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“JOURNAL OF ANATOMY
ORIGINALLY THE JOURNAL OF
ANATOMY AND PHYSIOLOGY
CONDUCTED ON BEHALF OF THE ANATOMICAL SOCIETY
OF GREAT BRITAIN AND IRELAND BY
ProressoR THOMAS H. BRYCE UNIVERSITY OF GLASGOW
Proressor EDWARD FAWCETT UNIVERSITY OF BRISTOL
Professor J. P. HILL UNIVERSITY OF LONDON
Proressor G. ELLIOT SMITH UNIVERSITY OF LONDON
ProrrssoR ARTHUR KEITH ROYAL COLLEGE OF SURGEONS
LINCOLN’S-INN-FIELDS, LONDON, W.C. 2 |
VOLUME LIV
OCTOBER I919—JULY 1920
CAMBRIDGE
AT THE UNIVERSITY PRESS
1920
ae
= \
. CONTENTS
FIRST PART—OCTOBER, 1919
PAGE
The Ripe Human Graafian Follicle, together with some suggestions as
to its mode of rupture. By AnTHuR THOMSON . . . . =. 1
Voluntary Muscular Movements in cases of Nerve Lesions. Bots Prof.
FrepErRIcK Woop Jones, D.Se. . . ss. 41
Sexual Differences in the Skull. is F. G. Parsons, ed Mrs bes
UENE eS ; 58
The Ileo-Caecal region of Callicebus Panis with some Observations
on the morphology of the Mammalian Caecum. rs T. B. JoHnsTon,
Me tae as. 66
On the Development of the Laryngeal Muscles in n Sanropida By! F. H.
Epcewortn, M.D. . : 79
s Persistent Foramen Primum, with Remarks on oe Nature and Clinical
i Physiology of the Condition. ee ALEXANDER BLACKHALL-MORISON,
mo. FR.C.P. 3 : : : i
In Memoriam. Professor ALEXANDER eo MD., ERS. ete.
1844-1919. Portrait. E. BarcLay-SMITH . ; ; s ; .
Reviews. The Peripheral Nerves te ee ee iene <2
SECOND AND THIRD PARTS—JANUARY AND APRIL, 1920
Studies on the Anatomical Changes which accompany certain Growth-
disorders of the Human Body. I. The Nature of the Structural
Alterations in the Disorder known as osama Exostoses. Fe: ARTHUR
KEITH Rens 101
Functions of the Liver in the Embryo By J. ERNEST FRAZER, F. R. C. s.
* (Eng.) Mee Serer aS 116
On the Development of the Hy pobre ne Laryngeal lisecias § in
Amphibia. By F. H. Epcewortn, M.D. . 125
Cardiac and Genito-urinary Anomalies in the same Subject. By A ALEX-
ANDER BLAcKHALL-Morison, M.D., F.R.C. re and Ernest HENRY
ew, MCA. 6 163°
- On the Parathyreoid Duct of Psu and its Relation to ‘ie Post- Pedachial
Body. By Dr MapcEe RoBerTSON ; 166
Note on Abnormal Muscle in Popliteal Space. By Prof. F, G. Parsons 170
Level of External Auditory Meatus. By Prof. F.G. Parsons. . . 171
Note on Recurrent Laryngeal Nerves. By Prof. F.G. Parsons . . 172
_ Hypertrophy of the Interstitial Tissue of the Testicle in Man. a rT.
RussELL GoDDARD ; a 173
vi Contents
The Ora Serrata Retinae. By G. F. ALEXANDER, M.B., Ch.B. (Ed.)
Note on the Occurrence of Ciliated Epithelium in the Oesophagus of
a Seventh Month Human Foetus. By F. H. Heatey, B.Se.
The Relative Positions of the Optic Disc and Macula Lutea to the
Posterior Pole of the Eye. By James Fison, M.A., M.D. (Cantab.).
The Microscopical Structure of the Enamel of Two Sparassodonts,
Cladosictis and Pharsophorus, as evidence of their Marsupial
Character: together with a Note on the Value of the Pattern of the
Enamel as a Test of Affinity. By J. THorNTON CARTER . :
A Cyclops Lamb (C. Rhinocephalus). By RecinaLp J. GLADSTONE,
M.D., F.R.C.S., and C. P. G. WAKELEY, M.R.C.S., L.R.C.P. ©
The Anatomy of a Symelian Monster. By T. B. Jounston, M.B., Ch.B.
Sexual Dimorphism in Rana temporaria, as exhibited in rigor mortis. By
F, A. E. Crew, M.B.
The Constrictor Muscles of the Branchial Arches in Acanthias Blainvillii.
By Epwarp PuHetps ALLis, Jr
The Tibia of the Australian — si W. Quan Woon: M. D.,
F.R.C.S. (Edin.)
Models of the Human Stomach iowie its foes vided Variogs: Con-
ditions. By A. E. Barcuay, M.A., M.D. (Camb.)
FOURTH PART—JULY, 1920
Motor Points in Relation to the Surface of the se _ R. W. Retp,
M.D., F.R.C.S.
A Case of Partial Tednepoddon 8 of the Mesogastie iVioora. By J. C.
Brasu and M. J. STEWART eS
The Pronephros and early Development of the M=sonsohiee in the
Cat. By Exizaperu A. Fraser, D.Sc. oo ea
On Certain Absolute and Relative Measurements of Human Vertebrae.
By Epear F. Cyriax, M.D. (Edin.)
Note on the Persistence of the Umbilical Arteries as Blindly-ending
Trunks of Uniform Diameter in the Indian Domestic Goat. oo
W.N. F. Woop.tanp, D.Sc., L.E.S.
Fissural Pattern in Four Asiatic Brains. ae SYDNEY J. Coie M.A.,
Wee een Re ;
Further Observations on the Gastro-intestinal Tract of the Hindus. By
Dr N. Pan ;
Review. Cunningham’s Manual of Practical Anatomy. Seventh edition
INDEX
PAGE
179
180
184.
189
196
208
217
222
232
258
271
276
rade
805
309
oe
824
3882
833
JOURNAL OF ANATOMY
THE RIPE HUMAN GRAAFIAN FOLLICLE, TOGETHER
WITH SOME SUGGESTIONS AS TO ITS MODE
OF RUPTURE
BY ARTHUR THOMSON,
Professor of Human Anatomy, University of Oxford
For the purposes of this paper the ripe Graafian follicle is defined as one
which, from its superficial position, its size, and the thickness of the wall
separating it from the ovarian surface, there is reason to believe is fast ap-
proaching the time at which rupture may take place. Added to this, must
necessarily be considered the condition of,the contained ovum. If evidence
is forthcoming that the ovum is passing through, or has passed, the maturation
stage, such is confirmatory proof that so far as the contents of the follicle
are concerned they are ready for discharge. If, as not unfrequently happens,
the ovum exhibits indications of degenerative changes, these must be taken
into account in any estimate that may be formed regarding the normal ap-
pearance of the follicle.
Admitting that coincident with its approach to the surface of the ovary,
the Graafian follicle enlarges, what are we to regard as the normal measures
of its size? One can readily understand that there may be, and are, consider-
able variations in the dimensions of a follicle which in other respects fulfils
the conditions which are to be regarded as indications of its ripeness.
Size of ripe Graafian Follicle. When reference is made to the various
British and foreign text-books, it will be found that there is great disparity
_ in the measures given. The dimensions recorded range from 2 mm. to 20 mm.,
the average size being about 15 mm. in diameter. In my experience this latter
figure is much too high. In the specimens I have examined of follicles ex-
ceeding a diameter of 5 mm. I have either failed to find a contained ovum or
when it was met with, it proved to be in a degenerated condition.
For these reasons a certain amount of caution is necessary before accepting
the figures usually quoted, for mere naked eye inspection of the ovary, on sec-
tion, may be misleading, since though the follicles exposed may be of consider-
able size, there is no proof that their contents are normal.
Nagel ((23), p. 44), to whom deference must be paid as a weliable observer,
says that the follicle may attain a diameter of 10-20 mm. before it ruptures,
and that no limits can be fixed to its growth within these figures; the test is
whether the follicle contains a normal ovum. Testut ((31), p. 696), on the other
Anatomy Liv 1
2 Arthur Thomson
hand, is much more conservative in his estimate; he describes the follicle as
usually measuring between 2 and 3 mm. or more, occasionally as much as
9mm. As will be noticed, his upper limit falls below the lower value given by
Nagel.
If it be that the larger figures, viz. 15 to 20 mm., are of common occur-
rence, it follows that the ovary in which such a follicle is found must present
a remarkable appearance, since the size of the ovary itself is usually recorded
as about 30 mm. in length, so that the presence of so large a follicle in its
substance would very materially affect the surrounding tissue, and would
greatly alter the external appearance of the organ.
It is possible that immediately prior to its rupture the Graafian follicle
may undergo a sudden and rapid increase in its size, but so far, in the material
at my disposal, I have not come across any follicles of the larger dimensions
given, which in other respects could be regarded as normal.
Possibly deductions as to the size of the ripe follicle prior to its rupture
have been made from the appearance displayed by the presence of corpora
lutea in different stages of development, but in regard to this it may be ob-
served, that we are without information as to the rapidity and extent of the
changes that may ensue within the follicle immediately after its rupture.
In the accompanying table the results are given, so far as the size of the
follicle is concerned, as observed in the material at my disposal.
Table I
Size of ripe Graafian Follicles containing Normal Ova
The measures are given in millimetres.
Specimen Diameters Distance from Surface
453 A 35* 1-63 x 2-00 x 1-96 0:3
Ol 122 4-53 x 3:14 x 4-90 0-3
453 B 14* 2-62 x 1-56 x 2-54 0:34
02 106 0-79 x 0-80 x 0-62 0-36
Ol 95 4:59 x 3-16 x 4-82 0-56
a5 227 3°20 x 3-08 x 5-20 0-6
380 98** 1-47 x 1-84 x 2-80 0-88
453A 3** 1-39 x 1-66 x 2-34 1-00
02 67 0-71 x 1-18 x 2-06 1-04
Ol 14 2-90 x 2:58 x 2-09 1-16
453 F 34 0-98 x 0-56 x 1-20 1-28
453 F 20 1-42 x 1-70 x 1-56 2-6
453 F 30 1-37 x 0-96 x 1-20 2-6
The specimens in this table are arranged in order of the thickness of the
wall which separates the Graafian follicle from the surface of the ovary.
Generally speaking, those with the thinnest wall are the larger follicles,
_ though this is not an invariable rule, as may be seen from an inspection of the
table. It would therefore appear that there is considerable variation in the
size of the follicle independent of its proximity to the surface.
In specimens 453 B 14 and 453 A 35 (marked *) the contained ova, after
The Ripe Human Graafian Follicle 3
examination, have been pronounced mature. In specimens 453 A 3 and 38098
(marked **), the contained ova are in the process of maturation.
Apparently the healthy Graafian follicle tends to be spherical, as if well
filled. In cases where it is irregular in shape and angular in form the contents
are generally found to be in a degenerated condition.
If the examples given in the above table are to be regarded as ripe for
rupture, their relatively small size suggests that they are in a more or less
quiescent condition, and that prior to their rupture they will undergo a sudden
and more or less rapid increase in their bulk when the appropriate occasion
arises. This is a matter which will be dealt with later in the paper.
Position of Cumulus
Another point on which there is much conflict of opinion, in the published
accounts, is the position within the Graafian follicle of the cumulus or discus
proligerus surrounding the ovum.
Nagel ((23), p. 57) very definitely states that “in man, and, as it seems, in
most mammals (Waldeyer, Frey, Henle) the cumulus always has this position
on the medial wall of the follicle, somewhat more to one side or the other of
the middle line, and consequently always opposite the stigma (the point where
the follicle ruptures).”” This view is acquiesced in and followed by Poirier
((25), p. 695, vol. m1.), Tigerstedt (32), and Piersol ((24), p. 1989).
MecMurrich ((18), p. 19) qualifies it somewhat by stating that the discus is
found “at one point usually on the surface nearest the centre of the ovary.”
H. N. Martin ((20), p. 78) takes a diametrically opposite view, assigning a
position to the cumulus usually corresponding to that “nearest the surface
of the ovary.”
A. Flint ((9), p. 759) expresses the opinion that “the situation of the discus
proligerus is not invariable; sometimes it is in the most superficial and some-
times it is in the deepest part of the Graafian follicle.”
Most authors maintain a discreet silence on the point, whilst J. H. Ray-
mond ((26), p. 627) accepts the view of Béhm and Davidoff ((3), p. 352) to the
effect that the discus proligerus with the contained ovum ultimately comes to
lie free in the liquor folliculi, a change which is brought about by the softening
of the cells forming the pedicle of the discus.
As the outcome of my own observations I feel justified in saying that the
position of the cumulus or discus proligerus is not always on the deep wall of
the follicle opposite the stigma, as stated by Nagel and others, but that in
fact it may be frequently met with on the most superficial aspect of the
follicle, i.e. that nearest the surface of the ovary, and consequently close to
the stigma or point of rupture. Indeed, the position of the cumulus appears to
be determined by no known law, and its occurrence on any part of the cir-
cumference of the follicle may be observed.
The view almost universally accepted, is that the discus proligerus remains
throughout the growth of the follicle adherent to the cells of the stratum
1—2
4 Arthur Thomson
granulosum through the medium of a pedicle which may vary considerably
in appearance, in some cases being long and attenuated, in others short and
wide. The appearance represented under the microscope will vary much
according to the plane of section, and any satisfactory elucidation of the
subject is only possible after the careful examination and reconstruction of
serial sections.
It frequently happens that a single section, or, it may be, a small series
of sections, would give support to the view that the discus proligerus with the
contained ovum lay free in the liquor folliculi. On more extensive examination,
however, so far as my own experience goes, these specimens can always be
traced so as to reveal a connexion with the cells of the stratum granulosum.
Such an observation, however, does not necessarily contravert the view taken
by Bohm and Davidoff, for it is possible, as will be hereafter explained, that
the cumulus and ovum may be found floating in the liquor folliculi, having
acquired that position by a means other than that described by these aie
viz. the division of the pedicle.
The advantage of having the ovum and discus proligerus floating fairly free
in the liquor folliculi is at once apparent when we come to discuss the mode
and manner of the discharge of the ovum when the Graafian follicle ruptures.
It is obvious that the position of the cumulus must stand in some distinct
relation to the mechanism which determines the escape of the ovum from the
follicle.
If one accepts the view that the cumulus is always situated on that side
of the follicle which lies farthest from the surface of the ovary, it becomes at
once difficult to explain how it is possible, by any increase of pressure in the
fluid contained within the antrum folliculi, for the ovum to be expelled
through an aperture which lies on the opposite side to that on which it is
placed. It seems more probable that the fluid pressure being equally exerted
in all directions, is rather likely to force the ovum more firmly against the
wall on which it rests. Hence the obvious advantage of a more superficial
position as claimed by Martin (loc. cit.), for there the ovum resting on or in
relation to the weakened wall of the follicle (stigma), where the rupture is
about to take place, will naturally be expelled through the orifice made in
the wall of the theca against which it lies, by the bursting pressure exerted by
the liquor folliculi. Such an explanation seems feasible, and would be one way —
of explaining the escape of the ovum in those cases in which the cumulus is
superficial in position. But the question naturally arises, is it the normal way?
In cysts which enlarge through the increasing amount of their fluid con-
tents, there is a tendency towards the production of marked flattening of the
cellular contents which line their more resisting envelopes. If this be the case,
we would expect to find the cells of the stratum granulosum lining the interior
_ of the follicle thinned and compressed, an appearance which we do not see;
- the absence of such a condition is probably to be accounted for on the supposi-
tion that these cells are really part and parcel of the liquor folliculi, forming
The Ripe Human Graafian Follicle 5
as it were a superficial layer of cells bathed in and surrounding the liquor
folliculi, overlying, but not intimately attached to, the “basal membrane” or
“external limiting membrane” of some authors (see Robinson (27) pp. 311 and
319) which lines the inner surface of the internal theca. It is on this layer that
the ‘pressure exercised by the contents of the follicle is apparently exerted,
else; were the cells of the stratum granulosum a constituent part of the wall
of the follicle, we would expect these cells, as already stated, to exhibit indica-
tions of the result of pressure. Reference will be made later to this basal
membrane, meanwhile it will be sufficient to suggest that possibly there is a
lymph space in association with it.
What holds good of the cells of the stratum iinalceunt must also apply
equally to the cells of the cumulus. It would be natural to expect that in cases
where the cumulus has a broad base and an absence of pedicle, the follicular
cells of which it is composed would react to such pressure as may be exerted
on them, were it not that they form a constituent part of the fluid and semi-
fluid contents of the follicle. What is true of these cells would also apply to
the ovum which they surround, consequently we are entitled to assume that
all the contents of the follicle within the basal membrane are subject to an
equality of pressure, whatever that pressure may be. For the present the con-
sideration of this subject is postponed until certain other details of the Graafian
follicle have been considered. Meanwhile I here place on record my own obser-
vations as to the position of the cumulus within the follicle.
In 15 Graafian follicles which might be accounted as “ripe,” and having
normal contents, the cumulus or discus proligerus was in seven cases situated
superficially, that is towards the ovarian surface. In two instances it lay deep
within the follicle, the term “deep” being here employed to indicate that
the cumulus was placed on the wall of the follicle farthest removed from the
surface of the ovary. In six follicles the cumulus lay to one or other side of the
follicle, intermediate in position between the superficial and deep positions
above indicated.
In 10 Graafian follicles either containing degenerate contents, or not so
advanced in growth, the cumulus was situated six times superficially, twice
laterally, and in two cases deeply.
These records are too few from which to deduce any reliable data, but are
sufficient to contravert Nagel’s statement, for out of 25 Graafian follicles the
cumulus occupies a superficial position in 13 cases, or about 50 per cent.
whereas it only occurs in the “deep” position; that accounted as normal by
Nagel, in four instarices or 16 per cent.
Liquor Folliculi
Concerning the manner of the production of the liquor folliculi there is
much divergence of opinion. The question at issue is whether the liquor
folliculi is of intercellular or intracellular origin.
Scattered among the follicular epithelium, contained within the Graafian
6 Arthur Thomson
follicle, are certain structures called the bodies of Call and Exner (4). These
have been variously interpreted, by some as vacuolated cells (the “‘ epithelial
vacuoles”? of Flemming ((8), p. 878)), by others as intercellular collections.
The prevalent ideas with regard to the origin of the liquor folliculi may be
briefly stated as follows. Nagel ((23), p. 54) regards it as formed partly by
transudation from the vessels surrounding the follicle, partly by disintegration
of the large follicular cells (the “‘ bodies of Call and Exner” or the “epithelial
vacuoles” of Flemming), whose protoplasm swells, finally to be completely
broken up, the nucleus at the same time crumbling away and finally breaking
up.
On the other hand C. Honoré ((14), p. 537), from his researches on the rabbit,
states that the stratum granulosum secretes the liquor folliculi just as the
epithelium of the tubes of the kidney secretes urine. He explains the presence
and appearance of the bodies of Call and Exner as follows. A certain number
of the cells of the stratum granulosum group themselves radially and secrete
a substance at first homogeneous. This central substance later becomes a
reticulum, and increases in size with the growth of the follicle; the reticulum
becomes finer, and a kind of peripheral membrane appears, at the same time
the radial arrangement of the surrounding cells becomes less evident. The
staining of these bodies in follicles of different sizes shews that their chemical
constitution is modified by age.
My own observations on this subject may best be explained by a series of
microphotographs, which I venture to think illustrate the successive stages
of the process, :
The feature which enables the observer to recognise them consists in the
arrangement, in radial fashion, of the follicle cells disposed around them. This
appearance is so characteristic that Call and Exner suggested that they were
of the nature of ova, and that the arrangement of the cells surrounding them
was comparable to the corona radiata encircling the ovum.
Within the area circumscribed by this radial formation of the follicular
cells, in a typical example, there is a mass of variable size, often of a more or
less clear, homogeneous matter, reacting to some stains in a selective way, but
generally presenting appearances which correspond in tint and density with
the reaction to the same stain of the coagulum in the antrum folliculi. The
nature of the material occupying the centres of these radially arranged folli-
cular cells has been variously interpreted. By some, these ‘‘ bodies”’ have been
regarded as the product of the liquefaction of the protoplasm of the follicular
cells (Nagel (22), p. 381; Waldeyer (34), p. 88). Bernhart considered them of a
fatty nature, but this view was combated by Bischoff, who held that they
failed to refract the light sufficiently to justify this assumption. Flemming
describes them as vacuoles of epithelial origin. C. Honoré regards them as
having an intercellular origin and as being due to the accumulation of the
products of the special activity of the radially arranged follicular cells around
them.
ee ae Ry ee ee
The Ripe Human Graafian Follicle 7
Boreae Antrfoll. Ba&CRE
ft?
i 2 ea Sage i
Str.gran, Rad. foll. cells ~ — Stregran.
Fig. 1. Shewing bodies of Call and Exner (B. of C. and E.) surrounded by radial arrangement of
follicular cells (Rad. foll. cells) in the stratum granulosum (str. gran.) of a human Graafian
follicle. x 900 diameters. Antr. foll. antrum folliculi. Specimen 280 G. 5.
a ict
i !
Anti: Foll. Rad. follcells BofC&E Cum. Cor'rad. Z.pell Ov.
Fig. 2. Shewing a body of Call and Exner (B. of C. and E.) surrounded by radial arrangement
of follicular cells (Rad. foll. cells) in the cumulus (cum.) of a human Graafian follicle. x 900.
Ov. ovum.—Z. pell. zona pellucida.—-Cor. rad. corona radiata.—Antr. foll. antrum folliculi.
Specimen 280 G. 4.
8 Arthur Thomson
Fig. 3. Ovum within the stroma of the ovary surrounded by follicular cells. As yet there is no
antrum folliculi. Near 1 of the watch dial there is a body ot Call and Exner surrounded by a
corona of follicular cells, within which the structure presents a homogeneous appearance.
x 400. Specimen O. 2. 59. 4.
Ovstr. — Int. theca. Ext. theca. Str: gran.
cy
Re ee,
% SEG aes Se | Z ae Z
Antr foll Cum. Ov. . BofC&E
Fig. 4. Section of a human Graafian follicle containing a maturing ovum. Ov. str. ovarian stroma;
Int. theca, internal theca; ext. theca, external theca; str. gran. stratum granulosum; antr. foll.
antrum folliculi; cwm. cumulus, with bodies of Call and Exner therein; ov. ovum; surrounded
by zona pellucida and corona radiata. B. of C. and E., Bodies of Call and Exner in the stratum
granulosum. x 100. Specimen 280. G. 2.
The Ripe Human Graafian Follicle 9
In attempting an elucidation of these various views it will be necessary
to draw attention first to the stage at which these bodies make their earliest
appearance, and the manner of their distribution.
Fig. 3 represents the appearance of one of these bodies as seen in a Graafian
follicle in which there is as yet no antrum folliculi. In the specimen shewn, the
body of Call and Exner is of large size as contrasted with cthers which occur
in the serial sections of the same follicle, and its contents react to the stain
(iron haematoxylin and Van Giesen) in such a manner as to be coloured a deep
orange. It may be noted that in follicles in which an antrum folliculi occurs,
under the same staining reagents the enclosed coagulum is usually tinted
yellow. The same relation is seen in specimens stained with Mallory’s con-
nective tissue stain, both coagulum and “bodies” are coloured blue, the latter
much more deeply. This cireumstance would suggest that the liquor folliculi
- is ‘of the same or similar nature as the matter contained in the bodies of Call
and Exner, though possibly more dilute.
The question of size, to which reference has been already made, is a matter
of some importance, as will presently be noted, as having a bearing on the
manner of formation of these bodies.
_In regard to their distribution. As stated above, they occur in follicles
prior to the formation of the antrum folliculi, and I have seen evidences of
what I took to be their genesis in follicles as early as the double-layered stage
of the follicular epithelium. Subsequent to the appearance of the antrum folli-
culi, they are met with equally amongst those parts of the follicular epi-
thelium which are ultimately to become the stratum granulosum, and in the
cumulus, as shewn in fig. 4.
When, however, by the increase in the size of the antrum folliculi, the
stratum granulosum becomes much thinned, then we find their occurrence in.
that layer much less frequent, until in advanced stages of the growth of the
follicle they cease to be met with in the stratum granulosum altogether.
Not so, however, in the region of the cumulus, for here, immediately
around the ovum and towards the basal part of the cumulus, they may be seen
in follicles which are to be regarded as near approaching rupture, to judge by
the thinness of the superficial wall and the mature condition of the odcyte.
Meanwhile it may be noted that these so-called bodies of Call and Exner,
in different stages of their development, exhibit very different appearances.
I am fortunate in being able to reproduce a microphotograph of the appear-
ances displayed in the basal region of the cumulus where that structure be-
comes continuous with the stratum granulosum. Here within the same field
certain appearances are to be noted which very definitely suggest that these
bodies are the result of changes actually taking place in single follicular cells,
or, it may be, in groups of such cells (fig. 5).
Fig. 6 is a view shewing in the centre of the field a follicular cell which is
remarkable on account of its size and appearance.
Enclosed within a definite cell wall the cytoplasm appears uniformly granu-
10 | Arthur Thomson
Fig. 5. Section through the base of the cumulus of a human Graafian follicle shewing three bodies
ot Call and Exner (a, a,b). Two of these (a, a) are seen to be formed from single follicular cells,
whilst 6 exhibits their origin from a group of follicular cells. x 900. Specimen 280. 12. 5.
