice in the paper that has just been
read. The author mentions that by cutting off the heads
of flies and grasping one of them between the finger and
thumb the proboscis with all its apparatus will be pro-
truded in the symmetrical arrangement proper for mounting.
I invariably make use of this method. Take the proboscis of
the blowfly for example. The flies are best when very young,
having been hatched in’ a dark box, otherwise their probosces
will be opaque and more intractable than when they have not
been hardened by exposure to air and light. Having cut off
the heads, they should be macerated for some hours in water,
then on grasping the head between the finger and thumb, the
proboscis will become highly inflated (indeed if the pressure
is too great it will burst), then nip it between two slips of
glass, having a small elastic band around them, to spring
them together, now cut off the head, and leave the proboscis
under pressure until it is dry; it will then retain its form,
which will be quite symmetrical, and may be finally mounted -
in Canada balsam in the usual way.”
After some remarks from Mr. Brooke the discussion closed.
The final Report of the Committee “ On the best uniform
method of attaching Object-Glasses to Microscopes,” was
read. Resolved that it be received and adopted. (‘'Trans,’ p.
39.)
December 9th, 1857.
Grorcr SHapsott, Esq., President, in the chair,
Captain John ‘Peel, 14, Ulster Place ; Geoffrey Bevington,
Esq., Wandsworth Common; J. J. Harding, Esq., 1, Barns-
bury Park; J. W. Harker, Esq., 24, Upper Barnsbury Street,
were balloted for, and duly elected members of the Society.
A short paper by Mr. B. J. Nowell was read, ‘ On the
Menai Straits as a locality for the Collection of Diatomacez.”’
The author adverts to the fact that the mud of which some
portion of the shore is composed is particularly rich in Dia-
tomacere, and states that the gathering is best pursued be-
tween high and low water mark, the surface and the bottoms
of the little pools being skimmed in the usual manner. The
united proceeds of these skimmings are to be placed in a
shallow vessel and exposed to the sun for some time and then
re-skimmed. It is then recommended that the usual manipu-
lations with hydrochloric and nitric acids, assisted by heat,
should be performed, the “ result being a collection replete
- with beautiful forms.” Some slides containing the forms
collected in this way having been transmitted by the author
PROCEEDINGS OF SOCIETIES. 123
to the President, that gentleman furnished the meeting with
the following list of species observed by- him on the in-
spection (cursory) of a few slides, and from which the rich-
ness of the locality may be judged of.
List oF SPecrIEs oF DIATOMS NOTICED IN Mupb FROM THE MENAI STRAITS
Coscinodiscus radiatus. Pleurosigma angulatum.
4a minor. Fe decorum.
ne excentricus. 3 litorale.
Eupodiscus sculptus. 5) distortum.
3 Sulous. a ? 1. sp.
45 CVASSUS. Grammatophora marinu.
2 ee radiatus. pS serpentind.
Actinocyclus undulatus. Melosira maculata.
Actinophenia splendens. Orthosira arenaria.
Triceratium favus. Biddulphia rhombus,
> elliptica. 95 aurita.
ie amphisbenda. ES turgida.
Pleurosigma balticum.
“On a peculiar Larve Form resembling Pluteus,” by Dr.
Cobbold. (‘Trans.,’ p. 50.)
~ “Directions for Making Spherules of Calcareous Salts, with
some Observations on Molecular Coalescence,” by G. Rainey,
Esq. (‘ Trans.,’ p. 41.)
A discussion followed the reading of this paper.
Professor Quekett stated that he had observed crystalline
spherules in the urme of the horse, in a specimen which had
been kept for many years in the Museum of the Royal Col-
lege of Surgeons.
Dr. Carpenter thought Mr. Rainey’s observations very
important ; but he believed that in shells there was a true
cellular structure.
Dr. Lankester said that Mr. Rainey’s observations were
interesting in connection with those made by Mr. Sorby
on the physical causes producing the Oolitic structure in
rocks.
Professor Busk referred to an oolitic deposit in the lake of
Mexico, which was produced, not by physical causes or spheru-
lation, but by the deposit of caleareous matter on the surface
of the ova of an insect which lived in the lake. The ova,
when recent, were eaten by the natives; but those which
were not taken for this purpose became cemented into a true
oolitic petrifaction.
124
ZOOPHYTOLOGY.
For the interesting additions to the Zoophytological
Fauna of Madeira, contained in the following list, we have been
indebted to Mr. J. Yates Johnson, so well known as an
assiduous cultivator of the natural history of that island,
and more especially of its marine productions. It is needless
to insist upon the importance of contributions from such a
locality towards a more complete knowledge than we as yet
possess of the geographical disposition of species; but the
consideration simply of such a short list as the present
suffices to indicate that, so far as its Zoophytology is con-
cerned, Madeira forms a connecting link between the Medi-
terranean, on the one hand, and with the Western and
astern shores of Africa and of South America respectively,
on the other ; connected with the latter, perhaps, through the
intervention of the Gulf-weed.
The number of species comprised in the collection is about
twenty-four, of which twenty belong to the Polyzoa, and four
to the class of Sertularian Hydrozoa.
The Polyzoa are arranged in the following families, with the
characters given in the ‘ B. M. Cat. ’
. Scrupariade.
. Salicornariade.
. Bicellariadee.
. Membraniporide.
. Celleporide.
Selenariadee.
. Idmoneade.
. Crisiade.
DIA or Rw TO
Class. Potyzoa.
1. Sub-order. CHErLostoMaTa.
1, Fam. Scrurariap#, Gray.
1. Gen. Hucratea, Lamx.
Unicellaria, Blainville.
1. #. Lafontii, Andouin, ‘ Expl.,’ p, 242; Savigny, ‘ Egypt,’ pl. xii,
fig. 2.
This beautiful and very remarkable species belongs to the
Mediterranean Fauna, occurring on the coast of Syria. It
ZOOPHYTOLOGY. 125
probably deserves to be raised to the rank of a distinct
generic type, in which case the name of Kucratea (Aud.)
might be retained for it and the &. Cordiert of the same
author.
2. Fam. Saticornariap#, Busk (‘B. M. C.,’ p. 15).
2. Gen. Nellia, Busk (‘ B. M. C.,’ p. 18).
Ll! W. Johnsoni, nu. sp. Pl. XIX, fig. 2.
Front of cell pyriform, pointed at bottom; margin raised, thick, smooth.
Mouth semi-orbicular, lower lip straight. Ovicell (?).
Hab. Madeira, Johnson.
Two small fragments only occur of this apparently distinct
form. The natural size is shown in the plate.
3. Fam. Bicertariap#, Busk (‘B. M. C.,’ p. 41).
3. Gen. Bugula, Oken.
1. B. gracilis, n. sp. Pl. XIX, fig. 1.
Cells biserial, elongated, of nearly uniform width throughout ; a short spine
on each angle of the aperture. Aperture not extending below the middle of
the cell. Avicularia capitate, blunt (?), of uniform size.
Hab. Madeira, Johnson.
Although, in the character of the cell, this species ap-
proaches in some respects near to B. plumosa, and in the
number of spines to B. turbinata (Alder), the comparative
shortness of the aperture and, above all, the extremely dif-
ferent habit, so far as that can be judged of from the small
specimen seen by us, appear to afford sufficient grounds for
‘its being regarded as distinct from either. .
3. B. flabellata ? Thompson.
a. var, biseriata s. Ditrupe.
Although we have named the form as above, it will
probably have to be regarded as a distinct species. Its
habitat is very peculiar, and as in the very numerous
specimens shown to us by Mr. Johnson, the most remark-
able uniformity was exhibited, both in this respect, and in
general size and habit, and no indication whatever existed of
a nearer approach to the usual form of B. flabellata, this
supposition is rendered the more probable. The Bugula
always grows in a small tuft, about half an inch in height,
and consisting of three to four narrow branches, close to the
mouth of a species of Ditrupa (D. acuminata). It might on
this account, perhaps, be denominated B. Ditrupe. A figure
and fuller description of it will be given in a future number
of the ‘ Journal.’
126 ZOOPHYTOLOGY.
4. Fam. Mempranirorip®, Busk (‘B. M. C.,’ p. 55). |
4. Gen. Membranipora, Blainville.
1. M. tuberculata, Bose. Pl. XVIII, fig. 4.
Cells oval; margin granular; aperture partially filled in all round by an
irregular jagged calcareous expansion ; two to four blunt spines or tubercles
above the cell, often united into a single bifid knob.
Hab, Madeira, Johnson; Rio de Janeiro, M‘gillivray; Gulf-weed wbique;
on fuel. *
Flustra tuberculata, Bose, ‘ Vers.,’ 2d ed., t. iii, p. 143 (ex. syz.)
Flustra membranacea, Esper, ‘ Flustra,’ pl. v.
_ This very abundant and extensively spread species we had
formerly confounded with M. membranacea (‘ B. M. Cat.,’
p- 56, pl. lxvin, fig. 2), with which, on superficial inspection,
we regarded it as identical, until our attention was directed
to it by Mr. Alder, who was inelined to consider it as dis-
tinct from that well-known form. We are inclined to regard
this opinion as correct. The way in which it covers the air-
vesicles of Fucus natans with its. beautiful calcareous network,
and spreads over the surface of other Fuci, closely resembling
the habit of WM. membranacea, taken with the circumstance of
each cell being crowned with two short tubercular spines, on
a cursory glance naturally induced the supposition that the
two forms were identical. They differ, however, in several
important particulars. MM. tuberculata appears to be far more
caleareous than M. membranacea, The front of the cell is
not oblong and angular, as is usually the case in the other
species. The margin in M. membranacea is thin and smooth,
and the area is not encroached upon by a calcareous ex-
pansion. The spines, also, as Mr. Alder points out, in M.
membranacea are usually, in part at least, flexible or corneous
(though this is not always the case), whilst in M. tuberculata
they appear to be invariably calcareous, short, thick, and
blunt; and in the older cells usually united, so as to form a
transversely elongated tubercle, thicker and more elevated at
the sides. The form appears to be confined to the South
Atlantic, and it is very generally met with on the Gulf-weed.
With respect to the appellation, it seems quite clear that this
is the form intended by Bose under the name of Flustra
tuberculata, and there is no reason, therefore, that his desig-
nation should not be retained. LEsper’s plate (we have not
been.able to refer to the text) is a very good representation
of the species as it occurs on Fucus natans.
Our figure gives a bad idea of the M. tuberculata, and a
better will be given in a subsequent number.
2. M. trichophora, n. sp. Pl. XVIII, fig. 2.
Front of ecll oval, expanded below and contracted above ; margin smooth
ZOOPHYTOLOGY. 127
or very faintly granular; no calcareous expansion; one or two very long,
slender, hair-like marginal spines on either side of the upper part of the
cell. Ovicell small, immersed ?
Hab. Madeira, Johnson (on shell).
The only form with which this can be confounded is M.
Flemingii, Busk (‘ B. M. Cat.,’ p. 58, pl. Ixi, fig. 2, and_ pl.
Ixxxiv, figs. 4—6), but from which it is clearly distinguished
by the characters above given, and especially by the absence
of any calcareous expansion, and the extraordinary length and
slenderness of the hair-like spines.
3. M. , i. sp.
A figure and description of this species will be given here-
after.
5. Gen. Lepralia, Johnson.
l. LZ. distoma,n. sp. Pl. XVIII, fig. 1.
Cells pyriform, attenuated below. Mouth semi-orbicular, with a straight
lower lip, separated only by a narrow bar from an avicularium, the opening
of which is nearly as large as the mouth, the two openings being encircled
by a raised border common to both. A depressed space on the front of the
cell, the bottom of which is perforated with six or seven pores. A row of
distant pores around the border of the cell.
Hab. Madeira (on fucus ?), Johnson.
From the form of the small fragments in our possession
they would seem to be growing all round the slender
branches of a fucus, but the species may turn out to belong
to the hgulate Eschare.
2. L. vulgaris, Moll. Pl. XVIII, fig. 3.
Cells oval, convex ; surface subgranular. Mouth semi-orbicular, lower lip
straight, with a median notch. Three or four superior marginal spines.
Ovicell small rounded. A slender vibraculum on each side of the cell about
the middle.
Hab. Madeira, Johnson ; Mediterranean, Moll.
Eschara vulgaris, Moll., ‘ Eschara,’ p. 55, pl. iii, fig. 10.
Escharina vulgaris, Lamarck, ‘H.n. d.s. V.,’ 2d ed., t. ii, p. 281 (ex.
syn. L. Dutertret).
Cellepora vulgaris, Lamx., ‘ Hist.,’ p. 94.
From Moll’s account, and the name he has given to this
species, it would seem to be very common in the Mediterra-
nean.
3. L. P n. sp.
This species will be afterwards described and figured.
4. L. , a. sp.? resembling Z. ventricosa.
This species will be afterwards described and figured.
5. L. sceletos, n. sp.
This species will be afterwards described and figured.
128 ZOOPHYTOLOGY.
6. L. radiata, Moll.
Cells sub-oval, marked in front with radiating lines of pores, in a circum-
scribed, nearly circular, raised space, usually not occupying the entire front
of the cell. Mouth semi-orbicular. Four to six marginal spines. Nume-
rous long intercellular blunt avicularia scattered over the polyzoary.
Hab. Madeira (on shell?), Johnson; Mediterranean, Moll; Zschara
radiata, Moll, ‘ Eschara,’ p. 68, pl. iv, fig. 17.
It does not seem quite clear whether this species should
be referred to Lepralia or Eschara, inasmuch as in one, of
the small specimens brought under our notice, it seemed as
if the growth sometimes rose up in an independent frond
from the surface upon which the rest of the polyzoary was
spread. We have followed Moll, however, in regarding it, at
any rate provisionally, as a Lepralia. He states that this very
elegant species covers other zoophytes and shells with a sin-
gle layer of cells. The cells, as he observes, are much crowded,
and consequently not unfrequently deformed and irregular
in their disposition. He describes the radiating line of
puncta as constituted of granules, but they are clearly rows
of minute pores. His description of the avicularia is very
good.
5. Fam. CeLtLerorip#, Busk (‘ B. M. C.,’ p. 85).
6. Gen. Cellepora, O. Fabricius.
1. C. Hassallii (?), Johnst.
This name is only given provisionally, though it will pro-
bably prove to be correctly applied. A figure and descrip-
tion of the form will be given hereafter.
2. C. ramulosa, Vinn.
6. Fam. Spvenartap#, Busk (‘ B. M. C.,’ p. 97).
7. Gen. Cupularia, Lamx.
1. C. Lowei, Busk (‘B. M. C.,’ p. 99, pl exvi).
2B Bs ,. sp.?
3. C. sSpen
Figures and descriptions of these two apparently new
species of Cupularia will be given hereafter.
2. Sub-order. CycLostomata.
1. Fam. Ipmonrap#, Busk.
1. Gen. Zdmonea, Lamx.
1. I. Adlantica, H. Forbes. Pl. XVIII, fig. 5.
Except, perhaps, in its comparatively greater size and
more robust habit, this form does not appear to differ in any
material respect from that which occurs in the Northern
ZOOPHYTOLOGY. 129
seas. (Vid. ‘ Annals Nat. Hist.,’ 2d ser., vol. xviil., p. 34,
pl. i., fig. 6.)
2. Fam. Cristapm.
Two species of Crisia, one of which appears to correspond
with C. dentata in a dwarf state, and the other to be as yet
undescribed, will be figured and described in a subsequent
number.
HypDkRozoa.
Fam. SERTULARIAD.
1. Gen. Sertularia, Linn.
1. S. disticha, Bose.
Hab. Madeira (on fucus), Johnson.
S. disticha, Bosc., ‘Vers,’ 2d ed., t. iii, p. 121, pl, xxi, fig. 2; La-
marck, ‘ Hist. d. An. s. V.,’ p. 154.
Dynamena disticha, Audouin, ‘Expl.’ I, p. 244; Savigny, ‘ Egypt,’
pl. xiv, fig. 2; Lamouroux, ‘ Hist. d. Cor. flex.,’
p- 181; Blainville, ‘ Act.,’ p. 484.
Dynamena distans, Bose, op. cit., p. 121; Audouin, ‘ Expl.,’ p. 243 ;
Savigny, ‘ Egypt,’ pl. xiv, fig. 1.
There appears to be no sufficient reason, from anything
which appears in the excellent figures of Savigny, why
D. disticha and distans should be separated. They both
occur on the Gulf-weed.
2. S. polyzonias, Linn. (in part). (Ellis, ‘ Corallines,’ pl. ii, fig. B. ;
S. Ellisiit, M. Edw. in Lamarck’s ‘ Hist. d. An.
s. V.,’ 2d ed., £. ili, p. 142.)
We are indebted to Mr. Alder for the distinction from
S. polyzonias (Linn. et Auct.) of a species having only three
denticles or angles on the mouth of the cell, in place of four
which may almost always be distinguished in S. polyzonias.
This species, under the name of S. tricuspidata, is described
and figured in his Catalogue of Zooph. of: Northumb. and
Durham’ (p. 21, pl. ui, figs. 1, 2). An additional character,
however, might perhaps be appended to those there given
as distinguishing S. tricuspidata from S. polyzonias, the
absence, viz., of four denticles from the mouth of the ovicell,
both male and female, which always exist in S. polyzonias.
Besides this, however, there seems reason to believe, not-
withstanding Dr. Johnston’s weighty authority on the other
side, that M. Edwards was right in suggesting that S.
polyzonias should be divided into two species, also distin-
cuished by the presence and absence of the denticles at the
mouth of the ovicell. In the form for which he proposes the
name S. Ellisit, the ovicell is clearly represented by Ellis
130 ZOOPHYTOLOGY.
(fig. B,) as it is in nature, with four denticles, whilst in that
marked a in the same plate, the ovicell is represented very
like that of S. tricuspidata. In the ventricose form of the
cells, however, Ellis’s fig. a differs so widely from Mr. Alder’s
S. tricuspidata, that it cannot be referred to that species ;
so that it is not improbable a third species, for which M.
Edwards would retain the term 8S. polyzonias, may be in-
cluded in the Linnean species.
The differences in the mouth of the ovicell do not depend
upon sex, for although,a considerable difference may be per-
ceived between the small white male cell and the larger
yellow female capsule, in S. polyzonias, the mouth has the
same conformation in both.
2. Gen. Cryptolaria, Busk (Micros. Journ., Vol. V, p. 173).
1. C. exserta, un. sp. Pl. XIX, fig. 3.
Mouth of cells exserted. Poljaion pinnate or bipinnate; branches
straight, rigid. Ovicell
Hab, vente Johnson.
This appears to constitute a second species of the genus
Cryptolaria, the other belonging to New Zealand, and in
which the mouth of the cell is completely immersed.
3. Plumularia.
A new species, belonging to the P. pinnata-group, will be
described subsequently.
ORIGINAL COMMUNICATIONS.
On STEPHANOSPHERA PLUVIALIS. Condensed from the Ger-
man of Professors Coun and Wicuura, in ‘ Nova Acta,’
vol. xxvi, Part 1. By Freprerick Currey, Esq., M.A.,
F.L.S.
Stephanosphera pluvialis was first observed by Cohn, in
1850, near Hirschberg, and described in Siebold and Kolliker’s
‘ Zeitschrift,’* vol.iv, part 1. It consists of a hyaline globe,
containing eight green primordial cells, arranged in a circle
in its equator. The globe rotates upon an axis perpendicular
to the plane in which the primordial cells are arranged, and
moves actively in space by the aid of cilia, two of which pro-
ceed from each of the primordial cells, and pierce the hyaline
envelope.
The primordial cells divide first into two, then four, and
lastly into eight portions ; these portions separate from each
other in a tangential direction, thus forming a dise round
which a cellular membrane is developed. Two cilia are pro-
duced upon each segment, and thus eventually eight young
Stephanospherze are formed, which eventually escape by
fissure of the parent-globe. This process was observed to
occupy about twelve hours. Dr. Cohn has also observed the
division of each of the eight primordial cells into a great
number of microgonidia, which swarm within the globe and
escape from it.
Under certain circumstances each of the eight cells secretes
a cellular covering, and swims about in the interior of the
globe in the form of free Chlamydomonas-like cells. Even-
tually they escape, either by fissure of the globe or by its
gradual dissolution, lose their cilia, form a thicker membrane,
become motionless, and accumulate at the bottom of the
vessel. If the vessel be then permitted to become thoroughly
dry, and afterwards be again filled with water, motile Stepha-
nospherz reappear, from which it seems probable that the
green globes are the resting-spores of the plant.
In the Hirschberg habitat the Stephanospherze occurred in
company with Chlamydococcus pluvialis, the resting-cells of
which are with difficulty, if at all, distinguishable from those
* Translated in ‘ Annals of Nat. Hist.,’ vol. x, pp. 321, 401.
VOL. VI. i
182 CURREY, ON STEPHANOSPHERA PLUVIALIS.
of Stephanosphera. In the county of Glatz, however, Cohn
found another habitat where the Stephanosphera was pro-
duced without Chlamydococcus, and accompanied only by
the red Rotifer, Philodina roseola.
About the same time Wichura found a dark red crust
covering some depressions on the surface of the mica-
schist rocks at Quickjock, in Lapland. Upon moistening this
crust Stephanospherz were produced, mixed, however, with
Chlamydococcus.
Afterwards Cohn and Wichura joined in a series of obser-
vations on the water from Heuscheuer (county Glatz), the
results of which form the subject of their paper.
This water was placed (at the end of August) m vessels
of common glass, green glass, &c., so as to test the effect
of light. Im the darker vessels the primordial cells re-
mained delicate, small, and distant from one another, whilst
in the transparent vessels they grew much larger; and as the
hyaline enveloping membrane did not extend in proportion,
the green cells eventually came in contact with one another,
and became spindle-shaped, with protoplasmic elongations.
(Ply TN, fis...)
After eight days the specimens grown in the transparent
and dark vessels respectively, differed so much from one
another that they might have been taken for different
species.
The size of the resting-spores varies very much, and it
seems probable that they grow considerably after attaining a
state of rest. Their colour is deep green (occasionally
yellowish or olive), and they have a nucleus, and frequently
a nucleolus.
When the water is permitted to evaporate gradually, the
resting-cells become yellow, and afterwards orange or red,
aud their contents have a more oily appearance. The authors
found that if the water was not permitted to evaporate, the
resting-spores, although continuing to live, did not become
developed into Stephanosphzerz, but when fresh water was
poured upon desiccated resting-spores twenty-four hours
sufficed for the production of motile Stephanospheeree. —
The followmg is the process of transformation from the
state of rest into the motile form.
The dried resting-spores take up the water, and their
contents (hitherto somewhat misshapen) gradually fill up the
cavity of the containing membrane, and become cloudy and.
granular (fig. 2); the border becomes yellowish, and the red
colouring matter is concentrated in the centre. The cells
then begin to divide, and the successive forms assumed in
CURREY, ON STEPHANOSPH HRA PLUVIALIS. 133
this process will be better understood by reference to figs. 3,
4, 5, 6, and 7, than by description. In passing from the
state shown in fig. 3 to that shown im fig. 4, the outer mem-
brane has gradually become invisible. Up to fig. 7 the pro-
cess has occupied about two hours. The four daughter-cells
(fig. 8) begin to quiver, and to endeavour to separate from
one another. ‘Two cilia are now perceptible at the pointed
extremity of each of the four cells (fig. 9), by the action of
which the group begins to move as a whole, and in a laboured
manner, in the water; ultimately, however, all trace of the
enveloping membrane and of the glutinous connecting sub-
stance disappears, and one by one the daughter-cells escape
and become free. Figs. 10, 11, and 12 exhibit different
forms of these free daughter-cells, which contain two, three,
or several granules (amylon?) and sometimes also vacuoles.
The sharp end is often prolonged into a colourless beak, as
in fig. 12. At this period there is no proper cellulose mem-
brane. At the moment of escaping their diameter never
exceeds 0'010 m.m., but they soon enlarge and attain a
diameter of 0:013 to 0°015 m.m.
Their form and the length of the beak is variable, the
latter being sometimes altogether wanting. In form and
motion they resemble exactly the naked primordial cells,
. which are produced by division from the resting-cells of
Chlamydococcus pluvialis. The authors have never seen the
resting-cells of Stephanosphera divide into more than four
parts, but think it not improbable that division into a greater
number (eight or possibly sixteen) sometimes occurs.
The length of time which elapsed between the immersion
of the dried resting-spores and the first appearance of the
motile cells varied from nine to twenty-four hours. It was
noticed that those resting-spores which did not produce
zoospores within six days never did so afterwards, although
they continued to live and were perfectly healthy.
Zoospores, produced in the month of November, did not
advance beyond the first stage. (Figs. 10, 11, and 12.)
Others, however, produced in March, remained only a few
hours in that condition, after which time a delicate membrane
was formed round the body of the primordial cell; this mem-
brane was at first closely attached to the primordial cell, but
became gradually enlarged by absorption of water into a
colourless enveloping vesicle (figs. 13 and 14), usually globular
but sometimes oval, having two openings, through which the
cilia penetrate. In this condition they attain a diameter of
0-017—0:022 m.m., and are not distinguishable from encysted
forms of Chlamydococcus pluvialis. Other zoospores, produced
134 CURREY, ON STEPHANOSPHARA PLUVIALIS.
on the Ist of April, 1857, attained a larger size, and the
protoplasm of the primordial cell, instead of retaining its
continuous outline, became elongated here and there into
simple or forked mucilaginous rays, which were either colour-
less or green from the presence of chlorophyll (fig. 15).
These rays are probably produced by the protoplasm adhering
at certain points to the surrounding membrane, and being
carried outwards by its growth. The Chlamydococcus-like
form only lasted a few hours: towards the evening the
zoospores mostly began to divide. In the first place, the
protoplasmic rays are drawn in, and the primordial cell be-
comes round; it then elongates itself in the direction of an
axis passing through the point of origin of the cilia, and by
the process of division assumes the forms shown in figs. 16
and 17. This state is usually attained by about nine o’clock
in the evening, and about eleven o’clock a constriction com-
mences in a plane at right angles to the former plane of
division, and eventually the primordial cell is divided imto
quadrants (fig. 18), each containmg a nucleus and a portion
of the red substance. The two cilia, which have retained
their activity, originate in the interspace between two
quadrants (fig. 18). About midnight usually, but sometimes
earlier, constriction recommences, and the form in fig. 19 is
attained. This constriction proceeds towards the middle .
point of the spheroid, by which the quadrants are bisected,
and ultimately divided into eight wedge-shaped portions,
whose contour lines, like the spokes of a wheel, meet in the
middle.
And now commences a further process of development,
which forms the ground of the generic distinction between
Stephanospheera and Chlamydococcus. For, whilst in Chla-
mydococcus the individual portions of a primordial cell sepa-
rate entirely from one another, each developing its own
enveloping membrane, and ultimately escaping as a uni-
cellular individual; in Stephanosphzera, on the other hand,
the eight portions remain united as a family. The coloured
contents of the individual portions become drawn back towards
the periphery in a centrifugal direction, a colourless plasma
remaining about the central point; this disappears at first in
the centre; a cavity is formed in the middle of the dise, and
as this enlarges the eight portions assume the form of a
wreath, consisting of eight globular or ellipsoidal bodies in
close contact (fig. 20), and usually not exactly in one plane,
owing to the outer membrane not having expanded in pro-
portion to the enlargement of the plasma. The original
cilia continue active, causing the motion of the whole
CURREY, ON STEPHANOSPH ERA PLUVIALIS. 135
organism, until the eight portions are completely individual-
ised, and then their motion ceases. But at this period each
of the eight parts may be seen to be provided with two cilia,
which are in motion so far as their limited space allows.