- Fig. 6. Section through the follicular epithelium shewing a an enlarged follicular cell prior to its
being surrounded by a corona of contiguous follicular cells. At 6 a similar follicular cell is
seen in process of being so surrounded. x 900. Specimen 453 A. 4. 5.
q
‘s
a
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a
:
;
Be
i
The Ripe Human Graafian Follicle 1]
. lar, and stains somewhat more deeply than that of the surrounding cells;
within this the nucleus shews up as a darker mass with no clearly defined
nuclear membrane such as is so characteristic of the surrounding cells, and
the chromatin granules are no longer isolated, but appear to be diffused
through the nuclear protoplasm (karyoplasm) in such a way as to impart a
darker tint to the whole nuclear substance, evidently a stage in the ultimate
dissolution of that structure.
In fig. 7 a further stage is exhibited. Here there is distinct evidence of a
vacuolation of the cytoplasm taking place within the cell membrane, while the
nucleus becomes less distinct and seems to be more diffuse. At the same time,
as will be seen in the figure, the surrounding follicular cells, by the increasing
ete \ 1 i
od b a a
Fig. 7. Section shewing vacuolation of cells composing bodies of Call and Exner, a,a,a. At b the
nucleus of one of them is disappearing. x 900. Specimen 280. 16. 5.
expansion of the central cell undergoing these changes, arrange themselves in
_ radial fashion, as would naturally be expected under the circumstances. In
the same field another such body is seen enclosed in typical fashion by the
characteristic radial formation of the surrounding follicular cells, though here
a large vacuole occupies the major part of the cell and the nucleus has dis-
appeared.
The occurrence of the vacuolation seems to vary in different examples;
in many this phenomenon does not occur till after the nucleus is completely
dissipated within the substance of the cell, so that the central mass produced
would seem to form a more or less homogeneous, seemingly solid, clearly stain-
ing material, occupying the centre of the radial formation of the follicular cells.
The change in the subsequent appearance of this substance is effected through
2
rae)
12 Arthur Thomson
Fig. 8. Section shewing the body of Call and Exner now reduced to the form of a reticulum by the
vacuolation of its substance. Around the vesicle so formed the contiguous follicular cells
are grouped in coronal fashion. x 900.’ Specimen 453 A. 4. 5.
sa Be zt Senn ave
See & % *S
on Bof C&E ' BofCc&E
Fig. 9. Section shewing how the bodies of Call and Exner (B. of C. and E.) may be compounded
of a number of follicular cells. x 900. Specimen 453 A. 4. 5.
_ The Ripe Human Graafian Follicle 13
the appearance either at the side of, or within it, of vacuoles of different sizes.
In the first instance these spaces may be small and few, in which case the
appearance presented is that of a coarse reticulum. In other cases the central
mass may be transformed into a fine reticulum by the presence of a number
of vacuoles which break it up in a more effective way, as seen in fig. 8.
Hitherto we have assumed that these appearances are the result of the
changes induced in one follicular cell, but there is evidence that groups of
cells may be agglutinated together, becoming, so to speak, encapsuled to form
the centre of a radial formation, thereby greatly increasing the size of the so-
ealled “body of Call and Exner.” Fig. 9 represents this appearance.
The individual cells of these groups appear to undergo the same changes
as those noted in the single cells already referred to, resulting in the fusion
/ { \
a a a
Fig. 10. Section of a body of Call and Exner vacuolated and shewing the disappearing nuclei,
a, a, a, of some of the cells of which it is compounded. x 900. Specimen 280. 12. 5.
of their products, and displaying this difference, that the size of the resulting
body is considerably larger, and the reticulum more complex.
A further proof of this is seen in fig. 10, where there is distinct evidence of
the presence of nuclear structures within the resulting reticulum.
The microphotographs here reproduced make it clear that the bodies of
Call and Exner can in no sense be regarded as due to the accumulation of the
products of the special activity of the radially arranged follicular cells around
them, as suggested by Honoré, but must be interpreted as the result of changes
in a follicular cell or group of cells, whereby modifications are induced in their
molecular structure, leading to the production of certain materials at different
periods of their dissolution, and ultimately resulting in a liquefaction of the
14 Arthur Thomson
bulk of their contents, which, together with a residual stroma, contributes to
the increase in the amount of the liquor folliculi.
In this respect my observations lead me to support the view advanced by
Nagel and others. There can, I think, be little doubt but that the radial
arrangement of the surrounding follicular cells is a purely mechanical result,
and that the so-called bodies of Call and Exner are merely to be considered
as foci of the processes which ultimately result in the breaking down of the
primarily compact mass of follicular cells, coincident with the production of
an antrum folliculi and the subsequent distension of that cavity with fluid.
In this way the major part of the follicular cells disappears. As to how they
are replaced or multiply, we have the evidence of Flemming ((8), p. 376 and
pl. XIX, figs. 32-84), who describes the frequent occurrence of karyokinetic
figures in the cells of the stratum granulosum of the cat and the rabbit, and
of Harz ((12) p. 874) who records mitosis in the follicular cells of the mouse,
whilst Nagel ((22) p. 379, pl. XXI, fig. 14) refers to it as demonstrated in the
human female.
In Professor A. Robinson’s memoir (27) I note the occurrence of mitotic
division as exhibited in his beautiful series of microphotographs (see fig. 58,
pl. X).
It follows that subsequent to the disappearance of the bulk of the follicular
cells, only a thin layer of cells, often only a single row in thickness, is left
lining the inner surface of the internal theca, and over-spreading the external
limiting membrane. This much reduced layer constitutes the stratum granu-
losum.
The only other situation in which the follicular cells appear to persist is in
the region of the cumulus, where in nearly all advanced Graafian follicles they
remain as a stalk or pedicle to the mass of cells which contains the ovum.
In these situations the follicular cells which may subsequently undergo
liquefaction, if this term may be employed, are not bedded in a compact mass
of surrounding cells, but often lie in such a position that one part of their
surface is only covered by a single layer of follicular cells, or may lie free in the
wall of the antrum folliculi. The first of these conditions is represented in |
fig. 11, where in the stratum granulosum the body comparable to that of Call
and Exner is represented by the cyst-like formation, the wall of which,
directed to the antrum folliculi, is formed of a thinned and spread-out layer
of follicular cells.
Fig. 12 shews the changes presented by a follicular cell superficially placed,
i.e. one of the cells lining the antrum folliculi. Here, within a vacuole, the
contained nucleus is exhibited undergoing evident dissolution. Similar changes
are also represented in fig. 18, in which case the change in the appearance of
the nucleus within the vacuole is less marked.
It would seem, in some cases, that the nuclear elements do not entirely
disappear, a fact which would account for the presence in the liquor folliculi
of the numerous nuclear-like bodies not unfrequently met with.
The Ripe Human Graafian Follicle 15
E oe = Sera 7 eS 1 : es . .
BoF C&E Strgran. Ant fol.
; Fig. 11. Section of a body of Call and Exner in the stratum granulosum (str. gran.) separated from
the antrum folliculi (antr. foll.) by but a single layer of follicular cells. x 900. Specimen
= 280. 12. 5.
oe
tr; cee i
Antr foll. a Strgran.
Fig. 12. Section shewing a follicular cell, a, of the stratum granulosum (sir. gran.) undergoing
dissolution. The nucleus is seen in an altered condition surrounded by a vacuolated space
which may either be an artefact of the nature of a retraction cavity or may contain fluid of a
different chemical constitution from that contained within the antrum folliculi (antr. foll.\
which is seen in the form of a coagulum. x 900. Specimen 280. 16, 5.
16 Arthur Thomson
In considering the changes in the follicular epithelium coincident with the
appearance and expansion of the antrum folliculi, a staining reaction which is
by no means infrequent must be here referred to. This consists in a marked
difference with which some of these follicular cells react to the same stain,
or combination of stains, It is best seen in the specimens which have been
subjected to the influence of some such reagent as Mallory’s connective tissue
stain, whereby some of the cells become stained of a pink or a yellow colour,
as contrasted with others (the majority) which exhibit a blue tint, an
occurrence which would suggest that some of the cells were undergoing a
change in their chemical constitution.
Antr foll,
4 Sey
a Str bran,
Fig. 13. Section shewing stratum granulosum (s/r. gran.) with a separated follicular cell (a) lying
within a vacuolated space within the coagulum occupying the antrum folliculi (antr. foll.).
The separated follicular cell (a) does not as yet present any appearance of undergoing change.
The vacuole around it may be an artefact or due to the vital activity of the cell (a). x 900.
Specimen 280. 14. 4. ;
It has been said that the cells of the stratum granulosum lining the interior
of the follicle and resting on the membrana limitans externa which separates
them from the inner surface of the internal theca, although often reduced to
a single row of cubical cells, yet exhibit no appearance of flattening or com-
pression, such as would be due to the result of pressure from within; for this
reason these cells must be regarded as a constituent part of the contained
liquid contents of the follicle, the pressure exercised by which is supported by
the internal theca overlain by the membrana limitans externa.
Another matter to which attention must be incidentally directed is the fact |
that the stratum granulosum is exceedingly prone to separate from the inner
theca of the follicle. In this connexion the observations of Robinson ((27),
p. 820) on the ovarian follicles of the ferret are of interest. After pointing out
be
an
on
‘a
4
_.
hy
e.
.
E
e
aa
q
The Ripe Human Graafian Follicle 17
that Wagener, Schottlinder, and Limon regard the membrana limitans externa
as a connective tissue structure, whilst Waldeyer and Nagel believe that it is
formed by the follicular cells, the latter asserting that it is similar at first to
the odlemma, Robinson proceeds to point out that in the ferret, the membrana
limitans externa does not react to stains in the same way as does the odlemma
(zona pellucida), and that when the follicular epithelium is detached from the
internal theca by the action of the fixative reagents, the membrana limitans
externa separates into two layers, as displayed in the figures he gives (figs. 58
and 60, pl. X). “The inner of the two layers,” continues the author, “is
connected with the outer ends of the follicle cells, and is possibly formed by
them in the same way that the external limiting membrane of the central
nervous system is formed by the outer ends of the neuroglial cells. The outer
layer is connected with the innermost flattened cells of the internal theca, and
it reacts like other connective tissue structures to connective tissue stains.”
He says further “Its function is unknown, but its constant presence indicates
utility, and it possibly regulates the passage of different materials in opposite
directions to and from the follicle.”
In regard to the staining affinities of the membrana limitans externa and
the zona pellucida in human material, our own observations do not correspond
with those of Robinson. In general, allowing for the difference in the density
of the two structures—the membrana being exceedingly delicate as compared
with the zona—the staining reaction appears to be very similar—both take
up the plasma stain as distinct from the nuclear stain. The appearance of
the membrana limitans externa is in every case very similar to that of the
capillary walls, in fact of all vessels which possess no muscular coat.
In sections of the rabbit’s ovary, which were examined after being sub-
jected to Mallory’s connective tissue stain (fixative: Flemming’s (strong)
formula), both the zona and the membrane were tinted blue alike. It was
noticeable that in the rabbit the membrane was a somewhat denser layer than
is revealed in the human Graafian follicle.
Observations on the human material at my disposal confirm the view that
the cells of the stratum granulosum are very prone to separate from the inner
surface of the internal theca of the follicle, and when this separation takes
place, the layer which intervenes, viz. the external limiting membrane, in-
variably remains attached to the connective tissue elements of the internal
theca. The separated layer of the stratum granulosum exhibits little appear-
ance on its outer surface of any but the feeblest connexion with this membrane,
and in most cases shews little evidence of any connecting fibres. In some
instances it would appear as if the union between the stratum granulosum and
the membrana limitans externa was sufficiently intimate to lead to a tearing
away of a layer of this latter structure, along with the eells of the stratum
granulosum, so separating it into two layers, as described by Robinson, the
inner being connected with the outer surface of the cells of the stratum granu-
losum, the outer still remaining adherent to the inner surface of the internal
Anatomy LIV 2
18 Arthur Thomson
theca, though no difference in staining reaction such as is described by Robin-
son could be discerned. The yee figures (figs. 14 and 15) represent
both conditions.
The fact that the ease with which the stratum granulosum appears to
separate from the membrana limitans externa seems to vary with the ripening
of the follicle, would suggest that this separation is a natural process, and not
necessarily an artefact as frequently supposed. The fact, too, that the mem-
brana limitans externa is at times prone to split into an external and an in-
ternal layer, where separation of the stratum granulosum takes place from the
inner surface of the internal theca, inclines one to the view that possibly this
intervening layer between these two mentioned structures may be in fact
permeated by an irregular lymph space, which weakens the bond between the
internal theca and the layer of the contained follicular cells, and so renders
more easy the separation of the two structures. For apart from the evidence
forthcoming in the examination of unruptured follicles, there is the cireum-
stance that immediately after the bursting of the follicle and prior to the
formation of a corpus luteum, the entire stratum granulosum is shed and dis-
appears, leaving only the internal theca and the membrana limitans externa
lining it. Moreover, through the courtesy of Professor Robinson I have been
able to note the fact that in the ferret the ovum after it has escaped from the
Graafian follicle is not only surrounded by the cells of the cumulus, but also
has connected therewith a considerable amount of a layer corresponding to
the stratum granulosum, thus proving that at the time of rupture the stratum
granulosum was in part or in whole discharged. These observations seem to
point to the separation of the stratum granulosum from the internal theca
as a normal process, and not necessarily an artefact as so many hold it to be.
This matter will be again referred to when the mode of rupture of the
follicle is discussed. ;
In concluding this section relating to the liquor folliculi; mention must be
made of the varieties of coagulum met with in the follicle, even when subjected
to the same fixing reagent. In many instances the coagulum exhibits the
appearance of fine ground glass, in others the granulations are coarser. In
some it takes on the form of an open meshwork. In all, as best seen at the
edges, the reticulum varies much in appearance, in some it is fine, in others,
coarse. These appearances, met with in what seem normal follicles, combined
with the variety of tint displayed when subjected to the same staining reagent,
suggest that the physical and chemical constitution of the liquor folliculi is not
always constant, but is undergoing change, it may be by the addition or sub-
traction of constituents which affect its density or alter the character of its
composition.
The Sheath of the Follicle
As usually described the specialised part of the ovarian stroma around the
follicle consists of two not very clearly defined zones, the internal theca and -
The Ripe Human Graafian Follicle 19
’—Memb. lirmt.
ext.
f.
4 i od >
BYs. ee Antr-foll. Bivs.
Fig. 14. Section shewing the appearance of the internal theca (int. theca) when the stratum granu-
losum has become separated from it. The membrana limitans externa (mem. lim. ext.) is seen
adherent to the internal theca. B.vs. capillaries within the internal theca filled with blood
corpuscles. x 700. Specimen O, 1. 103
Fig. 15. Section of the wall of a follicle shewing stratum granulosum (str. gran.) and internal theca
(int. theca) lying in apposition, with the external limiting membrane (mem. lim. ezt.) in be-
tween; at the point a this layer is seen to split, one layer (6) adheres to the internal theca,
the other (c) clings to the stratum granulosum; the interspace between is probably a lymph
space. B.vs. capillaries of internal theca: antr. foll. antrum folliculi. x 600. Specimen O. I.
20. 5.
2-2
20 Arthur Thomson
the external theca. The internal theca is composed of a loose cellular stroma
made up of round and spindle-shaped cells, and has a capillary net-work
throughout its substance. To the outer side of this lies the external theca, in
which zone, the tissue is denser, more fibrillar, and less vascular, though here
the blood vessels are larger, and furnish the branches which supply the capil-
lary plexus of the internal theca. In the theca externa there are also described
a number of hollow spaces which are interpreted as enlarged lymph channels.
A study of the appearance of the internal theca reveals the fact that this
layer becomes richer in capillaries as the growth of the follicle proceeds (see
Nagel, (23), p. 56); so also the round cells become larger and more numerous.
In some instances I have reason to believe that the theca interna over the area
which corresponds to the site of the cumulus is more vascular than in other
parts of the circumference of the follicle, a fact which, as will presently appear,
has some significance.
Not only does the internal theca appear to be richer in capillaries, but in
several instances, one of which is here represented (fig. 16), the capillaries are
not confined to the theca interna, but invade the substance of the follicular
epithelium, where it forms the base of the cumulus or discus proligerus.
So far as I am aware, no mention of this condition has hitherto been made,
and I was inclined to regard the first specimen I observed of this appearance
as of the nature of a haemorrhage. The sections, which were stained with
Mallory’s connective tissue stain, revealed the blood corpuscles as tinted a
brilliant scarlet, a feature which enabled us to trace with ease their disposition
and arrangement. By adopting a method of reconstruction it was possible
to prove the continuity of these collections of blood corpuscles, and to trace
their connexion with the capillaries of the internal theca; there was also
distinct evidence that around these collections of blood cells there was a ~
delicate membrane, directly continuous with, and presenting the same appear-
ance as, that enclosing the capillary channels of the internal theca. Obviously
it was hazardous to base any conclusion regarding the nature of this condition
on its occurrence in one particular specimen, consequently a search was made
to see whether it occurred in other follicles. The result was confirmatory, for
in several other instances the presence of blood corpuscles similarly grouped
and ensheathed was clearly demonstrated, though it must be admitted, that
but for the differential staining produced by the employment of Mallory’s
formula the occurrence of this particular arrangement might have been over-
looked.
On reviewing the eldcice however, it was particularly noticeable that,
with one exception, all the specimens exhibiting this feature were derived from
the same source, a woman who died of heart disease, and regarding the post
mortem of whom the report records the occurrence of “back pressure”
changes in many of the viscera. This condition may naturally be regarded
as answerable for the appearance displayed, and might be accepted as con-
clusive evidence that the arrangement of the capillaries represented is abnor-
The Ripe Human Graafian Follicle 21
mal, were it not for the fact that a similar condition was met with in the ovary
of a woman aged 35 who died of laudanum poisoning, in which case the ovum
contained within the follicle was degenerate. It may be that the administra-
tion of this drug is ‘alike responsible for the unusual appearance observed.
Whatever be the cause, and whether or no we are to regard the incidence of
Ante. Foll.
Cur. Byé. ~ Extetheca. Int. theca. Memb.limit.ext.
Fig. 16. Section through the cumulus or a human Graanan roilicle shewing ovum in situ sur-
rounded by the zona pellucida and corona radiata. The base of the cumulus is invaded by
capillaries containing blood cells. These are seen to be enclosed by distinct walls similar to
those displayed by the capillaries of the internal theca (int. theca). The membrana limitans
externa (seen at mem. lim. ext.) seems to disappear as a definite layer in the region correspond-
ing to the base of the cumulus (cum.). Eat. theca, external theca: anér. foll. antrum folliculi.
x 200. Specimen 453 F. 20. 4.
this feature as normal or abnormal, its occurrence is worthy of record, since
possibly, if normal, it may be the means of providing the ovum with an in-
creased source of nutrition, whilst if abnormal, it may account for degenerative
conditions which may arise in like or similar circumstances.
It is interesting to note that in the specimens taken from the woman who
died of heart disease, the presence of this condition did not appear to have any
22 Arthur Thomson
deleterious effect on the ova, for in the sections examined these appeared to
be normal. In the case of the woman who died from laudanum poisoning it is
open to doubt whether the degenerated ovum was a direct result of the poison
or secondary to the vascular changes present.
There arises in this connexion the question of the relation of the membrana
limitans externa (basal membrane) to these capillary invasions. It would
appear from an examination of the specimens in which this peculiar distribu-
tion of the vessels occurs, that in the neighbourhood of their entry into the
cumulus the membrana limitans externa has disappeared, and there seems no
line of demarcation to separate the follicular cells from the connective tissue
elements of the theca interna.
It must not be assumed that the cases I have recorded include all the
instances of blood within the follicle. Not unfrequently undoubted cases of
haemorrhage are met with, occurring either as scattered masses of blood
corpuscles within the substance of the follicular cell work, or else discharged in
bulk into the antrum folliculi. These collections we generally found associated
with molecular changes in the walls of the follicle, and also combined with
marked degenerative changes in the ovum itself. It may be that the appear-
ances I have noted, and here figured, are only an early stage of the process
which ultimately results in a diffuse haemorrhage. If so, they may be of
interest as shewing how this destructive process leading to the atresia of the
follicle is induced.
Of the changes which take place in the structure of the internal theca at the
point corresponding to the site of its ultimate rupture little need be said.
As the covering wall of the follicle in this region becomes thinner its vascularity
becomes reduced.
Already reference has been made to the membrana limitans externa (basal -
membrane). This, as has been said, intervenes between the inner surface
of the theca interna and the peripheral cells of the follicular epithelium which
lie within the follicle. It is shown in situ in fig. 17. :
As already described, when separation occurs between these two con-
stituents of the follicle, the bulk of the membrana limitans externa (basal
membrane) remains adherent to the flattened cells forming the inner surface
of the internal theca (see fig. 14). For this reason, the term “‘ basal membrane”
as applied to it, suggesting its intimate connexion with the cubical cells of the
stratum granulosum which overlie it, is misleading. Its behaviour and ana-
tomical disposition are more in accord with the interpretation of the term
“external limiting membrane” applied to it.
It should be noted that in many parts of the section of the wall of the
follicle this limiting membrane is the only layer which intervenes between the
capillary stream and the contents of the follicle, and if so be, as has been
suggested by its tendency to split into two layers, this limiting membrane
contains a series of lymph channels within its substance, it may well be that it
forms a structure of no little importance, not only in regard to the nutrition —
The Ripe Human Graafian Follicle 23
of the follicular contents, but also in connexion with the process involving the
rupture of the follicle itself.
The external theca. As already explained, there is no clear line of differentia-
tion between this and the internal theca; it differs from the latter in the absence
of a capillary network, and the greater density of its constituent layers, which
are largely composed of fibrillar tissue, derived from the surrounding ovarian
stroma, and concentrically arranged around the Graafian follicle. It is to the
nature of this tissue that attention must first be directed.
Schiifer (9), p. 648) thus describes the ovary: “Each ovary is formed of a
solid mass of fibrous-looking tissue (stroma), which contains between its fibres
Antr. foll.
bStr, gran.
—Memb. limit. !
ext.
l
|
]
]
bint. theca.
- _#
B.vs, Bs. B.vs,
Fig. 17. Section through the wall of a human Graafian follicle shewing stratum granulosum (sir.
gran.), membrana limitans externa (mem. lim. ext.) and internal theca (int. theca) all in contact.
B.vs. capillaries of internal theca containing blood. Anér. foll. antrum folliculi. x 700.
Specimen 453 B. 27. 3.
very many elongated cells like those of embryonic fibrous tissue...Along the
line of attachment (hilum) blood vessels and nerves enter and leave the ovary,
and accompanying these is a strand of fibrous tissue which contains plain
muscle amongst its fibres.”
Piersol ((24), p. 1987) says of the cortex of the ovary: “‘The stroma cells
somewhat resemble the elements of involuntary muscular fibre in appearance,”
and in reference to the medulla says it consists of fibro-elastic tissue and smooth
muscle accompanying the larger vessels. In this connexion it may here be
stated that in a specimen stained with Weigert’s elastic tissue stain the only
situation in which elastic fibres were recognised was in relation to the walls
\
t
24 Arthur Thomson
of the vessels—neither in the general stroma of the organ nor in the follicular
walls was there any evidence of the presence of elastic tissues.
Nagel ((23), p. 49) states that in the zona vasculosa there is “an extension
from the muscular tissue of the broad ligament along the larger vessels, better
marked in mammals than in man.”
It would seem, therefore, that in the groundwork of the ovary we have to
5 deal with fibrous and muscular elements, the differentiation of which is not
always an easy matter.
Winiwarter ((35) and (36)) states that the distribution of the muscular ele-
\ ment in the human ovary is identical with that exhibited in the cat, in which
a b Str gran.
a I i
|
Ovistr Memblimitext, Int.theca, Exttheca. ¢
Fig. 18. Section ‘hrough the wall of a human Graafian follicle. a, coagulum within antrum folliculi;
b, retraction space between coagulum and stratum granulosum (str. gran.): int. theca, internal
theca with capillaries; ext. theca, external theca with (c) bundles of smooth muscular fibre
differentially stained with safranin and light green. x 400. Specimen O 2. 52. 3.
animal he describe: it as entering into the formation of the external theca
of the Graafian follicle. Before I was acquainted with his conclusions I was
myself engaged in analysing the nature of the fibres of the external theca, and
had been led independently, through the staining reactions, to suppose that
all the fibrils were not of a like nature.
My attention was first directed to this whilst examining some specimens
stained with safranin and light green. With this reagent some of the con-
centric fibres of the external theca were stained a pronounced pink, which
stood out in contrast to the grayish green tint of the surrounding stroma.
Fig. 18 exhibits the appearance in a section through the follicular wall.
The coagulum within the antrum folliculi is stained a bright green in the
The Ripe Human Graafian Follicle 25
original specimen, the membrana granulosa is purplish in tint. The theca
interna is coloured a purplish gray, whilst in the theca externa there are
elongated fibres which, staining a pronounced pink, stand out in marked con-
trast to the surrounding grayish green stroma. Confirmatory evidence was
Memb. Hienit. ext.
3
ee eee ee veoh ages
Smee Sms. Smé
Fig. 19. Higher magnification of a portion of the same follicular wall as that shewn in fig. 18.
Str. gran. stratum granulosum; int. theca, internal theca; ext, theca, external theca, in which
are seen the fibres, s.m.f., which have been identified as smooth muscle fibres. Mem. lim. ezt.
membrana limitans externa, in this specimen not very clearly defined. x 600. Specimen O 2.
80.
also obtained from other specimens stained by Mallory’s method, wherein
corresponding groups of fibres were stained distinctly purple in contrast with
the surrounding bright blue colour; whilst in other sections of different
follicles subjected to the influence of Congo red, the same tissue elements were
revealed stained a dull violet, contrasted with the grayer colour of the tissue
around. It is only fair to say that these results were not obtained in all the
specimens examined, but so convinced was I of their significance that I em-
26 Arthur Thomson
ployed other and more refined methods, with confirmatory results. Fearing
lest my observations might be biassed, I handed over some unstained sections
to my friend Mr H. M. Carleton, the Demonstrator in Histology, with the
request that he would subject them to a careful examination. This he took
great pains to do, and finally admitted that on histological grounds, no less
than by reason of the staining reaction, the tissue undoubtedly contained
smooth muscle fibre. From my own material I am enabled to furnish a figure
of a highly magnified microphotograph which demonstrates these features
(fig. 19).
Whilst there is thus undoubted evidence of the presence of smooth muscle
in the external theca of the follicle, it is interesting to note that with certain
reagents, we may obtain, under a low power, a general view of the distribution
of this muscular element throughout the substance of the ovary as seen in
section. This is best demonstrated in sections stained with safranin and light
green; the colour differentiation effected is such as to indicate the presence
of a tissue of a peculiar staining quality which invades the substance of the
ovary along the line of the great vessels and follows them outwards as they
reach the area of their distribution towards the cortex. The general arrange-
ment of this particularly coloured zone conforms closely to the distribution
of the blood vessels as indicated in the figure which Clark (6) has published in
his account of the blood vessels of the ovary. As may there be seen, the smaller
vessels are traced to the. walls of the follicle, accompanied no doubt by the
strands of smooth muscle, whose general course is indicated by their greater
affinity for one of the constituents of the double stain. In the specimen ex-
amined the contrast between the differently stained areas was sufficiently
pronounced to indicate the general distribution of the smooth muscle.
In the human ovary it thus appears that smooth muscle is present in con-
siderable quantity, not so abundant as may be seen in lower forms, but still
in such amount as to play a considerable part in the functioning of the organ.
According to Winiwarter ((36), p. 639), all attempts have hitherto failed
to demonstrate the presence of this muscular element by experimental means.
I therefore consulted my friend Dr Gunn, the Professor of Pharmacology here,
who, after having had his interest enlisted in the question, determined to make
afresh attempt. He reports as follows: ‘‘The ovary (a rabbit’s) was suspended
in a bath of oxygenated Locke’s solution at body temperature. Movements
were recorded by a light-lever of high magnification, the method used being the
same as has been widely employed for the isolated uterus and other organs.
No spontaneous movements were shewn by the ovary. In one experiment
the ovary of a full-grown virgin rabbit shewed on the addition of adrenaline
to the Locke’s solution (in concentration of 1 in 200,000) a contraction of the
ovary characteristic of smooth muscle. Adrenaline stimulates the sympathetic
nerve ends in smooth muscle. The sympathetic nerve is a motor nerve to the
_ rabbit’s uterus. The experiment therefore indicated that the ovary contains
smooth muscle, innervated by the sympathetic, and that the innervation of
The Ripe Human Graafian Follicle 27
the ovary is qualitatively the same as of the uterus (in the rabbit). With high
lever magnification the amplitude of excursion was very small, indicating
a very small amount of contractile tissue.”
This experiment seems to set at rest all doubts as to the presence of fune-
tionally active muscular fibres within the stroma of the ovary, and as we have
already seen that fibres answering to the histological details of smooth mus-
cular fibres and reacting similarly to selective stains occur within the wall
around the Graafian follicle, it is evident that we have to hand a means which
‘may play a not unimportant part in the rupture of the follicle.
Fig. 20. Section through a nearly ripe human Graafian follicle; a, the surface of the ovary; here
the follicular wall is only about -2 mm. thick: 6, the cumulus containing the mature ovum,
note that it lies on the superficial aspect of the follicle, immediately opposite and close to the
thinnest part of the follicular wall. Both the cumulus (6) and the stratum granulosum (c)
are separated from the internal theca in the upper hemisphere; d, the external and internal
thecae combined, the magnification is not sufficiently high to differentiate these layers. In the
lower hemisphere of the follicle the cells composing the stratum granulosum are still adherent
to the inner surface of the follicular wall, the membrana limitans externa alone intervening;
the magnification is not sufficient to shew this layer; an/r. foll. antrum folliculi. x 18. Speci-
men 453 A. 35. 4. :
The Rupture of the Follicle
Having passed in review the various structures which enter into the for-
mation of the Graafian follicle and its contents, it may now be possible to
discuss the means by which the follicle ultimately ruptures and sheds its
contents. Before, however, proceeding to consider this question, it may not be
without advantage to reproduce a microphotograph of a Graafian follicle which
must have nearly reached the stage at which its rupture was imminent, to
judge by the appearances displayed (fig. 20).
28 Arthur Thomson
The estimated size of the follicle is 2:00 x 1-96 x 1-68 mm. As is readily
seen, the superficial wall of the follicle, i.e. that separating its cavity from the
surface of the ovary, is thin, only 0-2 mm. thick. The ovum contained within
the follicle is judged to be mature, since there is present in it a divided first
polar body, together with a second polar body, whilst the nucleus appears
to have returned to the resting condition. A figure of this oécyte has already
been published in my previous paper on the maturation of the ovum (33). For
all these reasons, we are justified in supposing that the follicle is ripe, and has
reached the stage in its existence when its collapse, and the liberation of its
contents, cannot for long be delayed if the physiological necessity arises.
But an examination of the figure enables us to realise certain unusual
features. First, we recognise that the ovum, surrounded by the cumulus, is so
disposed that it lies superficially within the follicle, and near, and in immediate
correspondence with the line of the stigma—the site corresponding to the point
of rupture. But secondly, it is obvious that throughout the superficia) hemi-
sphere (i.e. that directed to the surface of the ovary) the stratum granulosum
with the cumulus has become detached from the inner surface of the internal
theca; elsewhere, over the inner surface of the posterior hemisphere, it still
remains attached.
Obviously no better arrangement could be devised for the expulsion of the
ovum than that shewn here, for if the rupture be due to an increase in internal
pressure, the ovum would naturally, by the bursting pressure, be forced
through the orifice made in the weakened wall when that gave way. Unfortu-
nately, as we have already seen, the position of the ovum and the cumulus
is not always superficial, but may be, and often is, situated in relation to the
deep surface of the follicle, at a point opposite and farthest removed from the
stigma, in which case it is difficult to understand how, when the rupture occurs,
the discharge of the ovum is effected. Under these circumstances the doubt
arises in one’s mind, as to whether the ovum is not more likely to remain
lodged in the bottom of the empty cup.
The detachment of the cells of the stratum granulosum from the inner
. surface of the internal theca is a matter which has already attracted a con-
siderable amount of attention. The prevailing opinion is that the condition
is to be regarded as an artefact—that it is due to the retraction induced by the
coagulation of the liquor folliculi. Such an explanation seems feasible, and is
possibly the one that comes readiest to hand; before accepting it, however,
there are some other considerations that must be taken into account.
In the numerous examples of this condition which I have studied, I have
been struck with the fact that there is not always such a correspondence in
the contours and area of the retracted surfaces of the stratum granulosum
and the internal theca as one might expect if the separation of the layers were
effected by such mechanical means. It is not uncommon to find the stratum
granulosum floated well into the centre of the follicle, and twisted and in-
folded in such a way as to suggest that these layers were afloat in the fluid
The Ripe Human Graafian Follicle 29
contained within the follicle at a time prior to its coagulation. Further, they
often exhibit appearances as if undergoing disintegration, and are frequently
fragmented. In dealing with human material it is only fair to say that putre-
factive processes must not be overlooked. Yet withal, I confess I am by no
means assured that the condition is thus easily explained as being due to the
effects of coagulation by fixation.
There are additional reasons for hesitating to accept this view. First, the
case in which the cumulus is so disposed as to lie on the deep surface of the
‘interior of the follicle, the site assigned to it by Nagel and others as normal.
Under those circumstances it is difficult to see, as has just been observed,
how by any pressure sufficient to burst the follicle the ovum could be expelled
through an opening opposite in direction to the force to which it was being
subjected. As has been said, a more reasonable supposition would be that
it would be left in the bottom of the cup, and this, be it observed, is what is
supposed to have happened in those cases of ovarian pregnancy which have
been recorded, the explanation offered being that the ovum has failed to escape
from the ruptured follicle and that the entering spermatozoén has fertilised |
it in situ.
Second. Thanks to the kindness of Professor Robinson, I have had an
opportunity of seeing, amongst his collection of ferret material, an ovum, just
within the oviduct, apparently recently discharged from its follicle, which,
besides being surrounded by the cells of the cumulus, had, attached to these,
tags of tissue which could only be accounted for on the supposition that they
were remains of the sheet of the surrounding stratum granulosum.
Third. In one case I had the opportunity of examining a human Graafian
follicle which must have been quite recently ruptured. In this I failed to find
any trace of follicular cells—all that remained was the enfolded and engorged
internal theca, very definitely lined internally by the membrana limitans ex-
terna, without any trace, so far as I could see, of any follicular cells overlying
it. Within what was left of the cavity of the follicle were a few scattered blood
cells only?. .
This raises of course the vexed question of the origin of the corpus luteum.
Von Baer in 1827 propounded the view that the corpus luteum was derived
from the theca interna. This conception has been supported by Valentine,
His, Rokitansky, Kélliker, Gegenbaur, Paladino, Nagel, Bonnet, Schottlander,
Minot, Williams, Clark and others.
On the other hand Bischoff in 1842 expressed the opinion that the corpus
luteum is derived from the follicular epithelium. This view has received
support from Meckel, Pfliiger, Luschka, Waldeyer, Sobotta, Honoré, Marshall,
Van der Stricht, Heape, and Kries, amongst others.
Rabl in 1898 suggested a compromise, and concluded that the lutein cells
1 It is interesting to note that this specimen was obtained from the ovary of a woman whose
uterus exhibited evidence of the onset of menstruation.
30 Arthur Thomson
have a double origin, arising both from the membrana granulosa and from the
theca interna!.
Into this controversy I am not at present prepared to enter; all I can say
is that the human specimen I have here mentioned appears to confirm in every
respect the original contention of Von Baer.
There can be little doubt but that the liquor folliculi serves two useful
purposes: it acts as a source of nutrition for the ovum, as well as providing
a means for its protection. The production of this fluid by the disintegration
of the follicular cells through the agency of the so-called bodies of Call and
Exner has been already discussed (see p. 14), and need not now be further
alluded to. During this process of the dissipation of the follicular cells, with
a concomitant increase in the size of the antrum folliculi, there also appears
to be taking place a reproduction of these follicular cells to replace the wastage,
as evidenced by the occurrence of mitotic division observed amongst them.
To what extent this takes place it is difficult to say, but apparently there
comes a time when this source of reinforcement is reduced to the thin single
layer of cubical cells which represents all that is left of the stratum granulosum.
In some instances, the conditions are such that this remaining layer may all
but disappear, in fact in some cases I have failed to find evidence of it in parts
of the circumference of the follicle.
Support is given to this view by the observations of Miss Lane-Claypon
((16), p. 42) on the ripe Graafian follicle of the rabbit, in which she describes
‘almost complete disintegration of the membrana granulosa.”
A fact of some interest, be it noted, is that this condition is not necessarily
met with in follicles which one would regard as fast approaching their rupture,
as judged by their very superficial position and the thinness of their overlying
wall. This activity on the part of the follicular cells is no doubt sustained by
the nutrition derived from the fluids of the blood through the agency of the
capillaries of the internal theca, and possibly the liquor folliculi itself may be
increased in bulk by an admixture of constituents derived from both sources.
In this connexion, it is well to remember that interposed between the
peripherally placed follicular cells and the capillary zone of the internal theca,
there is the membrane which has been already alluded to as the membrana limi-
tans externa (basal membrane). Now, as stated, there is considerable doubt
as to the constitution of this membrane. We have seen that the union between
this membrane and the follicular cells is generally speaking very feeble, and
that the follicular cells are extremely liable to be detached therefrom, it may
be by artificial means, or possibly as the result of a normal process. In the
accompanying figure (fig. 21) there seems strong evidence for believing that
the separation of the stratum granulosum and the internal theca is effected
by the infusion of fluid between the two layers of the membrana externa,
and not by the dragging away by retraction of the membrana externa from
1 For the literature of this subject I am indebted to the papers of J. G. Clark (5) and F. H.
Marshall (19),
*
o
:
|
The Ripe Human Graafian Follicle 31
the internal theca, else how can we account for the appearance of distensions
within these spaces and the concavity of their walls?
As a consequence of this separation, whilst in the majority of cases the
bulk of the membrana limitans externa adheres to the inner surface of the
internal theca, yet the evidence produced (see fig. 15) of the splitting of this
layer so that one lamina adheres to the follicular cells, whilst the other remains
in contact with the internal theca, suggests that the structurefof this layer
is not so homogeneous as is usually described, but that sandwiched between its
a a Antr. foll. a
- Int. theca.
(ie RSS ee ae sitios
= ves eall Se ne a ee ee Ten ae
I 1
B.ys. | Memb, limit,int. Bs, B.ys,
_ Fig. 21. Section of human follicular wall shewing the commencement of the separation of the
stratum granulosum (sir. gran.) from the internal theca (int. theca). This appears to involve
the splitting of the membrana limitans externa through the distension of the lymph spaces
in it, so that larger spaces (a, a, a) are produced, the walls ot which through their concave
contours afford evidence of a pressure from within, due to the accumulation of fluid inside
the spaces. Note the position of the capillaries (B.vs.) of the internal theca (int. theca) in
relation to these spaces (a, a, a) the walls of which are formed by the split membrana limitans
externa, one layer of which adheres to the internal theca, the other forming what looks like
a basement membrane to the external layer of cells of the stratum granulosum. Anir. foll.
antrum folliculi filled with a reticulated coagulum. x 400. Specimen 453 B. 30. 6.
inner and outer strata there may be a weaker element, or, what is more prob-
able, a series of lymph spaces in direct contact with the capillaries of the
internal theca, as seen in the figure, on the one hand, and the bedded bases of
the follicular cells on the other.
This splitting of the external limiting membrane is a feature to which
Robinson ((27), p. 320, plate X, figs. 58 and 67) has already called attention,
though he attributes it to the use of fixatives. Granted that it is so, it may be
32 Arthur Thomson
the means of revealing potential spaces which at the time may not be dis-
tended, but this in no wise precludes the possibility of these being tissue fluid
channels,
My reason for dwelling on these facts is that they may possibly afford an
explanation of what happens when the follicle bursts. Various opinions have
been expressed in regard to the mechanism which brings about this pheno-
menon. The generally accepted view is that by a gradual increase in the bulk
of the contents of the follicle such a pressure is induced as will lead to the
rupture of the gradually weakening wall in the region of the stigma.
On the other hand, some, in order to bring the details more into accord
with the accepted facts, suggest that the rupture of the follicle is induced by
a sudden increase in the follicular pressure.
Nagel ((23), p. 60) and his followers attribute the rupture to changes taking
_ place in the tunica interna, whereby its vessels become highly developed, and
its cells multiply enormously, every cell increasing in size by the growth of its
protoplasm, at the same time the protoplasm becomes filled with a peculiar
crumbling mass of which nothing more definite is known, from which the
whole inner wall of the follicle (in the fresh condition even before its rupture)
acquires a yellowish colour. The tunica interna thus altered has an undulating
appearance, while its cells, which are now called lutein cells, and form a strong
layer many rows thick, are arranged in the form of papillae, into every papilla
runs a much-branched vessel. Through this growth of the lutein cells the
contents of the follicle are pushed towards the thinnest part of the follicle
(stigma) on the surface of the ovary, and thus the follicle is brought to its
rupture.
In respect of this I can only say that my own observations have not
enabled me to recognise these conditions in the still unruptured, though appa-
rently ripe follicle. The appearances described are such as are readily recog-
nised in the freshly ruptured follicle, preliminary to the formation of a corpus
luteum, though here unfortunately we are unable to form other than an ap-
proximate estimate of the time which may have elapsed between the rupture
and the examination of the specimen.
Clark (6), in discussing the matter, in part attributes the dehiscence of the
follicle to the peculiar arrangement of the vessels of the ovary, and was able
to demonstrate the rupture of the follicle following the introduction of a
carmine-gelatine injection. He also considers the occurrence of haemorrhage
within the follicle more frequent than its absence.
Heape (13) considers that in the rabbit the rupture is induced by the stimu-
lation of the erectile tissue, and not simply as a result of internal pressure
arising from increased vascularity, or a greater amount of liquor folliculi.
In a series of experiments Schochet ((30), p. 241) indicates that the liquor
folliculi possesses a digestive enzyme that can be demonstrated by dialysis and
other tests. As a tentative interpretation it is suggested that the rupture of a
Graafian follicle is due in part tothe digestion of the theca by the liquor folliculi.
The Ripe Human Graafian Follicle 33
Winiwarter ((36), pp. 640-41), in discussing the function of the smooth
muscle met with in the ovary, reviews the suggestions previously made by
Rouget 28), and Aeby (1), that the muscular tissue plays its part “‘by setting
in action a complex mechanism subject to physiological conditions of which
we are ignorant, and which simple galvanic stimulation cannot reproduce,”
the conclusion being that “the ovary, together with all the internal genital
tract, can undergo erection under the influence of a stimulus aroused, in the
ovary, by the distension of the Graafian follicles; the increase of tension in the
ovarian stroma brings on the rupture of the follicle, after which relaxation
follows; it is therefore the muscular tissue of the mesovarium which plays
the active part.” This hypothesis is also supported by Grohe (11).
Winiwarter’s own conclusion is that the muscular tissue in the mes-
ovarium acts in part by controlling the venous return from the organ, thereby
conferring on it an erectile power, probably associated with the period of rut,
or, it may be, aroused by the stimulus of coitus, whilst he suggests that the
presence of smooth muscle in the external theca of the Graafian follicle may be
a determining cause of its rupture.
Furthermore, it has frequently been suggested that the congestions which
occur within the pelvic organs at the menstrual periods, and the turgescence
of the associated organs which may occur during coitus, may have something
to do with the rupture of the follicles.
It is too complex a problem here to discuss the question of the relation
of ovulation to menstruation, suffice it to say that the bulk of the evidence
seems to point to the fact that there-is an intimate association between the
two phenomena, and that consequently those vascular changes which we
associate with the one may be in part responsible for certain of the processes
connected with the other.
As Eden puts it ((7), p. 6): “It is undoubtedly true that ovulation and
menstruation are closely related to one another. Whether they are coincident
or consecutive, and if consecutive, which precedes the other, we do not know
with certainty.”
Barnes ((2), p. 455), Dr Clelia Mosher@l) and Helen MacMurchy ((17),
p- 909) quoting Giles ((10), p. 115) and Dr Mary Jacobi (15), are all agreed that
there is normally a rise in blood pressure for a day or two prior to menstruation,
and a fall immediately on the onset of the fiow.
I am aware that the occurrence of apparently ripe Graafian follicles has
been recorded in young children prior to menstruation, and even in some
instances in the new-born child (Nagel (22), p. 418), but there is no evidence that
these ever ruptured or that the ova therein contained were capable of fertilisa-
tion; it is much more probable that the follicles became atretic.
Considering the foregoing suggestions and the observations on which they
are based, it would appear that well-nigh everything that could be said on the
subject had been already stated. A little reflection, however will, I hope,
induce the reader to believe that there are other ways of interpreting the
Anatomy LIV 3
34 Arthur Thomson
phenomena, and so bringing them more in line with what experience would
support.
I have endeavoured to suggest that the main function of the liquor folliculi
is to nourish, conserve, and protect the delicate ovum as it lies within the
follicle. Evidently a time arrives when, from the appearance presented, the
further production of the liquor folliculi by the disintegration of the follicular
cells is arrested, as evidenced by the reduction in number and change in
character of the residual follicular cells. At this stage we may assume that the
pressure within the follicle is stabilised, and may remain for unknown periods
undisturbed. It is therefore hard to believe that the pressure within the
follicle can be rapidly raised by any sudden increase in the amount of the fluid
derived from the follicular cells.
We have around the follicular cyst, if such I may call the liquor folliculi
enveloped by the stratum granulosum, a capillary plexus subject to all the
controlling influences of the sympathetic nervous system.
We have already alluded to this capillary zone as essential to the nutrition
of the follicular epithelium, though to what extent the liquid constituents
of the blood may contribute to the fluid bulk of the liquor folliculi we have
no information; but assuming that the liquor folliculi.is in main the product
of the follicular cells, it by no means follows that, since the source of that
supply is no longer active, the fluid derived from the blood in the capillaries
contributes no further to the increase in fluid contents of the follicular cyst;
controlled as is this supply by the sympathetic, it must necessarily react to
such stimuli as induce changes in the circulation directly concerned, or, it may
be, in harmony with vascular changes induced in the tissue around.
Sexual thoughts, sexual desires, coitus, the congestion associated with
menstruation, may all play a part, with what result?—the immediate and
sudden increase in pressure, involving, it may be, the transudation of a greater
quantity of the fluids of the blood, and thus increasing the pressure contents
of the follicle to its straining point. I suggest that in this process, when dealing
with a follicle the contents of which are ripe for discharge but quiescent, the
effusion of fluid poured out from the capillaries invades those lymph channels
which, we have reason to believe, intervene between the cells of the stratum
granulosum and the internal theca, thereby tending to separate the granular
layer from the inner wall of the follicle, and thus leading to the release of the
cumulus and its anchoring layers, so that it, with the contained ovum, lies
free and floating within the cavity of the follicle in such a way that it must
follow the stream of the fluid on its expulsion and release through the rupture.
In this way, possibly, is effected the liberation of the ovum and its associ-
ated follicular cells from the wall of the follicle, which B6hm and Davidoff (3)
have suggested as an initial stage in the escape of the ovum from the ruptured
follicle. According to these authors the ovum and the cells of the surrounding
cumulus, or discus proligerus, ultimately come to lie free and floating within
the liquor folliculi, a process which in their opinion is effected by the softening
The Ripe Human Graafian Follicle 35
of the cells of the pedicle of the cumulus, which thus leads to the separation
of the cumulus and the contained ovum from the stratum granulosum. I do
not deny the possibility of this happening, but I have not so seen it in any of
the specimens I have examined, for in all the cases in which I have been able
to follow, through a number of serial sections, the relations of an apparently
free cumulus as displayed in some sections, on careful search I have been able
invariably to trace its connexion with the stratum granulosum in other
sections. For these reasons I suggest that the same end is accomplished by
the stripping off of the entire follicular cyst from the inner wall of the internal
theca by the rapid effusion of fluid derived from the capillaries, for in no other
way can we account for the somewhat sudden increase in pressure which
appears to be a necessary accompaniment of the process of ovulation.
Whilst admitting that this is a phenomenon which is dependent on effects
primarily induced by the nervous mechanism controlling the circulation, we
must not overlook the fact that there are other contributory causes that may
play a part. We have hitherto assumed that the increase in internal pressure,
effected as suggested, is the determining cause of the rupture of the follicle,
for as soon as that pressure exceeds the resistance of the weakened wall of the
follicle in the region of the macula or stigma, rupture must inevitably take
place. On the other hand no regard has been paid to the possible influence of
muscular contraction as the determining cause of the rupture of the follicle.
The occurrence of smooth muscle fibre within the stroma of the ovary and
mesovarium is generally admitted. Why is it there? Of what use may it be?
Winiwarter ( (35), p. 640) has already suggested that, by its contraction, the
return of the flow of blood through the veins may be retarded, thus leading
to a state of engorgement or erection of the organ, which will of course react
on the capillary circulation and thus promote a more vigorous transfusion
of the fluid constituents of the blood, thereby increasing the amount of lymph
at certain selected and appropriate points; in this way, doubtless, assisting
in increasing the bulk of the follicular contents. At the same time that author
foreshadows the possibility of this smooth muscle acting as a potent factor
in the rupture of the follicle, for he describes the disposition of this muscular
tissue as not merely scattered throughout the stroma of the ovary, but also
forming a definite layer in the external theca of the follicle.
After the demonstration which I have here given of the occurrence of a —
definite muscular layer in the wall of the human Graafian follicle (see figs. 18
and 19), it would seem that we are justified in assuming that this definite
concentric layer fulfils some useful purpose. Its arrangement and disposition
inevitably suggest that by its contraction a compressing effect, rapid and
immediate, will be exercised on the contents of the follicle, thereby increasing
the internal pressure and consequently determining the rupture of the follicle.
How are these facts in accord with the results of experience? Assuming
that in the human female in the virgin condition there is a periodicity in
ovulation coincident with that of menstruation, we have an explanation of
3—2
36 Arthur Thomson
this apparent association, because, at that period, we have reason to believe
that the ovary shares in the general engorgement which occurs throughout
the genital tract; under these circumstances the conditions are such as to lead
to a slow and gradual increase in the amount of the fluid contents of the
follicle as derived from the blood, and distinct from those which are the
product of the follicular cells, which, be it noted, in a follicle fast approaching
maturity, have no further reserve to call upon. The further increase in the
fluid contents of the follicle is therefore dependent on conditions determined
by the local circulation, and if this condition be steadily maintained, there is
little difficulty in realising how the pressure may ultimately overcome the
resistance, and so the rupture of the follicle may be effected without any
necessary sexual disturbance other than that involved in the psychic and
emotional changes induced by menstruation.
On the other hand, there is reason to believe that ovulation takes place
at other times, and in other ways, than what may be termed the routine
method. It is a matter beyond dispute that under the influence of intense
sexual excitement, in coitu, women are occasionally cognisant of strange
happerfings, which they fail to describe, but by which they are deeply im-
pressed. Is it unreasonable to suggest that these sudden, ill-defined and
deep-seated sensations are the result of the rupture of a Graafian follicle? The
facts seem to fit the case. Granted the presence of an all but ripe and super-
ficially disposed Graafian follicle in what we may term a quiescent condition;
if the action of the mechanism above suggested be accepted, we have all the
means necessary to bring about rapid rupture. The exalted state of the
circulation will assist in the rapid accumulation of fluid within the follicle,
and its subsequent distension, whilst the instant response of the muscular
element in the wall of the follicle to the call of the sympathetic will immediately
result in a combination sufficiently effective to ensure the rupture of the follicle
and the discharge of the ovum.