(Compare fig. 21, which represents an instance in which the
division has only extended to four portions.) The separate
parts of the plasma now form eight independent but closely
packed membraneless primordial cells. Shortly afterwards
it is seen that a delicate membrane, common to them all, has
been secreted beneath the mother-cell-membrane, round the
disc formed by the primordial cells; this membrane at first
lies in close contact with the latter cells, following the con-
strictions of the disc, but afterwards becomes further and
further removed as it swells and tends to assume a globular
form (figs. 22, 23). By the motion of the cilia the mother-
cell-membrane is gradually thrown off, and the young family
escapes into the water (fig. 24). Its eight green primordial
cells still enclose the last traces of the red substance, which
gradually disappears, and instead of which are seen two
granules (fig. 25); the primordial cells are in immediate con-
tact at the sides, and are of an oval or globular shape; their
common enveloping membrane is at first constricted at the
border following the outline of the primordial cells; it even-
tually becomes globular, although continuing for a long time
much flattened at the poles, in the form of a disc-shaped
spheroid (fig. 24). When the Chlamydococcus-like unicel-
lular Stephanosphzera has commenced its division early in the
evening, the division into eight is perfected during the night,
and early in the morning the young family quits its cast-off
mother-cell-membrane.
In the course of the day the individual primordial cells,
and their common enveloping membrane, grow until the latter
attains a diameter of 0:°040—O0:048 m.m. During this growth
the shape of the primordial cells is changed by the formation
of various prolongations in the manner above described (fig.
1); but in the course of the afternoon the primordial cells
again become round, and during the evening division com-
mences in them precisely similar to the process in the uni-
cellular Stephanosphera; on the following morning we find
eight young families, with the common enveloping membrane,
which soon escape and go through the same process. It is
calculated that in eight days, under favorable circumstances,
16,777,216 families may be formed from one resting-cell of
Stephanosphera. It is remarkable that the division of the
primordial cells in Stephanosphera is confined to a certain
time of day ; it begins towards evening, and is completed the
136 NUNNELEY, ON THE CRYSTALLINE LENS.
following morning. The observations made in Lapland, at a
time when the daylight there lasted during the whole night,
the beginning and end of the division were observed to take
place at almost the same hours as in the observations made at
Breslau in the spring, when the day and night were almost of
equal length. Sometimes the division ceases after the forma-
tion of only four primordial cells (fig. 21). On one occasion
the authors observed a family with only three cells, one only
of the two halves first formed having undergone a second
division. In Lapland a family with sixteen cells was once
observed.
The authors then proceed to discuss the nature of the
resting-cells in Stephanosphera and Chlamydococcus, and
come to the conclusion that they are not spores; 7.e., that
they are not of the same nature as the red cells of Gidogo-
nium, Bulbochete, Draparnaldia, Chzetophora, Spheeroplea,
Volvox, &c.
They come to this conclusion upon two grounds: Ist, that
the resting-cells in question continue to grow after becoming
quiescent ; and, secondly, that it is probable (although not
yet proved) that the resting-cells increase by self-division,
thus producing new generations of resting-cells. These two
characteristics the authors consider inconsistent with the
idea of a spore.
In conclusion the authors notice the formation of mi-
erogonidia in Stephanosphzera, which takes place by the
division of the primordial cells into numberless small por-
tions. Fig. 26 shows a Stephanosphera, in which all the |
eight primordial cells have formed microgonidia; the indi-
vidual microgonidia (fig. 27 a, 6, c) become free by the dis-
integration of these eight groups into their constituent
portions. The authors think it not improbable that th
microgonidia exercise an impregnative influence in spore-
formation, but admit that there is no evidence to prove it.
On the Form, Density, and Strucruret of the CRYSTALLINE
Lens. By Tuomas Nunne ry, F.R.C.S.E., Lecturer on
Surgery in the Leeds School of Medicine, Surgeon to the
Leeds General Eye and Har Infirmary.
Tue Lens, as its name implies, is the most important por-
tion of the dioptical ocular apparatus. It is at the same time
the most perfect of its kind in the world. It has hitherto
(and probably will continue so to do,) defied the efforts of
NUNNELEY, ON THE CRYSTALLINE LENS. 137
human ingenuity to imitate. Hence, while its importance in
health, the great changes which it undergoes in disease, and
the skill and knowledge requisite for its treatment and
removal, have always rendered it an object of great interest
to the anatomist and surgeon—its perfect action in con-
verging the rays of light to a focus upon the retina, so as
practically, if not absolutely, to overcome the aberration of
sphericity, has caused its form, structure, and density to be
matters of the closest investigation and calculation by op-
ticians and mathematicians. The difficulties of the inquiry
have been at least equal to their importance, so that as much,
if not more, controversy and difference of opinion have
existed as to the structure of the crystalline lens, as of any
part of the eye.
As is well known, the lens is partially imbedded in the
anterior surface of the vitreous humour, where it is held in
situ by the elastic suspensory ligament. It lies immediately
behind the iris at the juncture of the anterior with the middle
third of the globe. In man, mammalia, birds, and reptiles it
is a double convex lens, of which the posterior surface is con-
siderably the more convex, particularly i the two former
classes. To the exact proportions which the curves of the two
surfaces bear to each other, opticians have necessarily at-
tached great importance. Many experiments have been made,
and far more numerous elaborate calculations entered upon
for determing it. Such inquiries are perhaps of more
interest and importance to the optician than to the anatomist
and surgeon; and from the nature and structure of the lens,
when made experimentally, are not susceptible of absolute
accuracy ; for it is almost impossible to measure, with mathe-
matical precision, the curves of a small, delicate, yielding
substance, like the lens. Moreover, it is beyond doubt, that
not only do the two surfaces differ somewhat in different im-
dividuals, but they vary very much in the same person at
different periods of life. There is a gradual flattenmg of the
surfaces, with an increasing density of the substance of the
lens, as age advances. In the new-born infant the lens is as
soft as rather thin jelly ; in old age as firm as suet. In infancy
the lens is comparatively convex to its form in the aged.
Fig. 1 (plate) shows their varymg forms—a in infancy, 6 in
the adult, ¢c inoldage. However, notwithstanding these diffi-
culties and changes, much interest and importance is attached
to the determining, with as much precision as the nature of the
case admits of, the form of the curves and the density of the
material forming the lens. So far as I am aware, Petit, in the
earlier half of the last century, is the only person who has care-
VOL. VI. M
138 NUNNELLY, ON THE CRYSTALLINE LENS.
fully and extensively experimentally investigated the first of
these problems ; for though many persons have since then, and
particularly Dr. Porterfield and Dr. Thomas Young, written
elaborately on the subject, it would appear their investiga-
tions have rather been theoretical and calculative, based upon
Petit’s measurements, than upon original experiment, except
perhaps Dr. Young; and from his statement I am unable to
determine whether he exclusively depended upon Petit’s
figures or not.* According to Petit the diameter of the lens
is about four or four and a half lines, and its axis two lines.
“The diameter of the sphere of which the anterior segment
is a part being from six to twelve lines, but most commonly
about seven and a quarter or eight lines; whereas the dia-
meter of the sphere of which its posterior segment is a part
is commonly only about five or six lines.’”+ According to
the calculations of Dr. Young the radius of the anterior
surface of the lens is ‘30, of the posterior surface *22 of an inch.
The following table will show the result of my measure-
ments of the lenses of different creatures. I give them only
as approximations to accuracy; for though I have taken every
care that I could exercise to ensure as much correctness as
possible, as I before said, I believe it to be impossible to
measure any single lens with absolute precision ; the result of
the whole must be looked at, and this, I think, will not be
far from the truth. One proof I think of the general cor-
rectness of the measurements, is the curious fact shown by
them, that the proportion of the curve of the posterior
surface to the diameter of the lens, is far more uniform than
that of the anterior surface. The radius of the posterior
curve differs very little in any of the creatures from the half
of the diameter of the lens, so that in fact the posterior
surface of the lens is nearly, but not absolutely, a hemisphere,
while the anterior is a segment of a much larger sphere, it
being on this surface that the variations at different ages in
the individual, and different creatures, take place much more
than in the posterior surface of the lens—a point of no little
importance to the ophthalmic surgeon. The table also shows,
that as we descend from man to fish, there is a gradual in-
crease in the convexity of the lens until in them it is a true
sphere, and that this increase in the sphericity is not neces-
sarily accompanied by an increase in the density of the lens,
as a reference to the table of the specifie gravities of the lens
will show. The measurements are given in parts of an English
inch.
* «Miscellaneous Works of Dr. Thomas Young.’ By Dr. Peacock.
Vol. i, Nos. 1, 2.
+ Porterfield’s ‘Treatise on the Hye,’ vol. i, p. 231.
NUNNELEY, ON THE CRYSTALLINE LENS.
HUMAN CRYSTALLINE LENS.
1. Large-sized adult male, one eye. :
2,3. Adult male (et. 25), died after accident,
both eyes exactly alike
4,5. Adult female (zt. 40), died from heart dis-
ae and albuminuria, both ones —
alike
6. Adult male (eet. about 50), one eye
7. Male (et. 65), died from softening of brain,
one eye .
8. Small female, one eye ‘
Average diameter of eight eyes . 3500
Average axis of eight eyes : "2000
Average radius of posterior curve of
lens of five eyes "1906
Average radius of anterior curve of
lens of five eyes . : 2551
Six months’ feetus
Nos. 4 and 5 were immersed for a few minutes
in water at 160° F., the measurements
were altered to—
In No. 4
No. 5
MONKEY.
1. Probably Jens somewhat too convex from
being a short time in dilute spirit
2. Ditto ditto
PIG.
1. Large, more than twelve months old
9. Smaller, about four months old
3. Of small breed
4, Ditto B :
Average diameter of lens : "4700
Average axis of lens . : "3500
CAT.
Adult male cat just killed, both eyes exactly
alike : : :
BULLOCK.
le é
2.
3.
4.
5.
G
(fe ; :
Average diameter of lens : Tih
Average axis of lens . 4.914
Average radius of posterior curve e of
lens. 3.483
Average radius of anterior curve of
lens). : é 4350
33
36
“36
“36
36
“OL
"25
ro3)
Dia-
meter
139
Radius of|Radius of
ani, Pomtrionantero
21 |-1697 |:2101L
“18 |°2022 | 2664
20 |°1896 | 2664
29 = 4
| = =
20 = po
14/)/ — we
*22 11614 | -2000
22 |°1503 |°1806
94); — | pes
90; — eee
4,4 — ae
32 we
82 |°2011 |:2128
"a2 |-2001 |-2198
“50
“50
“50
“50
.50
AT
“47
ale
"3483
3483
: «700-300-2417 |-2720
bel eles
"4350
"4350
140 NUNNELEY, ON THE CRYSTALLINE LENS.
SHEEP.
: Radius of|Radius of
Die | ani (oa
1. 57 |°40 |-2892 |-3338
2. 57 1°40 |-2892 |-3338
3. “57 1°40 |:2892 |:3338
4. 57 |°40 |:2892 |:3338
is 60 |°40 |°38075 |°3612
6. p . |°58 |°40 |°2952 |-3498
Ager. age diameter of lens Fi 5766
Average axis of lens . *4000
Average radius of posterior curve 2932
Average radius of anterior curve 3398
HARE AND RABBIT.
J. Hare , : ‘ . 1°46 1°37 1°2809 |°9453
9. Ditto : , ‘ . 1°46 1°37 1°2809 | °2453
3. Ditto, very large : : . 150 |38 | — —
4,, Rabbit, rather ‘small ‘ 4 . {43 1°32 1-2184 |°2350
5. Ditto, ditto 7 » 1:42 1539 | QOS 2275
Average diameter of lens i 4.540
Average axis of lens . *3520
Average radius of posterior curve 2231
Average radius of anterior curve "2382
BIRDS.—COMMON FOWL AND DUCK.
1. Very large cock, both eyes alike . » [32 |°22 |°1634 |:1872
2. Ditto, ditto : . {27 [21 |:1850 |-1539
DE Smaller cock, ditto : . {28 }:18 | — a
4. Hen, ditto F . 1°26 1:17 Wls4ab essa
5. Duck, ditto 5 . |°32 1:24 — ane,
6. Ditto, ditto 2 . {26 |°20 |°13804 |°1456
Average diameter of lens x *3850
Average axis of lens . : 2033
Average radius of posterior curve 1408
Average radius of anterior curve “1606
(Twelve lenses measured.)
The lens of No. 2 was immersed in water at
160° F. : » 1°26 | 23 11813 | 1456
REPTILES.
Alligator, both eyes alike . - . | 48 Ec _— | —
Small frog, ditto ; . . |°20 | 16 0509 0532
FISH.
Cod, large, both eyes . : . 1°58 1-58 Equal.
Haddock, ditto : : » |[°53, 1-63 | ise
Holibut, ‘eft eye ; ; . |°52 |°52 Ditto.
Ditto, right eye . 1°60. 1°50 Ditto.
In this fish the right eye, in all its measure-
ments, was smaller than the left, and it is a
curious fact, that though the right lens was
smaller than the left, yet its specific gravity was
somewhat greater.
NUNNELEY; ON THE CRYSTALLINE LENS. 141
The axis of the lens is a line drawn from the centre of its
anterior surface to that of its posterior. This in the human
adult measures from the *18 to ‘22 of aninch. The diameter
is a line drawn across from one point of the margin to the
opposite, so as to divide the junction of the two surfaces. It
measures from *31] to ‘36 of an inch in every direction, so
that the lens is circular in its outline. This it is commonly
regarded as being, not only in man, but in all animals. I am
not, however, quite certain that some, which have the
pupillary aperture very much extended horizontally, have
not the lens also slightly broader in the horizontal than in
the vertical direction. I have thought the measurements in
some instances have been so. The axis of the lens is supposed
to eorrespond exactly with the centre of the pupil. Now, as
this is in most persons somewhat, and in some considerably,
inclined towards the nasal side of the eye, were it so the axis
of the lens would not correspond with that of the eyeball,
but lie to its inner side. It is, however, far more probable
that the axes of the lens and of the eyeball exactly cor-
respond.
The lens consists of its proper structure and its containing
capsule. These are of totally dissimilar tissues.
It is curious to note the very exaggerated notions which
formerly were entertained as to the great density of the crystal-
ine lens. Thus Matrejean concluded, from some experiments
he made, that it is heavier than sulphuric acid or aqua
fortis. But Dr. Porterfield informs us that Dr. Robertson
weighed five crystalline lumens of the oxen’s eye and three
of the sheep’s, and found the mean of the oxen 1°1134, of the
sheep 1:1033, and of the eight to be 1:1083, from which he
presumes that of the human to be the same. Chevenix
states the sp. gr. of the human lens to be 1:079; of the sheep
1:180.* These experiments are too few in number to be relied
upon. ‘To determine the density of the lens in various crea-
tures I have taken the specific gravity of a great number.
The following tables will perhaps be thought sufficiently
extensive ,to enable a fair estimate to be arrived at; more
especially as these figures are not like those in the former
tables. They may be taken without hesitation as correct,
there being no difficulty in taking the sp. gr. of the lens. It
will be seen that Porterfield in his conjecture was not far
wrong as to the human lens, and that the average weight of
Dr. Robertson and mine, for bullock and sheep, wonder-
fully correspond, considering the individual lenses do not
* Simon’s ‘ Animal Chemistry,’ vol. ii, p. 419.
142 NUNNELEY, ON THE CRYSTALLINE LENS.
weigh alike, a fact which I was not aware of until after all
my experiments had been made. The tables show that,
while there is a general agreement in the sp. gr. of the lens
in animals of the same genus, there is a perceptible individual
difference, which age alone will not entirely account for. In
some few instances I have found the curious fact, that the
sp. gr. of the two lenses, from the same creature, are not
identical,* and the still more interesting one, that in such
cases the size of the denser lens has been somewhat less than
that of the lighter. This was well marked in the holibut,
Nos. 6 and 7. They also show that in true land-creatures
the sp. gr. of the lens is less than it is in water-creatures—
the density of the lens of the duck, for instance, is decidedly
greater than that of the common fowl—while the difference
in that of the fish and the bullock and pig is very marked.
The first table also shows that the lens is the densest of all
the ocular tissues—and particularly so in the fish—where,
from the density of the element from which it receives the
rays of light, we should @ priori expect to find it so.
Specific gravity.
Bullock, entire eye ‘ : . 10411
Lens taken from the same eye a2 5 . 11046
Pig, No. 1, entire eye : : . 10803
Lens taken from the same pig’s eye 11060
Pig, No. 2, eyeball, with portion of optic nerve ‘attached . 11-0710
Same eyeball without any optic nerve : . 105238
Portion of optic nerve alone. ; - 1:0578
Haddock, entire eyeball : ; - 1:0324
Lens taken from the same eye . ; 11684
The lens itself is also heavier than its capsule. The sp. gr.
of a pig’s lens, without capsule, was 1:1015 ; with the capsule,
1:0985. The average sp. gr. of four sheep lenses, with cap-
sule, was 1:1152; of two lenses, without capsule, 1°1584.
HUMAN LENS.
1. Young adult man . 5 ; : : 11304
2. Ditto : ; : : : 11304
3. Adult woman : é , : 1:0909
4. Ditto, : > . . 10967
4) 44484
Average ; : 11121
o
. Lens removed with anterior part of eyeball for disease of
cornea of more than two years’ standing, which resulted in
* Can this account for the fact of the focus of the two eyes differing, as is
certainly the case in some persons, there being no perceptible difference in
the appearance of the two eyes.
NUNNELEY, ON THE CRYSTALLINE LENS.
143
the first instance from granular disease of conjunctiva at
the gold-diggings. The sight was quite gone, and the other
eye painfully involved; the iris adhered to the opaque cor-
nea, but the lens appeared to be perfectly natural.
weight, however, was increased to
Its
} : 11960
Coagulation by water at 160° F. mereases the density of the
lens, thus—
No. 1, so treated, weighed 11666
2, ditto, ditto 11739
CAT. PIG (38 lenses).
Both lenses exactly alike . 11491 = ; : ; ae
3. 10864
BULLOCK (7 lenses). 3)3-2909
fr 1-107]
2. 11078 Average 10969
3. 11114 | HARE AND RABBIT (5 lenses).
4. 1:1046 | 1. Hare : . 11248
5. 1J111 | 2. Ditto 11065
6. TNOSF V3. WhO! 5 11234
‘i 11079 | 4. Rabbit. 11232
5. Ditto 11232
7)7°7596
5)5°6011
Average 11085
Average 11202
: COMMON FOWL (5 lenses).
PERE AG lenses): 1. Large cock Eis els |
Li 1:1143 | 2. Ditto 11366
2. 11178 | 3. Ditto 10975
3. VeTLIL. |, 4... Ditto 1:0975
4. TET76. ) 5.) Hen, 11250
4) 44.608 5)5°5697
Average 11152 Average 11189
COMMON DUCK (4 lenses).
5. Lens without capsule 11562 | 1. : : . 11600
6. Ditto 11607 | 2. 11600
3. ? 10952
9)2°3169 | 4. ° eeFLOS?
i" 4.) 4°5204
oe — Average 11301
REPTILES.
I have weighed the lens of the alligator, turtle, chameleon, toad, and
frog, but as the three former had been in spirit or Goadby’s solution, and,
from the time of year, I could only procure one small frog and toad, I
abstain at present from giving the figures, as I am doubtful of their absolute
accuracy ; but they are sufficiently so as to leave little or no doubt that the
specific gravity of the lens in these creatures is intermediate between mam-
malia and fish.
144 NUNNELEY, ON THE CRYSTALLINE LENS.
FISH (7 lenses).
1. Cod . : . Lotte
2. Ditto : : . Lalye
3. Haddock . ; oe bel toy
4. Ditto ° , . 11684
5. Ditto . 5 - Life
6. Holibut , : , iise3
7. Ditto . ‘ . 11645
7y8°2817
Average ; », d:188l
In estimating the sp. gr. of the lens it 1s essential that the
eye should be perfectly fresh. If the animal has been dead
any length of time the size of the lens is increased, but its
sp. gr. lessened. If it has been preserved in dilute spirit its
sp. gr. is diminished, while it is increased if it has been kept
in Goadby’s solution, which answers so well for many tissues.
The action of water at and above 160° F. is very uncertain.
In the hard lens of the fish it scarcely alters the sp. gr., but
commonly that of the softer lenses of birds and mammalia is
increased. I have therefore rejected all the calculations
made from lens which were not fresh—they include the lion,
several monkeys, many reptiles, many human, and other
creatures.
The same remark, as to the necessity of employing only
the lens of animals very recently dead, holds good in taking
the measurement of its curves. It soon becomes too convex
by imbibition of fluid; when preserved in spirit it also swells
out; if kept in Goadby’s solution it shrinks in size and be-
comes too flat.
Reagents act upon the lens almost as they do upon
albumen, yet not entirely, for though by boiling the lens its
outer portion at once becomes opaque, the inner does not, as
is best seen in the solid lens of a large fish, the centre of
which becomes like transparent horn, while the outer is like
coagulated white of egg.
The composition of the lens is given by Berzelius as—
Water . j ‘ ; . 58:0
Peculiar matter (protein compounds) . ¢ oor"
Hydrochlorates, lactates, and alcoholic extracts . 2-4
Phosphates and watery extracts : Bi tegen
Insoluble membranous residue : i yee
100°0
Simon (‘ Animal Chemistry,’ vol. ii) says, besides albumen
there is in the lens a peculiar substance resembling casein.
NUNNELEY, ON THE CRYSTALLINE LENS. 145
This he calls crystalline. He gives the composition of the
lens.
In the ox. In the horse.
Water ‘ - : » 165°762 60-000
Albumen : : , « ,28:290 25°531
Crystalline , : : - 10°480 14-200
1 eK Te f ss : . 0:045 0°142
Extractive matter, with chloride of sodium and
lactates . ; f - 0495 0:426
That the lens consists of fibres arranged side by side, in
concentric layers, superimposed upon each other, com-
mencing at the axis and passing from one surface or pole to
the other, has long been known, particularly through the
labours of Leeuwenhock, Derham, and Dr. Young; and that
the human lens has a tendency to split at first into three
sections, and then again into smaller, ordinary decomposition
or immersion in weak spirit, boiling water, and other coagu-
lating agents, readily shows; but the exact nature and
arrangement of these fibres were much debated and disputed
until a recent date. We are indebted to Sir D. Brewster for
the first accurate account of the microscopic anatomy of
this body,* and though in all particulars his description may
not be fully borne out, yet his investigations did much to
reveal the wonderful complicity of the minute anatomy of
the lens.
In order to examine the lens microscopically it should be
rendered opaque, and hardened by alcohol, chromic acid, or
hot water. If boiled for any length of time the fibres be-
come irregular. I find immersing the lens for three or four
minutes in water at 160°, and then adding to the morsel on
the object-glass a drop of very dilute chromic acid, to
develope the structure well. Acetic acid renders the fibres
beautifully transparent and clear, but does not harden them
so much as chromic, and soon acts upon them destructively.
Liq. potassz destroys them immediately, ammonia more
slowly.
The lens of a large fish, the cod or haddock for instance,
or of the frog or toad, should be selected for first observa-
tions, as the fibres are stronger and their markings coarser
than they are in birds, mammalia, or man; and of these
lenses the middle portion should be selected, as upon the
outer surface or margin the fibrous character is not well
developed, and near the axis the fibres are so attenuated and
delicate that their serrations are not so distinct. In other
respects, in all orders of animals, the fibres appear to be
* ¢Phil. Trans., for 1833 and 1836.
146 NUNNELEY, ON THE CRYSTALLINE LENS.
essentially of the same character, flattened, ribbon-like’
filaments, arranged side by side, so as to make a continuous
layer, and connected, or interlocked together at their sides
by serrations, which pass mutually into each other, just as
the cranial bones do at the coronal and sagittal sutures.
These serrations are by no means usually so uniform in size
or number as they have been figured by Sir D. Brewster,*
and they appear to me to be produced much in the same way
as those in the cranial bones are, by the development and
pressure of the fibres laterally against each other, and to
result from the granules, of which the fibres are ultimately
made up, pressing into the interstices of each neighbouring
fibre ; for they are most distinct in the fibres of the hardest
lens, and the serrations are largest and boldest where the
granules are the largest. They are better marked where the
filiform character is best developed, as in the middle rather
than at the axis or margin of the lens, and the serrations
become particularly developed by those reagents, which have
a corrugating effect upon the fibres, as chromic acid and
sulphuric ether.
The fibres pass from one surface of the lens to the other,
but whether every individual fibre does so, as stated by
Brewster, is, I think, very doubtful; indeed, it is scarcely
possible that all those near to the axis should do so, and, I
think, many may be seen towards either pole becoming so
attenuated as to be lost in, and amalgamated with, neigh-
bouring fibres, the serrated edges and individual character
being entirely lost. Each fibre is considerably broader at its
middle than at its ends, towards which it gradually tapers, so
that the greater width of the diameter of the lens over that
of the axis is rather caused by the increase laterally in the
middle of the fibres than by an additional number of fibres at
this part. The depth or thickness of the fibres does not vary
like the width, it appears pretty uniform in all the layers;
hence, while the outer fibres are broad and ribbon-lke, the
inner are almost cylindrical when separated, and when seen
closely packed together in a bundle they appear hexagonal.
This has doubtless led some observers into the error of de-
scribing them as hollow tubes. Leeuwenhock described the
number of layers as 2000 in the lens of a cod, and Sir D.
Brewster calculated the number of fibres in each layer of the
lens of a cod at 2500, and of the serrations in each fibre as
* If a lens (of the cod, for instance) be strongly coagulated and then
well dried, and a layer of the fibres be seen, the serrations are more uniform
and regular than if a single detached fibre be seen or they are in the recent
state.
NUNNELEY, ON THE CRYSTALLINE LENS. 147
12,500, which is, however, by no means certain. He assumes
that the breadth of all the fibres in each layer is uniform,
that the breadth of the fibres throughout the whole of the
layers is five times the thickness, and that the serrations
uniformly equal the thickness of the fibre, all of which
assumptions are incorrect, for, while the thickness is tolera-
bly uniform throughout all the layers, the breadth of the
fibres not only varies very much in the different layers, but
the fibres in the same layer vary very considerably im their
breadth, and the serrations are irregular in number and
boldness ; some being scarcely perceptible, while others pass
boldly and deeply, even bifurcating, into the adjoining fibre.
In the haddock and the cod I found a fibre, taken from
near the middle layer (equidistant from the margin and axis),
to measure in breadth 3:5 of an inch, of which the ser-
rations on each side measured z;355, or the two together
ss09, Or just equal to the breadth of the solid part of the
fibre. In this part of the lens I found 2700 fibres to the
inch linear, while close to the axis there were 5500 to the
inch; while at the extreme surface the fibres were so indis-
tinct as hardly to be formed; where they were, they measured
at least twice, or more, as much as in the middle layers.
(PL V1, Fie. 3.)
In the frog, from the middle layer of the lens, I found the
fibres to be about ;j5, thick and 3,55 wide, but by no
means uniform in size. The ribbon-shape of these is well
shown in fig. 4, where two fibres are twisted over upon
themselves. In the turtle and the alligator there is a
great difference in the size of the fibres, the outer being very
broad and flat as compared with those near the axis. (Fig. 5.)
In the fowl the fibres of the outer layers are very wide, as
much as 7755 of an inch, as compared with WES from near
the axis, most of which are not more than ;;155 of an inch,
but some are considerably broader. The smaller are eylin-
drical or slightly hexagonal, from pressure against each
other, while the larger are ribbon-shaped (fie. 65), Ani
the al the serrations are very sight, and the granules
composing the fibres are very minute.
In rodents, as the rat, squirrel, Bere and rabbit, the fas
measure at the oe of the lens sso, Im the middle 30009
near the axis sp/95 of an inch; the first bemg deeply serrated,
the latter very slightly so.
In a lens taken from a sheep just Sed I found its fibres
from outer EEGs to be oes z000 tO +345 wide; in the
ae layer z7s5p Wide, z3'55 thick; at the axis ,75. wide,
and sz!55 thick. In the ox the Sere vary as we proceed
148 NUNNELEY, ON THE CRYSTALLINE LENS.
from the circumference to the axis from 555 to ; of an
inch wide; and, as in all mammalia, the serrations are
small. Fig. 8, shows a transverse section of a bundle of
fibres from near the middle of the lens, in which the hexago-
nal form of the fibres is seen.
In the cat the fibres do not differ materially from those of
other mammalia, but are very easily rendered irregular the |
edge (fig. 9).
In man the fibres differ but little from those of other
mammalia. They are shown in fig. 10.
The fibres are very flexible when in a natural condition,
but after coagulation very easily broken ; hence they are re-
presented by Arnold as made up of short portions ; but they
are certainly long filaments, most of them passing from one
surface of the lens to the other. The broader surfaces of the
fibres appear to merely he in close apposition, where the
layers are superimposed upon each other, and to adhere as
all soft moist membranes do when in close contact, or, at
most, to be weakly connected by mucus ; hence the lens far
more readily separates into concentric layers than do the
fibres from each other laterally.
Kolliker describes the fibres to be thin-walled tubes filled
with a clear viscid albuminous fiuid. In this, I think, he is
in error, for though I have in some instances examined
lenses where the central cylindrical filaments appeared to be
tubular (particularly in the rat), they have been few and
some days after death; and though sometimes the edges of
the larger flat fibres present a darker lme, almost like a
double wall, this is never seen sideways, and is probably only
the effect of the edge of the fibres upon the hight when not
fully in focus; while in every instance, whether of mam-
malia, birds, reptiles, or fish, where the lens has been examined
immediately after death, the appearance has been so constant
that I think there can scarcely be a doubt that the filaments
are really solid fibres—uniformly clear, transparent, and ho-
mogeneous at first; but by heat, reagents, or decomposition
soon becoming granular, then separating into granules and
disappearing. These granules are smaller in birds and mam-
malia than in reptiles and fish. The whole substance of the
lens is harder and more dense in the latter classes than in the
former, particularly in the fish as compared with the bird.
In the latter the lens is soft and jelly-like throughout; the
central portion, though more dense than the outer, is not so
in anything like the same degree as it is in fish, where not
only is the whole lens more firm, but the central part is m
many genera of almost stony hardness, bemg difficult to cut
NUNNELEY, ON THE CRYSTALLINE LENS. 149
with a knife; the difference in the density of the two ele-
ments from which the rays of light pass in enterimg the eyes
of fish and birds being doubtless the cause of this difference
in the solidity of the lens in these creatures.
The arrangement of these fibres to make up the entire lens
is not less curious than the structure and connection of the
individual fibres.
Four principal types have been described by Sir David
Brewster, to one of which, or its subdivisions, the lens of
every aninial may be referred.
Ist. The first is the most simple, in which a single pole
passes through the axis of the lens to the opposite point, to
which all the fibres converge like the meridians of a globe.
Upon this plan is constructed the lens of all birds, of most
fish, and of some reptiles—the frog, for instance. Sir D.
Brewster names the frog as probably possessing the next
form of lens, that with two septa; but I have found it dis-
tinctly with one pole.
2d. The second type is found, amongst mammalia, in the
hare, rabbit, and porpoise only; in some reptiles, and in
several fish, of which the genus Salmo affords a good illus-
tration. In this arrangement there is a short straight lmne
passing through the pole from which the fibres symmetrically
diverge, and passing over the margin of the lens, reach a
similar line on the opposite surface, but which line is placed
at right angles to the first, so that every fibre in‘each layer
except four have their different parts lying in different planes ;
thus, instead of passing directly from one surface to the other,
they proceed in a curved direction round the lens. Such a
lens is said to have two septa at each pole.
3d. The third type is that of all mammalia except those
just named. In it there are three septa, diverging at angles
of 120° from each po'e, the septa of the posterior surface
bisecting the angles formed by the septa of the anterior sur-
face, thus making with them angles of 60°. “There are
three fibres having their origin in the anterior pole and ter-
minating at the extremity of the posterior septa, and other
three having their origin in the posterior pole and terminating
in the extremities of the anterior septa, which have their
parts all lying in one plane, while every other fibre of the
lens forms a curye of contrary flexure in order to carry it to
its proper termination in the opposite septum. Hence it
follows, that with the exception of the six fibres originating
in the poles, the parts of all the other fibres which constitute
the margin or rim of the lens are not parallel to its axis.”*
* Brewster, ‘ Phil. Trans.,’ 1836.
150 NUNNELEY, ON THE CRYSTALLINE LENS.
This form is readily seen in the lens of almost any adult
animal by the three sections into which it spontaneously
separates. I think I have observed the septa to be always
more regularly and distinctly marked on the posterior than
on the anterior surface, probably on account of its greater
convexity.
4th. The fourth type is when there are four septa placed
at right angles to one another, and being inclined at the two
surfaces at angles of 45° to each other ; were the lens trans-
parent and the septa seen at the same time, they would
appear like the eight radii of an octagon, inclined 45° to one
another. Few animals possess this arrangement ; the whale,
seal, and bear being all that Brewster has found it in.
Leeuwenhock described the whale has possessing five septa.
In other lenses of the same animals there are two, or even
three, centres of divergence, when there will be six radiations
of fibres.
In the human lens the arrangement of the fibres is the
most complicated of any, for while the type is the mammalian
tripod, and is best seen in the foetus, in the adult the planes
are more numerous, In consequence of the primary planes
immediately branching into secondary, so that a very com-
plicated curvature of fibres exists; the septa upon the two
surfaces frequently not being equal, those of the posterior
being more numerous than those of the anterior. In the
anterior nine septa and radiations are often found, in the
posterior surface twelve, which Arnold regards as the more
common arrangement in man. This complicity, however, is
only in the more superficial layers, for towards the axis the
normal mammalian triseptal division is preserved.
The general arrangement of the fibres of the lens in dif-
ferent creatures is most easily seen by immersing it for a few
minutes in water at 180° F., then allowing it to dry in a
warm room. In two or three days it will be found to have
split into different sections, according to the direction of its
septa, while the fibres then form good microscopic objects
and are easily preserved by simple mounting in glycerine,
but if kept im water they soon swell, the edges become very
irregular, the substance granular, and then breaks up.
Of the reason for these varying planes, or why they should
differ so much in different animals, we are in complete
ignorance ; no plausible conjecture has been offered. It has
been suggested they are for the purpose of enabling the
curves of the two surfaces of the lens to be modified so as to
adjust the eye to vision at different distances. It for long
has been a favorite idea with some anatomists and opticians,
particularly with the latter, that this power of the eye to
NUNNELEY, ON THE CRYSTALLINE LENS. 151
overcome the aberration of parallax, resides in the lens itself.
It was this preconceived notion that led Sir E. Home, to
describe the structureless suspensory ligament of the lens as
muscular, and determined the celebrated Dr. Young to see
true muscle in the serrated albuminous fibres of the lens
itself, and Porterfield to assert the contractile property of
the ciliary processes ; but that the complicated interlockings
of millions of serrated fibres, arranged in planes of varying
curvature and number, should conduce to easy and constant
modifications in the form of the lens is not a very probable
supposition. The contrary idea, that they are for the purpose
of preserving under every circumstance an unchanging sur-
face would seem the more plausible notion.
The capsule of lens is a perfectly transparent structure,
which, though apparently so dense, is very permeable, and,
like most animal membranes, allows exosmose and endosmose
very readily to go on. If placed in air the lens soon desic-
cates ; if put in water the capsule in a short time becomes
swollen and ultimately bursts from the fluid which passes
through it; if then punctured, its elasticity forces the water
in a jet through the aperture. Doubtless it is through its
pores the lens receives nutriment, as it is non-vascular. In
structure the capsule differs 7m toto from the lens; none of
the agents which render the lens opaque affect in the least
the transparency of the capsule, which it retains for long
after death. It is highly elastic, and closely embraces the
lens, whose form, I imagine, it tends most importantly to
preserve by an equable pressure. It is hard, dense, and
strong; yet it is readily torn, and is cut with a grating noise.
Itis so elastic that when divided it at once curls up, and that
always in a plane opposite to what it is laid down in. If
injured in the living eye, by even a very small wound, it
often forces the lens to escape into the aqueous chamber. In
its physical and chemical characters it appears to be identical
with the inner elastic layer of the cornea. It is quite struc-
tureless, and like it has a single layer of epithelial cells upon
its inner surface. Though when in a normal condition it
long remains unchanged by either reagents or decomposition,
very slight injury during life, as the least puncture, at once
renders it opaque, its elasticity is then lost, and it frequently
becomes a source of great annoyance to the surgeon by the
persistency with which it will remain expanded across the
pupil.
The inner surface is lined throughout by a single layer of
cells, similar to those found on the inner aspect of the cornea.
The cells are very transparent, are nucleated, and polygonal
152 NUNNELEY, ON THE CRYSTALLINE LENS.
figs. 11 and 12), but this I think results from mutual
pressure, for when detached and allowed to expand by
immersion in water they become circular, or nearly so.
These cells appear to form the connecting medium between
the capsule and the lens itself. Were it not that similar cells
are found in Petit’s canal, I should feel inclined to think they
are not merely the means of nutrition to the lens, but that
they are lens-fibres in process of development. Any wound,
however small, in the capsule during life, almost invariably
leads to opacity and absorption of the lens. The anterior por-
tion of the capsule is considerably, three or four times, thicker
than the posterior half of it. ‘This probably arises from the ex-
pansion of the suspensory ligament over it; or, if we suppose
the latter to be an extension from the capsule, from it passing
off from the capsule, just anterior to the margin of the lens,
to form the anterior wall of Petit’s canal, where it is striated,
from the continuation of the folds, which are received be-
tween the ciliary processes (zone of Zinn). At this point of
the capsule, just anterior to the margin of the lens, there is a
sudden thinning of it, and after turning over the edge of the
lens, the posterior capsule, though in other respects identical
with the anterior, is much thinner and weaker.
In a few hours or days after death the capsule is found
separated from the lens by one or two drops of interposed fiuid.
This is the Aguor Morgagni, and until very lately has been
considered as a normal condition of the living eye. This,
however, it certainly is not, for if the lens of any creature be
examined immediately after death no fluid whatever is found;
indeed, we can hardly understand how the vitality of the lens
could be maintained, or the lens be kept steadily in situ, which
for the purpose of vision would appear to be absolutely neces-
sary, were it surrounded by a bath of aqueous fluid, however
small. The least pressure of the muscles of the eyeball would
induce an oscillatory motion of the lens. The fluid is a post-
mortem effect; it is derived from the breaking down of the
epithehal cells, and by endosmose,from the aqueous and
vitreous humours.
In the adult neither vessels nor nerves can be traced in the
lens or its capsule; they are therefore regarded as extra-
vascular; but during foetal life, up to the period of birth,
and even some little time aftérwards, both contain vessels ;
indeed, the capsule is then covered with a beautiful network
of blood-vessels, derived, principally, from the central artery
of the retina, by means of a considerable branch, which
passes directly through the vitreous humour to the centre of
the posterior capsule, where it minutely subdivides, the
BRIGHTWELL, ON TRICERATIUM, ETC. 153
vessels forming a very free inosculation with each other. As
they approach the edge of the lens, which at this period does
not fully reach the margin of the capsule, and is somewhat
irregular at its cireumference, they have a tendency to run in
pairs, and pass directly straight over the edge on to the
anterior surface of the capsule, where they again spread out
and form a stellate network ; but at the period of birth not
so free as upon the posterior capsule; here they imosculate
with other branches derived from the ciliary processes and
iris, which at this period of life is in contact with the lens,
FurtHER Opservations on the Genera Tricreratium and
Cuatocreros. By T. Bricurwent, F.L.S.
My former papers on these Genera have been chiefly
confined to the description of species, and are necessarily
imperfect, and to that extent unsatisfactory, in consequence
of the difficulty of obtaining specimens in a living state.
The species being all marine, very few opportunities occur of
seeing them alive, and it is doubtful whether any one of
them has been seen in a state of conjugation. If, as one of
our highest authorities (the late lamented author of the
‘Synopsis of the British Diatomacez’) says, “neither size
nor outline can be wholly relied on, and striation is the best
guide for specific character and, when this fails, the arrange-
ment of the endochrome, or the habitat of the living
frustule,” it is obvious how few of the described species can
have been sufficiently known to warrant us in deeming them
finally established, and how important is every step towards
attaining a knowledge of the living diatom, and especially of
its modes of increase.
The recent discovery that the Diatomacez abound in most,
if not all, the Tunicata, and even in animals so small as the
Noctiluez, and that they are often found in those situations
in a living state, promises to add greatly to our knowledge
of the marine species. It was from sources of this kind that
I derived materials for my paper on the Rhizosolenia, and it
is from gatherings made from Noctilucee, and the stomachs
of Sulpe, that materials have been obtained, which will, I
trust, enable us to advance a step further in our knowledge
of the genera mentioned at the head of this paper.
VOL. VI. N
154 BRIGHTWELL, ON
I have already (vol. v, p. 191) explamed the origin
of the pseudo-nodule in Triceratium undulatum, and shown
that it is only the stump of a long cylindrical horn
proceeding from the centre of the triangular end of the
frustule, and further investigation has resulted in the dis-
covery that this and another species, about to be described,
and which we propose to name Triceratium malleus, are m
their living and perfect state, filamentous.
Triceratium undulatum has also presented itself under an
aspect different, I believe, from any hitherto observed among
the Diatomacee, and the character of which cannot at
present be satisfactorily determined. In this state the frustules
are placed one at each end of a mucous envelope, and are
separated from each other by the exact length of the horn
before described, and which proceeds from the inner end of
each frustule. The frustules themselves are surrounded by
siliceous bands united together lengthwise, having at each end
a thick fringe or comb of short bristles or setze. A horn also
proceeds from the external end of each frustule of equal
length with that from the internal, the whole presenting a
very abnormal and puzzling appearance. Further investiga-
tion may, and I think probably will, show that it is one of
what P. Smith terms “ the phenomena attending the forma-
tion of the reproductive body” in this genus, and which are
at present so imperfectly understood. In the state above
described, the frustules not unfrequently present on an end
view, a four-sided form, either square, or with the sides
deeply indented, confirming what we have before stated as to
varieties of this kind in several other species.
In the filamentous state these appearances are consider-
ably modified, the bands of silex beg more absorbed into
each other, the horns shorter, and the combs or fringes of
bristles or sete not apparent. In this state the sutural
division seems effected in the normal mode, resembling
somewhat, in the individual frustules, that of Biddulphia
Bailey. The end view of the frustules generally presents
the appearance of a triangular valve of silex imbedded
in a softer siliceous cushion, the sides of the valve having
each three undulations or indentations, evidently produced
by the bands before mentioned; but variations of this_
structure are not uncommon, and there is one variety in
which all the sides of the valve are perfectly straight.
The other filamentous species, called by us Triceratium
malleus from its resemblance to Malleus vulgaris, is larger
than Triceratium undulatum, is without horns, and has no
bands of silex surrounding the valves as in that species. On
TRICERATIUM AND CHATOCEROS. 155
an end view, the frustules are trilobed, the sides of the
lobes are irregularly indented, and the valve exhibits the
appearance of being composed of a series of thin layers of
silex. In the filamentous state, the frustules are narrower
than those of Triceratium undulatum ; and there is an ellip-
tical opening between them on each side.
Triceratium radiatum and Tr. Marylandicum (described by
me, ‘Quart. Journ. Microsc. Soc.,’ vol. iv), present in
the centre of the triangular end the appearance of a pseudo-
nodule, and are probably filamentous, and of the same habit
_as the two species already described. These species form a
section or sub-genus.
TRICERATIUM.
§ Filamentous.
—_
. T. undulatum. Frustules with a horn running from the
eentre of each end.
T. malleus, n. sp. Valves three-lobed; the lobes of
unequal length.
T. radiatuin ?
. LT. Marylandicum ?
ee
op
CHA&TOCEROS.
By the kindness of Dr. Wallich, I have been favoured with
perfect specimens of the species of Chztoceros named by me
Ch. Peruvianum (see vol. 11. p. 5), and which I had before
only seen in fragments detected in guano from the Chinca
Islands. Dr. Wallich’s specimens were taken from the sto-
machs of Salpz found in the Indian Ocean, and they afford
the only opportunity hitherto presenting itself of studying
any species of this genus in a perfect state.
The body, if 1 may so call it, of Ch. Peruvianum is com-
posed of two segments which are not symmetrical, the anterior
segment being (as described in the former paper) semicircular
at the end, and furnished with two horns, which take their
origin from two stout shoulders bending towards each other,
leaving a hollow space between them, and then recurve at a
right angle, and run tapering out to a very great length.
This anterior section may properly be called the head, the
other or posterior section being truncate, and terminating
also in two long horns proceeding from the inner part of the
segment. All four horns are of equal length, stoutly sili-
ceous, spinous, and tapering.
156
On a Simpite Metuopn of applying the Compounp MicroscoPE
to the Urrer or Lateran Surraces of Aquaria. By
Perer Reprern, M.D., London University, and King’s
College, Aberdeen.
(Read at the Dublin Meeting of the British Association, in August, 1857.)
Iv is important and convenient to have some simple
method of examining objects in Aquaria with the compound
microscope without disturbing them from day to day. The
plan adopted by Mr. Warrington, and described in the
‘Microscopical Journal,’ admits of the instrument being
adapted to a limited surface with facility; but it is often
desirable to be able to apply it to any part of a surface
measuring two feet or more in extent. This end is gained
by the arrangement described below.
The woodcut shows the instrument in the position requisite
(
for examining the contents of a bowl standing on the table,
or objects near the upper suriace of the fluid of an aquarium.
a is a heavy cast-iron foot, seven inches in diameter, into
which a vertical stem, 6, made of ordinary one-inch brass
tubing, two feet long, is firmly screwed or soldered. c is a
REDFERN, ON AQUARIA. esi
narrow ring sliding easily on the vertical stem, and composed
of two short sections of tube, one within the other. The
inner piece is cut entirely through at the spot d; and at the
opposite side, e, it is soldered to the outer one. Through the
outer of these pieces the screw, f, works upon the inner one,
tightening it and fixing the ring, c, at any height upon the
vertical stem.
g is a piece of tube three inches long, and split at the ends
so as to slide and rotate easily on the vertical stem, 4, on
which it can be supported at any height by the ring, c, which
is below and unconnected with it. # is another piece of
the same tube as g, placed at right angles across it, and
rotating upon it. The joint between g and / is the only
part of the apparatus which requires a brass casting to be
made specially for it; all the other parts should be made of ~
such materials as are used for gas fittings. It consists of a
thick circular dise of brass, an inch and a half in diameter,
soldered to the tube, g, on one surface, and accurately turned
in a lathe on its edge and the other surface, so that it may
fit very tightly imto a cap turned like itself, but soldered to
the tube, 2. These two parts fit each other like two of a
series of nested apothecaries’ weights. Between them a
leather washer is placed im a turned groove, and they are
then screwed firmly together by a large screw inserted and
turned through the hole, 7, cut in the front of the tube, h.
I found that however tightly this screw might be turned,
the joint, in which there is an exceedingly smooth motion,
was too loose, and I therefore got the pinching screw, 4,
158 REDFERN, ON AQUARIA.
adapted to tighten it by a contrivance similar to that in the
case of the rmg, c. A piece of the rim of the cap was cut
out to the extent of five-eighths of an inch at /, and a thinner
piece of brass, soldered only at one edge, was substituted for
it. A ring of thin brass, n, having a projecting piece, 9,
fixed to it by hard solder, was then applied and soldered
around the rim, with its projection, 0, over the space, /, from
which the edge of the cap had been removed. The screw,
k, working through 0, presses the thin plate of brass, m, upon
the edge of the brass disc, and without injuring the smooth-
ness of its surface, tightens the joint to any required extent.
p is a lever or arm of one-inch brass tube, twenty inches
long, sliding through the tube, A, and rotating within it. One
end of this lever is left open to receive a cylindrical piece of
lead, which is sometimes useful to balance the lever when
used with its arms of very unequal length; the other end is
closed by the cup of a large ball-and-socket joint soldered
into it. Loosening of this joint is prevented by the pinching
screw, 7”. To the ball is attached a short arm, carrying the
piece of tube, s, three inches long, sawn through lengthwise
at the part most distant from the ball, and cut away as re-
presented on the figure, so as to hold the tube of the body
of the microscope loosely enough to allow of easy sliding and
rotation for focal adjustment. I have the stem attached to
ball made of two pieces screwed together, so that I can sub-
stitute a cell holding a single lens or a doublet, to be used as
a simple microscope, for the split-tube carrying the body of
the compound instrument. To diminish the weight of the
body of the compound microscope, I make it of paper pasted
to form a thick tube, which is lined with black velvet. An
adapter, carrying the lenses, slides into it tightly at one end
and the eye-piece into the other.
When in use, the most favorable position for the transverse
arm, p, is near that represented in the woodcut, where it
forms a lever with arms of unequal length. After coarse
adjustment, by sliding the body of the microscope through
the split tube, s, a very convenient fine adjustment is made by
acting on the long arm of the lever.
It will easily be understood that a considerable range of
movement of the body of the microscope is allowed by the
ball-and-socket jomt—by the movements forwards and back-
wards, and of elevation and depression of the arm or lever,
p, without shifting the place of the foot, a; whilst by chang-
ing the position of the foot, and that of the ring, c, on the
vertical stem, the whole of a surface not higher than two
feet may be examined with readiness. When the transverse
WALKER-ARNOTT, ON ARACHNOIDISCUS. 159
arm has been carried up to the highest point of the vertical
stem, and the body of the microscope placed vertically, it
may be used on the surface of the fluid of an aquarium
standing two feet high; the upward and downward move-
ments of the transverse arm being then used for fine adjust-
ment.
This arrangement was made for me by Messrs. Farquhar
and Gill, plumbers and gas-fitters, of this city, for less than
thirty shillmgs ; but it must be borne in mind, that for cheap-
ness it is essential that selected pieces of ordinary brass
tubing be made use of, that the vertical stem and the trans-
verse arm be pieces of the same tube, and the pieces, g and
h, parts of another tube; also, that the ball-and-socket joint
be the one ordinarily used by gas-fitters. Many of the de-
tails of the arrangement, especially those connected with the
various pinching screws, may appear tedious in description,
but it will be found that these are poimts of great conse-
quence for securing comfort and facility in making any obser-
vation, and therefore I have described them at length. The
application of a good rack-and-pinion for the movement of
the body of the microscope would be a valuable addition, but
it would increase the expense considerably.
On AracuNoipiscus. By G. Warxer-Arnort, LL.D.
Before having a complete knowledge of the natural history
of Diatoms, it is necessary that we know—lst, where, when,
and by whom any object was first observed and brought
under the notice of naturalists, whether by name, descrip-
tion, or a figure: 2d, where, when, and by whom it was first
correctly named and defined by a precise differential (generic
or specific) character, the latter of these alone giving a
claim of priority.
It is not twenty years since the genus Arachnoidiscus was
known. Short as that period is, I have not been able to trace
its history with satisfaction. I shall, however, indicate here
the information I have obtained, and hope that those connected
with its discovery and description will complete the sketch
before it be too late: already one (Dr. Bailey) has been
removed.
It is generally said, and I believe with justice, that
160 WALKER-ARNOTT, ON ARACHNOIDISCUS.
Mr. Topping, and others in London, first observed these
disks in Ichaboe guano. This guano was discovered in 1843,
and was nearly all removed in the course of 1844.* Although
guano was long known on the west coast of South America,
I do not find that it was noticed for its diatoms until after
that of Ichaboe was examined.
Ehrenberg describes this genus under the name of Hemi-
ptychus ornatus: when and where that name was given I have
not traced, but believe it is in the ‘ Berl. Acad. Trans.’ for
1848 or 1849. The description given in Pritchard’s ‘ Infus.,’
2d. ed., p. 382, shows that it is the form with transverse
cost, and it is said to have occurred in “ Patagonian
guano.” But here let me state that there is great difficulty
in tracing the origin of guanos, not only from their being
adulterated or mixed by the guano merchants, but by the
preparers of objects for the microscope mixing what they got
from different ships, under the impression that they were
brought from the same place. Thus, some years ago, I pur-
chased a slide of Diatoms from guano understood to be from
Africa (Ichaboe); this contains the usual blue dises of that
guano, but besides these is a valve (broken by pressing down
the cover) of Hupodiscus (Aulacodiscus) formosus,+ which is
peculiar to Bolivian guano. Here some guano from Arica had
been mixed with that from Africa, the similarity of name pro-
bably leading to the supposition that the two samples had come
from the same locality. In Ehrenberg’s ‘ Mikrog.,’ tab. 35,
he gives a representation of “ Peruvian” guano. In the
description of the plate, however, it is stated to be from
Arica, which is in Bolivia or Upper Peru, not in Peru as now
limited. In the same work he exhibits the diatoms of two
samples of guano from Saldanha Bay. The sample A. ap-
pears correctly designed; but in B. all the species noticed
(Endyctia oceanica, &c.) are so copious in Peruvian guano
(called also Callao or Chinca), that I have no hesitation in
saying that Ehrenberg must have misplaced the labels of the
samples.
I therefore doubt if the Hemiptychus ornatus was derived
from Patagonian guano; but as the same form does occur in
Californian guano, I dare not say that Ehrenberg’s was not
from South America.
* Whrenberg’s earliest notice of guano diatoms was in 1844, and his
sample appears to have been obtained from London, and probably was
derived from Ichaboe.
+ Lu. (A.) formosus cupulis quatuor submarginalibus oblique mammeefor-
mibus apice papillo instructis, granulis in 1-1000 parte septem (sive in
1-100” parte sex) subaqualibus. —
WALKER-ARNOTT, ON ARACHNOIDISCUS. 161
In Smith’s ‘Synopsis of British Diatomacezx,’ p. 25, the
genus Arachnoidiscus is said to have been proposed by Bailey.
But I have before me the following extract of a letter from
Dr. Bailey, of date July 27th, 1853 :—“I see that Smith, in
his ‘ Brit. Diat.,’ gives me as the founder of the genus. This
is not correct, but the species is mine, and it is very different
from the A. Japonicus with which Smith confounds it.” The
founder of the genus was Mr. H. Deane, of Clapham, and it
was first noticed in a paper read by him before the Micro-
scopical Society on 17th March, 1847. This paper was not
published, and although it contained a general description of
the disk, no distinguishing character was given. Mr. Shad-
bolt, on 14th November, 1849, read a paper “On the Struc-
ture of the Siliceous Lorica of the genus Arachnoidiscus,”’
and confirmed the generic appellation. In Pritchard’s ‘ In-
fusoria,’ 2d. ed. (1852), the generic character will be found,
and there also the name is correctly ascribed to Mr. Deane.