If, under these conditions, this explanation be accepted, it would seem
to indicate that possibly the same may occur associated with minor degrees
of sexual excitement, so that, whilst in the human female ovulation may, in
the ordinary way, coincide with and be associated with the vascular changes
concomitant with menstruation, yet there may be no bar to the rupture of
a Graafian follicle at any other time, provided such be ripe, in the sense that
the ovum is mature, that the follicular cells have discharged their function
by providing the necessary nutriment and affording the requisite protection,
and assuming always that the follicle has acquired such a superficial position
in the ovary as will permit of its rupture. There is reason to suspect that it
may remain quiescent in this position until such conditions arise as may lead
to increased vascular activity, or it may be the incidence of such stimuli as
may react on the smooth muscle involved and so accelerate the process.
If it be doubted that the involuntary muscular fibre in the wall of the
follicle can act in this way, I would urge that we have abundant evidence
The Ripe Human Graafian Follicle 37
of its power of contraction in the appearance displayed in the wall of the follicle
after rupture, for there seems little doubt that the infolded appearance of the
engorged internal theca is in major part due to the compression exercised by
this contracting element, for there is no evidence of the presence of elastic
tissue to bring about this result.
RESUME
Briefly summarised the conclusions arrived at are as follows:
1. There is reason to believe that the size of the ripe human Graafian
follicle is usually very much overstated in the text-books. In the author’s
experience it is doubtful if Graafian follicles over 5mm. in diameter are
normal.
2. The position of the cumulus is not, as frequently stated, always situated
in the deeper part of the follicle, i.e. that furthest from the surface of the ovary.
It may occur in any position, but in the material available appears to occupy
a superficial position in about 50 per cent. of cases.
3. The so-called bodies of Call and Exner are follicular cells or groups of
cells undergoing such changes as result in their ultimate liquefaction and
disappearance to form the liquor folliculi.
4. The radial arrangement of the follicular cells around these bodies is a
purely mechanical result and is in no wise concerned with the elaboration of the
material which they surround.
5. The resulting liquor folliculi, primarily derived, as explained, from the
follicular cells, is destined for the nutrition, conservation and protection of
the ovum. It is doubtful whether it plays any active part in the subsequent
rupture of the follicle, the necessary increase in the tension of the follicle being
provided at the appropriate time by transudation of fluid from the blood
circulating in the internal theca of the follicle.
6. The stratum granulosum may be reduced to a single layer of cubical
cells. In some instances there is reason to believe that even this layer dis-
appears.
7. In consequence of this reduction in the number of follicular cells, there
comes a time when no further liquor folliculi of follicular origin is produced.
When this stage is reached, there is reason to believe that the follicle may
remain quiescent till other influences are brought into operation to determine
its rupture.
8. The cells of the stratum granulosum rest upon the membrana limitans
externa, a delicate layer which separates these cells from the inner surface of
the theca interna.
9. It is noteworthy that the cells of the stratum granulosum strip off very
readily from the membrana limitans externa. There is reason for suspecting
that this under certain conditions is a normal process resulting in the liberation
of the ovum so that it floats free in the liquor folliculi.
38 Arthur Thomson
10. There is evidence for believing that the membrana limitans externa
is not a simple single layer; but is permeated by potential lymph spaces,
which on being distended lead to its splitting into two layers.
11. On this assumption the cells of the stratum granulosum are therefore
separated from the capillaries of the internal theca by a network of lymph
channels into which the fluids of the blood may under certain conditions be
speedily discharged.
12. The rapid exudation of fluid in this situation has two consequences:
it strips the cells of the stratum granulosum off the inner wall of the follicle
and thus liberates the ovum and cumulus, and at the same time rapidly in-
creases the pressure within the follicle.
18. It is noteworthy that the vascularity of the internal theca increases
as the age of the follicle advances, that it tends to be more pronounced in that
part of the internal theca corresponding to the site of the cumulus, and in the
later stages least in the position overlying the stigma.
14, The amount of blood circulating in this capillary plexus will be
determined by the conditions which control the surrounding circulation,
either by increasing the flow, or, it may be, by retarding the venous return,
the latter, as suggested by Winiwarter, being possibly due to the action of
the smooth muscle constricting the veins and so leading to a turgescence of
the tissue.
15. Such vascular conditions may be associated with the congestion and
increased arterial pressure which precedes the appearance of the menstrual
flux, or may be the direct result of some excitatory stimulus of a sexual kind
operating through the sympathetic.
16. In either case the immediate result may be increased transudation
of tissue fluid into the follicle with the results stated in paragraph 2.
17. It is probable that under what we may regard as the normal con-
dition of: ovulation in the sexually inactive female, the vascular disturbance |
associated with menstruation is alone sufficient to raise the intrafollicular
pressure to the bursting point.
18. In the sexually active female there is reason to suppose that the same
effect may be independently induced by stimuli which react through the
sympathetic nervous system, provided there is at the time a quiescent ripe
follicle present in the ovary.
19. In such cases no doubt the muscular element in the ovary plays an
important part, more particularly that part of it which occurs in the external
theca of the follicle, for this, by contracting on a follicle already undergoing
distension owing to the exalted condition of the vascular supply, will naturally
tend to increase the intrafollicular pressure and so lead to the rupture of the
follicle.
20. If these conclusions be true it would follow that ovulation is not
necessarily limited to one particular period, but that under the influence of
appropriate stimuli it may occasionally occur at other times as well.
The Ripe Human Graafian Follicle | 39
In conclusion, I must express my thanks to my Laboratory Assistant,
Mr W. Chesterman, and to Miss Beatrice Blackwood, for the assistance which
has enabled me to carry out this research; they have both been untiring in
their efforts to carry out my every wish, and I am deeply sensible of their help
and co-operation.
To the Government Department of Scientific and Industrial Research, I am
indebted for the services of Miss Blackwood, who was generously placed at my
disposal as a research assistant.
REFERENCES
(1) Azsy,C. “Die glatten Muskelfasern in den Eierstécken der Wirbelthiere.” Arch. f. Anat. u.
Phys. 1861.
(2) Barnes, R. “An address on the pene of menstruation and pregnancy and labour, etc.”
Brit. Med. Journ. 1889, 1.
(3) Boum and Daviporr. “Lehrbuch Pe Histologie des Menschen.” Wiesbaden, 1895. Re-
vised and enlarged edition, in English, with title “A Text-book of Histology” edited by
G. Carl Huber, Philadelphia, 1904.
(4) Catt and Exner. “Zur Kenntniss des Graaf’schen Follikels beim Kaninchen.” Sitzungsber.
der Wien. Akad. txxt. 1875.
(5) Crark, J.G. “The Origin, Growth, and Fate of the Corpus Luteum.”” Johns Hopkins Hos-
pital Reports, vit. 1899.
(6) —— “The Blood-vessels of the Human Ovary.” Johns Hopkins Hospital Reports, 1x. 1900.
_ (7) Epery, T. W. “Manual of Midwifery.” 4th edition, London, 1915.
(8) Fuemmie, W. “Regeneration verschiedener Epithelien.” Arch. f. mikros. Anat. xxiv. 1885.
(9) Furst, A. “Handbook of Physiology.” New York, 1905.
(10) Gigs, A. E. “The cyclical or wave theory of menstruation.” Trans. Obst. Soc. Lond.
Xxxix. 1897:
(11) Grone, F. “Ueber den Bau und das Wachstum des menschlichen Eierstocks.” Virchow’s
Archiv, 1863.
(12) Harz, W. “Beitrage zur Histologie des Ovariums der Saéugethiere.”” Arch. f. mikros. Anat.
xxi. 1882.
(13) Heapz, W. “Ovulation and Degeneration of ova in the Rabbit.” Proc. Roy. Soc. B. xxvt.
1905.
(14) Honor&, C. “Recherches sur l’ovaire du lapin.”” Arch. de Biol. xv1. 1899-1900.
(15) Jacosr, M. “The question of rest for women during menstruation.”” New York, 1886.
(16) Lane-Craypon, J. E. “On the origin and life-history of se interstitial cells of the ovary of
the rabbit.” Proc. Roy. Soc. B. yxxvu. 1905.
(17) MacMurcuy, H. “Physiological Phenomena preceding or accompanying Menstruation.”
Lancet, London, 1901, m.
(18) McMourricn, J. Prayrar. “The Development of the Human Body.” 5th edition, Phil-
adelphia, 1915.
(19) Marsnatx, F. H. “The Development of the Corpus Luteum, a Review.” Quart. Journ.
' Micros. Sci. xurx. 1905.
(20) Marri; H. N. “The Physiology and Histology of Ovulation, Menstruation, and Fertilisa-
tion.” Hirst’s System of Obstetrics, 1888, 1.
(21) Mosner, C. “Normal Menstruation and some of the factors modifying it.” abas Hopkins
Hospital Bulletin, x1. 1901.
(22) Nacex, W. “Das menschliche Ei.” Arch. f. mikros. Anat. Xxx. 1888.
(23) —— “Die weiblichen Geschlechtsorgane.” Handbuch der Anatomie des Menschen, ed.
Bardeleben, Lieferung n. Jena, 1896.
(24) Prersor, G. A. “Human Anatomy.” Philadelphia, 1907.
(25) Porrrer, P. “Traité d’Anatomie humaine.” Paris, 1894-1904.
(26) Raymonp, J. H. “Human Physiology.” Philadelphia, 1901.
40
(27)
(28)
(29)
(30)
(31)
(32)
(33)
(34)
(35)
(36)
Arthur Thomson
Rosrnson, A. “The formation, rupture and closure of ovarian follicles in ferrets and ferret-
polecat hybrids, and some associated phenomena.” T'rans. Roy. Soc. Edin. tm. ptii, No, 13,
1918.
Rovert, ©. “Recherches sur les organes érectiles de la femme et sur l’appareil musculaire
tubo-ovarien dans leurs rapports avec l’ovulation et la menstruation.” Journ. de la Phy-
siol. de Vhomme et des animaux. 1858,
Scuirer, E. A. ‘Text-book of Microscopic Anatomy,” vol. 11. pt. i of Quain’s Anatomy.
London, 1912.
Scuocuet, 8. S. “A suggestion as to the process of ovulation.’ Anat. Record, x. 1916.
Trstut, L. ‘‘Traité d’Anatomie humaine.”’ Paris, 1905.
TiaERsTEDT, R. “Textbook of Human Physiology,” Trans. from the 3rd edition, and edited
by J. R. Murlin. London, 1906.
Tuomson, Artuur. “The Maturation of the Human Ovum.” Journ. of Anat. tm. Pts ii
and iii. April 1919.
Wapeyer, W. “Kierstock und Ei.”’ Leipzig, 1870.
WINIWARTER, H. von. “Contribution & l’étude de l’ovaire humain.” Arch. de Biol. xxv.
1910.
WINIWARTER, H. von, and Sarnmont, G. “Nouvelles recherches sur l’ovogenése et l’organo-
genése del’ ovaire des mammiféres (chat).”’ Arch. de Biol. xxtv. 1909.
VOLUNTARY MUSCULAR MOVEMENTS IN CASES
OF NERVE LESIONS
By Pror. FREDERIC WOOD JONES, D.Sc.
Wren, after the experience of a few months of war, peripheral nerve lesions
came to be treated upon what may be termed a wholesale scale, it was felt
by many clinicians that their experiences were fast outrunning the amount
of exact anatomical information obtainable in most of our text-books. In no
connection was this state of affairs made more manifest than in dealing with
those cases which demanded a precise knowledge of the action of living muscles
in the human body. Our anatomical text-books gave the actions of the mus-
cles, they also gave the innervation of these muscles, and the lines along which
information for the clinicians was to be had, consisted in arguing that since
a particular nerve has been divided, certain muscles will be paralysed, and
therefore the actions carried out by these muscles will not be performed.
The first stumbling-block—the lack of precise knowledge as to the arrange-
ment of the motor fibres in mixed nerves, and the exact site of origin of
branches to individual muscles—was soon largely rectified, but the question
as to what action any living muscle can actually perform is, as it always has
been, a difficult one to settle. Now, it has been within the experience of every-
one who has come in contact with a large series of cases of nerve lesions that,
at times, after the undoubted division of a motor nerve, the resultant paralysis
has not been so great as would have been expected from a study of text-book
anatomy. If it is taught in the text-books that a certain joint is bent by the
action of a definite muscle, and this muscle is supplied by a definite nerve;
then, when this nerve is divided, the expectation will be that since the muscle
is paralysed, the action of bending the joint will not be performed. Not by
any means uncommonly, this expectation is not fulfilled, for the patient con-
tinues to possess the power of bending the joint. Two explanations are at once
forthcoming to account for this anomalous state of affairs. It is possible that,
in this particular case, the nerve supply of the muscle is not that which is
usually given in the text-books—that some other nerve sends branches to the
muscle, and it is not paralysed at all. Or, it is possible that it is paralysed,
and that some other muscle, or combination of muscles, may perform the
action usually regarded as the exclusive function of this one. The first alterna-
tive has had its advocates, but we, as anatomists, need have little fear that a
large revision of the text-book teaching upon the nerve supply of muscles
will be necessary as an outcome of the study of war injuries. As a matter of
fact, routine electrical testing upon the structures as they are exposed on
42 Frederic Wood Jones
the operating table, should form a part of all operative work, and when this
is carried out, the instances in which an appeal has to be made to abnormality
of nerve supply, are reduced to a minimum. In all cases cited in this paper
this procedure has been adopted. With regard to the second alternative, there
is still a great deal of confusion. Much erroneous teaching has been put forward |
during the war, and many false conclusions arrived at in consequence of the
deceptive nature of some of the voluntary movements possible after complete
section of motor nerves. Testing voluntary movements is a business to be
undertaken with a judicial mind, and at the best it is a difficult affair. It is
easy to determine that a joint bends: it is by no means easy to determine
beyond doubt what agent caused its bending.
It must never be forgotten that in testing voluntary movements, we ask
the patient to perform some action ;—we do not ask him to use certain muscles.
The cortex of the patient neither knows nor cares of muscles, and his volition
will therefore be effected by any agent capable—even in the lamest, and most
halting way—of carrying out the volition. In some cases no agent having
the power to perform the desired movement will be at hand, but at times
some muscle may achieve a flicker in the right direction, or at times a perfect
substitute for the paralysed muscle is prepared to take on the work. In any
case, whatever beginning can be made at the business of reproducing the
lost movement, it is probable that it will be steadily cultivated by the patient.
The effort to perform a cortical volition by .any agent is very remarkable, the
most unlikely muscles will contract in an endeavour to effect the desired
movement ;—no man can flex his wrist with his platysma, but if the medical
officer and the patient are both determined on doing their best, many men
will attempt it. Among the muscles which will be called on in the attempt
to perform a lost movement, are the antagonists of the desired movement,
or any or every member of the groups of muscles having a general antagonism
to the movement of volition. If, as a substitute for the paralysed flexors of
a joint, the extensors of that joint be cortically activated, the volition of flexing
will naturally not be attained; but if the extensors of some neighbouring
joint be contracted, it is possible that a relative and passive flexion of the
paralysed joint will result, and thus the volition may be achieved. Once the
patient has learned this trick, the chances are that he will cultivate it, and the
working of his perfected effort may be extremely difficult to detect. In the
limits of the present paper, I have included “trick”? movements, because
although they do not throw much light upon normal muscular movements,
they have led ‘some observers to false assertions as to the incorrectness of
orthodox text-book teaching.
In all the cases which are recorded here, and from which conclusions are
drawn, the author has personally seen the condition of the nerve as exposed
at the operation, and has checked the finding by the electrical tests. If a nerve
is reported as divided, the statement means that the author has seen the
complete severance in the continuity of the nerve, and witnessed the failure
Voluntary Muscular Movements in Cases of Nerve Lesions 43
of the exposed nerve to react to faradic stimulation. When movement is
spoken of as being produced by the action of muscles, it must be understood
that a real active movement of the part is achieved. In no case has a mere
questionable flicker been reported as a voluntary movement. In all cases
illustrated, the patient has been so arranged that the active movement has
been carried out against the action of gravity.
A. Complete division of the musculo-cutaneous nerve
Paralysis of biceps and brachialis anticus. This is not at all a common
lesion, and in only one of the cases that I have seen was the nerve actually
Fig. 1. Paralysis of biceps and brachialis anticus. Plexus
lesion. Driver 8.
Flexion of elbow produced by supinator longus.
severed by the passage of a projectile. In only one case of complete division
(Pte. G. H. 8th R. Sussex, 2288), with the musculo-spiral intact, was there any
evidence that the brachialis anticus retained any power of contraction. In
this case the contraction was palpable but localised, and even in the most
advantageous position it failed to produce any flexion of the elbow. In every
case of paralysis of the biceps and brachialis anticus in which the musculo-
spiral nerve was intact, the elbow was capable of immediate and strong
flexion produced by the supinator longus (see fig. 1). Despite recent
teaching, the supinator longus is always a flexor of the elbow joint. The
44. Frederic Wood Jones
flexion of the elbow produced by the supinator longus is a powerful and precise
action, and it is carried out with the hand in a useful working position. It is
indeed often a matter of great difficulty to re-educate the patient in the use
of the brachialis anticus and biceps, even after these muscles have perfectly
recovered their voluntary contractibility.
B. Complete division of the musculo-cutaneous and the musculo-spiral nerves -
Flexion of the elbow is performed by the pronator radii teres (see fig. 2).
This flexion is nothing like so powerful, nor so complete, as that produced by
“
~
Fig. 2. Complete division of musculo-spiral and musculo-cutaneous. Lieut. L. B.,
gun-shot wound, left axilla, 24. iii. 18. Both nerves found divided, 22. iii. 19.
Flexion of the elbow produced by the pronator radii teres.
the supinator longus. The action requires some cultivation by the patient,
and even after a considerable interval the flexion may not be sufficiently
complete to raise the hand to the mouth. In the case illustrated, the pronator
radii teres was the only muscle which was used to perform the action, and the
flexion produced was a forcible and useful movement when the forearm was
maintained fully pronated.
The action of the biceps upon the elbow joint. Since there has recently been
some attempt at revision of the established teaching concerning the action
of the biceps as a flexor of the elbow joint; it is worth recording that apart
altogether from the phylogenetic history of this flexor, and its undoubted
Voluntary Muscular Movements in Cases of Nerve Lesions 45
action as a flexor in the normal living human subject, its action is well seen
in a very wide series of war injuries. Contracture of the elbow joint following
a flesh wound limited to the biceps muscle is a common enough condition, and
is comparable with the flexion of the knee so commonly seen following flesh
wounds of the hamstrings. Cases of spasm of the biceps may follow prolonged
splintage or slinging, and may be maintained with a hysterical basis for a
period extending over years. (Case. Pens. G. C. 6 Glocs. 267306, shrapnel flesh
wound middle R. Biceps—elbow flexed to right angle from 19. 7. 16 to 19. 5. 19.
No other muscle or nerve involved.) Discrete contracture of the biceps fascia,
without the involvement of any other structure, also produces flexion of the
elbow.
C. Complete division of the musculo-spiral nerve
(1) Paralysis of the extensors of the wrist. Although “‘drop wrist” is such
a classical symptom of musculo-spiral paralysis, and although it is so strikingly
Fig. 3. Complete division of the musculo-spiral. Lieut. L. B., gun-shot wound,
left axilla, 24. iii. 18. Nerve found completely divided, 22. iii. 19.
Extension of the wrist produced by flexion of the metacarpo-phalangeal joints.
complete in all cases of hysterical palsy, it not infrequently happens that
a most astonishing power to extend the wrist against gravity persists in cases
of complete division of the musculo-spiral nerve above the supply of all the
extensor muscles. The production of this extension is a true “trick” move-
ment, for it is done by pulling on the tendons of the extensor communis
digitorum by flexing the metacarpo-phalangeal joints with the interossei.
As the metacarpo-phalangeal joints are flexed, the digital extensors are tight-
ened, with the result that the hand is forcibly extended at the wrist joint
(see fig. 3). It will be readily understood that in all cases of trick movements
the detection of the trick is far more difficult than would be supposed from
an inspection of a photograph of the action, the patient often possessing a
subtle power to manipulate one joint while the observer’s attention is directed
to a neighbouring one.
46 | Frederic Wood Jones
(2) Although in a complete musculo-spiral lesion the metacarpo-phalangeal
joints cannot be extended, it must not be forgotten that the two terminal
phalanges may be straightened from the flexed position by the action of the _
interossei. This action is, at times, mistaken for musculo-spiral activity,
and it is especially liable to cause confusion if the hand be examined whilst
supported on a splint. 5
(8) The movements of the thumb in cases of division of the musculo-spiral
nerve have proved deceptive in a very large number of cases. It is by no means
uncommon for the patient to possess the power of extension in the terminal
joint, or at times to show ability to extend the thumb at the metacarpo-
phalangeal joint. In by far the greater number of these cases, the action is
produced as a trick movement, the terminal joint being first bent by the flexor
pollicis longus and then, when flexion is released, extension is produced
by the passive pull of the long extensor. But in other cases the movement
Fig. 4. Complete division of the musculo-spiral. Rim. F. O.,
gun-shot wound, upper third right arm, 23.i.17. Nerve found
divided, 3.ii.19. No response when tested on table.
Extension of the thumb in complete musculo-spiral paralysis.
is more complex. It will be noticed that when the thenar muscles act upon
the thumb, extension of the terminal phalanx is normally produced. This
extension may be brought about by the passive pull of the extensor pollicis
longus against the ulnar adductors of the thumb in the normal action. Or it
may be done by a direct pull upon the sesamoid, and so upon the head of the
metacarpal bone and front of the metacarpo-phalangeal joint. This pull tends
to bring the metacarpal forward, and so create a relative extension of the last
_ two joints.
In the patient illustrated at fig. 4 this was probably the case, since upon
the left side this patient had a complete division of the ulnar as well as the
musculo-spiral and was quite incapable of producing a movement in his left
thumb like that illustrated in his right. At times it is possible that the abduc-
tor brevis may produce an active pull upon the expansion to the long extensor
Voluntary Muscular Movements in Cases of Nerve Lesions 47
tendon: but I do not think these cases are at all common. All movements
of extension produced by the thenar muscles may usually be detected by the
wriggling motion imparted to the metacarpo-phalangeal joint of the thumb;
but it is not true, as is so commonly taught, that extension of the terminal joint
cannot be produced, in cases of musculo-spiral paralysis, when the thumb is
abducted, unless the precaution be taken that this abduction and immobiliza-
tion affects both the metacarpal and the first phalanx.
D. Complete division of the ulnar nerve
(1) Paralysis of the flexor carpi ulnaris is particularly difficult to test.
It is more easy to appreciate the voluntary action of this muscle in producing
the movement of ulnar deviation of the hand, than by attempting to estimate
its condition during active flexion of the wrist. There are probably few muscles
in the body in which the apparently simple task of estimating voluntary
action by observation and palpation, is so exceedingly difficult.
(2) The action of the interossei in producing adduction and abduction of the
digits may be simulated by other muscles, and great caution is needed before
statements are made as to recovery in ulnar nerve lesions on the strength of
the patient showing some ability to spread the fingers apart and close them
Fig. 5. Complete division of the ulnar. Lieut. A. W., gun-shot
wound, left elbow, 30. vi. 18. Test, 10. iv. 19, no response in ulnar
intrinsics.
Abduction of all the fingers produced by the action of the long exten-
sors. A, is the resting position of the digits—B, the position to
which they can be abducted by the long extensors.
together again. It is a commonplace that as we open our hands with the exten-
sors our fingers tend to spread apart, and as we close our fist with the flexors,
our fingers are adducted. The movement of abduction effected by the exten-
sors may be perfected in a very remarkable manner and it is not uncommonly
mistaken for interosseus action (see fig. 5). It is to be noted that in true
48 Frederic Wood Jones
interosseus abduction the fingers are all spread from the middle finger as
a centre, but in extensor abduction this does not hold good, for the fingers
are spread as a fan is opened and in the case photographed, the 4th digit
remains more nearly at rest than the 8rd. The only satisfactory method of
performing the test for interosseus action is to isolate each finger, and test
its power of adduction and abduction to and from the middle line without
permitting the long flexors or extensors to come into play. There are two
additional points to be noted concerning the abducting power of the extensors.
(8) The extensor minimi digiti proprius is an exceedingly powerful abductor
of the little finger. Its action may easily be mistaken for that of the abductor
minimi digiti: and the fact that the little finger possesses this added mechanism
of abduction accounts for the permanently abducted position which, the finger
takes up even long after the recovery of a sutured ulnar nerve (see fig. 6).
Fig. 6. Recovery after suture of the ulnar nerve; all ulnar muscles
with completely recovered voluntary power.
Persistent abduction of the little finger caused by the action of the
extensor minimi digiti and extensor communis digitorum.
(4) Although the extensor communis tendon to the index finger is able
to produce abduction of the index in the general movement of extensor ab-
duction, the extensor indicis proprius acts as a well-marked adductor. In the
absence of any interosseus power, therefore, the index finger may be both
-adducted and abducted to and from the middle line (see fig. 7).
(5) The action of the long extensors upon the two terminal phalanges may
prove a source of erroneous diagnosis. It has often been said that the action
of the long extensors upon these two joints is but a feeble one; and recently
it has been asserted very emphatically that not only have they no action
whatever, but by the anatomical arrangement of their tendons, it is impossible
that they should have-any action. It is quite certain that the anatomical
condition of the long extensor tendons, as properly displayed by dissection,
is such as to permit extension of the two terminal joints of the fingers. It is
equally certain that when the ulnar nerve is completely divided and the
action of the interossei is entirely absent, the two terminal joints of the fingers
Voluntary Muscular Movements in Cases of Nerve Lesions
Fig. 7. Complete division of the ulnar nerve.