In the ‘ Micrographical Dictionary’ it is said that Ehrenberg
had now withdrawn the name Hemiptychus, as there was
already a Hemipticha, a genus of Hemipterous insects.
I now come to the species. In Pritchard’s ‘ Infusoria,’
page 700, the species there figured is called A. Japonicus of
Shadbolt. Now Shadbolt’s specimens (figured im the ‘ Micr.
Soc. Trans.,’ 11.) were from South Africa, and (if there be
really more than one species) are not the same as the Japan
form, and consequently not entitled to that name. Then
again Bailey, as already said, gave the name of A. Ehren-
bergi to a species from California (Puget Sound), which he
supposed to be quite distinct from ‘A. Japonicus.”’ I cannot
find that Bailey ever published this species; but Smith, in
his ‘ Brit. Diat.,’ adopted it on the authority of De Brébisson,
quoting A. Japonicus of Pritchard as a synonym. It 1s not
very clear to me which Dr. Bailey meant. I have examined
a slide prepared in 1853 from the Puget Sound form (got off
an alga), and find it identical with the Japan one, but not
with what is figured by Shadbolt or Pritchard; and another
prepared by the late Professor Smith, and marked by him as
obtained by Professor Bailey from California, and sent on
22d October, 1856: but this is the African form figured by
Shadbolt ; so that, if there be no mistake on the part of Dr.
Bailey or Professor Smith, Dr. Bailey at first called the
Japan form A. Ehrenbergii, and afterwards applied that name
to the “A. Japonicus, Shadb.,” or African form. ~Smith has
certainly not shown his usual sagacity in the elucidation of
this genus; his generic character is nearly the same as Shad-
bolt’s and Pritchard’s, but does not apply to the figure given
162 WALKER-ARNOTT, ON ARACHNOIDISCUS.
in his plate 31. I can only explain this by supposing that
Mr. Tuffen West, in making the drawing had employed a
specimen of the true Japan form, perhaps from Mr. Deane;
while Smith had derived his generic character solely from
African specimens, aided, perhaps, by Mr. Shadbolt’s figure,
which he praises. In the African form there are irregular
costee or lines connecting the radiating lines, in addition to the
granules, and the granules are small; in the Japan form the
granules are large, and placed in transverse rows, but there
are no transverse costa. A slight comparison of Smith’s
figure with Shadbolt’s or Pritchard’s will make this difference
obvious.
In the ‘ Mikro-geologie,’ Ehrenberg figures two species,
both from earth, from the Island of Camorta, one of the
Nicobar group. His 4. Jndicus is quite the same as the
Japan one, having no transverse cost, while the A. Nico-
baricus seems the same as the African form.
If there be two distinct species, as is probable, the one
may be called A. Ehrenbergii, to comprehend the Japan
species, and that obtained by Dr. Bailey from California
prior to 1853, as also A. Indicus of Ehrenberg: the other, A.
formosus, to contain Hemiptychus formosus, Ehr., A. Japoni-
cus, Shadb., and A. Nicobaricus, Ehr. I have already pointed
out how these are easily distinguished. For A. Ehrenbergit
I can only indicate the Japan seas, California, and the
Nicobar islands, as the localities whence obtained. For A.
formosus may be assigned a much wider range, as South
Africa, Nicobar Islands, and West Coast of America. Which
the British one is I cannot say; I fear there is a mistake
about its occurring In our seas.
It is not improbable that of 4. formosus there are several
varieties ; in some, I find the transverse cost quite simple,
in others, much and irregularly branched, like the vems of
the leaf of a dicotyledonous plant, and in a form which I
have from Mauritius (growing upon Plocamium Telfairia) , the
radiating coste frequently (if not always with a good light)
pass between the double row of puncta around the pseudo-
nodule, and reach the pseudo-nodule itself; this structure
requires to be verified from other localities ; it seems intended
by Ehrenberg in his figure of A. Nicobaricus.
In all that I have examined, taken from off the Alga, the
lower valve is thinner, and sometimes differently marked
from the upper one; the characters I have indicated are
taken from the upper valve only.
There can be no doubt that these dises have (as said by
Shadbolt) a horny vegetable outer covering in addition to
.
WALKER-ARNOTT, ON ARACHNOIDISCUS. 163
the siliceous one, and that by too long boiling in acid, as is
necessary for guano, the marks are much obliterated, or en-
tirely removed. This, however, is not peculiar to the present
genus, but may be observed, more or less, in all diatoms,
although sometimes the vegetable pellicle is very thin, and
may be removed by a few seconds’ immersion in boiling nitric
acid. Itis this circumstance which gives a quite different
appearance to the same species, according as the preparafion
is made. Thus, in Actinocyclus the vegetable epidermis is
cellular, while the siliceous part is striated like a Pleurosigma ;
and when the vegetable part is removed, we often find nodules
or knobs along the margin (forming, then, the genus Ompha-
lopelta), not previously visible. ‘Those who describe diatoms
from slides are thus hable to commit great errors, and indeed
no certainty can be obtained, except by getting the recent or
growing diatom and examining it—lst, after being im-
mersed for a short time im cold acid, or simply washed in
boiling water; 2dly, after beimg boiled im acid for about half
a minute, or a whole minute at most; and 3dly, after being
boiled for a considerable time. We shall then see that many
of the supposed distinct species of authors are the same, pre-
pared in a different way. Of course deposits or guanos can
yield little or no information; although once a species has
been determined by the way I have indicated, we may be
able to refer forms occurring in guano or deposits to it, with
tolerable certainty.
In my paper on Rhabdonema, in the last number of this
Journal, I described the genus Eupleuria: since then I have
found E. pulchella, not uncommon on Ballia, from Cape North-
umberland, in South Australia. In that paper I noticed that
E. incurvata differed from the others by the annuli not being
cellular ; it is therefore probable, that it will have to be re-
moved from the genus, particularly if the supposed annuli in
that species prove to be only the siliceous connecting zone
split, as it occasionally does in various other genera, into thin
lamina. That this may be its true structure is rendered pos-
sible by the discovery of a new genus from Mauritius, growing
on Plocamium Telfairie (along with the Arachnoidiscus). This
new genus has certainly no annuli: the upper and lower
valves are as described in Hupleuria, and consequently it is
intermediate between that genus and Achnanthes; differing
from this last by the want of a stauros to the lower valve;
by the costze not proceeding to the extremities, at least, on
the lower valve; and by the valves being merely arched,
and not geniculate; it has no stipes, and seems attached by
the side, as in Kupleuria. To this genus the name Gephyria
164 WALKER-ARNOTT, ON ARACHNOIDISCUS.
may be given, the more especially that Hupleuria incurvata
(my original Gephyria) may be removed here. The costi
are about 6 in ‘001 in the Ichaboe species, while in the
Mauritius one they are much closer, 15 im ‘001. This last
may be called Geplyria Telfairie, after the late Mrs. Telfair,
who discovered the Alga in which it occurs. In this the ex-
tremities of the frustules are sharp; but I have, apparently,
the same species from the West Coast of Australia (obtained
by washing some Alge collected by Mrs. Drummond, and
sent me by Dr. Harvey), but in that the frustules are more
obtuse.
In my former paper I described Amphiprora Ralfsit ; mm the
same number (‘Trans.’) is a paper by Dr. Donkin, to which
I find it necessary to allude, on account of the want of
courtesy there shown (p. 33). When I transmitted my notes
to Professor Smith, Mr. Ralfs, or others, they were to be
held as mere notes ; and although any gentleman is at liberty
to see them, or to use them, after verifying them, all that I do
not myself publish must be regarded as private communica-
tions, and with which my name is not to be connected, if
published by others. Dr. Donkin gets some information
from Mr. Roper, and Mr. Roper gets his from Dr. Mont-
gomery, and Dr. Montgomery gets his from Mr. Ralfs, who
gave a slide, with a name attached, which name I have now
published. But I beg to say that Mr. Ralfs’ side was not
from material discovered by me, as Dr. Donkin asserts, and
that the identification of Dr. Donkin’s Plewrosigma rectum
with my Amphiprora Ralfsii, was not made by me. If Dr.
Donkin wishes to know what my species is, he must not
go to a slide named by others, or by myself, containing
several objects, but to my specific character,* for in drawing
it up I had reference to several forms, both in Mr. Ralfs’
gathering and found elsewhere; and any one may see from
it that several of Dr. Donkin’s supposititious species are
combined under that character; im fact, Mr. Ralfs’ gathering
contained, so far as I can comprehend his descriptions and
figures, Pleur. rectum, Wansbeckii, minutum, and probably
also angustum, which I consider one and the same species of
Amphiprora. Pleur. carinatum I ought perhaps to add to the
list, for I believe that the striz only appear oblique in con-
sequence of the position of the light; if a true Pleurosigma it
may be Pleur. obscurum, the only one with that peculiar ap-
* T might have made the diagnosis more precise by saying the valves,
although carinate, are not alate. This, however, is implied by not. noticing
an ala.
WALKER-ARNOTT, ON ARACHNOIDISCUS. 165
pearance. Dr. Donkin will allow me also to add, that his
S. V. and F. V. of Pleur. lanceolatum, belong not only to dif-
ferent species, but to distinct genera; that his Plewr. arcuatum
is only Pleur. fasciola: his Toxonidea insignis, the well-
known distorted state of Pleur. estuart ; his Tox. Gregoriana
the same of either Pleur. strigosum, or angulatum (I have
seen both distorted), but which I cannot say from his imper-
fect diagnosis of the species. His Cocconeis excentrica was
discovered by De Brébisson, in 1852, and was then called by
him C. orbicularis ; and his Epithemia marina, the HE, Radula
of the same French gentleman, afterwards distributed in slides
by Professor Smith as Nitzschia Radula ; this I have long had
from the Clyde, and also Teignmouth. His Amphiprora
duplex, judging from the figure and diagnosis, scarcely differs
from A. paludosa. It is to be regretted that Dr. Donkin did
not make himself acquamted with what others are doimg,
before rushing into type; and that, stead of giving the long
descriptions and figures, and multiplying species unneces-
sarily, he had limited his species by a short, concise character,
as every ¢rue naturalist must do who wishes his species to be
adopted or considered by others.
166
TRANSLATIONS.
Pretiminary Osservations on the Luminous Oreans of
Lampyris. By A. KOuuixker.
(From the ‘ Verhandl. d. Wurzb Phys. Med. Ges.,’ 130, VIII, 1857.)
I. ANATOMICAL.
1. Tur luminous organs of the various species of Lampyris
are of a special nature and well defined ; not to be confounded
with the adipose substance, and presenting a determinate
form, size, and position.
2. The males of Lampyris spendidula have two flattened
luminous organs, appearing white to the naked eye, on the
ventral aspect of the sixth and seventh abdominal rings;
to which corresponds an uncoloured spot in the chitinous
integument. The females have similar organs in the same
situation, but in them the one situated in the sixth ring is
double. Besides these, I find in the female Lampyris, four
to five pairs of lateral organs, which are not always disposed
symmetrically, and presenting the form of flattened globules,
situated on the sides of the abdominal segments from the
first to the sixth rg. The luminosity of these lateral organs
is brightest when they are viewed from above. When not in
a luminous condition, their pale transparent colour and deep
position render them difficult of detection without careful
dissection.
The females of L. noctiluca have two larger, yellowish-
white luminous plates on the ventral aspect of the sixth and
seventh abdominal rings, and besides these, two minute
organs on the eighth or caudal rmg. ‘The latter only, and
these of a smaller size and grayish transparent hue by day-
light, are present in the males of this species.
3. All the luminous organs, both ventral and lateral, pre-
sent essentially the same structure, consisting of an in-
vesting membrane, enclosing a parenchyma composed of
cells, trachee, and nerves.
4. The envelope is a delicate, structureless pellicle, on the
inner surface of which may be seen minute, very widely
scattered nuclei.
5. The cells of the parenchyma constitute a compact mass,
occupying the whole interior. They are of a rounded poly-
KOLLIKER, ON LAMPYRIS. 167
gonal form, and from 0:01” to 0°02” in size. With respect
to their contents, they may be divided into two groups,—
the pale and the ‘white, between which, however, transitional
forms may be observed. The former, or pale cells, contain
pale, delicate granules, and in them may be perceived a
minute, rounded nucleus; whilst the latter, or white cells,
are so densely filled with white, spherical, minute eranules,
having an oily aspect when viewed by transmitted light, that
no other constituent can be seen in them.
The disposition of these cells is such, that in the ventral
luminous organs of the female of both species, and of the
male in L. splendidula, the outer portion contiguous to the
chitinous integument consists of the pale cells, whilst the
inner or deeper part is constituted of the white. No very
definite line of demarcation, however, can be drawn between
the two. In the lateral, more detached, organs of the female
L. splendidula, and in the luminous organs of the male of
L. noctiluca the white cells occupy the entire surface. Al-
though, as it appears to me, in the former the dorsal, and in
the latter the ventral, aspect of the organs is less thickly
covered with them. In certain cases, also, the white cells
may be wholly wanting, or are represented by bodies con-
taining only a few white granules.
6. The numerous trachee enter from the upper, or, in the
lateral organs, from the inner, side, forming the most abund-
ant and elegant ramifications among the pale cells. The
finest twigs of these vessels which appear to form loops were
visible everywhere among the pale cells; but im the ventral
organs they are the most numerous on that surface of the
organ which is turned towards the external world, whilst in
the others they exist all over the superficies. The chitinous
integument of the larger tracheal trunks supplying these
organs supports, as elsewhere in Lampyris, fine hairs.
7. The nerves, which were not found except after prolonged
and troublesome resear ch, enter the organs in company with
the trachez and ramify among the pale cells, though by no
means so abundantly as the trachez. They are of a pale
aspect, here and there furnished with nuclei, and at the
points of division also with nucleated enlargements, from
which two to five branches are given off. The resemblance
between the pale cells of the parenchyma and nerve-cells,
suggested the possibility of some connection between the
former and the nerves, but hitherto I have not succeeded
in observing anything confirmatory of this supposition.
The ultimate termination of the nerves, also, remained
altogether in the dark.
168 KOLLIKER, ON LAMPYRIS.
II. PuystoLoGicaL.
8. The proper luminous substance does not consist in the
granules of the white cells, or the so-termed “ luminous
granules” of Leydig, under which that author also includes
some larger, radiated, opaque granules in the cells of the
adipose body in the female of L. splendidula, but in the con-
tents of the pale cells, as may be readily proved by direct
observation of the luminous organs under the microscope by
night, when the light of the lamp is shut off.
9. The contents of these luminous cells correspond, in all
their microscopical reactions, with an albuminous material ;
although, owing to the extremely minute quantity of the
substance which can be obtained, it has been impossible to
subject it to a more satisfactory chemical examination.
10. With respect to the granules contained in the white
cells, as well as to the larger radiated globules in the cells of
the adipose body described by Leydig, not merely and erro-
neously as luminous granules, but also as composed of an
inorganic matter, probably phosphorus! the simplest mi-
cro-chemical examination shows, that they consist of a uric
acid salt, which, so far as my experiments have hitherto
shown, represents urate of ammonia (NH,O, Ur). On the
addition of acetic or hydrochloric acid, the characteristic
crystals of uric acid are very speedily formed; whilst with
caustic soda and potass beautiful acicular bundles of the cor-
responding urate are produced. In fact, if two or three of
the luminous organs in L. splendidula are isolated by simple
dissection, the murexid-test, by means of nitric acid and
ammonia, may be directly applied, and will supply the most
convincing proof of the true nature of their contents ; and on
the subsequent addition of potass the characteristic purple-
blue colour. will be obtained. The production of the arbo-
rescent crystallization of sal ammoniac on the addition of
hydrochloric acid, and the circumstance that no residue is
left when the white substance is heated to redness, determine
that the base of the uric acid salt in question is ammonia._
11. All endeavours to detect the presence of phosphorus
in the luminous organs were fruitless. The organs of thirty
males of L. splendidula were treated with sulphuret of carbon,
and when this was allowed to evaporate on blotting paper,
no luminosity was evident, nor was the paper charred. When
organs which have been isolated by dissection are treated
with nitrate of silver, no black precipitate is formed. The
same was the case when a number of the insects were placed
KOLLIKER, ON LAMPYRIS. 169
in a small glass vessel and covered with a shallow dish, con-
taining a drop of a solution of the same salt.
12. The luminosity of Lampyris is dependent upon the
will of the animal, and exists by day as well as at night,
though very frequently absent in the day time; a circum-
stance evidently depending simply upon the fact that these
insects are, for the most part, nocturnal in their habits, and
usually lie concealed in the dark during the day. Movements
alone have no influence upon the production of light; and
even in the night time, individuals may be noticed performing
the most active movements, and yet showing no luminosity
whatever. Nor, also, has the concentration of light upon
the animals any effect; whilst they exhibit luminosity even
when they have been kept for days together in the dark.
13. Many irritants exercise an influence upon the produc-
tion of light, amongst which the following may be noticed :
(1.) Mechanical irritation —The crushing of the luminous
organs, or even a slight pressure upon them, from without,
invariably causes brilliant illumination. When the organs
are divided into small portions, or torn in pieces, the lumi-
nosity soon ceases. The light is also frequently manifested
when the head or thorax of the insect is cut off or slowly
crushed.
(2.) Electrical irritation—If the whole insect, or even
only its abdomen, when the luminosity is not present, is
excited longitudinally by a powerful induction-current, the
most brilliant illumination is instantaneously produced, which
usually quickly disappears again when the current is inter-
rupted. The same effect is produced when the poles are ap-
plied directly to the organs, and very frequently also when
the head alone is excited.
(3.) Temperatures—From the experiments of Kunde and
myself, which agree pretty nearly with those of former
observers, a temperature of +40° to + 60° R., always excites
a bright luminosity; and the same effect is produced, though
more rarely and with less certainty, by a temperature of
from — 3° to — 5° R. Under variations, also, of temperature
amounting to about 30° C., the luminosity is produced, as it is
almost always when the animal is transferred from a freezing
temperature to the warmth of the hand.
(4.) Chemical irritants.—In these experiments, the sepa-
rated abdomen only was always submitted to the reagent, with
which the part was in all cases kept completely moistened.
a. Caustic alkalies are powerful excitants of the luminous
organs—caustie potass, in fact, acting im all degrees of con-
centration, from 0°7 to 50 per cent.
VOL. VI. )
170 KOLLIKER, ON LAMPYRIS.
b. Acids —Very beautiful luminosity is produced by sul-
phuric, nitric, and hydrochloric acids, and in the case of
sulphuric acid, solutions containing from 75 to 75} per cent. are
efficient for the purpose ; hydrochloric acid acted in solutions
containing from 3 to 25 per cent.; mitric acid was tried, with the
same result, in a solution containing 22 per cent., which was
the only strength tried. The vapours, also, of the two latter
acids act as excitants of the luminous organs. Besides these,
a similar effect is produced by phosphoric, concentrated
acetic, tartaric, citric, oxalic, and a five per cent. solution of
chromic acid.
(5.) Solutions of indifferent substances, in certain degrees
of concentration, are also excitants of the luminous organs,
such as the haloid salts and the neutral salts of the alkalies and
earths, as well as sugar. Common salt acted as an excitant
in solutions containing 3 per cent. and upwards, phosphate
and sulphate of soda, in solutions of 4 to 5 per cent.
d. Other excitants are alcohol of 45 per cent. and upward,
anhydrous ether, creosote, lunar caustic, chloroform, and
chlorine.
e. No effect is produced by water, saliva, strychnia, dilute
solutions of salts and acids, oils, sulphuret of carbon, and
many metallic salts. Oxygen, also, from a single experi-
ment, would not appear to be a true excitant, for separate
abdomens, and entire insects not in a luminous state, fre-
quently do not exhibit any luminosity until after one or
several hours; but then, it is true, they shine long and
brilliantly.
14, The luminous property is destroyed by a great many
influences, although it always exhibits great tenacity. It is
always and speedily annihilated bythe mineral acids and caustic
alkalies ; and also—a circumstance that appears to me of
especial interest—by narcotics, which paralyse the nervous
power, as by the fumes of hydrocyanic acid and of conein
(experiments with the urara poison were unsuccessful).
In the experiments made with these poisons, the
animals under proper precautions for the protection of
the experimentalist, were placed in a small watch-glass,
and moistened with saliva; the watch-glass was then
introduced into a larger vessel containing the poisonous
vapour, so that the atmospheric air had free access. If
the insects experimented on were in a luminous condition,
the light was extinguished in from three to five minutes, and
at the end of five to ten minutes the luminous organs were
quite dead, and incapable of excitation by any means—
crushing, electricity, and caustic alkalies. The same effect was
KOLLIKER, ON LAMPYRIS. 171
produced when non-luminous individuals were exposed to the
poisonous vapours in question. The luminous organs were
in like manner destroyed by a powerful electric current,
alcohol, ether, organic acids, &c.
Of other injurious agents, many, at any rate, do not neces-
sarily annihilate the luminous property for ever. ‘Thus
animals which have been dried, are resuscitated when mois-
tened with water, and exhibit luminosity ; and, in the same
way, individuals benumbed by cold (0° to — 5°) are revived
by the warmth of the hand. Moreover, I have succeeded in
restoring the luminous property of entire insects, and of
isolated organs, which had been deprived of it by a solution
of salt containing 12 to 20 per cent.—that is to say, by the
forcible abstraction of water, by immersing them again in
water. There is thus no doubt that further experiments will
show, that, in the case of these organs, pretty nearly the
same phenomena of revivification take place as in the sper-
matic filaments and nerve-fibres.
Under favorable circumstances, the length of time during
which the excitability of the luminous organs is maintained,
and the light itself may be produced, is very considerable.
In moist atmospheres, as well as in diluted solutions of
salt, sugar, and albumen, the separated abdomen will often
continue in a luminous condition for twenty-four to thirty-
six hours. The greatest length of time during which I have
noticed the luminosity to continue, viz., forty-nine hours,
was in a moist atmosphere of oxygen. In water, that is to
say, when the animal is moistened all over, the luminous
property ceases to be manifested in a rather short time—
usually in one to three hours.
15. When insects moistened with a solution of salt were
placed with the cephalic and caudal extremities on the
cushions of Du Bois’s current apparatus, those in a luminous
condition, and especially females, deflected the needle of the
multiplier from 3° to 7°, the head at the same time appearing
to be positive. This result, however, was not quite constant,
and further experiments will be necessary before any further
conclusions can be safely drawn from it.
Non-luminous animals, even when they moved on the
cushions, usually afforded, with my multiplier of 16,000
turns, no indication whatever of a current, or, at most, did
not deflect the needle more than 1° or 2’.
16. I was very desirous of determining whether there was
any difference of temperature between the luminous and non-
luminous animals, but owing to the circumstance that the
experiments were delayed till quite the close of the season in
172 KOLLIKER, ON LAMPYRIS.
which the insects appear, the only result at which I arrived
was, with the aid of the thermo-electrical apparatus, to
determine that the temperature of the non-luminous females
was 17°C., in a room at the temperature of 20° C.
Results.
From the foregoing experiments, coupled with the anato-
mical facts, I conclude that the luminous organs are a ner-
vous apparatus, whose nearest analogues might be sought
in the electrical organs. All excitants of the nerves excite
the luminosity, and the agents which annihilate the nervous
functions, act injuriously in their case also. My experiments
wholly subvert the theory hitherto current, which assumes
the existence of a luminous material, secreted and deposited
in the organs, a sort of phosphorus, which, on the addition of
oxygen through the respiratory movements, becomes oxy-
dized, and consequently luminous. It must, indeed, be a
strange material which may be rendered luminous by acids
and alkalies, alcohol and creosote, salts and sugar, and has
its luminosity destroyed by prussic acid and conein. It
seems to me that the observations above detailed are capable
of but one explanation, viz., that the light is produced under
the influence of the nervous system, and in all cases is main-
tained only for such a period, whether long or short, as the
nerves, stimulated by the will or otherwise, act upon the
organs. With respect to the proximate causes of the light,
I have thought of the electrical light, and on light produced
by chemical action. Whether the former supposition be
worth further investigation, or whether it be at all possible—
by analysis of the greenish light of Lampyris, which micro-
scopical examination shows to consist of minute sparks—to
determine whether it be electrical or not, I will not
venture to decide. I am at present inclined to prefer
the second hypothesis, which also seems to be sup-
ported by the fact of the presence of urate of ammonia
in the luminous organs, as my experiments have shown.
Admitting that these deposits, from their position and their
being composed of very minute granules, may add to the
light of the luminous substance itself, still, seeing that
their number is very variable, it appears more probable to
refer their production to molecular changes in the luminous
matter, and to assume that the latter, which manifestly con-
sists chiefly of an albuminous substance, and is abundantly
supphed with oxygen by its numerous trachez, undergoes
during life a decomposition, one of the ultimate results of
which is urate of ammonia (NH,O, Ur).
PRINGSHEIM, ON ALG. 173
The evolution of light, therefore, would be an accompani-
ment of this decomposition (oxydation) of the albuminous
material, though it must of course be assumed that the de-
composition takes place under the immediate influence of
the nervous system ; in fact, even, it may be said that this
decomposition takes place so actively as actually to be
attended with the luminous phenomena, only in consequence
of its imtensity derived from the nervous influence, whilst,
under ordinary circumstances, albuminous substance, under-
going oxydation, is not luminous. If this explanation be
correct, we are here presented with another remarkable
instance of a direct influence exerted by the nervous system
on molecular changes, and which, although ina certain sense
analogous to what we know of the influence of the nerves
upon the electrical organs and salivary glands, as well as in
the action of the nerves upon the muscles, still at present
appears to be suit generis.
So much for the present. I hope next winter to be able
to publish my experiments more in detail, with the requisite
illustrations, although I may wait for another glow-worm -
season, in order to supply many existing deficiencies in my
observations. In any case, I shall then make due reference
to the numerous previous researches on the subject of the
luminosity of Lampyris, amongst which, as [ will at once
remark, the most satisfactory are those of my countryman,
Macaire, of Geneva (‘ Bibl. univers. d. Genéve,’ 1821, and
Gilbert’s ‘Annalen, 1822, p. 265), and endeavour, at the
same time, to bring into one view the physiological relations
of luminous animals in general.
PrincsuerM’s Researches on the Fecunparton of the Aucam.
By M. Monraenzt.
Tue following résumé, by M. Montagne, of Pringsheim’s
later researches on the fecundation of the Alge, appears
in ‘ L’ Institut’ for August 20th, 1856, and may be regarded
as a continuation of what has already appeared on the subject
in this journal.
“The second memoir of M. Pringsheim,” observes M.
Montagne, “is full of curious facts, leading to unexpected
results, and well deserves the attention of naturalists. It
contains, in fact, the establishment of the existence of the
174 PRINGSHEIM, ON ALG.
two sexes in some fresh-water Algee—the Conferve, in which
their existence had previously been scarcely suspected. It is
true that the motions of certain spores (zoospores) at matu-
rity had been remarked, and that this motion was caused
by the action of vibratile cilia, with which they are fur-
nished. Their germination even had been traced. But as to
antherogoids, or male organs, I know of no observer before
M. Pringsheim who had noticed them in the lower Alge,
and particularly in Cidogonium, one of the subdivisions of the
genus Conferva of Linnzus.
“Nothing is more marvellous than the phenomena attend-
ing the act of fecundation of these plants. The sexual appa-
ratus, the metamorphoses that the androspore or male organ
undergoes, and the act of fecundation itself, seem so many
facts contrived on purpose to excite our utmost wonder and
admiration.
“The species of Gidogonium are simple, filamentous Alge,
living in fresh water, and composed of cylindrical cells placed
end to end in a single series. They present this peculiarity,
that. the greatest number of species are marked by annular
striz placed on certain special cells. In one of these cells,
at the time of reproduction, the contents accumulate, become
condensed and distended, and sometimes produce zoospores ;
sometimes a single spore, which is detached, and falls to the
bottom of the water, when mature, to perpetuate the plant.
“This is all that was formerly known. We were completely
ignorant of what indueed the successive changes that the spore
underwent before it was detached. This is what M. Pring-
sheim has observed. In the same filament which produces
the female cells destined to propagate the plant, others may
be observed, generally shorter, in which bodies are developed
which might be compared to antheridia, since they enclose
the antherozoids. These bodies, ovoid, crowned with vibra-
tile cilia, and called by the author androspores* (Andro-
sporen), very closely resemble zoospores, but are very
differently organized. Escaping from the vesicle which in-
closes them, these androspores attach themselves at a deter-
minate moment firmly on the female cell. The filament,
whole and unbroken until now, opens its joints at the level
of one of the striz like a soap-box, to allow of the protrusion
of the membrane containing the gonimic matter or the
potential spore. This protruding portion, which the author
calls fecundating tube (Befruchtungschlauch), is perforated
by a round opening at the spot where the androspore had
s, * These are the organs which have been termed Microgonidia by Alex.
raun,
PRINGSHEIM, ON ALGZ. 175
implanted itself, a sort of ambulatory testicle for which I can
find no comparison. The act of fecundation takes place,
after the fall of a little operculum from the androspore, by
the introduction of a spermatozoon, or Saamenkirper, as it is
called by M. Pringsheim, into the mass of endochrome
(chromule) of the female cell. This introduction is effected
through the lateral opening existing at the summit of the
fecundating tube, and which performs the part of a micro-
pyle. Before this act, the female cell, in order to permit the
entrance and action of the spermatozoon destined to com-
municate the germinating faculty to the spore, remains open,
but no sooner is the act accomplished, than the cell surrounds
itself with a second membrane which prevents any further
intrusion.”
Such are the facts observed by M. Pringsheim. But, adds
M. Montagne, “we must not forget that it is to French
naturalists we are indebted for the first information on these
interesting questions. It was a member of this Academy,
the illustrious Reaumur,* who first thought of seeking for
the two sexes in the Algze, and but little more would have
given the honour of this discovery to him. It was nearly a
century and a half after his fruitless researches, that two
botanists more fortunate, M. Decaisne and M. Thuret, suc-
ceeded in establishing the existence of antherozoids in the
same receptacles of the Fuci where Reaumur had vainly
sought for and thought he had found male fiowers. Since
then, the Academy of Sciences, in proposing as the subject
for the grand prize in natural history, in 1847, the study of
the zoospores and the antheridia of the Algae, excited
renewed efforts on the part of M. Thuret, and of MM. Derbés
and Solier—efforts which have been rewarded, and which
have given a new impulse to these studies, the effect of
which we now see in the observations of many phytologists,
amongst others of M. Pringsheim, and of which it is as im-
possible to calculate the consequences as to limit the term.
“J will add, in conclusion, that all observations published
up to this time on those families of the vegetable kingdom
in which species of the most simple organization are met
with, goes to prove that the law which governs the function
of reproduction is becoming more and more generalised, and
that, with some modifications dependent on special conditions,
it is common alike in plants and animals.”
* Reaumur, “ Description de fleurs et de graines de divers Fucus,” &e.,
‘Mém. de l’Acad. des Sc.,’ 1711, p. 381, and 1712, p. 21.
176
REVIEWS.
Introduction to Cryptogamic Botany. By the Rey. M. Te.
Berkexey, M.A., F.L.S. London: H. Bailliere.
TuereE is no department of natural history that has been
more indebted for its progress to the employment of the
microscope than that of the structure of Cryptogamic Plants.
So little was the nature and structure of these plants known,
that Linnezus applied to them the term Cryptogamia, on
the supposition that no process of reproduction existed in
them analogous to that which occurred in the stamens and
pistils of higher plants. The history of the discovery of the
reproduction of these plants, by the agency of sperm-cells
and germ-cells, is one of the most brilliant pages in the re-
cords of microscopic research. Although their structure has
been well described and illustrated in the works and papers
of Lindley, the Hookers, Henfrey, Berkeley, Broome,
Thwaites, Ralfs, and the late William Smith; till the publi-
cation of the present work by the Rev. M. J. Berkeley, we
had no book in our language especially devoted to the con-
sideration of their structure and affinities. Few persons could
bring to this task more qualifications than Mr. Berkeley. He
has devoted unusual powers of observation and careful re-
search to the study of the Fungi, and is known for his work
on the British forms of this family, wherever the science of
botany is cultivated. In this work he has devoted the same
qualities of mind to the revision and criticism of all that has
been done by other observers in the remaining families of the
Cryptogamia, and has produced a volume that will be valued
by all who are engaged in the study of this most interesting
and important branch of scientific vestigation. Not only
does Mr. Berkeley’s work give a very complete account of the
various families of Cryptogamic plants, but it contains a large
amount of philosophical reflection and sound advice, which
cannot but be useful to the young student. In his introduc-
tory chapter he especially draws attention to the value of
researches on the lower plants ; and points out the errors those
are likely to fall into, who, whilst skilful in the use of the
microscope, have neglected the first principles of scientific
inquiry. We give the following extract as an example.
“T shall not dwell upon the extreme and manifold interest of the several
BERKELEY, ON CRYPTOGAMIC BOTANY. 177
objects which come within the view of the Cryptogamist. If variety and
delicacy of structure, beauty of form and colour, and the nicest transitions
from group to group, from genus to genus, besides a host of curious ques-
tions of {physiology and adaptation of means to particular ends, are worthy
to engage attention, Cryptogams most surely will not be amongst the
most unprofitable objects of study. There will be scope, too, for the acutest
powers of thought and observation, unless he is content merely to skim the
surface of things. Even independently of the necessity of using optical
instruments, a point often much exaggerated, for if the minutest points of
physiology in Phenogams are deeply studied, no less an amplifying power is
necessary, and perhaps even greater tact and skill in manipulation, the dif-
ficulties which arise from the wide limits within which not merely species
but aceredited genera are capable of varying, are sufficient to exercise the
highest mental qualifications. It does not follow, however, that the end
obtained should be at all proportional to the necessary labour. The objects
which the accomplished Cryptogamist has in view are not comprised within
the mere determination of species or the admiration of the exquisite forms
and combinations which meet him at every turn. If he aims at nothing
higher than the first, he may indeed be useful in his generation, provided he
be cautious enough, and possessed of sufficient self-denial to prevent his
striving to glorify himself, rather than to clear the road for investigators of
higher pretensions. If beauty of form and singularity of structure be alone
his object, his time may be passed agreeably enough, but in most cases, like
ten thousand microscopists of the present day, he will be but a mere trifler,
without any better aim than innocent amusement; or if he be a dabbler in
science, with some wish to attain a reputation which he has not the patience
to seek after by a continued course of study and mental discipline, he will
be deriving general inferences from isolated half-understood facts to the
detriment and confusion of real science. Perhaps, of all literary dissipation,
the desultory observations of the mere microscopist are the most delusive.
And even where the objects are higher, it is well that every one whose
attention is much directed to this greatly abused instrument, should remember
that if he wishes to penetrate the secrets of nature he must look beyond his
microscope, a fact of which some microscopists of considerable reputation do
not seem at all aware. The paramount importance of the subject is to be
seen in far different matters.
“The first great point is that the physiologist is able, in the simpler
Cryptogams, to study the several organs of which the higher vegetables are
composed, isolated and altogether removed from other structures which may
impede the view, or by their rupture cause confusion. If, for instance, it is
desired to ascertain the mode of growth in cells, he will be able to appeal to
the simpler Alge, whether grumous or filamentous. In the one he will be
able to trace step by step the division of the primitive mother-cell, with
nothing to prevent his view in consequence of the great transparency of the
walls; or if he take one of the simple or branched Conferve, he will be able
to assist at the origination not merely of two new cells from the subdivision
of one, but the formation of a new cell by pullulation from the walls.
Meanwhile he can ascertain exactly what changes the endochrome is under-
going, he can watch the part which the cytoblast bears in the process, and
can sometimes trace its partition. He can investigate in many cases, as in
Zygnema and its allies, or much more in Chara and Nitella, the currents
which traverse the length and breadth of the cells; he can trace thickening
of the walls by the deposit of new coats, and in some cases the shelling off
of those which are effete and have performed their office. He can observe,
moreover, the wonderful union of separate filaments, the formation of a vital
spore from the union of the contents of neighbouring cells, and many other
178 BERKELEY, ON CRYPLOGAMIC BOTANY.
points of interest, which throw more or less light on the processes which
occupy the attention of the investigator of the vital processes of the higher
vegetables. Amongst the lowest vegetables he will find many facts wliich
will give him points of comparison with inmates of the animal kingdom; he
will see apparent Infusoria existing as mere vegetable organs, and will find
them performing functions under a form which he will in vain hunt for
amongst the higher vegetables, and if his attention be turned to those
Cryptogams which more closely resemble these in outward appearance, he
will find a form of spermatozoid so closely resembling the impregnatory
bodies of the higher animals, as to open his mind more strongly than ever to
a conviction of the intimate bond by which all the members of the organized
world are bound, though he may not subscribe to those theories which deny
the existence of definite groups. There can be no question in these cases of
the spermatozoids being developed in perfect freedom within the mother-
cells, and not mere appendages separated from their walls, and endowed.
with a vital action, similar to that of the cilia, so common to mucous sur-
faces, as many animal physiologists assert. Such investigations will come
in aid then of those relative to the development of spermatozoa in animals,
and similar advantages will be presented in many other instances, and con-
sequently the cryptogamic student will be able to form more exact notions
as to vital action in the animal and vegetable kingdoms than are usually held
by those who confine their investigations to either division of the organized
world. Again, though spiral vessels are comparatively rare in Cryptogams,
opportunities of studying their development and nature are nowhere more
available than amongst the Hepatice, where they occur without the inter-
vention or attachment of any other issue, while in Zyguzema the curious and
multiplied spiral bands may with ease be traced from the first formation of
the cells in which they are developed.
“There is another point of immense importance, which the cryptogamic
observer has in a peculiar degree the power of studying successfully. Ques-
tions often arise as to the point whether cellular structure can originate
without the presence of a previous mother-cell. It is a question, for in-
stance, whether cells are ever formed in Phanogams from mere organizable
sap, as presumed by Mirbel in his paper on the Date Palm; or again,
whether, in what is called organizable lymph in the animal world, cells can
originate freely without pullulation from the neighbouring tissue with which
the lymph is in contact. In the blood, once more, are blood-globules, or in
unhealthy conditions, pus-globules, ever formed simply from the constituents
of the blood itself, without the concurrence of previously formed organisms ?
Now in those fungi in which, as in Spheria and Peziza, the reproductive
bodies are generated by the endochrome of the fructifying cells, the Cryp-
togamist has the power of watching the development of the spores from
the very moment when the endochrome commences to be organized,
and he can with confidence assert that they are not the creatures of pre-
viously existing cells, but the produce of the endochrome itself. He
will be able to compare with this what takes place in the embryo sac of
Pheenogams, and will be better prepared to appreciate all the arguments
which bear upon the Schleidenian Theory of the formation of the embryo.
Both the formation of the albumen and of the embryo itself will then be
studied with greater zest, and he will certainly, after watching the origin of
spores within an ascus, be able to judge better of what takes place or does
not take place within the pollen tube. It is true that many of the points [
have mentioned may be examined profitably in Phenogams, but always
with more difficulty, and seldom with such precision or with such satisfac-
tion and conviction to the observer, and there is one point which must
always be borne in mind, that the objects in question grow and are developed
BERKELEY, ON CRYPTOGAMIC BOTANY. 179
under his eyes, if he possesses proper powers of manipulation, which will
searcely ever be the case with Pheaogams, if the parts be freed ever so
neatly from the surrounding tissues. Nay, the examination of the develop-
ment of cells in such genera as Hematococcus and Gleocapsa will help even
the Zoologist, for nothing ean be more close than the mode of development
in these, and of the vitellus in the eggs of certain Mollusca.
“The bodies, indeed, which are so much alike, or in other words, are
homologous, identical, that is, in structure and genesis, though not in func-
tion, may not always be of equal value; but the student will learn as much,
perhaps, from the observance of their differences, as if they were in every
respect perfectly accordant.”
Some of the earlier of these remarks may perhaps be
regarded as seyere, but they are the result of the observation
and reflection of one who has entitled himself to be regarded
as a master of the subject on which he writes, and must be
received with all due respect. The following passage is on
a subject which has recently undergone discussion in our
pages, and will be read with interest.
“Nor will a few words on this subject of species be completely out of
place, though we have incidentally touched on it before. It is one which
the cryptogamic student will meet with at every turn. It is a common
opinion that cryptogamic species are so variable, that it is impossible to cir-
cumscribe them with specific characters; and, to be studied with certainty,
they must be studied in the herbarium. ‘The practised eye will there detect
similitudes between widely different forms which no definition could convey.
Now there is certainly much truth in this notion, but more perhaps, from
the wrong conception of authors than from the intrinsic difficulty of the
case. So long as essential characters are neglected, and fleeting external
characters put in their place, difficulty must needs exist, and the student
will never be certain that he has come to a correct decision till he has seen
an authentic specimen, or compared his own decision with that of other
botanists as manifested in extensive herbariums. A state of uncertainty is
always one of more or less pain, and the temptation to a solution of the dif-
ficulty by the supposition that he has made some new discovery, will often
present such attractions as to prove insurmountable. Nor will he find it
possible, without that mental discipline which arises from a patient study of
every detail of structure, and of the various shapes which organs may assume
under different circumstances. Without such discipline, like certain German
authors of some repute amongst persons uninstructed in the subjects they
profess to handle, he will propose a new name for every difference, even such
as are manifestly merely temporal and accidental, and, on the contrary, he
will unite whole groups which belong to entirely different categories. It
would be easy to point out glaring examples, both amongst algologists and
mycologists. One of the worst amongst Phenogamists, perhaps, is the
erection of that state of the inflorescence of several species of Cissws, in
which the peduncles are deformed by the presence of an internal parasite
(Puccinia incarcerata, Lév.), into a distinct genus of Phenogams; though
this is not worse than referring the same Alga received from different
sources to two or more distinct genera, and that not among the lower or
more obscure species, where there might be some excuse for such a pro-
ceeding, or the association of plants so totally different, as Puccinia and
Trichothecium. Nor is the correct appreciation of species of so little
consequence as is sometimes vainly supposed. ‘The only way in which
180 BERKELEY, ON CRYPIOGAMIC BOTANY.
we can arrive at anything like accurate views of geographic botany,
or the distribution of plants over the globe, is by a correct estima-
tion of species. If two Floras be formed on different principles—while
in the one the species are accurately limited, and forms which vary only in
some subordinate point, and not in essential characters, are grouped under
one common name; in the other, not only every marked variety, but even
accidental variation, is elevated to the rank of a species,—it is impossible
to form any correct comparison, and this is the more necessary in Crypto-
gains than elsewhere, because the species have notoriously such a wide
diffusion, and because their technical, though not their essential characters,
are so very variable. The great point in all these cases is never to describe
from single or imperfect specimens, where there is some form evidently very
closely allied. It may not be possible, perhaps, always to avoid error, but
a little caution will be most advantageous, both as to one’s own individual
character as a botanist, and to science in general. And if species are once
accurately characterised, there will be far less difficulty than may be imagined
as to genera. Nothing is more vain than to run down botanists as mere
makers of species, as though it did not take as much knowledge and tact to
limit species well, as to ascertain a few detached microscopical facts without
deriving any general views from such study, or ever seeing the relative
bearing of such observations. ‘The physiologists of the present day, at
least too many who have some name in science, are absolutely doing the
very thing which they profess to despise in species-makers. A proposer of
bad, ill-defined species is no promoter of science; still less is the so-called
physiologist who draws from isolated half-observed facts, conclusions which
the very next observation may entirely destroy. We may regret, indeed,
sometimes the over-caution of the prince of physiologists, but such over-
caution is ten thousand fold more praiseworthy, and tends more to the
advancement of science, than crude, hasty, and ill-considered theories founded
on imperfect observations, because what it does bring forth is essentially a
KTnpa €¢ ae, and, even when incomplete, is a sure stepping-stone for the
acquirement of some further eminence.”
As we at first stated, it is in the structure of the repro-
ductive organs in Cryptogamic plants that most has been
done by the aid of the microscope. On this subject we
extract the followimg passage from Mr. Berkeley’s luminous
introductory chapter.
“ Tt is desirable, again, before entering further on this argument, to say
a few words on the reproductive organs of Cryptogams, at least on the
female organs, for there is little or no similarity between the male organs of
Cryptogams and Phenogams. There are no proper pollen globules, no
germinating of a cell to bring the walls in contact with the embryo-sac; nor
is there any agreement between the mode of generation of the grumous
matter or fovilla and the spermatozoids.
“In the more simple cases there is nothing at all analogous to flower, but
certain privileged cells are separated from the threads or compact tissue of
the matrix, whether naked, or produced within a special tube or sac, and
constitute the fruit. ‘These germinate almost exactly like pollen grains, and
reproduce the species. ‘There are, sometimes, several kinds of spores upon
a plant, all capable of reproduction, though differing in appearance. These
spores, then, are homologues of the individual cells of Phaenogams, which,
at times, are equally capable of reproduction in the shape of buds.
“The spores, or what have the appearance of spores, do not always
reproduce the plant immediately, even in plants of such a low grade as
BERKELEY, ON CRYPTOGAMIC BOTANY. 181
Fungi. In the higher Fungi, certain cells swell and become clavate, pro-
ducing on their surface a number of little points, each of which is terminated
by a spore. In remella, this clavate swelling has much the appearance of
fruit, but the points upon its surface are greatly elongated, and true fruit at
last is produced. In certain cases, these spores produce from their surface
minute processes, supposed by Tulasne to be male organs. These can only
be seen with a nice adjustment of the light. Their existence has been
verified by myself and Mr. Broome; their functions, however, at present
must be considered doubtful. In the gelatinous fungus, which is so
comnion on Juniper (Podisoma), the bodies I have represented are very like
these sporophores in Tremella, but they germinate truly like other spores,
and are remarkable for germinating at definite points. The threads they put
out produce in fact the true fruit. This holds good equally of all the blight
or rust-like Fungi, such as affect corn and other living plants.
‘A different order of things prevails amongst the higher Cryptogams.
The spores germinate and produce a more or less foliaceous mass, which
after impregnation bears fruit containing bodies like the original spores, or
a plant capable of bearing such spores, in which case it is called a prothallus.
After a time, certain pitcher-like processes project from it, or are sunk in
its substance. A cell at the base of these urns, when impregnated, grows
after the fashion of the first cell of the embryo in Phenogams. In some
cases, then, the cells which arise from germination are developed, as in
mosses, into a plant directly, reproducing spores by which the cycle is again
accomplished ; in others, as in Ferns and Club-mosses, an embryo more or
less resembling those of Phznogams is first generated, which strikes root
and sends out an ascending stem, which sometimes grows into an enormous
tree, producing every year a crop of spores. The spores, then, in these
different plants are of very different values, and in no respect homologous
with the seeds of plants. Cryptogams have, in fact, no true separable
seeds, though, in the highest forms which they assume, they generate an
innate embryo. Without some such notion, though I am obliged to antici-
pate matters to be described more fully hereafter, 1t is scarcely possible to
estimate the true relations of Cryptogams to Phenogams.”
In gomg through this work we had marked several
passages as adapted for introduction into our pages, but
these are so many, that we can only recommend our readers
to purchase the volume, in order to become acquainted with
them. We must, however, give one more illustration from
the details of the work, and this one we take from Mr.
Berkeley’s account of the Hyphomycetous Fungi. To this
group belong that very interesting series of organisms known
by the name of moulds.
“The species contained in the division Hyphomycetes, consist of Fungi
which, like Mucorini, are known under the common name of moulds. All
organized matter is soon compelled by their agency to undergo chemical
change, or when chemical change has taken place supplies a fitting matrix
for their development. ‘The common blue mould of cheese, the brick-red
cheese mould, and the scarlet or orange strata which grow on tubers or
roots stored up for use, when commencing to decay, are familiar examples.
Nothing, however, escapes their ravages. The silk or cloth stored up in
our wardrobes, the meal and sugar of our kitchens, nay, the very glass of
our windows, suffer in greater or in less degree. Ina few cases, as in cheese,
182 BERKELEY, ON CRYPTOGAMIC BOTANY.
their growth is encouraged, and steps are even taken to inoculate untainted
cheeses; but in other instances they are a destructive poison, unless, indeed,
the evil effects which have arisen from the use of certain mouldy provisions
are to be ascribed to the decomposition of the matrix, rather than to the
mould itself. Some of the species are developed with extreme rapidity, and
a few years since, when the barrack bread was so much affected at Paris by
a species of Penicillium, a very few hours were sufficient for its development,
and the mould was in active growth almost before the bread was cold.
Indeed, it was proved satisfactorily that the spores of this species are
capable of enduring a temperature at least equal to that of boiling water,
without losing their power of germination: Such facts, then, are no proof
of spontaneous or equivocal generation. Dutrochet found, indeed, that the
chemical nature of substances had great influence on the species which grow
upon them, and that albumen was almost a perfective preventive. This,
however, is simply in accordance with facts relative to the distribution of
Phenogams over the surface of the earth. The chemical composition of the
soil has a great deal to do with that distribution. The occurrence of
moulds in closed eavities has been mentioned above, and the extent to which
the spores or other reproductive bodies insinuate themselves in the most
deeply tissues. Dutrochet professes to have seen milk-globules changed
into the spores of moulds, or at any rate developed into moulds. Certain it
is, that when milk is arrested for a long time in the udder of the cow, and
forms clots there, moulds are frequently found, and that they find their way
into cavities which are almost closed to external influences, as in the urinary
bladder of man, and that under more than one form. Such anomalies may
at first surprise us, but they may, nevertheless, admit of explanation, as the
presence of the larvee of tape-worms in deep-seated organs, and even in the
brain, which was so long a stumbling-block of science. On surfaces freely
exposed to the air, as the pulmonary cavity, or communicating with it occa-
sionally, as the walls of the stomach, they are not unfrequently developed,
under peculiar conditions of disease.
“One of the most remarkable qualities possessed by certain moulds is
the power they have of producing or accelerating fermentation. Yeast is,
in fact, nothing more than a peculiar condition of a*species of Penicillium,
which is capable of almost endless propagation, without ever bearing perfect
fruit. Attempts have been made to show that the structure of yeast-
globules is different from that of ordinary moulds, but without success.
It appears that wherever exosmose and endosmose take place, there is
chemical action; and thus, when yeast is mixed with any saccharine matter,
a multitude of points are presented at which an active interchange is going
on between the contents of the globules and the external fluid, and at
which chemical action can take place. ‘The process is only accelerated by
the presence of the ferment, or rather the fermentation is regulated, and
the putrefactive and acetous fermentation which might otherwise be esta-
blished, effectually controlled. Under proper conditions of temperature,
the acetic fermentation will take place on the application of yeast, but not
so surely or speedily as by the mycelium of the Penicillium, which is known
under the name of the Vinegar plant, a filamentous condition instead of
vesicular,
“The production of yeast depends upon the extreme facility with which
moulds adapt themselves to peculiar circumstances. The proper position of
such moulds is upon the surface of decaying substances ; but several species
are capable of sustaining life when completely immerged. In such a con-
dition they cannot produce any real fruit, but they are propagated by means
of shoots from the mycelium. Substances, which rani prove fatal to many
other vegetables, as solutions of arsenic, opium, and many other poisonous
BERKELEY, ON CRYPTOGAMIC BOTANY. 183
chemical substances, do not prevent the growth of moulds. One form
proves an intolerable nuisance in electrotyping, being developed in the
solution of copper used in that process, and becoming itself eventually
thoroughly electrotyped. Under such circumstances, they have the power
of separating the metal or other noxious principle, while they avail them-
selves of any nutritive matter with which it may be combined. ‘These fluid-
born states of Penicillium, and other more or less allied Mycelia, are often
regarded as Alge, but they have no affinity with those vegetable pro-
ductions.
“One genus of moulds was long considered as peculiarly destructive to
living vegetable tissues, and the grape mildew, peach mildew, blane de
rosier, &c., are all attributable to it; but it has already been shown that
these supposed species of Oidiwm are not true moulds, but merely states of
different species of Zrysiphe. This is, however, not the case with that class
of moulds which belong to the old genus Botrytis, or to Corda’s genus or
subgenus, whichever may be the more correct term, Peronospora. These
moulds run, by means of their mycelium, amongst the loose tissue of the
leaves, and at length protrude fertile branches through the stomates.
Tulasne, Caspary, and others, have lately discovered that there is another
form of fruit, with far more complicated and larger spores developed at the
base of the fronds. The genus Artotrogus of Montagne very probably in-
cludes such forms of fruit. But not only are they destructive to vegetable
tissues. Where they penetrate into the intimate organs, as in the case of
the silkworm and several other insects, they soon produce death. The
muscardine, which is caused by Betrytis Bussiana, is capable of being pro-
pagated by inoculation, or even without any injury of the tissues the mere
ae of rubbing a few spores upon the body is sufficient to propagate the
isease.”
Our long extracts will afford a good example of the style and
matter of the book. They also indicate the value we attach to
its contents. However much we might be tempted to criticise
some of Mr. Berkeley’s views, the present general notice of
the work is not the place. Our estimate of his labours will be
found in our most cordial and earnest recommendation of it
to all who are engaged in the study of the lower forms of
plants. Every one who possesses a microscope, and wishes to
make his observations upon the innumerable forms of vege-
table organisms by which he is surrounded available for the
purposes of science, cannot do so more effectually than by
making himself master of the contents of this valuable intro-
duction to Cryptogamic Botany.
184:
NOTES AND CORRESPONDENCE.
On the Structure of Amphora, a genus of Diatomacesz, and the
Diagnosis of its Species—-When Linnzeus said that all objects
of natural history must have a specific name, he did not mean
a trivial name (which was not then invented), but what is called
a short, distinctive character, otherwise it is not imperative on
others to adopt the trivial name imposed, or recognise it in any
way. The want of short characters (intended to place clearly
before the mind the few essential points of difference between
supposed new and already known forms or species) cannot be
supplied by figures or diffuse descriptions of the entire object,
as these leave quite in the dark the precise marks of dis-
tinction observed by the writer, if such actually existed. In
composing either a defining character or a detailed descrip-
tion, it is also necessary to use the technical language of that
science. Recently, in referrmg to Dr. Gregory’s paper on
the Diatomacez of the Clyde, published in the last part of
the ‘Transactions of the Royal Society of Edinburgh,’ I
regretted that this patient observer had neglected these
rules, and thus enveloped his whole memoir in an almost
impenetrable cloud; thus not only precluding himself from
claiming any right of priority of names, in the event of
the same form being afterwards correctly characterised by
another under a different name, but depriving the paper
itself of its claims to be considered a scientific one. The
same unfortunate cloud renders it difficult to understand
what Dr. Gregory’s actual views of the structure of Am-
phora are; although, from expressions used by him, he
appears to enunciate the theory, that what other writers call
a simple frustule, ought to be considered as a double one.