Pte. W. R., gun-shot wound, left elbow, 17. iv. 18.
Nerve found completely divided, 11. xii. 18, Test,
9. v. 19, no faradic or voluntary response in any
ulnar muscle. Photo, May 1919.
Adduction of the index finger produced by the extensor indicis
proprius. Abduction by extensor communis digitorum.
Fig. 8. Complete division of the ulnar nerve. Pens, C. H. H., gun-shot wound, right
elbow, 21.x.17. Nerve found completely divided, 26. iv. 19. Test, 26. iv. 19, no faradic or
voluntary response in any ulnar muscle. Photo, May 1919.
Extension of the two terminal phalanges by the extensor communis digitorum.
Anatomy LIv. 4
49
50 Frederic Wood Jones
can be extended by the action of the long extensors acting alone. This is not
an abnormal action, it is one that can be witnessed in any ease of division of
the ulnar nerve, though the extension produced may not be so complete in all
cases.as in that illustrated at fig. 8.
(6) The statement that in complete ulnar lesions the metacarpo-phalangeal
joints of the little and ring fingers cannot be flexed is, as a rule, incorrect.
Although in the characteristic position of ulnar paralysis this joint in the little
finger is extended, and the flexor digitorum sublimus has already produced
a flexion of the first interphalangeal joint, nevertheless, a considerable degree
of bending may be produced in the metacarpo-phalangeal joint by further
action of the tendon of the flexor sublimus. In the ring finger, flexion of the
metacarpo-phalangeal joint is readily produced by the flexor sublimus in cases
of complete ulnar paralysis.
E. Complete division of the median nerve
(1) Several incorrect teachings concerning the failure to produce flexion
in certain finger joints are current at the present time. The amount of paraly-
sis that follows complete section of the median nerve is far less than would be
imagined as the result of a study of anatomical text-books, and it is far less
than that asserted by some observers of nerve injuries during the war,
(2). It is said that in cases of complete median interruption, the patient
is unable to flex the second phalanges of any of the fingers. Flexion of the
second phalanges, however, can readily be brought about by the flexor pro-
fundus after this muscle has bent the terminal joint. The second phalanges
of minimus, annularis, and medius, can always be bent in complete median
paralysis by the action of the intact flexor profundus (see fig. 10). The flexion
produced is of a characteristic type, and may best be described as “ winding
up the finger.”
(3) It is also asserted and emphasized by deductions from observations
on the cadaver that the interossei cannot produce flexion of the metacarpo-
phalangeal joints; these joints being bent by the action of the lumbricales
only. This teaching is absolutely wrong, and it has led to the very incorrect
diagnostic criterion that in median nerve paralysis the metacarpo-phalangeal
joints of index and medius cannot be flexed. Every case of complete division
of the median nerve has power to flex the metacarpo-phalangeal joints of these
fingers, and the flexion in these cases is produced, as it is in the normal subject,
by the action of the interossei, although, of course, the lumbricales assist in the
action (see fig. 9).
(4) The common statement that the distal phalanges of index and medius
cannot be flexed, needs very careful qualification. If the index finger be grasped,
_ and the patient is told to bend the top joint of that finger only, no action of
flexion is produced. If the same test be applied to medius, a definite flexion
movement can usually be evoked. But if the patient is merely asked to bend the
fingers, or especially if he is asked to make a fist, then some flexion of all joints
Voluntary Muscular Movements in Cases of Nerve Lesions 51
of all the fingers is produced. In some cases a very fair fist may be made in
vases in which the median nerve is completely divided (see fig. 10). Evidently,
Fig. 9. Complete division of the median. Pte. C. W., gun-shot wound, left arm,
10.iy.18. Median found divided, 17. vii. 18. No voluntary or faradic response iu
median muscles, 26. iv. 19.
Flexion of index and medius at the metacarpo-phalangeal joints.
Fig. 10. Complete division of the median. Pte. A. H., gun-shot wound, right arm,
21. iii. 18. Nerve found divided, 21.ix.18. No voluntary or faradic response in median
muscles, 12. v. 19.
Ability to make a fist with the median divided above the supply of the long flexors of the
digits.
if the volition is a general one, the main action of the flexor digitorum pro-
fundus brought about by the route of the ulnar nerve is sufficient to produce
a flexion of all the fingers. But if the volition is merely limited to the exclusive
4—?2
52 Frederic Wood Jones
median portion destined for the index finger, then no contraction of the muscle
takes place.
(5) Flexion of the terminal joint of the thumb is sometimes possible in
median nerve lesions in which the long flexor is paralysed. The flexion, though
definite, is not complete, and is stamped by that characteristic inability to
operate in the presence of any resistance which usually accompanies move-
ments produced by relaxation of opponents.
(6) Flexion of the metacarpo-phalangeal joint of the thumb has been said
to be impossible without the action of the muscles innervated by the median
nerve: but the ulnar muscles inserted to the ulnar sesamoid are capable of
producing this movement, and in this instance, as in the next two to be
examined, we have an example of the almost utter impossibility of diagnosing
lesions of the nerves supplying short muscles of the thumb merely by looking
~ ~
Fig. 11. Complete division of the median. Pte. C. W., gun-shot wound, left arm,
10. iv. 18. Nerve found divided, 17. vii. 18. 26. iv. 19, no faradic or voluntary
response in any median intrinsic muscle.
Opposition of the thumb in complete median paralysis.
at the movements of which the thumb is capable. Electrical tests and careful
palpation of the thenar muscular mass are essential preludes to a diagnosis.
(7) It is best to state quite dogmatically at the outset that the complex
combination of muscular movements which gives effect to the volition of oppos-
ing the thumb to the other digits, is often perfectly carried out in cases of
complete division of the median nerve (see fig. 11). In performing this action,
some muscle is needed to pull the metacarpal bone of the thumb in a palmar
direction, another muscle is required to move the thumb towards the ulnar
side of the palm, and to complete the process of perfect opposition some
muscle is required to produce a rotation of the thumb. The extensor ossis
metacarpi pollicis produces a forward movement of the metacarpal bone,
and in the production of opposition in cases of median paralysis the part
played by this muscle is generally apparent. When the thumb is pulled in
a palmar direction, the adductor pollicis will produce the ulnar sweep, and,
Voluntary Muscular Movements in Cases of Nerve Lesions 53
with effective opposition from the extensor ossis, will also produce a deceptive
degree of rotation of the thumb. In many cases in which the movement of
opposition is quite perfect, that part of the adductor obliquus muscle which
is inserted to the radial sesamoid effects a rotation not to be distinguished
from true opponens opposition as in the case illustrated in fig. 11. Digital
examination of the metacarpal of the thumb will reveal the atrophy of the
opponens in these cases, but mere inspection of the movements produced may
not be taken by any anatomist or any clinician as evidence of median recovery.
(8) The loss of the abductor pollicis in median paralysis is often extremely
well compensated by the power of the extensor ossis metacarpi pollicis to pull
the whole thumb in a palmar direction. A good deal of reliance has been
placed on the “abduction test” in cases of median paralysis: but in a certain
Fig. 12. Complete division of the median. Nerve divided for pain, 20.ii.19. No
recovery, 26. v.19.
“‘Abduction’’ movement of the thumb produced by extensor ossis metacarpi pollicis.
number of cases this spurious abduction brought about by a muscle innervated
by the musculo-spiral nerve is a very well defined and forcible action, though
naturally its range of movement is never so great as in that produced by the
abductor brevis (see fig. 12).
F. Complete paralysis of both median and ulnar nerves
(1) It is in this condition that the typical “ape hand” is developed.
The essential features of this hand are the flatness of the palm, and the
rotation of the thumb in a direction opposite to that produced by the
opponens (see fig. 13). The thumb ranges itself alongside the index finger with
its palmar surface directed in a palmar direction, in the same manner as the
remainder of the digits. It is rather curious that the production of this position
54. Frederic Wood Jones
of the thumb is ascribed by Benisty! to the action of the adductor pollicis-—
a muscle which is of necessity paralysed in these cases.
The muscle which produces this movement in the thumb is the extensor
pollicis longus which is thus, as regards rotation of the thumb, the opponent
of the opponens.
Fig. 13. Complete division of ulnar and median nerves. Pte. J. B.
Typical position of the thumb produced by the rotating action of the
extensor pollicis longus unopposed by the intrinsic thenar muscles.
x
Fig. 14. Complete division of both ulnar and median. Pte. A. B., gun-shot wound,
right arm, 10.iv.18. Both nerves found divided, 11. vi. 18. No recovery, 26. v. 19.
Flexion of the fingers produced by extension of the wrist.
(2) One very curious and deceptive action seen in some cases is that
illustrated in fig. 14. Although all the finger flexors are completely paralysed,
distinct and forcible flexion, which enables the patient to scratch with the
finger nails, and to close the hand, is readily carried out. This trick action
1 Clinical forms of nerve lesions, 1918, pp. 55 and 116.
Voluntary Muscular Movements in Cases of Nerve Lesions 55
is exactly the opposite to that mentioned in those cases of musculo-spiral
paralysis in which the wrist may be raised by bending the fingers; for here
the bending of the fingers is effected by raising the wrist.
(3) An action which has led to more confusion in diagnosis than probably
any other, is that power of wrist bending which is normal to the extensor ossis
metacarpi pollicis. The movement of the wrist produced by this muscle is
illustrated in fig. 15, and in this case the action effected against gravity is a
forcible one, although under these conditions its range is not very great.
G. Nerve lesions of the lower extremity
In the leg there are but few voluntary muscular actions which are likely
to deceive, but it may be said at once, that if voluntary power is examined
for with the patient lying on his back with his heel resting on the couch,
~
Fig. 15. Complete division of ulnar and median. Pte. A. R., gun-shot wound, left axilla,
19. vii. 18. Both nerves found divided, 13. xii. 18. No faradic or voluntary response in
any median or ulnar muscle, 5. iv. 19.
Flexion of the wrist produced by the extensor ossis metacarpi pollicis.
almost any conclusion may be arrived at. The patient has only to push or to
pull against his heel as a fixed point to produce movements of his foot in either
direction; and this push or pull may be effected by any muscle capable of
taking a leverage from the couch.
(1) The action of the peronei as elevators (dorsi-flexors) or depressors
(plantar-flexors) of the foot has been somewhat debated, In the first place,
the peronei belong to the external popliteal group of muscles and their normal
action on the foot is to produce eversion. Eversion is itself a movement of
greater possibilities in the position of dorsi-flexion. But it has often been said
that anatomically the peronei—or some of them—are muscles which produce
plantar-flexion. There is no doubt that in the normal condition the peronei
act with their group, and come into play during dorsi-flexion of the foot.
Suppose, however, the internal popliteal nerve is completely divided and the
56 Frederic Wood Jones
calf muscles are paralysed, will a movement of plantar-flexion be produced
by the peronei? In the great majority of patients there remains no power to
depress the foot under these conditions, for the peronei, even if anatomically
capable of producing plantar-flexion, cannot be dissociated in their action
from the remaining muscles, supplied by the external popliteal, which produce
dorsi-flexion. But, at times, the patient possesses the power of contracting
the peronei without contracting the other external popliteal muscles ;—he can
dissociate the action of the peroneus group. In these cases plantar-flexion,
and eversion is the result; and if the action be not carefully studied, it may be
mistaken for evidence of internal popliteal recovery (see fig. 16). One might
therefore say that normally the peronei were muscles which do not act upon
the ankle joint, but which produce eversion of the foot usually in a position
Fig. 16. Complete division of the internal popliteal ;
verified, 30. v. 19.
Action of the dissociated peroneti muscles.
of dorsi-flexion, but that occasionally, in cases of internal popliteal paralysis,
they may be dissociated by the patient from the remainder of their group
and be used as plantar-flexors when they act alone. This is a case of the volition
demanding plantar-flexion finding in some persons an agent not usually
employed in this service.
CONCLUSIONS
The purpose of this paper is to emphasize the fact that estimating the
condition of injured nerves by the study of the voluntary movements of which
the patient is capable, is an extremely difficult, and at the best, somewhat
uncertain business. That the re-education of muscles, in cases of nerve injury,
is a matter requiring far more anatomical knowledge than is often brought
dos Ga teh dis he ictal Scat —T
x
oa =
Se LL Ee Ne TE ee ee eet ee
Voluntary Muscular Movements in Cases of Nerve Lesions 57
to bear upon it; since without proper care it will certainly result in the educa-
tion of trick movements which, when perfected, are accepted as evidences
of recovery. That much of the teaching upon muscular action which has been
put forward from a study of nerve lesions during the war is erroneous.
Finally that anatomists should exercise great caution before authoritative
sanction is given to teaching which may lead to false estimates of the damage
done to nerves, and the recovery of nerves after operation; since on the one
_ hand operation may be negatived or delayed, and on the other operative pro-
cedures which are futile may be encouraged, or legitimate operations may be
estimated as having an unreal success. In either case that period which marks
the transition from the sphere of activity as a serving soldier to that of useful
civil employment may be very much prolonged. When, as during the war, the
problem affected the welfare of thousands, it behoves anatomists to exercise
an attitude far more judicial—far more critical—than has been evidenced up
to the present time.
I wish to express my indebtedness to Major-General Sir Robert Jones
and to Major Rowley Bristow for the opportunities for clinical investigation
that form the basis of this paper.
SEXUAL DIFFERENCES IN THE SKULL
By F. G. PARSONS,
Lecturer at St Thomas’s Hospital,
AND Mrs LUCAS KEENE,
Lecturer at the School of Medicine for Women
Mone than a year ago one of us worked out the average contours of 30 male
and 30 female, eighteenth century, skulls from the Clare Market district,
though there was then no time to work out or call attention to the sexual
points of difference between them.
As a matter of fact there was no way of being sure how far they were
rightly sexed because few anatomists have the chance of testing their capa-
bilities in this way on a series of skulls of known sex.
Still we propose to take the two series of tracings as a starting point and
to see whether any of the differences between them are repeated in other
series.
In the first place, on comparing the two norma verticalis tracings (fig. 8), it
is evident that the female skull is shorter and broader in proportion than is the
male, and it is no surprise to find that its cranial index is 775 while that of
the male is 755. As it is obviously an important point to settle whether any
definite allowance should be made for sex in comparing different groups of
skulls we looked up the records of the other series of English skulls lately
measured and found them as follows:
Hythe 3 79:9 2 81:9
Rothwell 3 76-3 9 75-8
Moorfields ¢ 75:5 2 75-0
Whitechapel 3 74:3 2 73-1
The results of this investigation were not very encouraging; Hythe showed
the same preponderance of 2 per cent. in the female index noticed in the Clare
Market series, but in the other three groups the males had a larger index than
the females. We felt therefore that it was essential to get some material where
the sexing was not the arbitrary work of an expert whose personal equation
was unknown, even to himself, and we turned to the records of Anglo-Saxons
because, as they are generally buried with male or female weapons and orna-
ments, there is much less chance of mistaking the sex than in later English
burials.
22 male Saxons gave us an index of 74-3, and 23 females one of 75:3.
Later on, Dr Duckworth of Cambridge helped us very much by sending
us records of 160 bodies from the dissecting room on which both the head
Sexual Differences in the Skull 5
and the skull measurements had been taken and in which, of course, there was
no doubt of the sex. :
The cranial index of 120 male skulls was 75-8 and of 40 female 78-2.
As we were unable to get any more series the sex of which was definitely
known except the series of soldiers at Millbank in which there were no females
for comparison, we had recourse to the living head and measured 150 male
-_ medical students at St Thomas’s Hospital and 150 female students at the Medi-
eal School for Women.
This, of course, brought us up against the allowance which it is necessary
to make for the soft parts in comparing the living head with the bare skull.
Until lately craniologists have followed the example of Miss Lee in allowing
11 mm. for these, but Dr Gladstone found that a little over 7 mm. was sufficient,
while Dr J. H. Anderson suggested 9 mm.
Our method of testing the thickness of the covering tissues was to run a
needle through a thin dise of cork, the needle was then stuck into the scalp
until it touched the bone, when the cork was moved down to the skin; then
the needle was withdrawn and the distance between the cork and its point
This method was so simple that a large number of records could be ob-
tained in London post-mortem rooms in a short time and we soon had ample
_ evidence that 8 mm. was a good allowance for the soft parts in both the length
and breadth of the skull. This is the more satisfactory in that it is midway
between Gladstone’s and Anderson’s results.
With regard to height, it is not enough to allow for the thickness of the
tissues on the vertex and in the roof of the external auditory meatus, because
in a dried skull the ear plugs of the auricular craniometer are in quite a different
position to that they occupy with the soft parts in place; they are much
nearer together in the skull and the removal of the soft parts may merely
allow them to approach one another while their centres still occupy the centre
of the canal. Another point which has to be taken into account is that the
cartilaginous meatus is rising as it passes inward.
In practice we found that scraping the soft parts out of the bony meatus
- until the plugs could occupy the position they would take in the dried skull
made a difference on the average of 1-5 mm. and this we attributed largely
_ to the slope of the meatus. We would therefore suggest allowing 5-5 mm.
_ for the difference in height between the living head and the dried skull, 4 mm.
for the scalp and 1-5 for the meatus. This is rather less than Anderson suggests
___ but is somewhere very near the average.
In practice it will be found that the change from the cranial to the cephalic
index means an addition of 1 per cent.
_ Another comparison available was between the male and female patients
in St Thomas’s Hospital whom we may regard as representative of the modern
_ migratory Londoner of the lower and lower middle class, while a still further
one was between the male and female visitors to the British Association’s
60 F. G. Parsons and Mrs Lucas Keene
meetings as quoted by Dr Macdonell. These probably would represent pretty
much the same class of society as the male and female medical students;
that is to say, perfectly nourished individuals interested in intellectual occu-
pations.
If we now tabulate the results of these (with the possible exception of the
Anglo-Saxons) definitely sexed series we get the following:
Excess of ? index
Anglo-Saxons 3 (22) 75-9 2 (23)76-3 0-4 per cent.
London Medical Students ¢ (150) 78:7 92 (150)79'5 O08 ,,
Cambridge Dissecting Room ¢ (120) 78-01 9 (40) 79-6 16 ,,
London Patients 3 (50) 77-7 9 (60) 798 16 a
It seems therefore that all the material which has not been subjected to
arbitrary sexing agrees in giving the female heads a higher index than the male
by about 1 per cent., and if this ratio should be confirmed in the future we may
have in it a useful method of checking the correctness of our endeavours
in sexing unknown collections of skulls'.
The next point is to determine whether the female skull has increased
its index by decreasing its length or increasing its breadth in proportion to
the male and for this the length and breadth averages are necessary.
Ty: Br. L. Br.
London Med. Students® 36 198-4 152-3 9185 147
British Association 61981155 $2 185°6 148-8
Cambridge Dissecting Room ¢ 194-3 151-5 9186 148
London Patients 6 1938:3 150 9 182-4 144-7
Clare Market $6196 150 92186 146
In other words, among the London Medical Students the length of the 9
head is 95-1 per cent. of that of the male while the breadth is 96-5 per cent.
In the British Association length is 93-7 percent.
rae ee breadth is 95-7 me
In the Cambridge Anatomy School length is 95-7 ,,
s ss breadth is 97-7 __,,
In the London Patients lengthis 944 ,,
ms a breadth is 96:5 _,,
It will therefore be seen that in all these separate groups the ratio of the
breadth of the female is 2 per cent. nearer that of the male than is the length,
or, in other words, that there is a 2 per cent. greater loss of length than of
breadth in the female English skull compared with the male.
Having traced the sexual difference to the length it naturally became a
question whether it might not be accounted for by the greater development
of the frontal sinuses in the male and the only means of checking this which
occurred to us was to take the ophryo-maximal measurements and see whether
1 Since writing the above we are interésted to note that Fleure and James found the same
increase of the cephalic index in the female sex in Wales. Journ. Anthrop. Inst. 1916, p. 48.
Sexual Differences in the Skull 61
there was the same proportional difference between the sexes that was noticed
in the glabello-maximal; the argument being that, as the ophryo-maximal
length only affects the brain containing part of the skull while the glabello-
maximal represents brain and air, any difference in the proportion of the two
lengths to the breadth must be due to a difference in the air containing part.
In the large series of skulls at Hythe which one of us measured (Journ. of
Anthrop. Inst. vol. xxxvm. p. 419) it was found that the difference between
_ these two lengths was, on an average, 2 mm. for male skulls and nothing at all
Fig. 1.
for the female. We have repeated the measurements on 100 patients in St
Thomas’s Hospital, 50 males and 50 females, with the same result.
Assuming that this difference is approximately accurate, we find that, if we
deduct 2 mm. from the glabello-maximal length of the 150 St Thomas’s
_ Hospital male students’ heads, the length of the 150 Women’s School students
is 96-65 per cent. of the St Thomas’s length and the breadth 96-5 per cent.
In other words that the female heads were 3-5 per cent. smaller than the male
in both the antero-posterior and transverse diameter. This is exactly what
we were looking for because on removing the 2 mm. due to air, the proportions
_ between length and breadth become the same in the two sexes and so the
_ cephalic index becomes the same.
62 F. G. Parsons and Mrs Lucas Keene
When we came to the other series, however, the results were not so satis-
factory from this point of view, but the simplest thing will be to tabulate the
four sets of results.
Qshorterthan j 9 narrower than ¢
London Medical Students 3-5 per cent. 3-5 per cent.
London Hospital Patients 45 e BG:
Cambridge Dissecting Room 3:3 ie 23. 4,
British Association 5:4 Be,
From this it appears that the subtraction of 2 mm. from the male length
does not equalize the proportions of length and breadth except in one series
out of four. The other three agree in requiring another 1 per cent. removed
from the male in order to equalize the cephalic index in the two sexes,
The amount is not great, but it is worth noticing, and our available material
makes us think that the average English female skull is slightly broader, in
proportion to its length, than the male even when the increased size of the air
sinuses in the latter is allowed for.
One has, of course, to think whether there is any reason why the medical
students should not have fallen into line with the other series, and the only
one we can suggest is that they were all young adults in whom, perhaps, the
sinuses were not as well developed as in the older groups.
On Checking the Sexing of Skulls
As all the different series of skulls in which the males and females were
known agree in showing the female head as 2 per cent. broader than the male
in relation to its length it appears that we have a check on the accuracy of
the arbitrary sexing of those large series in which the sexes are not known.
Judged in this way the following results are interesting:
2 index>3 - Qindex< fg
(80 g 309) Clare Market 2 per cent.
Hythe 1:5 a
Moorfields 6 per cent.
Whitechapel 3 %
Rothwell 5 ere
The Clare Market and Hythe series therefore answer our expectations well
enough, but the other three show the reputed males with a higher cephalic
index than the females, a condition of things which is not in harmony with
the evidence at present before us and makes us regard their accurate sexing ©
as probably not very happy.
The Facial Index
On comparing the norma facialis tracings of the two sexes in the Clare
Market series it will be seen that the males have an average length of 121 mm.
from the nasion to the lower chin level against 116 mm. in the females
while the greatest bizygomatic breadth is 129 mm. in the males against
123 mm. in the females. This means that the proportion of the length to the
Sexual Differences in the Skull 63
breadth of the face or facial index is 93-8 in the male against 94-3in the female.
This, of course, is in the dried skull and we do not know any other collection
of skulls, either accurately or tentatively sexed, with which to compare this
because in all the collections we know the lower jaws are missing. We are,
therefore, thrown back upon living faces with all the difficulties of adequate
allowance for soft parts.
. After careful examination of sections of faces we suggest 8 mm. as an
ample allowance for the soft parts in the breadth and 4 for those in the length, —
_and this would make the living Clare Market index 91-2 for the males and 91-6
for the females. - :
Fig. 2.
Against this we have to set 58 male students of St Thomas’s Hospital with
an index of 870 and 100 female students from the Women’s School with one
_ of 863, which means that while the Clare Market female facial index is practi-
_ eally equal to the male, the living female students’ index is 99-2 that of the male
This makes us doubt whether any use can be made of the facial index for
sexing purposes, and our work, so far, is negative from this point of view.
The Breadth-height Index
: The difference in the appearance of the cranial vault is rather striking
_ when the norma facialis of the two sexes is viewed side by side and suggests
. difference in the breadth-height index. If this index is to be checked in the
iving head it will be necessary to use the auricular height which may be
64 F. G. Parsons and Mrs Lucas Keene
ascertained by taking the height of the vertex above the Frankfurt plane and
adding 6 for half the external auditory meatus.
This gives 120 mm. for the males and 115 for the females, and, when the
maximal breadth is divided by it, the index is 84-5 g and 83:39. This differ-
ence in the index means that the female skull has lost 4-2 per cent. of the male
height but only 2-8 of the male width.
At present we have little material definitely sexed with which to compare
this, but as far as 108 male and 25 female medical students go we find the
proportion is the same because the male breadth-height index is 89-8 and the
female 88-2.
This is the cranial index, not the cephalic, obtained after deduction of
8 mm. from the breadth and 5-5 mm. from the height.
Bimolar Width
Professor Keith has lately called attention to the diminution in the width
of the palate in modern English compared with Saxon skulls; here we are only
concerned with sex and it is striking how much narrower the female palate
is than the male. The distance between the maxillary tuberosities in the males
is 62 mm. while in the females it is 54 mm., and it will be noticed that the
same line which joins the tuberosities is continued on to the lower jaw. In the
maxillary width the female skull is 8 mm. narrower than the male, but in the
wider mandibular width in the same line the female is only 6 mm. less than
the male. Unfortunately we are unable to check this record at present on
certainly sexed material.