To make this more intelligible to those not generally
interested in such pursuits, I would refer to the structure
of a diatom, as explained by Smith in his ‘Synopsis of
British Diatomacee ;’? and recommend the mode of proving,
by Canada balsam, whether the frustule is single or double.
When tested in this way, what is commonly called a simple
frustule is found to be actually so, and of one cell, so
that Dr. Gregory’s hypothesis is untenable. The struc-
ture of the genus Amphora appears to have been also
slightly misunderstood by Kutzing and Smith. The real
form of the frustule is not a spheroid, as they must have
considered it, but rather like that of a coffee-bean, rounded
at the back and hollowed out in front, the line connecting
MEMORANDA. 185
the two terminal and central nodules of each valve being the
median line; this line and the central nodule are thus not
marginal, as hitherto described, but exactly as in other
diatoms in which such are found. An Amphora would thus
chiefly differ, by the half of the valve on the one side of the
median line being concave, while the other was convex;
whereas, in most genera of the group the two halves of the
valve are precisely alike.
The form and structure of the frustule being established,
the parts capable of affording good distinctive marks for species
next require to be examined. All naturalists agree, that if these
are taken from variable parts, they must be of less importance
than if derived from those that are subject to little or no
variation; and that no observation can be relied on, of a
permanent kind, when taken from parts known to change
their appearance rapidly. Thus, the zone connecting the two
valves of a diatom, which, from being a mere line, is under-
stood to attain the whole breadth of the frustule in the course
of twenty-four hours, has been deservedly rejected; and
hence it is to be feared that few or none of Dr. Gregory’s
species of “Complex Amphore,’ which owe their peculiar
appearance to it, will stand the test of diagnostic characters.
As the striz, costz, or furrows, are the same on both sides of -
the median line, and as the valve is folded, those at the back
of the frustule must be seen through the medium of the sur-
face nearer the eye, and crossing those belonging to it, so that
observations on these relate entirely to the accidental position
the frustule happens to be in. This compels one to depend
chiefly for essential characters—Ist, on the small portion that
is seen between the median line and the apparent outline of
the frustule; and 2d, on the form of the frustule itself, pre-
vious to the siliceous connecting zone commencing the process
of self-division.
No certain conclusions can be drawn as to what is a new
form or species from deposits or dredgings, on account of the
impossibility of procuring the species in an isolated state, and
consequently of studying them independently; the same
species putting on very different aspects, and different species
assuming the same aspect at particular stages of self-division.
Some species of diatoms have both an habitual and an
accidental appearance. Thus the whole genus Pleurosigma is
- habitually sigmoid; but P. estuarii, P. strigosum, and some
others occasionally appear reversed or twisted, both extremi-
ties being on the same side of the median line; P. reversum,
fig. 105 of Dr. Gregory’s paper, will illustrate an accidental
state; the whole supposed new genus Toxonidea of Donkin
VOL, VI. If
186 MEMORANDA.
is formed of species of Plewrosigma in the same predicament.
On the otber hand, the entire genus Cyméella is habitually
reversed, although specimens may occur assuming accidentally
the appearance of a Pleurosigma. 'These accidental appear-
ances are sometimes caused by actual resupination, some-
times from preparing to form spores, and sometimes by a
mere change of position.
Microscopical differences are by themselves of little im-
portance. To see is one thing; to understand and combine
what we see, another : the eye must be subservient to the mind.
Every supposed new species requires to be separated from its
allies, and then subjected toa series of careful observations
and critical comparisons. To indicate many apparently new
species is the work of an hour, to establish only one on a sure
foundation is sometimes the labour of months or years. In
microscopical natural history as much scrutiny is required to
prove a new form to be distinct from its allies as in chemistry
to discover a new alkaloid, or in astronomy to demonstrate
the identity of two comets. A naturalist cannot be too
cautious. It is better to allow diatoms to remain in the
depths of the sea, or in their native pools, than, from imper-
fect materials, to elevate them to the rank of distinct species,
and encumber our catalogue with a load of new names so ill
defined, if defined at all, that others are unable to recognise
them; the same object can be more easily attamed by attach-
ing them, in the mean time, to some already recorded species,
with the specific character of which they sufficiently accord.
In all such cases the question to be solved for the advantage
of naturalists is not, whether the object noticed be a new
species, but whether it has been proved such, and clearly
characterised.—E. Watker-Arnort, Dowanhill, near Glas-
gow.
On the Structure of Rhabdonema and other Diatomaces
with compound frustules.—It is with much reluctance I take
up my pen to make the following remarks on this subject.
During the progress of the ‘ Synopsis of British Diatomacee,’
by the late Professor W. Smith, a frequent correspondence was
maintained between us, in which he constantly acknowledges
the value of my assistance in his investigations, and promised
to give me due credit for it in the work.
The difficulties attendant on a clear comprehension of the
structure of the frustule in the genera in question were con-
siderable ; like nearly all the Diatomacez they are too minute
for actual dissection, and whilst very opaque dry, the appear-
ances presented in this state, so far as they could be made out,
MEMORANDA. 187
did not altogether harmonise readily with those in balsam.
Professor Smith, in several letters to me (May to October,
1853), expressed his inability to form clear conceptions of
their structure, and begged me to pay particular attention to
them, and try if I could make it out when engraving them,
At one time, in the course of correspondence, he writes, ‘“ I
do not quite understand your views ;” at another, ‘I believe
you will prove eventually in the right.”
The subject occupied my thoughts much, and many an
hour of patient labour was spent in the examination of speci-
mens. 1 : : : : ue
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VOL. VI.
242
On Triceratium and some New Aiiep Forms, with figures.
of the same. By Surgeon G. C. Watticu, M. D., Bengal
Army. (Plates Xi, Si:
«Tir want of short characters,’ observes Professor Walker-
Arnott, “ (intended to place clearly before the mind the few
essential points of difference between supposed new and
already known forms or species) cannot be supplied by figures
or diffuse descriptions of the entire object, as these leave quite
in the dark the precise marks of distinction observed by the
writer, if such actually existed.”
Toa certain extent this remark is true. But in the present
state of our knowledge of that class of microscopic organisms
to which Professor Walker-Arnott refers, its application 1s
attended with so much difficulty, that, in the absence of
somewhat detailed description, or accurate figures, the task
of establishing clear views of special differences of structure
becomes well nigh hopeless. Theoretically, it may be a
matter of perfect simplicity to lay down definitions; and
rules may be offered whereby, in the ordinary researches of
natural history, such definitions shall be limited to a given
number of words. But great obstacles present themselves in
practice, where the microscope stands between the observer
and the object he is analysing. ‘To describe clearly and con-
cisely what is seen by the unaided vision, may be an easy
matter; but, in the case of organisms visible only under a
high magnifying power, and which demand an experienced
eye for their interpretation, the case becomes very different.
It is here that illustrations afford the greatest possible assist-
ance, and frequently accomplish in a moment what would
otherwise demand hours of anxious and tedious labour. Good
definitions are indispensable ; but, under every circumstance,
their value is much enhanced by well-executed figures.
We see this exemplified strikingly in the ‘Synopsis of
British Diatomaceze.’ Nothing can surpass the general con-
ciseness of the definitions there given; but few will, I pre-
sume, deny that a number of instances might readily be cited,
where those definitions would fail to convey the clear com-
prehension imparted by the masterly figures appended to
them.
There is another reason why accurate illustrations are of
the highest value. As the number of new forms increases, and
data are thus afforded for revising errors of classification,
WALLICH, ON TRICERATIUM. 243
those figures become landmarks, and th-ough them are
afforded the means of ready comparison and reclassification.
In no family, perhaps, is the remodelling of characters, and,
in this particular ease, even of generic nam2, more necessary
than in Triceratium. Recent additions to it clearly showing
that outline, the character upon which it was originally, and,
I may say, almost entirely, instituted by Ehrenberg, is not to
be relied on; and that mere form may vary to a very great
extent, whilst other characters, derived from important struc-
tural analogies, at once point out how little value is, in reality,
to be attached to it. Two of the species I am now about to
describe exhibit this circumstance in a remarkable degree;
the one a normally four-sided, the other a normally five- sided
form; but both, nevertheless, distinct Triceraiia.
The first of these, to which I propose giving the specific
name of 7’. serratum, was obtained by me at St. Helena,
along with numerous other new and highly interesting forms
of living Diatoms, in dredging at oon twenty to thirty
fathoms. Its characters are as follows
Frustule free, constituting a ped prism. Valves
quadrilateral, quadrangular—furnished with a_horn-like
process at each angle ; and from four to six elongated spines
furcate at their extremities. Connecting band composed of
four quadrangular plates, joined together “by regularly ‘ dove-
tailed”’ margins. These plates, in common with the valves
_themselves, “marked with a delicate but well-defined hexa-
gonal cellulation.
This form is remarkable chiefly for the very peculiar struc-
ture of its connecting membrane, which exhibits four distinct
plates, having their communicating margins serrated, so as
to fit into each other with accuracy. From this character the
name is borrowed. The notches, or serre, are rectangular.
Across each plate, during division, there is to be seen an
arcuate narrow band, along which the cellulation is inter-
rupted. ‘This band is expanded at its extremities. As divi-
sion advances, each plate may be observed to consist of fwo
layers, on the concave aspect of the arcuate band; which
recede from each other; the upper one exhibiting the nor-
mal cellulation ; whereas the lower (which is, in reality, a
continuation of the other half of this plate) presents only a
number of dots, the cellulation being imperfectly developed.
In a memoir by Mr. Brightwell, “of Norwich, to which I
shall again have occasion to refer, he mentions that the
siliceous plates, forming the connecting membrane of the
Triceratia generally, “are formed of several distinct layers
of silex, dividing like the thin divisions of talc.” These
244: WALLICH, ON TRICERATIUM.
layers, I believe, with all deference to so deservedly high an
authority, are, however, rarely more than two, and arise from
the plates, during the commencement of division, in the frus-
tules of this and many other genera, always consisting of two
pieces, which, at first, entirely overlap each other; but, as
the process advances, recede from each other, and whilst so
receding, appear like three distinct parallel annuli, the centre
being less diaphanous, and its markings more confused, in
consequence of its being, in reality, the overlapping and
double portion referred to. This appearance has led to much
uncertainty and doubt in descriptions of the connecting mem-
brane, inasmuch as, from its transparent structure, markings
when they exist in the lower plates, are seen through those
in the upper. In those genera in which the valves assume
at times a great relative depth, we find not only that the
connecting membrane is more largely developed, but that
the valves are furnished with a constricted rim, to which the
margin of the annular plate is attached, as if to afford a more
powerful point of resistance from whence it can extend itself.
In Amphitetras, and certain species of Triceratium and Bid-
dulphia, the existence of marginal rows of puncta on the
annulus, in close proximity to the markings on its surface
generally, proves that the growth of each plate of the con-
necting membrane takes place at the margin furthest off
from the valve to which it is attached. Were it not so, the
rows of marginal puncta would recede from the central mark-
ings, an effect opposed to what in reality occurs. Growth
thus takes place in both plates at once—the overlapping, to a
greater or lesser extent, being dependent on the rate at which
the new valves within happen to be developed. In the newly
separated frustule, one end may constantly be seen imbedded
in its own half of the connecting membrane, which, for a
time, remains attached to it. The same structure exists, I
believe, in nearly all the genera, although more readily discern-
ible in some than in others, from the greater facilities they
afford as regards size and figure. It may be thus seen in
Mimantidium, Odontidum, Denticula, Eunotia, Grammatophora,
Amphitetras, Biddulphia, Isthmia, Melosira, Coscinodiscus,
Hydrosera, &c. I may observe, in passing, that the figures
given in the ‘ Synopsis of British Diatomacee’ of Biddulphia,
Amphitetras, and Isthmia, show the general aspect of the
connecting membrane—but without any allusion, on the
part of the author, to the striking mode of development now
described.
The arcuate bands are always arranged in the same direc-
tion, that is, their concave or convex aspects always face
WALLICH, ON TRICERATIUM. 245
towards the same extremity of the frustule on all four sides.
Valve slightly convex on its surface; cornua well defined, and
projecting in both front and end views ; spines elongate, not
marginally disposed; valve deeply constricted between the
bases of the cornua and its free margin, which is everted ;
connecting membrane projecting boldly. Length -0094;
breadth ‘0063 ; diameter of each side of valve ‘0059 to ‘0070.
Cellulation 9 to 11 in ‘001. Taking the characters given
in the ‘ Synopsis’ as our guide, it would be more easy to recon-
cile this form with Amp/hitetras than with Triceratium, inas-
much as “the cubical outline,’ to quote the text, “ distin-
guishes it from all other forms.” - But in Amphitetras, the
frustules cohere into a zigzag filament ; the connecting mem-
brane is imperfectly annulate and indefinite; the cellules are
circular and inconspicuous at the angles of the valve.
Whereas in the St. Helena species, the frustules never form
a filament: the connecting membrane is definite and consists
of four distinct plates; the cells on both the valves and con-
necting bands are similarly marked with a conspicuous and
regular hexagonal cellulation ; and lastly there exist the well-
developed cornua and spines not seen in Amphitetras.
Again, viewed as a Triceratium, the chief distinguishing
type of that genus falls to the ground; for whilst the species
under notice occurs abundantly in the locality named, in no
instance has a three-sided frustule presented itself. There
must be some limit to type, and therefore when the character
fails, as it is here shown to do, upon which the individuality
of a genus in a great measure rests, the alternative remains
of either cancelling that character, or of separating the form
in which so constant an anomaly exists. In this instance it
must be borne in mind that the four-sided form is therefore
the typical one, and yet that analogies of structure clearly
indicate its position amongst the Triceratia.
The nearest approach to its characters, I find in the
‘Smithsonian Contributions, entitled ‘Notes of New Species
and Localities of Microscopic Organisms,’ by Professor
Bailey, of New York. A plate is there given of a frustule
of Triceratium setigerum which, on a cursory examination,
might be considered identical with the St. Helena Diatom.
But, in the first place, it is to be inferred that the connecting
band in that species offers no peculiarity, inasmuch as no
allusion is made to such ; and, in the next, the characters given
indicate its distinctness, the “bases,” as they are termed,
‘being triangular, bearing three large obtuse projections or
horns, at the base of each of which is placed a setiform
process.”
246 WALILICH, ON TRICURATIUM.
Professor Bailey states that this form is allied to 7. spino-
sum, which has been found in the fossil state in Virginia ;
but the same reasons that s separates the St. Helena species
from the Triceratia, of course apply equally to this.
In the valuable paper on Triceraiium contributed to the
‘Journal of Microscopical Science’ for July, 1856, by Mr.
Brightwell, three forms demand notice as being at first sight
allied to the one under discussion, namely, 7. sedigerum of
Bailey, T. orbiculatum of Mr. Shadbolt, and T. formosum of
Brightwell, the last being the 7. armatum of Mr. Roper.
Before noticing Mr. Brightwell’s characters, 1 would draw
your attention to a remark he makes on Professor Bailey
having referred a four-sided form of Triceratium to the genus
Amphitetr as, namely, that “the projection of a connecting
membrane beyond the suture of the valve, which is one of
the characters of Amphitetras, is not seen in these square
forms.” A remark, if strictly accurate, at once fatal to any
alliance between the St. Helena Diatom and those four-sided
varieties, referred by Mr. Brightwell and others to the three-
sided typical form.
In a former paper on the same genus, in the ‘ Journal’ for
July, 1853, Mr. Brightwell gives figures of three-, four-, and
five-sided varieties of 7. striolatum, a name he alters in the
recently published memoir into 7. formosum, already alluded
to. Now in none of these does the connecting membrane
project in the slightest degree. The colour of the frustule is
moreover pale brown, indicative of very minute cellular struc-
ture, whilst the horns are simple projections, and no spines
exist on the surface of the valves; and lastly it is very much
smaller than 7”. serratum.
Amongst Mr. Brightwell’s species, 7. armatum comes
nearer to the St. Helena form than any of the others. Mr.
Roper, to whom we are indebted for a description of this
species, thus characterises it in the ‘ Microscopical Journal’
for July, 1854:
“ Frustules large, with straight or slightly convex sides.
Angles produced into horn-like processes, with rounded ex-
tremities ; cellular structure minute, partially radiating to-
wards the sides and angles; six or more spurious processes
projecting from the surface of the valve.” Mr. Roper’s
specimens are described as approaching closely to 7. tri-
daciylon, of Ehrenberg, a form also figured by Mr. Brightwell.
But he states that 7. armatwn is deficient in the siliceous
plate that is shown to exist around the sides of T. tridactylon.
Mr. Roper thinks his specimens are not identical with Pro-
fessor Bailey’s T. spinosum, whereas the spines are shown,
WALLICH, ON TRICERATIUM. 247
both in Mr. Roper’s and Mr. Brightwell’s figures, to be sub-
marginal.
Mr. Brightwell again figures several varieties of 7. armatum.
The first being the only one that in the least resembles the
St. Helena form. But his figure is represented as being the
front view of that described by Mr. Roper, which has already
been shown to be distinct, and is clearly proved to be so,
from the other figure given of a front view of a four-sided
specimen, in which the cells are circular; the connecting
membrane is marked as in Amphitetras, and its margin ex-
hibits a bold fimbriated border.
The next form to which I shall refer is a very large and
beautiful Triceratium, obtained by dredging at St. Helena, in
form thirty-five to forty fathoms, and to which I propose to
give the specific name of T. fimbriatum.
Its characters are as follows :
Frustule three-, rarely four-sided; sides convex; angles
furnished with short cornua; cells large, hexagonal; mar-
ginal border between horns furnished with a series of two-
lobed flabelliform and pedunculated fimbriz; connecting
membrane marked with diamond-shaped striation.
The circlet of remarkable fimbrize at once serves to distin-
guish this species. These arise from the outer edge of the
marginal row of cells, by delicate pedicles, which immediately
expand into broad filabelliform discs, having their flat
surfaces parallel to the margin of the valve, and divided
down their centre by a deep notch. These fimbriz are very
similar in outline to the architectural decoration called “ Greek
tiles,’ which are small separate mouldings, placed at intervals
on the cornice of a building, along the side of the roof, and
serve to conceal the ridge formed by the overlapping of the
roof tiles. In some frustules there exist also, at each angle
of each hexagonal cell, minute dot-like processes (recently
figured by Mr. Roper as existing in Hupodiscus tesselatus),
which, seen in profile when a portion of the valve is broken
up, prove to be minute discs of similar character to the fimbriz
just alluded to.
This species has, however, another peculiarity which would
render the specific name of favus especially applicable, had
it not been already assigned to the typical species, to denote
the similarity, in superficial aspect only, of the hexagonal
markings to the honey-comb. Each hexagon in the St.
Helen form being, not merely a simple depression dependent
on the mode in which the siliceous element is secreted by the
inner cell-membrane on its own surface, but a deep hollow
cell, with perpendicular sides, of sufficient depth to be
248 WALLICH, ON TRICERATIUM.
readily measured, when seen in fragment and in profile; and
which, a priori, indicates the presence throughout each cell of
the membranous structure from which it is thus deposited.
The floor of these cells is also minutely punctate, the puncta
being arranged in quincunx.* The minute puncta only re-
quire careful illumination and a power of 400 diameters to
render them quite distinct. At first sight the double out-
line visible in the hexagonal cells, as seen in certain positions,
might be considered as due to refraction. But, on obtaining
a fragment in an oblique position, the perspective view of
the receding cells leaves no doubt of their true character. I
would observe that similar cellulation appears to me to exist
in other discoid forms, although too minute to be as readily
interpreted.
On a side view of the valve, below the outer series of cells,
a single row of small rectangular markings is observable.
The valve is slightly constricted around the margin. The
horn-like processes are directed upwards, as in 7. favus, but
do not project beyond the angles. The constant character of
the outline of the valves in this species is remarkable, imas-
much as it answers to the figure formed by describing an arc of
a circle, with a radius equal to the magnified diameter of one
side of the valve; taking off, on that are, the same radius,
and describing a second and like are; and, lastly, making the
point of intersection thus obtained the centre wherefrom to
complete, with still the same radius, the third arc, or side of
the figure required.
The measurements are—
Diameter of each side of valve, from ‘0047 to ‘0175; dia-
meter of each cell ‘00034; cells 3$in°001; depth of hexagonal-
cell-walls -00026; length of fimbriz :00046; breadth the
same ; striation on connecting band 48 in ‘001.
Although, m general character, this species is no doubt
closely allied to 7. favus, the remarkable cell-structure and
fimbriated border sufficiently distinguishes it.
Mr. Brightwell, in the ‘ Journal of Microscopical Science’
for July, 1853, p. 249, describes a new species by the name
of T. grande and to this a figure is appended which, in the
end view, is very similar to T. fimbriatum. But T. grande
has no border, whereas 7. comptum, also described and
* This basal plate, when the valve is fractured, presents a remarkable
and somewhat obscure feature, inasmuch as its line of fracture does not
always correspond with that of the valve generally, and would thus appear
in some measure distinct—a fact which I cannot help thinking has led to
such lower plate in some of the discoid forms being looked upon as distinct
species,
WALLICH, ON TRICERATIUM. 249
figured in the same place, under the sub-tribe with “angles
spinose,” is much smaller, has nearly straight sides, but ex-
hibits “a projecting fringe, stated to consist of oval depres-
sions.’ Specimens of T. comptum in my possession, obtained
from Californian guano, clearly correspond with Mr. Bright-
well’s, and corroborate the distinctions from T. fimbriatum.
Mr. Roper, in the Journal of the Society for July, 1854,
p- 283, gives a figure also of T. comptum,'Ehr., which he
states as having “a row of cells projecting above the margin
of the valve ; sides straight or slightly convex, the horn-like
processes short and obtuse; and cellular structure large.”
But although Mr. Roper is doubtful whether his specimen
may not be a young form of 7. favus, he leans to the opinion
that the length of the angular processes and fringe-lke row
of cells appear to give it a distinctive character.
The next form is from brackish water in the Delta of the
Ganges, and is undoubtedly new. I propose to call it 7. an-
nulatum. The characters are—Valve minute, triangular ;
angles slightly produced, rounded; sides shghtly concave ;
tri-radiate, and having its surface covered with minute
puncta; the more close aggregation of which, in concentric
rings around the common centre, gives the valve an un-
dulated appearance.
The rays are thickenings of the siliceous epiderm which
pass from the centre of the valve outwards in the direction
of each angle, gradually becoming fainter as they approach
the latter. In lke manner the puncta are more numerous
and are more closely aggregated as they approach the central
portion; whilst, at the extreme angles, the markings are
almost entirely wanting.
Diameter of each side -002.
The next species, which I propose to call T. pentacrinus,
although normally a five-sided form, is also distinctly refera-
ble to that genus. It was obtained off St. Helena, in thirty
fathoms water, in a living condition. The characters are
as follows :
Frustule free, constitutmg a pentangular prism; valves
somewhat convex, pentangular, each side deeply convex ; with
short stout cornua at each angle. Surface spinous; divided
into compartments, by interrupted bands, which radiate
irregularly from the centre, and inosculate laterally with
each other. Cellular structure minute, consisting of circular
dots. Connecting membrane annulate, indefinite, marked
with dots arranged in quincunx, and which become more
minute as they advance from the margin towards the median
line of the annulus, and are partially interrupted at the
250 WALLICH, ON TRICERATIUM.
angles. Around the margin a row of oblong cells, placed
side by side.
The peculiar ribbed character here seen is conformable to
that shown, in a modified degree, in several already described
species. For instance, in the J uly number of the Society’s
Journal for 1856, Mr. Brightwell characterises and figures
no less than nine forms, all of which present the ribbed
structure more or less. ‘To these markings, in some of the
forms, Mr. Brightwell applies the term of “ canaliculi’? In
the form under notice now, the ribs are, however, simple
thickenings of the siliceous epiderm, which are neither
tubular, nor dip down at all into the cavity of the frustule,
so as to form pseudo-septa. The puncta are arranged im rows
following the radiate direction of the ribbed partitions
referred to. The horn-like processes appearmg more like
inflated prolongations of the angles of the valve, the apices
being minute and capitate. Valve constricted deeply between
the bases of the horns and its margin. Spines numerous,
irregularly placed, short and furcate. Connecting membrane
projecting boldly, hyaline, with the undulating outline given
by the form of valve, and its concave margins Anflecteds
Diameter of frustule -0023; depth about -0020.
T have met both with four- and six- angled varieties of this
species; but these are rare. ‘The first is not unlike that
figured by Mr. Shadbolt in the Society’s Journal for October,
1853, p- 17; but as the front view is not given, it is
difficult. to say positively whether the two are identical.
Mr. Shadbolt describes his species as ‘‘ having the margins of
the valves considerably hollowed out or emarginate, and
folded over so that each valve is not unlike in form to a
collegian’s cap. The surface being elegantly but somewhat
irregularly ornamented with delicate markings.”
Two remarkable Diatoms remain to be described in this
paper, the characters of which, I believe, are essentially new.
For although, at first sight, one of the species appears allied
to the filamentous T7riceratia, its marked identity in structural
peculiarities with the second, which is obviously distinct,
leaves no reasonable doubt on the subject.
Again, the second form, under a cursory examination,
might be referred to Biddulphia, but its ‘unquestionable
affinity, as I apprehend, to the first, would, with equal force,
separate it from that genus. In both cases another and ver y
conclusive example being afforded of the small real value
that attaches to definitions based on mere outline.
The species to which I allude were obtained by me from
the Gangetic Sunderbunds, in brackish water, well within
WALLICH, ON TRICERATIUM. 251
influence of the tides; and were found growing attached as
a soft mossy stratum upon submerged Alew or tree stems.
Been the beautiful jointed-looking filaments, I have desig-
nated the eee by the name of Hi ydrosera. The characters
are as follows
Frustules attached, forming elongated direct filaments.
Frustules either triangular prisms or compressed cylinders,
attached to each other at each angle by a mucous cushion.
Valve cellular, furnished with perfect septa; and, on one side
only, with a remarkable series of aperture-like appendages.
Connecting membrane quite plain; hyaline.
Although the association of the triangular with the com-
pressed form may, at first sight, appear untenable, the
other characters common to both, and more especially the
remarkable processes observable on one side only of each
valve, appear conclusively to establish the fact of their ranking
under the same genus. The two species I have named
respectively H. triquetra and H. compressa.
The specifie characters of the first are as follows: Frustule
athree-sided prism, having a portion of each angle partitioned
off by a septate process, which is partly given off from the
inner wall of the valve itself, and partly, as in Rhabdonema
‘and Mastogloia, from the connecting membrane. Valve
triangular, sides undulated, surface reticulated. Angles
rounde d, obtuse, and smooth, but furnished with two or three
stout minute spines. On one side only of each valve, at the
central portion of its outer margin, from two to five minute
punctate appendages exist. Connecting membrane compound,
its outer annulus exhibiting a continuation of the valvular
septa, plain, annulate and undulate. Front view of frustule
a parallelogram, rather longer than broad when not under-
going division. F.V. length, from ‘0017 to ‘0050 Breadth,
the same. KE.V. diamicter: the same. Cellulation from
Sto Ldn 001..