Zygomatic Width:
The Bizygomatic width or face breadth has been considered already in
connection with the facial index and we now wish to consider it from the norma
verticalis in connection with the width of the cranium.
In looking at this norma it is evident that the male skull is a good deal
more phaenozygous than the female and the question arises whether the
zygomata are more splayed in the male or whether the vault of the skull is
fuller in the female in the anterior part of the temporal fossa. We shall pro-
bably get a better idea of this if we compare the bizygomatic width with the
maximal skull breadth rather than with the inter-stephanic width.
If we do this we find that the zygomatico-maximal index or proportion of
the zygomatic width to the maximal width is 90-9 per cent. in the male, and
87-0 per cent. in the female. This indicates that the zygomatic arch is distinctly
wider in relation to the skull width in the male than in the female. We were
able to check this in the male and female medical students in whom the male
index was 89-7 per cent. and the female 88-5 per cent. These observations
were made on 53 male and 100 female students. |
Apparent tapering forward of the Skull
Apart from the difference in zygomatic width the male skull appears to
taper away in the anterior temporal region much more than the female does;
Sexual Differences in the Skull 65
in other words that the pterionic region in the female is fuller than in the male.
A useful measurement is to our hand in the breadth taken a quarter of the
way back along the length of the skull. This in the male is 115 and in the female
112. Contrasting these with the maximal width we get an index of 81 in the
male and of 81-2 in the female.
This index suggests that the appearance of fulness is illusory and due to the
feeble development of the zygomata in the female.
a LE - -a~ \
--—-*. Shr = Or - =
CONCLUSIONS
From the material at present at our disposal we have come to the following
conclusions about the English skull.
1. That the female skull is shorter in proportion to its breadth than is the
male by 2 per cent. and that this difference is not fully accounted for by the
greater development of the frontal sinuses in the male.
2. That in those series of artificially sexed skulls in which this proportion
is markedly departed from the sexing has probably been unsuccessful.
3. That the facial index does not differ in the two sexes.
4, That the female skull is lower in proportion to its width than the male,
by from one to two per cent. when the auricular height is taken.
5. That the female skull is some 8 mm. narrower in the width of the palate
than the male.
6. That the zygomatic arches are wider in proportion to the maximal
breadth of the skull by 4 per cent. in the male than in the female.
Anatomy LIV 5
THE ILEO-CAECAL REGION OF CALLICEBUS PER-
SONATUS, WITH SOME OBSERVATIONS ON THE
MORPHOLOGY OF THE MAMMALIAN CAECUM
By T. B. JOHNSTON, M.B., Cu.B.,
Professor of Anatomy, University of London, Guy’s Hospital Medical School.
‘Tue material on which this note is based consisted of three specimens of the
South American monkey, Callicebus personatus, and one specimen each of
Dasypus seaxcinctus, Tatusia novemcincta and Cyclothurus didactylus, which
were collected by the Percy Sladen Expedition to Brazil in 1913 and which
were placed at my disposal by Professor J. P. Hill, to whom I desire to express
my indebtedness and my thanks.
Caecocolic i
Sunctior
Caecum"
Ni a”
Se je
cal
Fig. 1. Tleo-caecal region of Callicebus personatus. Ventral surface.
-Eaternal appearances. In each case the commencement of the colon was
distinctly dilated, although the length of gut involved was not constant, being
4 cm. long in two cases and 8 cm. long in the third—the “caecal colon” of
Keithq). The succeeding portion of the gut was in a state of tonic contraction
for a distance of 8 cm. in the two former specimens and for 2-5 cm. in the
third specimen. The term “caeco-colic sphincteric tract”? has been suggested
by Keith (6) for this portion of the large gut. From this point onwards to the
anal canal, the colon showed a series of sacculations, each separated from its
neighbour by a firmly contracted portion, varying from -5 cm. to 1 cm, in
length.
Only two taeniae coli could be made out. They were situated, the one on the
dorsal surface and the other on the ventral surface of the colon near the
mesenteric border, but their edges were not sharply demarcated.
The Ileo-Caecal Region of Callicebus Personatus 67
The Caecum, which occupied the right iliac fossa, was demarcated from
the colon by a circular depression which passed downwards and medially
across the gut (fig. 1). In each of the three specimens it was distended and
its capacity was rather greater than that of the stomach. In none did it contain
2 gas. Its conformation was different in each case. In one (fig. 1), it was about
12 em. long, and was curved to the left in a L-shaped manner. In another,
it was 15 cm. long and formed a flat coil of.one and a half turns. In the third,
it was 16 cm. long and formed a spiral coil of one and a half turns, the com-
___ mencement of the second turn of the spiral passing dorsal to the first turn. In
each case it was clear that growth had been greater along the anti-mesenteric
__ than it had been along the mesenteric border of the gut and that the coiled
: - eondition had resulted from an earlier U-shape.
8
The anterior and posterior vascular folds of Huntington (2) were present and
the artery contained in the latter was in two of the three specimens the longer
vessel and extended to the apex of the caecum.
E In each case the caecum gradually tapered from its commencement to its
___ apex, and in no case were taeniae coli distinct on its surface.
¥ The Ileum terminated in the right iliac fossa by passing upwards and
laterally into the medial aspect of the colon, where its entrance was marked
on the surface by a V-shaped furrow (fig. 1). It was closely applied to the wall
of the caecum.
Internal appearances. The mucous membrane of the commencement of
the colon was smooth except on its dorsal wall where a few longitudinal
corrugations were present.
The ileum protruded into the colon for -5 em. and its mucous membrane
was thrown into ridges parallel to its long axis. The upper lip of the opening
was quite distinct but the lower lip was not so salient owing to its relation to
_the caeco-colic valve.
The caecum was separated from the colon by a well-developed caeco-colic
valve, annular in shape with a central opening and so placed that the plane
of its aperture was directed upwards and medially. The valve was widest
at the medial side of the gut, where it lay immediately below the termination
of the ileum. The mucous membrane on both of its surfaces was thrown into
radiating ridges (fig. 2), and, on the medial side, these ridges were directly
continuous with the longitudinal ridges of the ileal mucous membrane.
On the lateral side of the gut the caeco-colic valve was in the same plane as the
upper lip of the ileo-colic valve, but, owing to the obliquity of its peripheral
attachment, which corresponded to the depression on the outer surface (fig. 1),
on the medial side it lay immediately below the lower lip of the ileo-colic valve.
In this situation it hung downwards towards the caecum, presenting a spout-
like appearance (fig. 2).
Over the ventral surface and along the anti-mesenteric border of the
caecum, the mucous membrane was smooth, but longitudinal corrugations
were strongly marked over the dorsal surface and along the mesenteric border.
5—2
68 T. B. Johnston
At the base of the b (fig. 1), two prominent transverse corrugations were present
on the mesenteric border of the gut.
No lymphoid patches were recognisable in the ileo-caecal region on naked-
eye examination.
Microscopical appearances. The upper or colic lip of the ileo-colie valve
was, as is usual, covered on its outer surface with mucous membrane typical
of the large intestine and on its inner surface with mucous membrane typical
of the small intestine. The circular muscle coat of the latter was prolonged
into the substance of the valve, but the circular coat of the large intestine
ended abruptly at the base of the valve, where the longitudinal muscle fibres
met and interlaced without becoming continuous with one another and without
entering into the formation of the valve.
Sections through the lower or caecal lip of the ileo-colic valve also passed
through the eaeco-colic valve on the mesenteric border of the gut. The circular
{20 oe /leum
: Ca0cecocouc
lalve
oN
Caecunv~
Fig. 2. Ileo-caecal region of Callicebus personatus. A window has been made in the wall of the
gut so as to expose the ileo-colic and caeco-colic valves.
muscle coats of the ileum and caecum lay side by side, separated only by a few
longitudinal fibres of the caecum and by some connective tissue, for some
distance from the ileal termination. On separating from one another, that of
the ileum entered the ileo-colic while that of the caecum entered the caeco-
colic valve. The mucous membrane corresponded in its arrangement with the
circular muscle coats. The villi disappeared at the apex of the lip of the ileo-
colic valve and the mucous membrane, where it was associated with the
circular muscle coat of the caecum, assumed the characteristic features of the
large intestine.
The caeco-colic valve was covered on both colic and caecal surfaces by
The Ileo-Caecal Region of Callicebus Personatus 69
mucous membrane typical of the large intestine, which was loosely connected
with the underlying muscle. The entire thickness of the circular muscle coat
of the colon passed into the substance of the valve, as did that of the caecum,
so that the valve contained two layers of circular muscle fibres which became
continuous near its free margin. These two layers carried in with them on their
outer surfaces a fine layer of longitudinal fibres derived from the longitudinal
muscle coats of the colon and caecum respectively. These fibres could only
-be traced into the middle of the valve and, thereafter, the two layers of circular
muscle fibres were only separated by connective tissue (fig. 3).
The majority of the longitudinal muscle fibres of the colon were directly
continuous with the longitudinal muscle fibres of the caecum.
The caecal wall showed no difference in structure throughout the whole
of its extent, i.e. the mucous membrane near the apex was indistinguishable
Fig. 3. Longitudinal section through the anti-mesenteric border of the gut at the junction of the
caecum and the colon of Callicebus personatus, to show the structure of the caeco-colic valve.
_ from the mucous membrane of the rest of the caecum. Small nodules of lym-
phoid tissue were found in the submucous tissue but they were not more
numerous near the apex than elsewhere.
Particular observations. The size of the caecum of Callicebus personatus
relative to the size of the stomach and the presence of a competent caeco-colic
valve constitute strong evidence that in this genus the caecum has a definite
function to perform in connection with the process of digestion. The thickness
of the circular muscle coat in the valve indicates that it acts as a powerful
and efficient sphincter, and it is probable that the longitudinal fibres which
enter into its constitution provide a muscular means of relaxation.
__ Fig. 3 shows clearly that the muscular core of the valve is not produced
by a localised thickening of the circular muscle coat of the gut, but constitutes
a true infolding of the whole thickness of that coat, a condition similar to that
described by Sappey (3) in the spiral intestinal valve of Raja. Owing to the
70 T'’. B. Johnston
obliquity of the peripheral attachment of the valve, many of the circular
fibres which are found in it laterally, must, as they are traced medially, leave
the valve and re-enter the wall of the colon, ultimately reaching the medial
wall of the gut on the same level as the upper or colic lip of the ileo-colic valve.
It would seem, therefore, to be not improbable that the contraction of these
fibres approximates the lateral part of the caeco-colie valve to the upper lip
of the ileo-colic valve, in this way causing the ileum to open into the caecum
through the oblique inlet of the former. As already pointed out, the medial
part of the caeco-colic valve is in intimate relation with the lower lip of the
ileo-colic valve and its spout-like appearance suggests that the contents of the
ileum may pass directly into the caecum.
The condition of the vascular folds of the caecum corresponds to what
Huntington (2) described for the closely allied Ateles ater, namely that either
the ventral or the dorsal fold and its contained artery may be the longer. It
may be stated that the external appearances of the ileo-caecal region of Calli-
cebus personatus and Ateles ater are very similar, but I have not had an oppor-
tunity of examining the internal and microscopical appearances of the latter.
As compared with the ileo-caecal region of Callicebus personatus, the
condition found in the old-world monkey presents some manifest differences.
In a specimen of Cercopithecus aethiops which I examined, the stomach pos-
sessed a capacity eight or ten times greater than that of the caecum, which was,
relatively, much smaller than the caecum of Callicebus personatus. The shape
of the caecum in all the old-world monkeys is attributable to the fact that .
growth along the anti-mesenteric border of the gut has been in excess of the
growth along the mesenteric border. Thus, in Cercopithecus aethiops, the
caecum is L-shaped.
In all the old-world monkeys, the proximal part of the caecum is sacculated
and these sacculations—produced in the same way as the sacculations in other
_parts of the colon—are separated from one another by deep furrows, which
do not, however, pass completely round the gut, being absent at the mesenteric
border. It follows that taeniae coli are well marked on the caecum in its
proximal part. In Callicebus personatus, on the other hand, the sacculations
are absent and the taeniae coli are not distinct.
In the old-world monkeys the terminal tapering of the caecum is abrupt, °
unlike the condition found in Callicebus personatus, but the diminution in
calibre is not sufficient to justify its identification as a vermiform process.
The arrangement of the peritoneal folds in Callicebus personatus has been
described on p. 67. In Cercopithecus aethiops the intermediate non-vascular
fold is very well developed and forms a large triangular fold which occupies
the angle between the terminal part of the ileum and the medial wall of the
proximal part of the caecum. The anterior and posterior vascular folds, how-
ever, are very short so that the vessels they contain run practically on the gut
wall.
In the specimen of Cercopithecus aethiops which I examined, the ileo-colic
1 iy Oe ete en ee
‘: oO ae
sf
The Ileo-Caecal Region of Callicebus Personatus 71
valve was found to be directed tailwards, i.e. towards the caecum, and the
terminal part of the ileum passed posteriorly and laterally into the colon.
The specimen had been preserved in formalin and I believe that the condition
was probably brought about by post-mortem and abnormal muscular con-
traction. At the same time it is clear that the particular muscular contraction
which produced the condition after death may be able to produce the condition
during life.
In the interior of the caecum of Cercopithecus aethiops, the furrows sepa-
rating the sacculations on the outside formed definite folds containing circular
muscle fibres. These folds may have acted as a sphincter for the caecum, but
they were not continued all round the gut; they were produced by the differ-
ence in length between the longitudinal and the circular muscle coats; and
they did not constitute a true caeco-colic valve.
If the condition of the ileo-caecal region of the new- and old-world monkeys
be compared with the condition found in the anthropoid apes, it will be found
that the increased growth along the anti-mesenteric border of the caecum is the
most striking characteristic which all three groups possess in common.
The small size of the caecum relative to the stomach, the possession of
definite taeniae coli and the corresponding caecal sacculations, and the
absence of the caeco-colic valve are characters which the anthropoid shares
with the old-world monkey.
On the other hand, the anthropoid differs both from the old- and the new-
world monkeys in possessing a vermiform process. It also possesses both an
intermediate non-vascular ileo-caecal fold and a well developed dorsal vascular
fold’.
It will be seen, therefore, that so far as the ileo-caecal region is concerned,
the old-world monkeys are much more closely allied to the anthropoids than
are the new-world monkeys.
It may be of some interest to point out that, as regards both the caecum
_and the caeco-colic valve, Tarsius tarsius, which Wood Jones (14) excludes
from the Lemurs, closely resembles Callicebus personatus.
General observations on the mammalian ileo-caecal region. In human
anatomy, the term caecum is used to denote that portion of the large intestine
which lies on the proximal side of the ileo-colic valve. In comparative ana-
tomy, the term is not always used to describe the same morphological entity.
The caecum of the monkey corresponds exactly to the human caecum, but
the caecum of the rabbit, the horse and some other mammals includes, in
addition, the proximal part of the colon proper. This difference is not always
borne in mind, but Keith (6) believes that the proximal part of the colon proper
should be regarded as functionally part of the caecum and he terms it the
*“caecal colon.”’ He has indicated that he considers that the “‘caecal colon”
1 The morphology of these folds is fully discussed by Huntington (2).
72 T'’. B. Johnston
is morphologically the primitive vertebrate caecum and that the diverticular
blind end appears at a later stage in phylogeny.
In the present paper consideration is being restricted to the morphology
of the caput caecum coli of human anatomy, and I would be content to draw
attention to the risk of confusion in nomenclature and to point out that the
‘‘ caeco-colic valve,’ which Sisson (4) describes in the horse, is not identical with
the caeco-colic valve of Callicebus personatus.
The frequent occurrence of a competent caeco-colic valve is overlooked by
Chalmers Mitchell (5) when he makes the following statement: “‘The normal
caecum of mammals, however, always appears to be a forward continuation
of the hind-gut, the one cavity being directly continuous with the other in the
simplest fashion, except in those cases in which it is slightly complicated by
vestiges of the presence of the second caecum of an original pair.” It is not
possible to regard the caeco-colic valve as a vestige of the presence of the second
caecum of an original pair, even if one agreed with the author in his view that
the primitive mammalian caecum was a paired structure. When it is remem-
bered that the caeco-colic valve is a true sphincter of the caecum, that amongst
mammals it is sometimes present, sometimes replaced by an intra-colie valve,
and sometimes completely absent it will be evident that its value as an aid in
studying the morphology of the caecum is by no means negligible.
In opposition to currently accepted ideas, Keith (6) has put forward the view
that the human caecum is not in a state of retrogression. He regards the
commencement of the colon, which is usually found to be dilated, as a feeding
chamber for the caecum, the passage of the chyme being effected by anti-
peristaltic waves, which Cannon (7) and Barclay Smith (8) have described. Keith
points out that the portion of the colon immediately beyond the dilatation
is very commonly found tonically contracted in mammals and in birds, and
he looks upon it as a sphincter for the caecum and “caecal colon.” Conse-
quently he has suggested the term “‘caeco-colic sphincteric tract”’ to denote it
and he believes that, in man, the upper part of the ascending colon represents
this tract and functions as a sphincter for the human caecum. He draws
attention to Berry’s (9) work on the vermiform process in support of his view
that the human caecum is an actively functioning part of the alimentary
canal,
Annular valves, very similar to the caeco-colic valve of Callicebus per-
sonatus, are found in the alimentary canals of many fishes and reptiles, and
are clearly very primitive in type, but they are none the less competent and
efficient in their action. Many of Keith’s observations were made on the rat
and he has himself referred to the presence of a caeco-colic valve which he has
figured. He does not explain, however, why, in the presence of a competent
valve, a “caeco-colic sphincteric tract” should be necessary, nor does he
explain why, if a sphincter is required, a tonically contracted tube should
take the place of a primitive annular valve. The ‘“‘caeco-colic sphincteric
tract”? would appear to be destined, like the oesophagus and the human de-
The Ileo-Caecal Region of Callicebus Personatus 73
scending colon, to act as a passage for the rapid conduct onwards of incoming
contents, and not as a sphincter.
Huntington 2) has drawn attention to the fact that “representatives of all
the main types of ileo-colic junction are found within a very limited zoological
range, as within the confines of a single order...differences in the method of
nutrition have impressed their influence on the structure of the alimentary
canal and have led to the evolution of varying and divergent types of ileo-colic
junction.” This is an indication that the possibilities of variation are limited,
-and I believe that they are very much fewer than Huntington lays down.
Asymmetry in origin and asymmetry in growth are the outstanding character-
istics of the mammalian caecum, and I believe that the primitive mammalian
eaecum was asymmetrical, i.e. a diverticulum derived from the anti-mesenteric
border of the colon just beyond the ileal termination, such as is found in some
reptiles, e.g. Pseudemys elegans, Eunectes marinus, etc. As the caecum en-.
larged and its functional activity increased, a caecal sphincter was developed.
Further caecal progress necessitated the redistribution of, or increase in,
the lymphoid tissue, with the consequent appearance of the vermiform pro-
cess. Variations of diet led to retrogressive changes in form. Retrogressive
_ changes at an early stage may account for the complete absence of the caecum
in Dasyurus viverrinus. Retrogressive changes at a later stage may account
for many of the reduction forms found in carnivora. Finally, retrogressive
changes imposed on the most advanced form may account for the reduction
in size accompanied by the retention of the vermiform process found in the
wombat, the antbropoid apes and man.
Wood Jones (14) has recently put forward a somewhat unorthodox view of
the morphology of the caecum. “The human vermiform appendix,” he says,
“although usually regarded as a particularly degenerated rudiment, is strangely
like that of such simple creatures as some of the pouched animals of Australia,
and the very different structure found in the monkeys is most likely a special-
isation from a primitive condition which is retained in man.”’ From this one
might with some justice infer that the author believes that the simpler the
animal, the more primitive the type of the caecum, but, as Huntington has
shown, all the main types are to be found within the limits of a single order.
The conception that such a caecum as that of Callicebus personatus or of
Cercopithecus aethiops has been derived from a condition similar to that
found in man and the anthropoid apes is one for which I am unable to find any
supporting evidence. On the other hand, I have tried to show that the vermi-
form process is present in two types of caeca. In the one, the caecum is rela-
tively large and obviously plays an important part in the digestive process
and this increased functional importance demands a redistribution of the
lymphoid tissue, which is manifested by the presence of the vermiform process.
In the other, the caecum is relatively small, it possesses no true sphincter,
its wall is sacculated—a common condition in large, actively functioning caeca
but uncommon in relatively small caeca, which do not possess a vermifor,,
74. T. B. Johnston
process—and its general characters are such as to suggest strongly that it is
a reduction stage of the first group.
Retrogressive changes necessarily are associated with loss of function and
the caecal loss of function will be indicated in the first place by the disappear-
ance of the sphincteric valve.
I therefore conclude that, in the determination of the phylogeny of a given
caecum, the condition of the caeco-colic valve is of the greatest importance. |
In putting forward this suggestion as to the primitive mammalian caecum,
I am aware that it is in agreement neither with the conception of Huntington (2)
nor yet with that of Chalmers Mitchell (13). The former refers all mammalian
caeca to a primitive vertebrate type with no caecum, and he derives the various
types found to-day in different ways from a condition similar to that found in
Echelus conger.
Chalmers Mitchell (13) believes that the single mammalian caecum is the _
persistent member of a primitive pair of caecal appendages, homologous with
the paired caeca of birds. He compares the paired caeca of birds and the paired
caeca of the little ant-eater, Cyclothurus didactylus—which are both laterally
placed—with the paired caeca of Petaurus sciurens, in which the large caecum
is anti-mesenteric in position and the (?) vestigial caecum is connected to the
mesenteric border of the gut, and he states that any anatomist would agree
that the structures involved are the same.
This statement would only be justified if the author had brought forward
evidence to show how caeca, which were previously lateral in position, came
to be situated on the anti-mesenteric and mesenteric borders of the gut, and,
in the absence of such justification, one cannot concede that the paired lateral
caeca of Cyclothurus didactylus ave identical with the so-called paired caeca
of Petaurus sciurens.
If, therefore, we exclude the paired caeca of Petaurus sciurens and other
forms where the larger structure—usually accepted as the caecum—is anti-
mesenteric in position, there still remain certain mammals which have been
described by Flower (10), Owen (11) and other observers as possessing paired
lateral caeca. The list includes the armadilloes, Dasypus sexcinctus, Dasypus
villosus and Tatusia novemcincta, the little two-toed ant-eater, Cyclothurus
didactylus, and the Manatee (Chalmers Mitchell).
The Manatee possesses a bifid caecum, springing from the anti-mesenteric
border of the gut, and can be excluded as an example of the paired lateral
caeca.
In Tatusia novemeincta, the condition at the ileo-colic junction is de-
scribed differently by different authors. Huntington cites it as an example of
the symmetrical type of ileo-colic junction, with median transition of the ileum
and, although he does not definitely make the statement, it can be inferred that
he, like Flower (10), regards the caecum as being absent. Chalmers Mitchell on
the other hand describes the same animal as possessing small paired globular
caeca. Both these authors agree in believing that the “ paired lateral caeca”’
The Ileo-Caecal Region of Callicebus Personatus 75
of Dasypus sexcinctus and Dasypus villosus constitute an advanced stage of
the condition found in Tatusia novemeineta.
Examination of the ileo-colic junction of Tatusia, when the gut is empty,
is sufficient to satisfy the observer that growth along the anti-mesenteric
border of the commencement of the colon has been
definitely greater than it has been along the mesen-
teric border (fig. 4). Further, the longitudinal muscle
coat of the ileum passes continuously on to the anti-
mesenteric border of the colon and there constitutes
a definite taenia coli. This does not occur on the
lateral aspects of the ileo-colic junction, and I be-
lieve that the condition represents a well-marked
transition stage between the condition where the
ileum is in direct linear continuity with the colon,
and the condition which Huntington describes as
the right-angled type of ileo-colic junction. I regard
the ee ea ane RR border od oe ~ & Neo-cercel Tease
atusia novemcincta, ventral
commencement of the colon as the true caecum. surface showing anti-mesen-
When the colon of Tatusia is artificially distended _tetic taenia coli and asym-
the lateral wall of the commencement of the colon ™°*7i*#! ileo-colic junction.
tends to bulge, and these two bulgings are separated from one another by the
anti-mesenteric taenia coli already referred to. These bulgings are regarded
by Chalmers Mitchell as paired lateral caeca, but I prefer to regard them as
the first stage in the production of a bifid caecum.
Anti me
taenia colt,’
G /
/ -
ge 3 “D C2 M he J
of bihid caecum Mi Ca00CH = =
_ Fig. 5. Tleo-caecai region of Dasypus sexcinctus Fig. 6. Ileo-caecal region of Dasypus sexcinctus
showing anti-mesenteric aspect with well- showing asymmetry which indicates the
marked taenia coli separating the two ex- true caecum.
tremities of the bifid caecum. ©
This view is strongly confirmed by the condition found in Dasypus sev-
cinctus. In this animal the anti-mesenteric taenia coli and its continuity with
76 T. B. Johnston
the longitudinal muscular coat of the ileum are very striking (fig. 5). The colon
is asymmetrically dilated at its commencement—-the true caecum (fig. 6)—
but further growth of the anti-mesenteric border of the gut has been modified,
because the taenia coli has not kept pace. As a result Dasypus sexcinctus
possesses “‘ paired lateral caeca”’ which I regard as a typical unpaired caecum
with a bifid extremity, and a modification of this caecum may, with justice,
be believed to be the origin of the bifid caecum of the Manatee.