The punctate appendages are visible also in F.V. on both
valves on same side of the frustule; and in the filament, on
the same side throughout. Around them the siliceous
epidermis thickened. Free ends of the septa of valve
hollowed out, the cusps resting on imperfect septate pro-
cesses given off from the connecting membrane. The outer
margin of the latter much thickened, and giving to the
F.V. the appearance of a siliceous hcop encircling the margin
of each valve. Connecting membrane, of two plates or hoops,
during division, as mentioned in Tuceratium. The spines at
the angles very minute, and requiring careful illumination,
with a power of from 300 to 400 diameters, to bring them
252 WALLICH, ON TRICERATIUM.
out clearly. They are probably of use in strengthening the -
mucous cushion whereby the angles are held together; the
filaments being remarkably tenacious. Frequently composed
of from thirty to forty frustules.
The frustules vary greatly in size, but never in general
contour, although the sides are at times more inflated than
at others. The side exhibiting the punctate processes being
generally the most convex. In lke manner the angles are
sometimes acute, sometimes subacute; an angular bend
existing in the end view, where the septa coalesce with the
margin. Cellular structure thickest at centre of valve, and
varying to a limited extent in coarseness, although always
large and easily seen in this species. Under a power of 200
diameters, the marking seems minutely cellular; but ampli-
fied to 400 diameters, it is shown to consist of a number of
large reticulated polygonal spaces, having a tendency to the
hexagonal character, and divided by narrow lines or ribs,
which coalesce with each other. Entire frustule perfectly
siliceous. Endochrome equally distributed, granular, and of a
pale but rich green.
In H. compressa the characters are :
Frustule, a compressed cylinder, forming lengthened fila-
ments, as in H. ¢triguetra. Valve elliptical, sides undulated.
Angles subacute. Valve in E.V. divided into three compart-
ments by two septa thrown across it. Angles smooth and
occasionally exhibiting two or three very minute spines, as in
the former species. ‘The punctate appendages on one side
only. Connecting band plain, annulate, undulate, imdefi-
nite. F.V. as in H. triqueira, a parallelogram, with subacute
angles.
In the front view the three compartments are inflated ; the
central one being the largest. Ends full, rounded, and hyaline,
with no trace of cellulation.
F.V. Length of frustule, ‘0017 to 0048; breadth, :0017
to ‘0048. §.V. length, from ‘0017 to :0048; breadth, -0006
to ‘0014. E.V. length, from -0017 to ‘0048. Breadth of
central compartment, ‘0017 to ‘0084. Breadth of terminal
compartment, ‘00086 to ‘0014. ;
It is difficult to suggest, with any approach to certainty,
the purposes subserved by the unsymmetrically placed lateral
processes alluded to. But, in all probability, they are ana-
logues of the central and terminal nodules of other diatoms.
On a future occasion, I hope to offer some remarks on the
peculiarity they present, and to poimt out more particularly
their resemblance to the unsymmetrically placed puncta in
Gomphonema geminatum, and in two new Indian species of
WALLICH, ON TRICERATIUM. 253
Cocconema and Gomphonema, which are, in like manner
distinguished by these remarkable appendages.
The only genera with which Hydrosera can at all be con-
founded, are—Terpsinoé of Ehrenberg, Anaulus of the same
author, and Tetragramma of Professor Bailey ; the last being
in reality, however, nothing more than a variety of Terpsinoé
musica, and therefore not demanding further notice.
In Terpsinoé the frustules are described as “ tabular and
obsoletely stipitate,’ a character which might apply to
H. compressa, but which at once fails in H. triquetra. The
filaments, however, assume a “ zig zag”’ form, and the cellular
structure is “ very minutely punctate,’ with no appearance of
reticulation.
I admit that it was a question resting chiefly on how far
H. triquetra can be safely separated from [7. compressa, that
induced one to remove the latter species from Terpsinoé, to
which it bears a strong resemblance in its “tabular” or
rather compressed form, but from which it differs materially
in the presence of the lateral appendages, the spinous angles,
and the direct nature of its filament.
In Lithodesmium the valves are described as triangular, but
they are distinguished from those of the present genus by
their “extreme smoothness,” transparency, and their not
being cellulate. Two sides only beimg symmetrical and
“ undulated,” whilst the third “is doubly excised or notched.”
Lastly, in Anaulus “the frustules never form a filament, but
are single, and neither furnished with tubular processes,
nodules or apertures.* The separation of Hydrosera is how-
ever completed, I submit, by the presence of the very re-
markable appendages I have described, and which afford a
character so very distinct from what is to be seen in any
other alluded genera.
* Vide ‘Micrographic Dictionary,’ and Kiitzing, “Species Algar.”
254
REVIEWS.
Clinical Lectures on the Principles and Practice of Medicine.
By Joun Hucues Bennert, M.D., F.R.S.E. Edinburgh:
Adami aiid Charles Black.
A.tHovcH this is a second edition of a work well known,
and its main purpose beyond the sphere of our criticism, we
think it right to bring it before the notice of our readers,
because it contains a large amount of matter bearing directly
on microscopic research. Dr. Bennett is one of those teachers
of medicine, who has, from an early period of his career,
recognised the importance of conducting pathological re-
searches by the aid of the microscope, “and in this work
abundant evidence is afforded of the value and necessity of
this instrument to the practitioner of medicine. In an early
number of this Journal (volume I, page 223), we reviewed Dr.
Bennett’s ‘ Introduction to Clinical Medicine, and recom-
mended it to the notice of our medical readers, as conveying a
just estimate of the value of the microscope in pathological re-
search. In the present work the practieal application of this
instrument to the various forms of disease in which it may be
employed is fully brought out. In fact, with regard to a large
number of the forms of disease no true theory of their
nature can be formed independent of an investigation by the
aid of the microscope. It is in the section devoted to the
principles of medicine that Dr. Bennett handles the facts
supplied by microscopic research in the most masterly
manner. This section should be studied by all those who
are anxious to understand the intimate causes engaged in the
production of disease, and what are the changes which are
necessary to the establishment of health. We should not
pretend, even had we space here, to criticise Dr. Bennett’s
theoretical or practical conclusions from the observations he
records, but we draw attention to them, as showing the com-
parative valuelessness of any observations or deductions on the
intimate nature of organic disease without microscopic in-
vestigation.
We select two passages from this section of the work on
exudation and degeneration, not on account of any novelty
they present, but as illustrations of the manner in which the
subject of pathology is treated.
“Tubercular exudation has been spoken of as presenting a miliary infil-
BENNETT'S CLINICAL LECTURES. 255
trated or encysted form; but these distinctions have no reference to struc-
ture, but merely to the extent and age of the exudation. It generally
presents a yellowish or dirty-white colour, and varies in consistence from a
substance resembling tough cheese to that of cream. Sometimes it is soft
at one place, and indurated at another. On section, when tough, it pre-
sents a smooth or waxy, and when soft, a slightly granular surface. On
pressure if is friable, and may break down into a pulpy matter, but never
yields a milky juice.
* A small portion squeezed between glasses, and examined under the
inicroscope, presents a number of irregular shaped bodies approaching a
round, oval, or triangular form, varying in their longest diameters from the
1-2000th to 1-1200th of an inch. These bodies contain from one to seven
granules, are unaffected by water, but rendered very transparent by acetic
acid. ‘They are what have been called tubercular corpuscles. Tiey are
always mingled with a multitude of molecules and granules, which are more
numerous as the tubercle is more soft. Occasionally, when softened tu-
bercle resembles pus, constituting scrofulous purulent matter, we find the
corpuscles more rounded, avd approaching the character of pus-cells. They
do not always, however, on the addition of acetic acid, exhibit the peculiar
granular nuclei of these bodies.
“The gray granulations described by Bayle may be seen on careful ma-
nagemnent of the light, after the addition of acetic acid, to contain similar
bodies to those described as tubercle corpuscles, closely aggregated toge-
ther, with their edges indistinct, and containing few granules.
“Cretaceous and calcareous tubercles, on the other hand, contain very
few of these bodies, their substance being principally made up of numerous
irregular masses of phosphate of lime, and a greater or less number of
erystals of cholestrine.
“Tubercle corpuscles may be associated with pus and granular cells, as
well as those peculiar to glandular organs or mucous surfaces in various
stages of fatty transformation and disintegration. With all these they
have frequently been confounded.” (pp. 1438, 144.)
Futly Degeneration of Muscle.—“There can be no doubt that the fibro-
albuminous substance constituting flesh is capable of undergoing a trans-
formation into fat. Of the exact chemical nature of that transformation
we have yet to be informed; but it may not only be observed in the dead
body, but may be produced artificially, by exposing muscle to a running
stream of water, whereby it is changed into adipocere. In voluntary muscle,
we observe that the degeneration commences with diminished distinctness
of the transverse strie, especially at the circumference of the fasciculus.
As this extends inwards, minute molecules of fat occupy the position of the
stri, and at length obliterate them; gradually these coalesce, globules of
various sizes are formed within the sarcolemma, and the normal structure of
voluntary muscle disappears. During the early changes the fasciculus be-
comes soft, exhibits a tendency to crack crossways, and ultimately is so
pulpy as to be capable of being squeezed easily into an amorphous mass,
from which large oil-drops exude. To the naked eye, the muscular sub-
stance becomes paler, and more and more fawn-coloured, and at length
yel.ow, whilst its normal density is greatly diminished. These changes are
easily observed in the heart, in which organ they have been made the sub-
ject of special research by Ormerod, Paget, Quain, and others. The histo-
logical and clinical researches of Dr. Quain on this subject are of the
greatest importance.
* Allthe voluntary muscles, however, are susceptible of undergoing a si ni-
lar lesion, and it may be not unfrequently seen in those of the lower ex-
tremity after long-continued paralysis, disease of the hip-joint, or other
256 BEALE, ON URINE, ETC.
lesions which necessitate immobility of the parts. In this case, and occa-
sionally in the heart itself, in addition to the transformation of the muscular
fasciculi above described, adipose tissue accumulates between them, and by
compressing their substance adds to the rapidity and completeness of the
transformation. In such cases the muscles are of a pale yellow colour,
yielding on section large quantities of oil, while they preserve their usual
form and fibrous look. J have seen all the muscles of the lower extremities
so affected. Occasionally, while some muscles exhibit this transformation
in its last stage, others close beside them present their normal red colour,
so that the limb on dissection resembles the alternate red and fatty streaks
of bacon. In this case the degenerated muscle has the whole of its fasci-
culi transformed into adipose cells, with nuclei.
“Tn involuntary muscles fatty degeneration may also be observed, al-
though it is by no means so common as in voluntary ones. In this case,
oily molecules are deposited in the elongated fusiform cells of which the
texture is composed, which by their pressure on the nucleus cause its disap-
pearance. Whether the distended pregnant uterus shrinks to its normal
proportions after delivery wholly in consequence of such a degeneration
(Heschl) is a point not yet determined in pathology. But there can be no
doubt that many of the greatly enlarged fusiform cells of the organ, do be-
come more or less crowded with fatty granules.” (pp. 226-228.)
In his preface, Dr. Bennett states that he has “been long
persuaded that mere description of morbid appearances, and
especially of those that are made visible by means of the
microscope, communicate only feeble or imperfect ideas to
others.” He has accordingly abundantly illustrated his work
with wood-engravings, of which there are nearly five hundred
in the volume, mostly devoted to microscopic appearances.
This work will, we are sure, greatly enhance the reputation
of Dr. Bennett as a practical pathologist, and find its way to
the study of every scientific practitioner of medicine.
Illustrations of the Constituents of Urine, Urinary Deposits, and
Calculi. By Lionet 8S. Beatz, M.B., F.R.S. London:
Churchill.
Tue object of Dr. Beale in preparing these illustrations
has been to place in the hands of medical students and prac-
titioners of medicine, at a moderate price, a series of correct
representations of the various deposits found in healthy and
morbid urine, as well as of salts held in solution, or formed
by chemical re-agents in this secretion. The work contains
thirty-seven plates, with upwards of one hundred and seventy
figures and accompanying letter-press, and seems well
adapted to secure the object Dr. Beale had in view in its
publication. It embraces almost all possible forms of objects
that could be presented to the student in connexion with the
urine. It is also accompanied by a frontispiece and wood-
cut, illustrating the anatomy of the kidney,
PROCEEDINGS OF SOCIETIES.
MicroscoricaL Society, April 21st, 1858.
Dr. Lanxesrer, President, in the chair.
General Alexander, Henry Carr, Esq., and Dr. G. Walker
were balloted for, and duly elected members of the Society.
The following papers were read :
“On some Diatomaceze found in Noctiluca miliaris, with
the best means of obtaining them,’ by Colonel H. H. C.
Baddeley.
“ Note on Campylodiscus Hodgsonii,” by Dr. G. A. Walker-
Arnott.
“ Account of Microscopical Observations and Collections
made during a residence in India, and the voyage home,” by
Dr. Wallich, illustrated by a large collection of drawings and
objects.
May 19th, 1858.
Grorcr Jackson, Esq., in the chair.
Dr. Wallich, W. T. Rickard, Esq., Rev. R. S. Bower, and
Dr. F. Bossy were balloted for, and duly elected members of
the Society.
Mr. Roper read a paper “On the Genus Biddulphia and
its Affinities.”
June 16th, 1858.
Dr. Lanxester, President, in the chair.
Thomas Leonard, Esq., and John Smith, Esq., were bal-
loted for, and duly elected members of the Society.
H. W. Lobb, Esq., read a paper “ On the connecting link
between the Animal and Vegetable Kingdoms.”
Papers by W. Hislop, Esq., “ On anew Secondary Stage;’’
and by Captain Mortimer Slater, ‘‘ On certain new forms
of Butterfiy Scales from India,” were read.
The President made some remarks on the occurrence of
VOL. Vi: U
258 PROCEEDINGS OF SOCIETIES.
Protococcus pluvialis in large numbers in a pond near
Harleston, Norfolk, and exhibited specimens.
A paper by Fitzmaurice Okeden, Esq., “On the Diato-
mace of the South of Wales,” was read, illustrated by 214
mounted specimens of Diatomaceze, which were presented to
the Society. The special thanks of the Society were returned
to Mr. Okeden for his valuable present.
The meetings of the Society were then adjourned until
October next. :
Some difficulties having occurred in the practical applica-
tion of Whitworth’s gauges recently recommended by the
Society for the purpose of establishing an uniform screw for
object-glasses, it was resolved, at the meeting of the Society on
May 19, that ‘“'Two dozen steel taps be made for the use of
makers of microscopes, wishing to adopt the universal attach-
ment for object-glasses recommended by the Society.”
If one of these taps be made to. enter the body of the
microscope, it will receive any object-glass having a screw of
the dimensions recommended, and the cylindrical gauges will
not be required.
The set of taps is in course of construction, and may in a
few days be obtained of Mr. Williams, the Assistant-Se-
cretary to the Astronomical Society, Somerset House, at the
price of 5s. each.
Dusiin Naturat History Socrety, May 7th, 1858.
The President in the chair.
The Rev. Eugene O’Meara read the following paper, “ On
the occurrence of Anthozoids in Pleurosigma Spencerii.”
“On Friday evening, April 30th, I was engaged in the
examination of a gathering I had made two days previous
from a running stream. On looking into the microscope I
was much struck with the peculiar appearance of one of the
forms that first presented itself in the field, a Plewrosigma
Spencerii. The usual colour of the endochrome in this
species is pale brown, but in the present instance it was a
beautiful green. A number of granules of a bluish-green
colour were distributed through the cell. In a few minutes
I observed that the greater portion of the granules, at least
PROCEEDINGS OF SOCIETIES. 259
two thirds, moved with a sudden jerk to the lower part of
the cell. Some of the granules passed out of the valve, and
immediately after an anthozoid issued from the cell. Shortly
after another made its appearance, and another, until six or
eight had been extruded. All these organisms proceeded in
the same manner from the valve, and exhibited themselves in
the same spot, within, what appeared under a quarter-inch
objective with No. 2 eye-piece, about one sixteenth of an inch
from the extremity of the valve. In form the anthozoids, if
at rest, would have presented very much the appearance of a
spike of thistle-down. The head was of a pale-green colour,
and round it the tail was lashed from side to side with great
activity. On the same occasion several forms were observed
presenting similar appearances, with anthozoids moving
rapidly about in their immediate neighbourhood. Among
these were two or three of the species named Cymatopleura
Solea, but in no case, except the one just alluded to, did I
observe them issuing from the valve. On the evening fol-
lowing that in which the preceding observation was made, I
examined a drop from the same gathering, when a great
change was noticed to have taken place in the appearance of
such Diatomaceous forms as occurred, compared with that
which they presented the evening before. But few granules
were seen. The endochrome also had changed its colour
from green to olive, and instead of being diffused through the
cell, was, in many instances, collected to a narrow band along
each side of the cell, or at the opposite ends of it. In some
cases these bands had broken up into isolated portions, and
in others the valve was as free from endochrome as if it had
been treated with acid.”
The President dwelt on the necessity for repeating this
observation, and suggested whether these were anthozoids
or spermatozoids. In either case the observation was per-
fectly new, aud would therefore most probably be disputed ;
and therefore there was the greater necessity for repeating,
and, if possible, confirming the observation, and the more
glory should this discovery be confirmed.—Dudlin Paper.
260
ZOOPHYTOLOGY.
Notes on two New Britisu Potyzoa.
By Frep. D. Dyster, F.1.5.
Sub-class. P. GyYMNOLAMATA.
Order. CHEILOSTOMATA.
1. Fam. Bicrttariap#&, Busk (‘ B. M. C.,’ Part I, p. 41).
1. Gen. Huzleya, nov. gen., mihi.
Polyzoary flexible, corneous or sub-calcareous. Cells biserial, pyriform,
alternate. Aperture sinall, sub-terminal, unarmed. No avicularia or
vibracula.
1. Sp. #. fragilis, n. sp. Pl. XXI, figs. 1, 2. Sp. unica.
Hab. Tenby, Dyster.
The polyzoary, in this species, is from half an inch to one
inch high, flexible, and white. The cells wider and rounded
above, attenuated below; the upper portion of one being
closely appressed to the slender lower part of the cell above.
The dichotomous branches usually spring from the upper
and back part of a cell, and occasionally, though rarely,
from the middle or side. The aperture is small, rounded or
semicircular above, and straight below. The margin is
wholly unarmed, and not thickened. No vibracular or avi-
cularian organs exist in any part. The ovicells have not
been observed. The polypide i is ten-armed. 'The species was
first noticed by me in a marine aquarium.
2. Fam. Scrupariap®, Busk (‘ B. M. C.,’ Part I, p. 28).
2. Gen. Brettia, nov. geu., mihi.
Polyzoary erect, free, corneous, flexible. Branches given off behind and
above the aperture of a cell.
2. Sp. B. pellucida, n. sp. Pl. XXI, figs. 3—5.
Hab. Tenby, Mrs. Brett ; Dyster.
The polyzoary, about half an inch high, is perfectly trans-
parent ; the cells are much elongated, fistular, with an oval
aperture, rounded above, pointed below, and furnished with
from five to nie marginal spines, irregularly placed. The
polypide has ten arms; and the ovicells haye not been ob-
served. This species was also first noticed in a marine aqua-
rium by Mrs. Brett.
It is singular that neither of the foregoing forms should
ZOOPHYTOLOGY. 261
have been detected in their natural habitat. The Huzleya
grew in a tank of my own filled, of course, with water from
the Bay, which had not been changed for many months. The
other beautiful Polyzoan was found by my friend Mrs. Brett,
in a tank devoted to Actinie, but of which the water was
changed pretty frequently.
I had long observed the presence of the Huxleya in my
tank, but fully believing it to be Eucratea chelata, had never
taken the trouble to examine it, and, unfortunately, when I
did so, the polypides were dead, and nearly decomposed.
They appear to communicate very freely with the general
sarcode of the polyzoary, as much so as in Laomedea and
other hydroid Polypes. The retractor muscles are very long.
The nearest form to Huxleya would probably be Halophila,
Gray (‘B. M. Cat.,’ p. 43, pl. xxx).
In the case of Bretiia, its discoverer laid it aside after
gathering it, and it was not examined till after death; but
there is no reason to suppose that there is anything dis-
tinctive about the polypide.
On some MAavEIRAN Potyzoa.
Collected by J. Yates Jonnson, Esq.
(Continued from No. XXII, p. 129.)
We here give figures and descriptions of some species of
Madeiran Polyzoa, additional to those contained in a former
part of the Journal.
]. Fam. BriceLtiartap#, Busk.
1. Gen. Bugula, Oken.
1. B. ditrupe, n. sp., Busk. Pl. XX, figs. 7, S.
Cells biserial, elongate, fusiform. Aperture wide, elongated, with two
or three marginal spines on the outer and one on the inner side of the
aperture above. Avicularia capitate, attached to the side of the cell below
the middle.
Hab. Madeira, Johnson. On the shell of Ditrupa acuminata.
The present species is distinguished from B. flabellata by
the biserial arrangement of the cells, and from B. dentata
by their elongated and fusiform shape. Independently, how-
ever, of these characters, the general habit and very peculiar
site of growth of B. ditrupe, formeriy noticed, would alone
suffice to indicate its specific independence.
262 ZOOPHYTOLOGY.
2. Fam. Mrmpraniponip&, Busk.
2. Gen. Membranipora, Blainville.
1. M. antiqua, n. sp., Busk. Pl. XX, figs. 1, 2.
Area of cell pyriform, irregular, arched above, and either pointed or
truncate below. Aperture sub-trifoliate, or somewhat contracted on the
sides below the middle. Septa simple, not grooved. Numerous vibracular
cells irregularly scattered throughout the polyzoary among the others, of an
eusiform or falciform figure.
Hab. Madeira, Johnson (on shell).
A considerable number of fossil species of Membranipora,
ard several of Hschara, are characterised by the presence in
various points of the polyzoary of cells differmg in form and
size from the common polypide-cells. From analogy with
similar cells in several species of Lunulites, which are known
to be vibracular organs, there is little or no doubt that the
cells in question in the Membranipore and Eschare are of
the same kind. And this supposition is further confirmed
bythe circumstance, that in MW. stenostoma, Busk (‘ B. M. Cat.,’
p- 60, pl. c, fig. 1), avicularian cells are present, similarly
disposed with relation to the polypide-cells.
This peculiar character in the present species, by which it
is distinguished from all other recent Membranipore with
which I am acquainted, with the single exception above no-
ticed, renders it a form of particular interest, when compared
with many fossil species, occurring as it would seem in the
Cretaceous formation. Instances of these will be found in
the ‘Paléontologie Frangaise’ of M. D’Orbigny, and more
especially in the forms described and figured as—
Cellepora Xiphia, p\.dcexiii, figs. 3, 4.
ee Xanthe, ib., figs. 5—7.
A Michaudiana, pl. decxii, figs. 3, 4.
= Xelimia, ib., figs. 15, 16.
3 Parisiensis, ib., figs. 13, 14.
Semieschara simplex, pl. decix, figs. 1—4.
55 excavata, dccx, figs. 6—9.
As well as in Hagenow’s ‘ Bryozoen der Maastrichter
Kreidebildung,’ in the forms denominated—
Cellepora Koninckiana, pl. xi, fig. 10,
, depressa, ib., fig. 13,
3 camerata, ib., fig. 9,
and others.
3. Gen. Lepralia, Johnston.
1. L. sceletos,n. sp. Busk. Pl. XX, fig. 3.
Outline of cell oval; anterior wall constituted of rib-like spines, six or
seven on each side, which meet and interdigitate on the median line. An
ZOOPHYTOLOGY. 263
ascending spine at each lower angle of the aperture. Avicularia of a blunt,
rounded, elliptical form, scattered over the polyzoary among the cells.
Hab. Madeira, Johnson.
A very peculiar and well-marked species, characterised not
only by the skeleton-like appearance of the cells, some re-
semblance to which may be occasionally observed in L. nitida,
but more especially by the large blunt avicularia scattered
wregularly among the cells, as in L. monoceros, Busk, and
L. margaritifera, Quoy and Gaim (‘ B. M. Cat.,’ pl. ci), in
which latter the avicularia, though far smaller, are of pretty
nearly the same shape as those of L. sceletos.
2. L. radiata, Moll. Pl. XX, figs. 4,5. (‘ Quart. Journ. Micros.
Sc.,’ vol. vi, p. 128.)
3. Fam. CELLEPORID2.
4. Gen. Cellepora, Fab.
l. C. Hassallii (var. a). Pl. XX, fig. 6.
The only difference apparent between the present form,
and that taken as the typical species in the ‘B. M. Cat.,’
p. 86, pl. cix, figs. 4, 5, 6, is the absence in it of the punctures
in the ovicell. Whether this is alone sufficient to constitute
a specific distmection, may be considered doubtful. For the
present, I am inclined to regard the Madeiran form simply as
a variety of the British.
ZOOPHYTOLOGY.
s
DESCRIPTION OF PLATES.
PLATE XX. ~ ‘
Fig. yO
— 1—Membranipora antiqua, x 25 diam.
oa : ry) ” Xx 50 d.
3.—Lepralia sceletos, x 50 d.
4— ,, radiata, x 50d.
5.—An avicularium of LZ. radiata.
6.—Cellepora Hassalii (var. a).
—7.—Bugula ditrupe, nat. size.
8.— ,, as x 50d.
PLATE XXI.
1, 2.—Aualeya fragilis.
3—5.—Brettia pellucida.
PND RX oO) JOURNAL,
VOLUME VIL.
A.
Achnanthes brevipes and parvula, 92.
Actinocyclus triradiatus, 23.
Allman, Dr. G. J., ‘On Fresh-water
Polyzoa,’ reviewed, 36.
Alge, fecundation of, by Pringsheim,
173.
# Fresh-water,
207.
Alternation of generations and parthe-
nogenesis, 79.
Amphiprora, notes on the genus 198.
e complexa, 201.
is duplex and paludosa, 165.
- Ralfsii, 91, 164, 198.
Amphora, structure of the genus, 184,
202.
55 marina, 206.
pS membranacea, 24.
5 Proteus, 206.
suleata, 24.
Aquarium, Dr. P. Redfern on applying
the microscope to the, 77, 156.
» R. Warington on the, 67.
Arachnoidiscus, history of the genus,
159, 188.
Ehrenbergii and Japo-
nicus, 161.
yy Indicus and Nicobari-
cus, 162.
F. Currey on,
ornatus, 162, 195.
Archer, ‘William, catalogue of Desmi-
diacee, 73.
Archives of Medicine, Review of, 114.
Association, British, Proceedings of, 77.
Aulacodiscus formosus, 160.
B.
Baur, A., on ossification of primordial]
cartilage, 26.
»
Beale’s ‘ Constituents of Urine,’ 256.
» ‘How to work with the Micro-
scope,’ reviewed, 43.
Bennett, Dr., ‘ Principles and Practice
of Medicine,’ reviewed, 254.
Berkeley’s ‘Introduction to Cryptoga-
mic Botany,’ reviewed, 176.
Biddulphia aurita, Baileyi, rhombus,
and turgida, 19.
Blood-corpuscles, J. B. Hennessy, on,
81.
Bowerbank, Dr. J. S., on the vitality of
the Spongiade, 78.
Brightwell, T., on Rhizosolenia, 93.
op on Triceratium and
Chetoceras, 153.
British Association for the Advance-
ment of Science, 77.
Beale’s ‘Archives of Medicine,’ re-
viewed, 43.
C.
Carpenter’s ‘ Zoology,’ reviewed, 117.
Cartilage, primordial, on the ensiieanigy
of, by A. Baur, 26.
Caterpillars, on the crystals contained in
the Malpighian vessels of, 33.
Chetoceras Peruvianum, 155.
Cobbold, Dr. T. S., on a naked-eyed
Medusa, 1
Cocconeis excentricus and orbicularis,
165.