There remains for consideration the condition found in the little two-toed
ant-eater, Cyclothurus didactylus, of which Hunter (12) says: “There are.two
caeca as in birds.’’ Flower’s (10) description is as follows: “The colon is short
and is very remarkable for having at its commencement a symmetrically dis-
posed pair of short caeca, narrow at the base, and rather dilated at their
terminal blunt end, and communicating with the general cavity by very
minute apertures.”
Orittce of left- ,
lateral caecal oulgrowth ™®
Lleo-colic valve \\
Lett lateral caecal-->—/ mm
outgrowth Tie
Fig. 7. Ileo-caecal region of Cyclothurus didac- Fig. 8. Sagittal section through ileo-caecal:
tylus, ventral view showing the “ paired region of Cyclothurus didactylus along line
lateral caeca.” shown in Fig. 7. The asymmetrical ileo-
colic transition is shown and the position
of the true caecum is indicated.
Huntington (2) classes it as a more advanced stage of the condition found
in Dasypus sexcinctus, but the caeca of these two animals show very striking
differences. In Dasypus, as already noted, the paired caeca are separated
from one another only by the anti-mesenteric taenia coli. In Cyclothurus, their
attachments are very widely separated (fig. 7). In Dasypus, the caeca are of
a size in conformity with the size of the colon, whereas in Cyclothurus they
are relatively very small. In Dasypus, the caeca are widest at their connection
with the-colon; in Cyclothurus, they are very narrow at their colic ends, but
dilated and bulbous at their blind extremities, a curious condition to which
Flower (10) has drawn attention.
A sagittal section through the ileo-colic junction of Cyclothurus (fig. 8)
shows the same asymmetrical transition as has been already pointed out in
The Ileo-Caecal Region of Callicebus Personatus 77
Tatusia novemcincta, and a similar degree of increased growth along the anti-
mesenteric border of the colon.
Transverse sections through the stalk or proximal part of the caecal out-
growth show that the mucous membrane is thick and vascular and that the
lumen is relatively small. In the distal two-thirds, the lumen is much larger
but the mucous membrane is not so thick. A complete longitudinal muscular
coat is present throughout, as in the vermiform process of other animals.
Unfortunately, in the specimen examined by me the material had not been
fixed with a view to microscopical examination, and I am therefore unable
to describe the appearance of the mucous membrane, beyond saying that it
appeared to conform to the type usually found in the caecum.
: Consideration of the differences which have been enumerated above leads
me to regard the paired lateral caecal outgrowths as new formations and the
dilatation at the commencement of the anti-mesenteric border of the colon
(fig. 8) as the morphological caecum.
It is clear therefore that the paired caeca can be explained in such a way
as to bring them into line with other mammalian caeca and that they do not
constitute an insurmountable obstacle to the acceptance of the views which
have been put forward in this paper.
CONCLUSIONS
1. The caecum of Callicebus personatus is an actively functioning part of
the alimentary canal.
2. The caeco-colic valve is the true caecal sphincter.
8. Where the functional caecum does not correspond to the morphological
caecum, e.g. in the horse, the rabbit, ete., the caeco-colic valve is replaced by
an intra-colic valve.
4, The human caecum, which possesses no competent caeco-colic or intra-
colic valve, is in a condition of retrogression.
5. The primitive mammalian caecum was an asymmetrical structure
derived from the anti-mesenteric border of the colon immediately beyond the
ileo-colic junction by increased growth over a localised area.
6. The paired lateral caeca of Dasypus sexcinctus and Dasypus villosus
are regarded as the extremities of a bifid caecum.
7. The paired lateral caeca of Cyclothurus didactylus are new formations
and do not correspond to the morphological caecum.
At the same time, one recognises that much valuable information, which
has still to be obtained with regard to the comparative embryology of the
caecum, is not yet available and that it may therefore be necessary to modify
one’s views in the light of subsequent knowledge.
I desire to express my thanks to Mr G. L. Birbel, who is responsible for
figs. 1 and 2, and to Miss Muriel Sutton, B.Se., who is responsible for fig. 3,
for the care and trouble which they have taken over these drawings.
78
(1
7
(2
—
(3
~
(4
~
(5)
(6)
(7)
(8
(9)
~~
(10)
(11)
(12)
(13)
(14)
T. B. Johnston
REFERENCES TO LITERATURE
Kerrn, A. “Anatomical Evidence as to the Nature of the Caecum and Appendix.” Proc.
Anat. Society of Great Britain and Ireland, Nov. 1903, p. 1.
Huntineron, G.S. Lhe Anatomy of the Human Peritoneum and Abdominal Cavity London.
Henry Kimpton, 1903.
Sappry, Px. C. Quoted in Oppel’s Lehrbuch der Vergleichenden Mikroskopischen Anatomie.
der Wirbeltiere. Jena, 1897, p. 311.
Sisson, 8S. The Anatomy of the Domestic Animals. Philadelphia and London. W. B. Saunders
Coy. 1917.
‘Mrronett, P. Coatmers. “Further Observations on the Intestinal Tract of Mammals.”
Proc. Zool. Soc. 1916, pp. 183-251.
Kerrn, A. “The Functional Nature of the Caecum and Appendix.” Brit. Med. Journ.
1912. Vol. 1. pp. 1599-1602.
Cannon, W. B. The Mechanical Factors of Digestion. 1911.
Barouay SmituH, E. Proc. Camb. Phil. Soc. Vol. x11. 1902.
Berry, R. J. A. “The True Caecal Apex. or the Vermiform Appendix; its minute and com-
parative Anatomy.” Journ. Anat. and Phys. 1900. Vol. xxxv. p. 83.
Fiower, W. H. “Lectures on the Comparative Anatomy ot the Organs of Digestion of the
Mammalia.” Med. Times and Gazette, 1872. Vol. u. p. 591, ete.
Owen, RicHarp. Comparative Anatomy and Physiology of Vertebrates. Vol. m1. London,
1868.
Hunter, Jonn. Essays and Observations. Vol. 1. p. 181. London, 1861.
MrrceHEy, P. CHatmeErs. “On the Intestinal Tract of Mammals.” Trans. Zool. Soc. Vol. xvm.
pp. 437-536.
Woop Jones, F. The Problem of Man’s Ancestry london, 1918.
ON THE DEVELOPMENT OF THE LARYNGEAL
MUSCLES IN SAUROPSIDA
By F. H. EDGEWORTH, M.D.
Ina paper published in 1916 I showed that in the pig the laryngeal muscles,
other than the Crico-thyroid, are developed from the Constrictor oesophagi.
__ In this paper evidence is given that the laryngeal muscles of the Sauropsida
have a similar derivation. .
Reptiles. The laryngeal cartilages of Reptiles (vide Henle and Géppert)
consist of a cricoid, and two arytenoid cartilages articulating, or continuous, |
with it. The musculature consists of a Dilatator laryngis and a Constrictor
laryngis. Laryngei are present in some cases.
These muscles were considered by Géppert (1899) to be homologous with
those of Amphibia, and like them, to be derived from branchial muscles,
As far as I know, yo description has hitherto been given of the development
_of the cartilages or of the muscles.
Hochstetter (1908) stated that in Reptiles (Emys lutaria, Anguis fragilis,
Tropidonotus, Lacerta agilis) the lungs are developed from paired lateral or
ventro-lateral grooves of the epithelial lining of the oesophagus. At their
anterior ends they communicate by a transverse bifurcation groove, whilst
in front of this and continuous with it a median ventral groove develops. The
pulmonary sacs grow backwards from the hind ends of the pulmonary grooves.
The bifurcation and branchial grooves are folded off from the oesophagus,
from behind forwards.
Schmidt (1913) stated that in embryos of Calotes, Mabuia, and Ptycho-
zoon, the lungs are developed from the oesophagus, as paired diverticula at the
_ junction of its lateral and ventral walls. The trachea is developed later,
behind the branchial region, as a shallow median groove in the floor of the
oesophagus. It extends backwards and soon joins the transverse bifurcation
groove which unites the pulmonary diverticula. In Calotes and Mabuia,
though most marked in the former, there are two tracheal grooves, of which
the left becomes the permanent groove, whilst the right gradually disappears
by being taken up into the left groove. The tracheal groove subsequently
extends forwards into the pharyngeal region, the epithelium in the median
line of the floor of the pharynx thickening into a plate. Meanwhile the separa-
tion of the trachea from the oesophagus proceeds cranially, right up to the
solid epithelial plate. The breaking through of the tracheal lumen into the
pharynx was not observed—it occurs later. The solid epithelial plate corre-
sponds in position to the larynx. :
80 F. H. Edgeworth
The development of the laryngeal muscles was followed in Chrysemys mar-
ginata and Tropidonotus natrix. |
In a 6mm. embryo of Chrysemys (figs. 1-3) the open tracheal groove
extends from the bifurcation groove, 180 yw behind the 5th gill-clefts, forwards
to 80 » behind them. In front of this the oesophagus has a more oval shape.
. The oesophagus and tracheal groove are surrounded by cells of uniform appear-
ance and no indication of oesophageal or laryngeal muscles is visible.
- 5th gill-cleft
trans. groove yee * trach, lary. groove
Fig. 3. Fig. 4.
i 4% br aortic arch *
D/L sth gill-cleft
trach. lary. groove
Fig. 5. Fig. 6.
a
39 br aortic arch: as =
trachea
In an embryo of 7 mm. (figs. 4-6) the tracheo-laryngeal groove begins 140
behind the 5th gill-clefts, and is continued forwards to the level of the 4th gill-
clefts; it is a deep groove in the oesophageal region and at the level of the 5th ~
gill-clefts; it then becomes wider and shallower and is barely marked at the
level of the 4th gill-clefts. The trachea behind the bifurcation groove and the
tracheo-laryngeal groove are surrounded by aggregated mesoblast cells—the —
first indication of the laryngo-tracheal skeleton. The forepart of the oesopha-
gus is surrounded, dorsally and laterally, by the -shaped primordium of the
Constrictor oesophagi and laryngeal muscles.
ee hee ep eee? Pe Say es,
The Development of the Laryngeal Muscles in Sauropsida 81
In an embryo of 8 mm. (fig. 7) the primordium of the laryngeal muscles
has separated on either side from the Constrictor oesophagi. It extends from
170 pu behind, to the level of, the 5th gill-clefts. The recurrent laryngeal nerve
passes towards it.
In an embryo of 9 mm. (figs. 8-10) the tracheo-laryngeal groove extends
from 100 » behind the 5th gill-clefts to the level of the 4th gill-clefts. The
_ tracheal lumen is continued forwards to the level of the 5th gill-clefts. The
primordium of the laryngeal muscles extends from 140 y behind the 5th gill-
clefts to the level of the 4th gill-clefts.
- From this time onwards the increasing curvature of the embryo made
_ another method of measurement necessary. In an embryo of 8-1/2 mm.
crown-rump length—-slightly more advanced than one of 9mm. in total
length-—there is but little change. The tracheo-laryngeal groove begins 50 uw
behind, and the laryngeal-muscle-primordium 90 yw behind, the 5th gill-
clefts.
In an embryo of 12 mm. crown-rump length (figs. 11-14) the trachea has
altogether separated from the oesophagus, so that the laryngeal epithelium
is continuous only with that of the branchial s. pharyngeal region, from the
level of cornu branchiale i to that of the cornu hyale. The laryngeal muscles
_ lie solely in the branchial s. pharyngeal region. Their primordium, on each
side, has separated into the lateral half of the Constrictor laryngis and the
Dilatator laryngis. The former meets its fellow in the mid-dorsal and mid-
ventral lines. The latter lies external to the Constrictor.
In an embryo of 15 mm. (figs. 15-16) crown-rump length the ventral
surface of the Constrictor is attached to the Basibranchiale. The cricoid and
arytenoids form a continuous, slightly chondrified mass, which is continuous
posteriorly, with the tracheal skeleton.
In Tropidonotus the younger embryos have a cork-screw form so that
measurements of length were not possible, and the stages described are arbi-
trarily named.
In stage (i), the earliest available (figs. 17-20), the continuity of the tracheo-
laryngeal with the oesophago-pharyngeal epithelium extends from 30 pu
behind the 5th gill-clefts to the 4th gill-clefts. The primordium of the laryngeal
muscles, just separated from the Constrictor oesophagi, extends from 90 yu
_ behind to the level of the 5th gill-clefts. The recurrent laryngeal nerve passes
to its hind end.
In stage (ii) (figs. 21-22) the continuity of the laryngeal with the pharyngeal
epithelium extends from the 2nd to the Ist gill-clefts, i.e. is only in the Ist
branchial and hyoid segments. The primordium of the laryngeal muscles
extends from the 8rd to mid-way between the 2nd and Ist gill-clefts.
In an embryo of 3 cm. the condition of the laryngeal skeleton and laryngeal
muscles is identical with that in a 6 em. embryo, except that chondrification
has not taken place.
In a 6 cm. embryo (figs. 23-27) the larynx is raised in a median projection
Anatomy Liv ~ 6
82 F. H, Edgeworth
lary. trach, groove
Fig. 7.
4* br. aortic arch.
lary. trach.groove
basihyale
cricoid.c.
Sauropsida 83
un
The Development of the Laryngeal Muscles
84 F, H, Edgeworth
of the floor of the mouth overlying the tongue. The laryngeal and tracheal
skeleton forms a continuous whole and is chondrified. The cricoid has median
superior and inferior processes projecting from its front edge. The arytenoids
are continuous with the cricoid. The primordium of the laryngeal muscles
has separated into the Laryngei dorsalis and ventralis and the Dilatator.
The Laryngeus dorsalis arises partly from the dorsal surface of the cricoid and
from its anterior superior process and is partly continuous with its fellow across
the middle line without any raphé; it is inserted into the dorsal surface of the
arytenoid. The Laryngeus ventralis arises from the sloping upper edge of the
cricoid and from its anterior inferior process; it is inserted into the ventral
surface of the arytenoid. The Dilatator arises from the side of the trachea
and from the cricoid, passes forwards and slightly upwards and is inserted
into the external edge of the arytenoid.
lary.trach.groove , lary. trach. groove
Fig. 30. Fig. 31.
Birds. Weber and Buvignier stated that in the duck the primordia of the
lungs develop as paired ventro-lateral diverticula of the oesophagus, and the
laryngo-tracheal canal later, as a median ventral groove of the oesophageal
wall; in the fowl the pulmonary and laryngo-tracheal primordia develop
simultaneously.
This was confirmed by Résler, who also showed that in the sparrow, goose,
swallow and pee-wit, the primordia of the lungs develop before the primordium
of the laryngo-tracheal canal.
These observers did not investigate the forward extension of the larynx
- into the pharynx.
In a 8-1/2 day embryo of Gallus (figs. 28-81) the tracheo-laryngeal groove.
extends from 150 y behind the 4th gill-clefts to a little in front of it. Dense
mesenchyme surrounds the oesophagus and tracheo-laryngeal groove.
The Development of the Laryngeal Muscles in Sauropsida 85
In a 4 day embryo (figs. 32-35) the anterior-posterior limits of the
tracheo-laryngeal groove are the same; the groove is a little deeper in front
of the 4th gill-clefts. The primordium of the Constrictor oesophagi and laryn-
geal muscles is present as a horse-shoe shaped mass arching over the oesopha-
gus and tracheo-laryngeal groove.
a pri lary. ms
lary. trach. groove
Fig. 36.
4% gill-cieft
Fig. 35. Fig. 38.
In a 5 day embryo (figs. 36-88) the tracheo-laryngeal groove extends
from 170 » behind the 4th gill-clefts to the level of the 3rd gill-clefts. The
primordium of the laryngeal muscles has separated, on each side, from the
ventral edge of the Constrictor oesophagi; it extends from 140 » behind the
_ 4th gill-clefts to the level of the 3rd gill-clefts. The recurrent laryngeal nerve
lies on its outer side.
86 F. H. Edgeworth
In a 6 day embryo (figs. 39-41) the tracheo-laryngeal groove is con-
tinuous solely with the pharyngeal epithelium, extending from just in front
of the 4th gill-clefts. The lumen of the trachea extends into the ventral part
of the larynx. The primordium of the laryngeal muscles extends from 160 pw
behind the 4th gill-clefts to the level of the 8rd gill-clefts. In front of the 4th
gill-clefts it is broader and thicker than it is behind, and approaches its fellow
ventrally.
In a7 day embryo (figs. 42-44) the primordium of the laryngeal muscles has
separated into the (lateral half of) Constrictor laryngis and Dilatator laryngis.
The former is obliquely situated and meets its fellow dorsally and ventrally.
In a 10 day embryo (figs. 45-47) the primordia, not yet chondrified, of the
cricoid, procricoid, and arytenoid, cartilages are distinguishable in the dense
mesenchyme surrounding the larynx.
The above described phenomena in Sauropsida can be summarised as
follows. The tracheal and laryngeal epithelium is formed, from behind
forwards, as a median groove in the floor of the oesophagus and pharynx.
In Chrysemys and Gallus the infolding extends forwards into the last bran-
- chial segment—the 8rd branchial in Chrysemys and the 2nd branchial in’
Gallus. In Tropidonotus, probably in relation with the secondary form of the
tongue, it extends into the hyoid segment. The trachea is constricted off from
the oesophagus, from behind forwards. In the laryngeal region the walls of the
groove come together, and the lumen is afterwards established, in continuity
with that of the trachea, from behind forwards. The aditus opens, much later,
by separation of the lips of the groove.
The laryngeal musculature, on either side of the tracheal groove, is formed
by separation of the ventral edge of the M-shaped primordium of the Con-
strictor ‘oesophagi. It migrates forwards into the branchial s. pharyngeal
region. The recurrent laryngeal nerve grows forwards concurrently. The
muscle primordium separates, in Chrysemys and Gallus, into the lateral half
of the Constrictor laryngis and Dilatator laryngis; in Tropidonotus into the
Laryngei and Dilatator.
The laryngeal and tracheal cartilages are developed by chondrification in
a thick cellular sheath which develops round the larynx and trachea. In
Chrysemys and Gallus the arytenoids become separate structures, in Tropi-
donotus they remain in continuity with the cricoid.
On the primitive form of the laryngeal muscles in Sauropsida. Géppert
stated that in Tropidonotus natrix and Coronella laevis Laryngei dorsalis and
ventralis are present, that in Crocodilus biporcatus the Constrictor consists
anteriorly and posteriorly of sphincter fibres and in the middle of Laryngei,
and that in Midas and Sphargis coriacea whilst the main mass is a Best
there is anteriorly a Laryngeus ventralis.
He concluded from the above that the primitive form in tiles is Laryn-
gei and that a Constrictor is secondary. (He had previously come to the same
opinion in Amphibia.)
a ae I, H. Edgeworth
This, however, is by no means certain, for in Tropidonotus (vide figs. 24-27)
the dorsal musculature is in part a Constrictor, in Chrysemys and Gallus the
developmental stages show no trace of the Constrictor being formed by fusion
of Laryngei. Hoffman states (in Bronn) that in Reptiles the usual condition «
is a Constrictor, and Gadow that the condition in Birds is a Constrictor.
These facts suggest that the ancestral Sauropsidan condition was a Dila-
tator and a Constrictor laryngis.
Some further considerations on the laryngeal muscles are deferred to a later
paper.
I have to thank the Bristol University Colston Society for defraying the
expense of the above described investigation.
July 11, 1919.
LIST OF FIGURES
The figures are taken from serial transverse sections—in all cases the lowest number denotes the
most anterior section.
Chrysemys.
Figs. 1-3 through anembryo6 mm. long. Fig. 1 through the 5th gill-clefts, figs. 2 and 3 behind
them.
Figs. 4-6 through an embryo 7 mm. long. Fig. 4 through the 4th gill-clefts, fig. 5 through the
5th gill-clefts, fig. 6 behind them.
Fig. 7 through an embryo 8 mm. long behind the 5th gill-clefts.
Figs. 8-10 through an embryo 9 mm. long. Fig. 8 through the 4th gill-clefts, fig. 9 through the
5th gill-clefts, fig. 10 behind them.
Figs. 11-14 through an embryo 12 mm. crown-rump length.
Figs. 15-16 through an embryo 15 mm. crown-rump length.
Tropidonotus.
Figs. 17-20 through an embryo, stage (i): fig. 17 through the 4th gill-clefts, fig. 18 through the
5th gill-clefts, figs. 19 and 20 behind them.
Figs. 21-22 through an embryo, stage (ii): fig. 21 through the 2nd gill-clefts, fig. 22 between the
2nd and 3rd gill-clefts.
Figs. 23-27 through an embryo 6 cm long.
Gallus.
Figs. 28-31 through an embryo of 3-1/2 days’ incubation; fig. 28 through the 3rd gill-clefts, —
fig. 29 between the 3rd and 4th gill-clefts, fig. 30 through the 4th gill-clefts, fig. 31
behind them.
Figs. 32-35 through an embryo of 4 days’ incubation; fig. 32 through the 4th gill-clefts, figs. 33-35
behind them.
Figs. 36-38 through an embryo of 5 days’ incubation; fig. 36 through the 3rd gill-clefts, fig. 37
through the 4th gill-clefts, fig. 38 behind them.
Figs. 39-41 through an embryo of 6 days’ incubation; fig. 39 through the 3rd gill-clefts, fig. 40
between the 8rd and 4th gill-clefts, fig. 41 through the 4th gill-clefts,
Figs. 42-44 through an embryo of 7 days’ incubation.
Figs. 45-47 through an embryo of 10 days’ incubation.
The Development of the Laryngeal Muscles in Sauropsida 89
ABBREVIATIONS
arytenoid c. arytenoid cartilage
br. aortic ar. branchial aortic arch
const. lary. . constrictor laryngis
const. oesoph. constrictor oesophagi
ec. branchiale i cornu branchiale i
c. hyale cornu hyale
cricoid ec. cricoid cartilage
dilat. lary. dilatator laryngis
dor. aor. dorsal aorta
hypobr. sp. ms. _ primordium of hypobranchial spinal muscles
lary. dors. laryngeus dorsalis
lary. vent. laryngeus ventralis
oesoph. oesophagus ;
procricoid ec. procricoid cartilage
proc. ant. inf. cric. processus anterior inferior of cricoid cartilage
proc. ant. sup. ceric. processus anterior superior of cricoid cartilage
procricoid c. procricoid cartilage
postbranch. bdy. postbranchial body
_ pri. lary. ms. primordium of laryngeal muscles
rec. lary. n. recurrent laryngeal nerve
sup. lary. br. x. | superior laryngeal branch of vagus
lary. trach. groove laryngo-tracheal groove
trans. groove transverse groove
= vagus nerve
REFERENCES
Epceworts, F. H. (1916). On the development and morphology of the pharyngeal, laryngeal,
and hypobranchial muscles of Mammals. Quart. Jour. Micr. Sc. Vol. 61, Part 4.
Gorrert, E. (1899). Der Kehlkopf der Amphibien und Reptilien. n. Theil. Reptilien. Morph.
Jahrb. Bd. xxviu. Heft 1.
—— (1901). Beitrage zur vergleichenden Anatomie des Kehlkopfes und seiner Umgebung, mit
__ besonderer Beriicksichtigung der Monotremen. Semon. Zool. Forschungsreise.
Hentz, J. (1839). Vergleichend anatomische Beschreibung des Kehlkopfs mit besonderer Beriick-
sichtigung des Kehlkopfs der Reptilien.
Hocusretter, F. (1908). Beitrage zur Entwicklungsgeschichte der Europaischen Sumpischild-
kréte (Emys lutaria Marsili). 2. Die ersten Entwicklungsstadien der Lungen und die
Bildung der sogenannten Nebengekrése. Kaiserl. Akad. d. Wissen. Math, Natur. Klasse,
Bd. Lxxxiv.
Rosier, H. (1911). Ueber die erste Anlage der Lungen und der Nebengekrise einiger Vogelarten.
Anat. Hefte. 134. Heft (44 Bd. H. 3).
Scumipt, V. (1913). Ueber die Entwickelung des ere und der Luftrohre bei Reptilien. Anat.
Hefte. 146. Heft (48 Bd. H. 3).
Weser and Buvienrer (1903). L’origine des ébauches pulmonaires chez quelques vertébrés
supérieurs. Bibliogr. Anat. T. 12, Fasc. 6.
PERSISTENT FORAMEN PRIMUM, WITH REMARKS ON
THE NATURE AND CLINICAL PHYSIOLOGY OF
THE CONDITION
By ALEXANDER BLACKHALL-MORISON, M.D., F.R.C.P.
M. G., 43 years of age, married, and the mother of five healthy children,
was admitted on July 15th, 1918, under my care at Mount Vernon Hospital
at Northwood. She was stated to have had rheumatic fever when a child
seven years old, and for twelve months prior to admission to have suffered
from a degree of dyspnoea with soe asks of the heart and some swelling
of the feet.
On examination, the apex beat was found to be in the sixth left interspace .
five inches from mid-sternum in the dorsal position. On right decubitus the
apex beat -was in the fifth left space three inches from the mid-sternal line.
‘That is, there was no symphysis cordis. The left upper ventricular dulness
lying on the back was at the third left rib and the right cardiac dulness at the
left edge of the sternum. There was systolic pulsation in the suprasternal fossa
and some fulness and pulsation in the right external jugular vein.
There was a systolic bruit of rather high pitch, loudest in a space three
inches from mid-sternum to the apex beat. It was traceable to the left and
distinctly audible in the left paravertebral groove and also, but less so, in the
right paravertebral groove. The aortic valves were heard to close perfectly in
diastole and there was no reduplication of the second sound of the heart.
The closure of the pulmonary arterial valves was palpable. While, therefore,
I had some doubt as to the precise character of the lesion, I was inclined to
regard it as one permitting reflux through the mitral valve. I think I was justi-
fied in doing so, for reasons which I need not detail here, but I was, neverthe-
less, wrong, as the conditions found after death proved. The pulse rate at this
period was 84 to 96 and its rhythm regular.