» Seutellum, y, 24.
Cohn and Wichura, Professors, on Ste-
phanosphera pluvialis, 131.
Cornea, on the normal and morbid, 49.
Coscinodiscus concinnus, jimbriatus,
limbatus, and perforatus, 20.
= excentricus, labyrinthus,
and stellaris, 21.
cs ovalis, 22.
266 INDEX TO
Cryptogamic Botany, Berkeley’s Intro-
duction to, reviewed, 167.
Crystalline lens, T. Nunneley on the,
136.
Crystals, H. OC. Sorby on the
microscopical structure of, 190.
Currey, F., on Stephanosphera pluvialis,
13].
o on Fresh-water Alge, 207.
DD:
Deane, Henry, on the history of Arach-
noidiscus, 188.
Desmidiacee, Archer’s Catalogue of, 73.
Diatomacee, from the Menai Straits,
123.
3 marine species of Northum-
berland, 118.
an new species of, by F.C. S.
Roper, 17.
ay with four valves, 201.
Ap with lamellar zones, 201.
Donkin, Dr. A.S., on the marine Diato-
macez of Northumberland, 118.
Drilling holes in glass slides, 121.
Dublin University Zoological and Bota-
nical Association, Proceedings of, 73.
E.
Ellis, G. Viner, on involuntary muscular
fibre, 63.
Entopyla australis, 195.
Epithemia marina and Radula, 165.
Eunotia, notes on the genus, 202.
Eupleuria incurvata and ocellata, 195.
0 species of, 89, 163.
Eupodiscus formosus, 160.
i radiatus and tesselatus, 19.
F.
Facets, hexagonal, on finding the number
of, in a given circle, by H. M., 83.
Farrants, R. J., on a medium for
mounting objects, 118.
Fecundation of Alge, by Pringsheim,
Wey.
Frustrella hispida, Dr. Redfern on, 79,
96.
G.
Gegenbaur, on marginal bodies of the
Meduse, 103.
Generations, alternations of, Dr. Lan-
kester on, 79.
Geological Society, Proceedings of, 190.
Gephyria incurvata, &c., 91, 164,
JOURNAL.
H.
Harting, Prof., on the refractive ndex
of fluids, 107.
Hemiptychus ornatus, 160, 195.
Hennessy, J. B., on blood-corpuscles,
81.
Herapath, Dr., on the detection of
strychnia, 62.
Hexagonal facets in a circle, 83.
Higgins, Rev. H. H., on the cultivation
of mosses, 64.
Himantidium, notes on the genus, 202.
His, Dr., on the cornea, 49.
Hislop, W., on object-finders, 192.
Hogg on the Microscope,reviewed, 117.
I.
Inflammation of cornea, Dr. W. His on,
54.
Involuntary muscular fibre, G. V. Ellis
on, 63.
” ” Jos. Lister
on, 5.
nN
Ue
Jackson, Mr., on object-finders, 192.
Johnson, J. V., on the zoophyto-
logical fauna of Madeira, 124.
Jones, Joseph, on physical influences
exerted. by living membranes upon
chemical substances, 189.
K.
K6lliker on muscular fibre, 31.
» on the luminous organs of
Lampyris, 166.
L.
Lacteal fluid, on the flow of, by Jos.
Lister, 81.
Lampyris, Kolliker on the luminous
organs of, 166.
Lankester, Dr. E., on the alternation of
generations and parthenogenesis in
plants and animals, 79.
Linnean Society, Proceedings of, 64.
Lister, Joseph, on involuntary muscular
fibre, 5.
5, on the flow of the lacteal fluid
in the mesentery of the mouse, 81.
Lithographs, Lionel Beale on obtaining,
115.
Lyons, Prof., on micrometric measure-
ments, 81.
M.
Malpighian vessels of caterpillars, crys-
tals in, 33.
INDEX TO
Maltwood, T., on a new object-finder,
192.
Medicine Archives, by Lionel Beale,
MGS
Medium for mounting objects, R. T.
Farrants on a, 118.
ie Dr. Cobbold on a naked-eyed,
ae Gegenbaur on, 103.
Membranes, - organic and inorganic,
their physical influences on chemical
substances, 189.
Micrometric measurement, Prof. Lyons
on, 81.
Microscope, Jabez Hogg on, 117.
i fifty-pound prize for obser-
vations with the, 59.
how to work with the, by
Lionel S. Beale, 43.
Microscopes, compound, on the applica-
tion of, to aquaria, 77.
Microscopical Society, Proceedings of,
118, 192, 257.
Miliolitide, W.
Indian, 193.
Mosses, Rey. H. H. Higgins on the
cultivation of, 64.
Mounting flies, 122.
+ objects, 118.
Muscular fibre, Kolliker on, 31.
K. Parker on East
N.
Naked-eyed Medusa, Dr. Cobbold on a,
ule
Navicula, notes on the genus, 200.
a dilatata, 25.
Fr Libellus, 201.
a Liber (3, 25.
% palpebralis, 23.
* Scalpellum and Scalprum,
198.
Nitzschia Radula, 23, 165.
> virgata, 23.
Nowell, B. J., list of Diatomacee from
the Menai Straits, 123.
Nunneley, T., on the crystalline lens,
136.
on the retina, 217.
Nympheeacez, Dr. Ogilvie on the stel-
late bodies of the, 59.
O.
Object-finders, on new, 192.
Ogilvie, Dr. G., on the stellate bodies
of the Nymphzacee, 59.
Ossification of primordial cartilage, by
A. Baur, 26.
JOURNAL. 267
Lets
Parker, W. K., on East Indian Milio-
litide, 193.
Parthenogenesis, Dr. Lankester on, 79.
Pleurosigma, notes on the genus, 196,
200.
» . @estuarii and angulatum,
197:
os angustum, 164.
oF arcuatum, 165.
3 Balticum 8, 197.
5 carinatum, 164.
5 compactum, 91.
ae elongatum, 197.
> lanceolatum, 165, 197.
PP minutum, 164.
Pe guadratum, 197.
ee rectum, 164, 197.
sy transversale 3, 25, 197.
PA Wansbeckii, 197.
Polyzoa, Review of Dr. Allman on
Fresh- water, 36.
Pringsheim on the
Alge, 173.
Prize of £50 for observations with the
microscope, 59.
Publication of private correspondence,
196.
fecundation of
R.
Ralfs, J., on the siliceous cell of
Diatomacez, 14.
Ralph, T. S., on illuminating objects,
118.
Ae on mounting objects,
118.
Redfern’s, Dr. P., method of applying
the microscope to aquaria, 77, 156.
* on Frustrella his-
pida, 79, 196.
Retina, structure of, 217.
» rods of, 238.
Refractive index of fluids, Professor
Harting on, 107.
Rhabdonema, species of, 91.
+p structure of, by T. West,
186.
Rhizosolenia, T. Brigltwell on, 93.
Roper, F. C. S., on new species of
Diatomacee, 17.
Royal Society, Proceedings of, 62.
Royal Institution, Proceedings of, 67.
S.
Schlossberger on crystals in Malpighian
vessels of caterpillars, 33. ;
268 INDEX TO
Siliceous cell of Diatomacee, by J.
Ralfs, 14.
Sorby, H. C., on the microscopic
structure of crystals, 190.
Spongiade, Mr. Bowerbank on the
vitality of the, 78.
Stellate bodies of Nympheacez, by Dr.
G. Ogilvie, 59.
Stephanosphera pluvialis,
on, 131.
Strie of Diatoms; relation between
their direction and the arrangement
of their dots, 200.
. vary in appearance according
to the mode of preparation, 163.
Strychnia, Dr. Herapath on the detec-
tion of, 62.
Surirella australis, 195.
Synonyms, reference to unpublished,
196.
F. Currey
ite
Thaumantias achroa, 1.
Toxonidea, notes on the genus, 199.
, Gregoriana and insignis,
165, 197.
Triceratium, filamentous
species of,
1595.
JOURNAL.
U.
Urine, illustrations of constituents of,
by Dr. Beale, 256.
V.
Vessels, minute, in web of frog’s foot,
structure of, 8. j
W.
Walker-Arnott, Dr. G. A., on Am-
phora, 184.
7 on Arachnoidiscus, 159.
7 on Arachnoidiscus, Pleu-
rosigma, Amphiprora, Eunotia, and
Amphora, 195.
0 on Rhabdonema and Eu- -
pleuria, 87.
Warington, R., on the aquarium,
67.
Wenham, F.H.,on drilling glass slides,
and mounting portions of flies, 121
West, Tuffen, on the structure of
Rhabdonema, 186.
Z.
Zoophytological fauna of Madeira, by
J. Yates Johnson, 124.
Zoology, by W. B. Carpenter, 117.
Zoophytology, 124, 260.
PRINTED BY J. BE. ADLARD, BARTHOLOMEW CLOSE.
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ZOOPHYTOLOGY.
DESCRIPTION OF PLATES.
PLATE XVIII.
Fig.
1.—Lepralia distoma, X 25 d.
Tas 50:d"
2.—Membranipora trichophora, X 25 d.
2a. x 50d.
3.—L. vulgaris, X 25 d.
3a. xX 50d.
3 6.—Ovicell, x 25 d.
4..—Membranipora tuberculata, x 50 da,
5.—-Ldmonea Atlantica, x 25 d.
PLATE XIX.
1.—B. gracilis, x 50d.
2.—Nellia Johnsont, n. sp.
2a. x 50d.
3.—Cryptolaria exserta, n. sp.
oS a. - xt Sued:
35. . © 50d.
JOURNAL OF MICROSCOPICAL SCIENCE.
DESCRIPTION. OF PLATE III,
Illustrating Mr. Roper’s paper on some New British
Diatomacecz.
Fig.
1.—Lupodiscus tesselatus.
db. Ditto, structure highly magnified,
2.—Coscinodiscus labyrinthus.
b. Ditto, structure highly magnified.
3.—C. (?) stellaris.
4.—C. (?) ovalis.
5.—) 23
é. 39 29
The figures all magnified 400 diameters, except those taken from Khrenberg.
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JOURNAL OF MICROSCOPICAL SCIENCE.
DESCRIPTION OF PLATE VI,
Illustrating Mr. Currey’s paper on Stephanosphera pluvialis.
Fig.
1.—A full-grown Stephanosphera in which the germ-cells have become
spindle-shaped with protoplasmic elongations.
2.—Full-grown resting-cells.
3.—The beginning of division in a resting-cell.
4,—A resting-cell in which division has advanced further. The outer
membrane is no longer perceptible.
5, 6, 7, 8, 9.—Subsequent successive stages of division, showing (in 9)
the formation of cilia.
10, 11, 12.—Naked zoospores.
13, 14.—Encysted zoospores.
15.—An encysted zoospore with protoplasmic elongations of the primor-
dial cell.
16, 17.—Division of encysted zoospores.
18, 19.—More advanced stages of the same.
20,—A young eight-celled Stephanosphera family.
21.—A family of only four cells.
22, 23.—Young Stephanosphere with the cellular envelope still visible
within the membrane of the mother-cell.
24.—Young Stephanosphera with the cellular envelope somewhat flattened.
25.—Young Stephanosphera viewed equatorially. The outer membrane is
constricted between the primordial cells, and the latter exhibits
chlorophyll-granules.
26.—Formation of microgonidia from the primordial cells of a young
Stephanosphera family.
27.—Free microgonidia.
All the figures x 500.
JOURNAL OF MICROSCOPICAL SCIENCE.
DESCRIPTION OF PLATE VII,
Tllustrating Mr. Nunneley’s paper on the Crystalline Lens.
Fig.
ee Lens of infant. 64. Of young adult. c. Of old person.
2.—Enlarged lens, to show the different curves of its two surfaces and the
arrangement of its layers of fibres.
' 3.—a. Two fibres from the middle part (midway from margin and axis) of
lens of haddock. 4. Of cod, after being in boiling water and
well dried, when the fibres are very clear and transparent.
' 4.—a. Three fibres from middle part of lens of frog. Two are shown
completely twisted over, by which their flat riband-like form is
well seen. 4. A group of fibres seen on the edge.
5.—From turtle. a. Two fibres from near the surface of lens. 6. A
fibre from the same layer in ether, to show the serrations more
developed by this agent. c. Four fibres from near the axis, where
many are almost cylindrical, and marked with longitudinal lines as
though made up of smaller filaments.
6.—From lens of a cock. a. Cells filled with granules from quite the
outer surface of lens close to the capsule. 6. Other of these cells
elongated, as though changing into fibres. c. Fibres from outer
layers of lens. d. Fibres from tear the axis of lens, nearly
cylindrical, but some, as on right, are larger and flat, and at e a
broad one is shown curved over.
7.—Fibres from the lens of rat, squirrel, and hare. a@. From middle. 4.
From near axis of lens of rat. c. From near outer part of lens of
squirrel. d. Four fibres from middle of lens of hare after coagu-
lation and being dried, two are seen flat, and two on edges.
8.—From lens of ox. a. Fibres from near surface. 8. From near middle.
c. From near axis of lens. d. Bundle of fibres broken transversely
from near middle of lens. e. Bundle of fibres seen edgeways.
9.—From cat. a. Two fibres from outer layer showing how very irregular
in outline they become from the effect of water at 212°F. &.
Fibres from near the middle of lens (midway between axis and
margin) of other eye of same animal.
10.—From human lens. a. Fibre from outer layer seen on the flat surface.
6. Another fibre from same layer curved over. c. Fibre seen on
its edge. d. Fibres from near the middle of Jens.
11.—Epithelial cells from inner surface of capsule of lens. a. From anterior
capsule. 0%. From posterior, where I have found them arranged
more or less in rows, so as to present a somewhat beaded appear-
ance. From sheep.
12.—Cells from inner surface of anterior wall of Petit’s canal or suspensory
ligament, in some animals they are more or less oval, and contain
a nucleus with nucleoli, from sheep. All these cells are rendered
more distinct by acetic acid.
13.—Cells from inner surface of capsule of lens of duck.
The figures are magnified 450 diameters.
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JOURNAL OF MICROSCOPICAL SCIENCE.
DESCRIPTION OF PLATE VIII,
Illustrating Mr. Brightwell’s paper on Triceratium and
Cheetoceros.
Fig.
1.—Tr. undulatum, end view.
2.—The same, front view. ‘The frustules are united often in a filament of
six to eight frustules.
3.—Tr. undulatum in the doubtful state, with endochrome.
4.—The same without the endochrome, showing the banded and fringed
frustules.
5.—The same, a four-sided end.
6.—Tr. malleus, end view.
7.—The same, in filament.
8.—Var. of Zr. undulatum, Monterey earth.
9.—Chetoceros Peruvianum.
10.—The same.
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JOURNAL OF MICROSCOPICAL SCIENCE.
DESCRIPTION OF PLATES X, XI,
Illustrating Mr. Nunneley’s paper on the Structure of the
Retina.
PLATE X.
Fig. :
1.—Vertical section of human retina, to show the relative position of its ele-
ments—(plau of). 1, choroid coat ; 2, rods ; 8, outer layer of granular
cells; 4, indiseinct fibrous layer; 5, inner layer of granular cells,
in which are imbedded larger vesicular cells, and towards the inner
surface is found, 6, the vascular layer, which consists of delicate
vessels derived from the larger branches of the central artery of
retina, which run on the inner surface of 7, which is the layer
formed by the fibres of the optic nerve; 8, transparent cells
attaching the retina to the hyaloid membrane.
9.—Human rods, x 4:50 linear.
3.—Rods in various stages of alteration. a@. By the addition of water, or
after the eye has been in dilute spirit, or a short time after death.
6. After being treated with dilute chromie acid. ec. After twenty-
four hours’ immersion in Goadby’s solution. x 450.
4.—Inmer surface of posterior portion of human retina, to show the
granular layer with larger circular cells amoagst which the nerve-
fibres run; to thé left is seen an artery dividing into two branches.
x 450. ‘
5.—Same surface with 1-12 object-glass, and achromatic condenser, x 600,
without nerve-fibres, to show the clear transparent cells (probably
enlarged by endosmose), and the cellular character of the so-called
granular layer, which consists of true cells containing very refractive
nuclei.
6.—Nerve- fibres from posterior part of human retina; they appear to
bifureate and to join each other again. x 450.
7.—Ilvregular fiat cells found in the eyes of most, if not ail, animals.
a. Krom human feetus. 6. From pig. ¢. From sheep. d. From
bullock. Alijust dead. x 450. Are they caudate gangliform cells ?
8.—Turkey. @. Conoidal rods surmounted by coloured globules. 6.
Coloured globules of various sizes detached. ¢. Cylindrical rods.
d. Qvoid bodies with coloured globules. x 450. ¥
9.—Retina of birds. @. Conoidal rod with coloured globule from canary
bird. 6. Conoidal rods with ecloured globules from various breeds of
domestic fowls; in the same bird the size and exact shape varies,
perhaps, at least to some extent, depending upon varying pressure
against each other. ¢. Cylindrical rods not surmounted by coloured
globules. d. Ovoid bodies (bulbs, cones) with coloured globules.
e. Coloured globules seen on outer surface of retina as though with
anucleus, which they do not possess. / Coloured globules seen in
PLATE X (continued).
Fig.
profile, showing a small spur, by which possibly they adhere to the
conoidal rods, though in the great majority this spur cannot be
seen; they appear to be true globules. g. Conoidal rods and ovoid
bodies become granular.
10.—From duck. a@. Cylindrical rods, which are larger and more numerous
than in the fowl; in one duck all the rods were cylindrical, aud many
of them were surmounted by the ruby- and canary-coloured globules :
there were none conoidal, except such as shewnate. 46. Conoidal
rods from another duck. ¢. Ovoid bodies without coloured globules.
d. Ovoid bodies with coloured globules. e. Ovoid bodies with a
conoidal leg attached at the zzzer side ; this process becomes detached
and breaks up into dises, as do the cylinders, while the more globular
portion becomes granular; so that it is difficult to say whether
these are ovoid bodies with a portion of rod and globule accidentally
attached, or whether the ovoid bodies are not really altered conical
rods deprived of the inner process. jf. Cylindrical rods and ovoid
body with coloured globules accidentally attached. x 450.
1].—From swan and goose. a. Conoidal rods with coloured globules. 4.
Ovoid bodies with similar globules. c. Three of the rods altered.
d. Coloured globules fusiform in shape. e. Strong cylindrical nerve-
fibres in retina from swan, jf. Cylindrical and conoidal rods. gy. Ovoid
bodies. %. Rods curled round so as closely to resemble ovoid bodies.
2. Rod curled into hook at one extremity. x 450.
12.—From Guinea fowl. a. Outer surface of retina with rods and globules
in situ. 6. Coloured globules detached. x 450.
13.—From green turtle. a. Long and short cylindrical rods, neither of
which are very numerous. &. Conoidal rods, for the most part sur-
mounted by a coloured globule. c. Ovoid bodies surmounted by
coloured globules. d. Very nearly similar bodies without coloured
globules. e. Ovoid bodies with a short cylindrical leg attached at
inner side, intwo of them it is seen breaking off; they are surmounted
by coloured globules. f These different bodies after the lapse of
a few hours; immediately on the addition of water; and also from
another turtle, which, before being killed, was in a very languid and
feeble condition. g. Average size of ruby globules. 4%. Of canary
globules. ¢. Three of these globules in profile to show spur which
some appear to possess, but by far the greater number seem to be
true globes; when not exactly in focus, as the globules of birds,
they appear to have a nucleus, which, however, they have not. 7.
Nerve- fibres forming a layer in retina. 4. Finely granular cells.
x 450.
14.—Turtle; form, size, and position of elements of outer coat of retina,
showing the cylindrical and conoidal rods with the coloured globules,
and at their base the ovoid bodies. x 450.
15.—Section of retina of turtle. a. Rods. 8. Coloured globules. c. Ovoid
bodies. d. Granular cells. e¢. Nerve-fibres and blood-vessels. (7.
Transparent cells between last and the hyaloid surface. x 450,
PLATE XI.
Fig.
1 —Portion of back part of retina of bullock seen from the inner surface,
to show nerve-fibres and layer of granular cells, which have been
partially removed the better to show the fibres forming a layer, with
1-12. x 600.
2.—Fibrous layer of retina, showing varicose enlargements in the nerve-
fibres, and also double-walled cerebral cells. x 450. From back
part of retina of rabbit. L haye seen the same structures in the ox
and the sheep, but not quite so distinctly.
3.—Varicose fibres and clear oii-like cerebral cells from optic nerve in the
pig, at its entrance into the eyeball.
4,—ILayer of cells attaching retina to hyaloid membrane ; at first they are
perfectly transparent, but soon become very finely granular. They
are found in most animals, and are very distinct in the rabbit.
5.—From turtle. ‘There are a few large flat cells with large irregular
granular nuclei. x 450. Are they the caudate gangliform cells ?
6.—From birds. a. Conoidal rods after some hours’ immersion in dilute
spirit, showing, towards the czwer end, a conical process with a
transverse mark as though breaking off here. &. Nerve-fibres from
anterior part of retina of Cochin cock; after being forty-eight
hours in dilute spirit, they formed a complete layer imbedded in the
granular ceils; many of the fibres could be traced for a considerable
distance, others were much shorter as though terminating at various
points, all were more or less varicose ; the dilations showing double
walls, and with them were some double-walled cells. c. Delicate
cells, which are during life, or immediately after death become,
minutely granular; they are very abundant in all birds. d. Perfectly
transparent cells, which soon become very large and irregular in size
and shape, probably from pressure and overlapping each other; they
appear to form a layer between the retina and hyaloid; these are
from the canary bird; they are not larger in the goose or turkey
than in this little bird. x 450.
7.—Capillary vessels of human retina; the artery from which they are
given off measured 1-100 of an inch in diameter; the capillaries
not more than 1-4000; washed with dilute liquor potasse, which, by
erie the nerve-structures, renders the congested vessels very
istinct.
8,—Terminal vessels in human retina. They form a series of loops a little
distance from the ora serrata. a. Ciliary processes. 0. Loops of
capillaries joining to form trunk, e.
9.—From frog. a. Very large cylindrical rods ; most, however, are of size
seen at 6. Some of these are rather broader at their inner extremity
than at the outer; many, but not all, are surmounted with a light-
brown coloured globule, like those of birds and the turtle, but with
much less colour; these are shown detached at c. They should not
be shown with nuclei. d. Rods changed by the addition of water ;
they curl up, become granular, and look like coffee-berries. e. Rods
after addition of salt and water, which induces much less change than
water. jf. In one frog I found three rods with conical inner ends,
and transverse marks as here shown. g. A few large cells with
pigment-granules, not much unlike some found in the brain, are seen.
«K 450. ;
PLATE XI (continued).
Fig.
trom toad. a. Three rods; the majority are not so long as the
longest. &. Size of pale yellowish globules attached to some of the
rods. xX 450.
11.—From alligator. a. Rods. 4. Fibrous layer of retina when fresh.
c. Same layer with granular cells after six hours’ immersion in dilute
spirit; the nerves have become varicose. xX 450. .
12.—From chameleon. a. Rods. 4, Granular cells, with which are some
larger-brain cells. ce. Nerve-fibres of retina. x 450.
13.—From golden carp, Cyprinus auratus. a. Cylindrical rods. 6. Conoidal
bodies, cones jumeaux, at first perfectly transparent. c. These same
bodies, after a short time, or immediately on the addition of water,
the lower bulbous portion swells, becomes granular, irregular, splits
in the middle, forming the coffee-berry body, breaks up, and
disappears, while the surmounting conical leg breaks off, splits into
dises, as do the cylindrical rods, and disappears. d. Ovoid ceils of
various sizes, of a dark fuscous colour; they resemble brain-cells.
e. Nerve-fibres of retina. x 450.
14.—From sand-dab, Platessa limanda. In this fish the cones are not
numerous, the rods and granular cells are far more so. a. Rods.
b. Conoidal bodies. x 450.
15.—From litile weaver, Trichinus vipera. In this fish the cones are very
distinct, and far more numerous than in the last, but very few have
the clear conical leg, and for the most part they lie singly and not
in pairs as is common in fish. The rods are neither numerous nor
well developed. «@. Rods. 4. Cones, which in this and the last fish,
if not in life granular, become so before they can be examined. x 450.
16.—From whiting, Merlangus vulgaris, which is a good fish for examination,
the cones being well developed, a. Small rods. 4. Cones with
single bulbs and double conical legs, at first perfectly transparent
and homogeneous, but in a very short time immersion in dilute spirit,
or instantly on the addition of water, the changes shown at ¢ occur,
and they disappear in granules. x 450.
17.—From eel. a. Rods, which are numerous. &. Cones, which are not so
numerous. c¢. Brownish red transparent cells, in character not unlike
the coloured globules of birds, except that they contain a nucleus.
They are not more than half the size of the blood-globules, and they
are circular; on the other hand, they are much too large for the pig-
ment-cells of the choroid, which in colour they resemble. d. Com-
mencing change in rods or cones, which now (with 1-8) resemble, in
size and form, au oatcorn. xX 450.
18.—From cod, Gadus morrhua, where the retina is very thick and its ele-
ments simple. @. Normal form and size of cone, the bulb is perfectly
transparent and homogeneous; the conical process is single and has two
transverse strix, where it soon breaks. 6. Cones altered a few hours
after death. ¢. A cone seen to alter while under examination, a large
granular vesicle formed in the middle, and at each end was a long fibre ;
these subsequently swelled out, became granular, and disappeared.
d. Inner surface of retina, some hours after death, showing the large
flat nerve-flbres become greatly varicose; they are imbedded in a
layer of granular cells, with which are also found many large traus-
parent cells. x 450.
rat =.
-
WWest Lips
JOURNAL OF MICROSCOPICAL SCIENCE.
DESCRIPTION OF PLATES XII, XIII,
Illustrating Dr. Wallich’s paper on Triceratium and
Hydrosera.
PLATE XII.
Fig.
1.—Front view of 7riceratium serratum.
2.—Valve of ditto.
3.—More highly magnified view of one of the connecting plates during
division, showing serrated edge and arcuate band.
4.—T.. jimbriatum, front view.
5.—Valve of ditto.
6.—Fragment of valve exhibiting cellular structure.
7.—Profile of a fragment, showing depth of cells.
8.—Profile of fimbriz.
9.—Three of the fimbrize, seen under a power of 600 diameters.
10.—7. pentacrinus, front view.
11.—Valve of ditto.
12.—Connecting membrane of ditto.
13.—Portion of ditto.
14.—7", pentacrinus, four-sided variety.
15.—T. annulatum.
16, 17.—Two newly separated frustules, showing the supersistent counect-
ing band, formed of the siliceous plates of their halves of the parent
frustule ; the other or second layer having receded from these, and
remained attached to the other newly liberated frustules.
PLATE XIII.
1.—Portion of Hydrosera triquetra in natural state.
2.—Frustule of ditto, seen from above, as laid on one of its sides, the
central angular ridge only being in focus.
3.—Connecting membrane of same, showing one of the plates forming the
annulus, with its imperfect septa. The other plate behind it out of
focus.
4.—End view of valve of same, showing cellulation under a power of
950 diameters, the spines at the angles, and processes on one
side.
5.—Broken valve, showing one of septa.
6 —Portion of same valve under power of 350 diameters, showing reticu-
lated structure.
7.—Portion of filament of H. compressa in natural state.
8.—Frustules of same undergoing division, and exhibiting the lateral
appendages.
9.—Connecting membrane of same.
10.—End view of ditto.
11.—Side view of ditto.
12.—Enlarged view of lateral processes.
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