Examined later, the physical signs remained much the same, but the area
of cardiac dulness was increased, and the pulse rate was accelerated and it had
become irregular. The patient had, at this period, a long sustained attack
of paroxysmal tachycardia, when the pulse rate reached 198 in the minute.
There was passive congestion of both lungs and enlargement of the liver with
signs of commencing stasis in the systemic venous system, From this grave
condition the patient partially recovered; the paroxysmal tachycardia sub-
sided, the pulse rate falling to 92-112; she was able to leave her bed and to sit
on a reclining chair and expressed herself as feeling better. But the heart
Persistent Foramen Primum 91
had entered on the last phase of progressive failure. There was increasing
evidence of anasareca, of effusion into the serous cavities in chest and abdomen,
and of albuminuria. She became ever more restless and sleepless and finally
died collapsed and comatose on Oct. 15th, 1918.
The post-mortem examination was made by Dr Kinton, Resident Super-
intendent of the Hospital, assisted by Dr R. J. Cyriax, the House Physician.
The heart after removal from the body was placed in weak formalin solution
for examination later by myself, and I am indebted to Dr Cyriax for the draw-
ing of the conditions found, which I now exhibit.
The general data discovered, bearing upon the condition of the heart,
which need be mentioned were, that there was serous effusion into the pleurae
_ and peritoneal cavity and that the pericardial sac contained three ounces of
_ fluid instead of the normal drachm or two; the liver was enlarged, weighing
61 ounces, and showed the usual passive congestion of progressive cardiac
failure, as did the lungs and the kidneys. The latter weighed six and five ounces
=e respectively and their capsules stripped off easily. The spleen weighed six
ounces.
The condition of the heart is as follows: It weighs after evacuation of blood
and hardening in formalin solution, one pound seven ounces, that is, it has
at least twice the average weight of the normal female heart. On the anterior
surface of the left ventricle, near its apex, there is a milk spot measuring 2-5
by 3 cms.
The right auricle is markedly hypertrophied. The auricular wall near the
auriculo-ventricular junction measures 1-5 cms., that is, about half an inch.
The musculi pectinati. crista terminalis and other muscular markings are well
defined. The foramen ovale is large and completely closed. The entrances of
the inferior and superior venae cavae are normal and the muscular anterior
wall of the superior caval entrance powerfully hypertrophied. The orifice of
the coronary sinus is rather smaller than usual.
Below and anterior to the coronary sinus and immediately above the
insertion of the septal cusp of the tricuspid valve there is an orifice large enough
to admit the forefinger and passing directly into the left auricle. The attach-
ment of the septal cusp partly by very short cordae tendinnae and chiefly by
direct adhesion to the moderator band in the right ventricle is extremely short
and tight. It could have exercised little valvular function. The anterior
cusp appears to be normal and the posterior rather smaller than usual. The
atrio-ventricular orifice admitted three fingers and from its anatomical con-
dition probably permitted regurgitation into the auricle. All measurements
it will be noted are after immersion in formalin solution and, therefore, are
probably smaller than in life.
The right ventricle is powerfully hypertrophied, its wall having a diameter
of 2 ems. near the auriculo-ventricular junction and of 1-5 ems. about the
middle of the chamber. The moderator band is well developed and the columnae
carneae and trabeculae generally, powerfully hypertrophied. The valves of
92 Alexander Blackhall-M orison
the pulmonary artery are normal, competent and rather capacious. The
pulmonary artery itself is dilated and its wall thicker than usual but there
is no atheroma. The left auricle is normal and in no way hypertrophied. The
left auriculo-ventricular orifice admits two fingers from above. The finger
passed through the persistent foramen primum, goes directly into the left
atrio-ventricular orifice. The left ventricle although well developed muscu-
larly is not markedly hypertrophied. Its walls measure at thickest 2 ems.,
the cavity is not dilated and the papillary muscles and trabeculae generally
are not hypertrophied. The mitral cusps are well formed and apparently com-
petent. The aorta is practically free from atheroma, rather below the average
Persistent Foramen Primum showing interior of right
auricle and ventricle. The walls are held apart by glass
rods. 4 nat. size. R.A. right auricle; f.o. foramen
ovale; ¢.s. coronary sinus; f.p. foramen primum;
t.v, tricuspid valve; R.V. right ventricle.
in size and its walls are thin. The three semilunar cusps are normal and the
posterior one attached to a deep sinus of Valsalva. There are two patent
coronary arteries. The interventricular septum is perfect.
Remarks. As the interauricular curtain (septum primum) is dropped, in
embryo, towards the endothelial cushions which mark the line of the auriculo-
ventricular valves, in certain cases, the growth of the septum is arrested and
a communication between the auricles remains, which under normal circum-
stances would not be present. A section of the arrested curtain, examined
microscopically, shows it to be a true arrest of development and not the result
of any foetal endocarditis (Morison, Journ. of Anat. and Phys. vol. XLvit. p. 467).
Persistent Foramen Primum 93
This communication may be large or small. In a case which I showed before
this Society in 1913 (Journ. of Anat. and Phys. loc. cit.) it was very large and
incompatible with any length of life. The child, a male, died when six months
old, after having been under observation for one month. It showed after
death, collapsed lung with scattered patches of induration, which were pro-
_ bably atelectatic, although they were not examined microscopically—a
_ persistent foetal state. There was hypertrophy of the right auricle and ven-
- tricle, none of the left auricle and little of the left ventricle and, as in the
_ present instance, a small coronary sinal orifice. The bruit observed clinically
_ was also systolic and apical but heard best in the back.
Professor Keith remarks, in his lectures on Malformations of the Heart
(Laneet, vol. 1. 1909, p. 485) that this defect “is not necessarily accompanied
_ by grave disturbance of the heart.’’ The defect is, however, very apt to be
_ associated with some abnormality of the auriculo-ventricular valves as is
_ readily conceivable from the position and nature of the defect. Dr Maude
Abbot (Osler and McCrea’s System of Med. vol. tv. p. 357, 2nd edition) relates
that, in five out of seven cases reported by Rokitansky, the anterior segment
_ of the mitral valve was “cleft from its free border to its insertion.” In the
_ ease which I now show the mitral valve was normal but the septal cusp of the
_ tricuspid valve was, as I have stated, adherent to the moderator band so as
__ to be functionally incompetent.
Although, as in the present case, the bearer of the lesion may live for a con-
_ siderable period and fulfil the ordinary functions of the human being—in this
_ ease the cardiopath as stated had five children and was 43 years of age—I do
not know whether any of the cases presenting this defect have been much older.
If they have, it will probably be found that the defect had developed in such
a manner as to leave the atrio-ventricular orifices well guarded by their
valves.
In 1918, I showed before the Society the heart of a man with a much
stenosed pulmonary arterial orifice, a shrunk right ventricle and a hyper-
trophied and dilated right auricle. The owner of it died at the age of 72, but
in this case, the avenue of relief between the auricles was a largely patent
foramen ovale, the septa of the auricles and ventricles being otherwise nor-
mally complete. But patency of both the foramen ovale and foramen primum
may co-exist (Thomson, Proc. Anat. Soc. 1902-3, xxxvi.). The case I now
show (Mrs G.’s) also illustrates the secondary pathological changes usually
observed in persistent foramen primum, namely, general escape of the left
chambers from hypertrophy, some hypoplasia of the aorta, dilatation of the
pulmonary artery, marked hypertrophy of the right chambers and, as I have
pointed out, a certain smallness of the orifice of the coronary sinus.
To a clinician, all such conditions, primary and secondary, are of interest,
as indicating where the strain of conducting the circulation has been most
felt by the heart. As these points are a matter of morbid physiology they may
be mentioned here. I should myself feel disposed to modify the conclusion
94 Alexander Blackhall-M orison
expressed by Professor Keith already quoted, by maintaining that the defect
‘is not necessarily accompanied by grave disturbance of the heart,” but only
for a time, and that it always ultimately causes grave disturbance and is
incompatible with length of life in proportion to the degree in which the atrio-
ventricular valvular apparatus is involved in the genesis of the defect.
Clinically the rhythm and situation of the bruit audible in these cases
is of interest. In both my cases the bruit was systolic in time, mainly apical
in situation and audible (unlike the presystolic bruit of mitral stenosis)
posteriorly as well as anteriorly. Without atrio-ventricular valvular defect
or incompetency, one would expect any bruit present in persistent foramen
primum to be presystolic, that is, auricular systolic in time. But if this time
of the bruit be observed in such a case, it will probably be found as I have stated,
that it is audible posteriorly as well as anteriorly. It is very desirable in all
cases of congenital heart disease, if any bruit be present, that it should be very
carefully noted as to character, rhythm and localisation, for diagnostic pur-
poses,
It is evident from what has been said as to the condition of the chambers
in the left or arterial heart that the strain of the circulation in these cases is
chiefly upon the dextral chambers.
The hypoplasia of the aorta, taken in connection with the dilatation of
the pulmonary artery, in the absence of left auricular dilatation and hyper-
trophy, together with the lack or small degree of hypertrophy of the left —
ventricle, points to a deficiency in the normal plenitude and permeability
of the pulmonary circulation. This is probably due in a measure to a per-
sistence of the foetal condition, in so far as the defect diminishes the aspirative
and propulsive force of respiration. In the completely foetal condition, the
extent of the pulmonary circulation being at a minimum and the transmission
of the blood to the arterial system secured by adequate channels, no dilatation
‘of the pulmonary artery occurs, but the right chambers preponderate in power
and in muscular development over the left.
In persistent foramen primum, on the other hand, extra uterum, the lungs
are in action, and a large quantity of blood does reach the pulmonary circula-
_ tion but without the full aid of the aspirative force resident in the normally _
constituted left heart. With the closure or the practical closure of the ductus
arteriosus under these circumstances, the powerful right ventricle, while it
fails to drive sufficient blood through the lungs into the left heart, tends, in
diastole, to retain blood in the pulmonary artery and its main branches.
Hence their dilatation and the baggy valves which guard that vessel. The
incomplete plenitude of left cardiac blood thus serves to explain the total —
absence of left auricular and the comparative absence of left ventricular
hypertrophy in these cases and likewise the hypoplasia of the thin walled
aorta met with in many such instances. That very considerable hypertrophy
of some parts of the organ is, nevertheless, present is proved by the notable
increase in the weight of the organ and this, in the absence of vascular or renal
Persistent Foramen Primum 95
_ conditions, is calculated to induce hypertrophy of the cardiac muscle from
_ other causes than the purely mechanical cardiac defect.
_ Finally, it may be stated that the bearer of the congenital defects (fora-
-men primum and abnormal tricuspid valve) in the present instance, although
stated to have suffered from rheumatic fever as a child, showed no evidence
in endocardium or pericardium of consequences of that disease. The changes,
therefore, noted in the organ were a result of the congenital anatomical
states described and the modified physiological actions which resulted from
them. Here again, then, as in other cases I have shown to this Society, the
importance of integrity of the valvular apparatus, for an efficient and easy -
conduct of the circulation through the heart, is manifest.
.
$n Memoriam
Prorrssorn ALEXANDER MACALISTER, M.D., F.RB.S., Etc.
1844—1919
Owxr of the earliest and strongest links in the history of the Journal of Anatomy
and of the Anatomical Society has been broken by the deeply lamented death
of ALEXANDER MACALISTER.
Ever active in promoting the interests of the Journal his name is appended
to an interesting paper on muscular anomalies appearing in the first volume
and its earlier pages are rich in his learned and thoughtful contributions. In
1898 he joined the editorial staff becoming acting editor in 1910. As acting
editor he was indefatigable, reading every paper submitted to him with the
most scrupulous and meticulous care and earning the gratitude of many a
contributor for advice, information and help. He was always of the opinion
that the Journal should be well illustrated and spared no trouble and expense
to this end.
The Anatomical Society must regard Macalister as one of its parents. It
was initiated in 1887 as the result of a series of week-end conferences held at
Cambridge in 1886 between Humphry, Lockwood and himself. For years he
was a constant attendant at its meetings, took an active part in its proceedings,
and was its President in 1898. In 1889 he drew the attention of the Society
to the desirability of a scheme for coordinated research. The resulting Com-
mittee of Collective Investigation accumulated a considerable amount of
valuable information but came to an untimely end. He always held the view
that the Journal should be under the direct management of the Society and it
was largely due to his warm advocacy and unselfish interest that this was
brought about last year.
The story of Macalister’s early life reads more like a romance than sober
fact. He was born in 1844 in Dublin, whither his father, Robert Macalister
of Paisley, had migrated to succeed Will Carleton, the Irish novelist, as Secre-
tary to the Sunday School Society of Ireland. Robert Macalister, blessed with
a large family and a slender purse, destined his son Alexander to a business
ealling. As a school-boy he developed the most diligent habits and early
displayed a love for biological study spending all his available leisure time in
the Glasnevin Botanic Gardens. There he attracted the attention and interest
of the Curator who recognising that he was no ordinary boy persuaded
his father to let him study Science. Consequent on special recommendation
Phot. by Lafayette
Proressor ALEXANDER MACALISTER,
M.A., M.D., LL.D., D.Sc., F.S.A., F.RS.
oti --
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:
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anal
In Memoriam: Professor Alexander Macalister 97
he was allowed to commence his medical studies at the Royal College of Sur-
geons of Ireland at the incredibly early age of 14. From this point his progress
was meteoric. He was appointed Demonstrator of Anatomy at the College
at 16 and at 17 obtained the double qualification. Entering Trinity College
Dublin, he was elected Professor of Zoology at the University of Dublin while
still an undergraduate, and was precluded from proceeding to an honours
degree in Science, the would-be examinee being an examiner. Could anyone
imagine a more Gilbertian situation? In addition to his professorial duties
he lectured on Botany, Geology, Astronomy and I know not how many other
sciences at Alexandra College, Dublin. In 1877 he was appointed Professor
of Anatomy and Chirurgery at Trinity College, Dublin and Surgeon to Sir
_ Patrick Dun’s Hospital. Six years later he succeeded Humphry in the Chair
_ of Anatomy at Cambridge, where he laboured incessantly and with the utmost
devotion for 36 years, for the same length of time as Turner held the corre-
sponding chair at Edinburgh.
In his early years Macalister was a most prolific writer—text-books,
monographs and papers following one another with startling rapidity. Special
attention may be recalled to his “Observations of Muscular Anomalies,”
read in abstract before the Royal Irish Academy in January 1871, and com-
piled during a Summer recess in the previous year. A complete survey of
the variations affecting the whole muscular system of man it was a most
amazing piece of work and a wonderful tribute to his immense patience and
untiring energy. Careful study reveals the fact that not only did he collate
everything that had evér been written on the subject but 50 per cent. or more
of the material-which he presents is the result of his own personal observations
—observations which having stood the test of years and been confirmed again
and again have become classical. He confesses to having taken part in the
dissection of over 690 subjects, while the tedious and intricate dissections
necessary to furnish him with such numerous examples from the face, sealp,
pharynx, soft palate, etc. transcend the imagination. This is the work of a
young man of 26, immersed in professorial duties and busily engaged in laying
the foundations of two large treatises on Zoology to appear a year or two later.
His great text-book of Anatomy, great in more senses than one, was
published in 1889. There are few anatomists but owe a debt and that a
considerable one to its pages. Utterly unlike anything that has appeared
before or since it was no mere compilation but original in thought and treat-
ment, replete with personal observation and an index of the man himself.
If fault it had it was that of compression. Macalister had so much to tell and
the confines of a large text-book were for him so limited that he was forced
to prune, curtail and abbreviate at every step. The wonder is that no second
edition ever appeared but therein lies a tragedy. An interleaved copy of the
book was always lying on his table and in this he daily added new facts, obser-
vations and reflections until in a few years time it was full to overflowing. One
day it disappeared never to be found again. Its loss was met with characteris-
98 In Memoriam: Professor Alexander Macalister
tic and cheerful fortitude, but it was a blow from which he never recovered,
and it sealed the fate of a subsequent edition.
Macalister was wont to give a course of lectures on the historical aspects
of Anatomy in the Summer term at Cambridge. Choosing a new subject year
by year he covered a vast field, giving his critical acumen full play, displaying
a wonderful power of broad survey and discovering links hitherto unsuspected.
Most especially is it to be regretted that he never fulfilled the hope expressed
in the preface of his text-book to write a “detailed history of the progress of
Anatomical discovery.’’ No one in the world was better equipped for the task.
Exploring anatomical literature had long become a habit and he had spent
much of his life in the University Library at Cambridge, rich beyond compare
in the works of the earlier anatomists. He gives us some foretastes of what
might have been in his “‘ Memoir of James Macartney,” “A Sketch of the His-
tory of Anatomy in Ireland,” “‘ The History of the Study of Anatomy in Cam-
bridge” and “Archaeologia Anatomica” which appeared from time to time
in the Journal of Anatomy, and which though unsigned were the products of
his pen.
The eminent service Macalister rendered in elevating Anatomy from a
mechanical study into a living science is perhaps insufficiently realised at the
present day. No bare fact ever presented itself to him but it set him thinking of
the part it played in the mystery of life and the problem of existence. This
may not be apparent in many of his writings, but was pre-eminently so in his
teaching and influence. An exception to this general statement is afforded by
“Some Morphological Lessons taught by Human Variations,” a Robert Boyle
lecture delivered at Oxford in 1894. Therein he sets forth in masterly fashion
the deductions he draws from a study of variations to the garnering of which
he had always been irresistibly attracted.
Endowed with a marvellous and orderly memory, infallible and almost
uncanny in its tenacity for minute detail, Macalister had the most astounding
facility for accumulating information and facts not only from books but at
first hand from dissecting room and museum. He would devote endless pains
and infinite patience to obtaining and noting new facts, but once acquired
they seemed to lose further interest and he could rarely be prevailed upon to
publish them. Not a tithe of them appear in his published writings, some lie
stored in countless note-books, but many alas! are gone with him. In the
disposal of his stores he was generosity itself, they were offered freely and openly
to one and all to make what use of them they liked.
His lectures were an intellectual treat and are held as most valued recol-
lections by all who were privileged to listen to them. His facile eloquence,
lightened by occasional flashes of quaint dry humour, would at times fascinate
and almost mesmerise his hearers. Following no tradition, shackled by no
exigencies of examination, a rich spring of anatomical knowledge, ornate with
morphological illustration and historical interlude, flowed out in a quiet but
inspiring stream.
In Memoriam: Professor Alexander Macalister 99
No professor ever spent so many hours in the dissecting room. He revelled
in the practice of his art and was the neatest and most rapid exponent I have
ever seen, devoting the same scrupulous care to the most trivial display as to
the most intricate manipulation.
To do adequate justice to Macalister’s great learning and scholarship is
an impossible task. Although he knew more about the anatomy of the human
_ body than any man living, anatomy after all was but a small part of his mental
_ equipment. He was an able mathematician and familiar with many languages
__ both living and dead. In Archaeology, Zoology, Egyptology, Theology, Bibli-
eal history, to mention but some of the subjects which aroused his interest,
_ he was an inexhaustible mine of knowledge. In discussion on many and
_ diverse subjects, he was conspicuously the authority and source of accurate
_ information, often to the confusion of the expert. His indefatigable industry
‘and insatiable thirst for knowledge persisted throughout life and in these
_respects he never grew old.
Despite his great attainments he had the most kindly and gentle disposi-
_ tion, was ever considerate for the opinions and feelings of others and endeared
| himself to all who met him. It was an inestimable privilege to have known
| himand his loss leaves a blank which can never be filled.
E. B.-S.
iy
Lo
REVIEWS
THE PERIPHERAL NERVES
"| He aid of the anatomist—in many places his personal aid—has been much sought by the
surgeon in the extensive and detailed knowledge of the peripheral nervous system which has
been demanded of him during recent years. It is with considerable interest, therefore,
though mingled with a sense of the personal loss, that one turns to the volume on this subject
by the late Professor Paterson '!, knowing that it has been written by an anatomist of authority
and by one with the experience of the R.A.M.C. officer. His book is founded, even at first
sight, on a wide basis, since by an appeal to the general morphology and development of
nerves he has aimed primarily at an explanation of the principles which govern the facts
of peripheral nerve distribution. One may doubt the value of, or even disagree with the
views expressed in, for example, the chapter on “‘The Nature of the Limbs,” but that
Professor Paterson was correct in adopting the broader plan will be felt at once, even by those
who may be introduced for the first time to morphological concepts, not merely from the
educative point of view, but, for instance, as affording the only assistance towards under-
standing the ‘‘plan” of the common variations of nerves which otherwise remain a seemingly
uncalled-for mystery.. He has incorporated in his general account of the nerves, in a way
which will be recognised as peculiarly his own, many of his own deductions on the critical
questions of the subject, and the trained observer is well seen in his notes on the vascularity
of the ends of the severed nerves. The book does not aim at being encyclopaedic nor claim
to be a book of reference, but as a general statement of the anatomy of the peripheral
nervous system by a recognised authority on that subject, if is indeed worthy of the study
of those whose work requires the knowledge it contains, and whose inclinations lead them ~
to seek more than the mere summation of fact. The anatomist will pay it the attention it
merits from his regard for the writer.
The other book before us on this subject—Dr Whittaker’s revisal of the late Professor
Hughes’ Handbook of the Nerves of the Body?—is a concise summary of the main facts of the
distribution of the peripheral nerves and the sympathetic system, and should serve excel-
lently as a preliminary statement for one revising the empiricism of these subjects. It is,
however, the pure hard fact of systematic anatomy, and, though not detracting from its
usefulness on that account, is essentially a summarised extract of any good anatomy text-
book. The plates are purely diagrammatic, and as such are of assistance to the text. They
are well reproduced.
1 The Anatomy of the Peripheral Nerves. Prof. A. M. Paterson, M.D., F.R.C.S. Henry Frowde
and Messrs Hodder and Stoughton. pp. vi+165, 12s. 6d. net.
2 Nerves of the Human Body. C. R. Whittaker, F.R.C.S.(Ed.) E. and§. Livingstone, Edinburgh.
pp. vili+ 72. 12 plates. 3s. 6d. net.
STUDIES ON THE ANATOMICAL CHANGES WHICH
ACCOMPANY CERTAIN GROWTH-DISORDERS
OF THE HUMAN BODY
By ARTHUR KEITH,
Royal College of Surgeons of England
I
THE NATURE OF THE STRUCTURAL ALTERATIONS IN THE
DISORDER KNOWN AS MULTIPLE EXOSTOSES?!
Donarxe the last ten years I have paid particular attention to the structural
alterations which occur in men and women who are, or have been, the subjects
of disease of one or more of the glands of internal secretion®. In several
instances I have to admit, that the relationship between the structural
alterations and a disorder of the glands of internal secretion is highly problema-
tical; in many cases, however, such as acromegaly, giantism, precocity of
sexual development and cretinism, we must admit that there is a direct
connection between a disordered action of the endocrine glands and the
appearance of a crop of structural changes. My aim in studying these disorders
_ has been to gain a more accurate knowledge of the mechanism of normal
growth—for a knowledge of the conditions which determine the shape and
size of the various structures of the animal body must always have a prime
importance for anatomists. In her aberrations, as I shall attempt to show,
Nature often uncovers parts of her very elaborate growth machinery.
The disorder which I am to deal with first—multiple exostoses—is usually
placed by surgeons in the category of tumours, but a close examination of
its anatomical changes shows that it should be definitely placed among the
disorders of growth and given a name to indicate its true nature. The name
I propose, one suggested to me by Mr Morley Roberts, is Diaphysial aclasis,
because the main incidence of the disturbance falls upon the modelling or
pruning of the diaphyses or shafts of bones. My attention was drawn to the
nature of this disorder in the following way. In the summer of 1918 Capt. J. A.
Annan sent to the War Office Collection at the Royal College of Surgeons a
series of X-ray plates he had taken of a young man, aged 20, serving as a
private in a labour battalion in France. This man had been admitted to the
8rd Canadian General Hospital where he was recognised as a subject of
ooo publication of this Research has been defrayed by a grant from the Medical Research
? An Enquiry into the Nature of the Skeletal Changes in Acromegaly.” Lancet, 1911, 1. p. 993.
“Abnormal crania, Achondroplastic and Acrocephalic.” Journ. of Anat. and Physiology, 1913,
vol. Xtvi. p. 189. “Progeria and Ateleiosis.” Lancet, 1913, 1. p- 305.
Anatomy Livy 7
102 Arthur Keith
multiple exostoses. The bony tumours situated in the neighbourhood of the
knee and ankle, unfitted him for active duties and he was discharged
from the army. My attention was arrested by the skiagraphs taken from
his knee joints. An exact drawing is given of the appearance of the lower
end of the left femur and upper end of the left tibia in Fig. 1. The lower
femoral epiphysis is normal in size and outline, but the lower end of the femoral
shaft is represented by a cylindrical mass of irregularly formed bone, showing
*
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Fig |. Fig 2.
Fig. 1. Drawing from a skiagraph of the region of the left knee of a man aged 20, the subject
of multiple exostoses (} nat. size).
Fig. 2. Drawing to illustrate Hunter’s modelling process.
a gravely disturbed architecture. The irregular mass of bone represents the
growth of several previous years. The cylindrical medullary shaft instead of
reaching almost to the epiphysis is separated from it by an irregular column
90 mm. long by 75 mm. wide as measured on the skiagraph. Similarly between
the modelled shaft of the tibia and its upper or proximal epiphysis is interposed
an ill-formed cylinder, 60 mm. long by 80 mm, wide. The right knee showed a
corresponding disorder of growth. In both right and left limbs the femoral
Changes accompanying Growth-disorders of Human Body 103
and tibial diaphyses had commenced to unite with their corresponding
epiphyses. Further enquiry showed that there were similar disturbances at
the lower ends of the tibia and fibula, at the upper end of the femur, at the
distal ends of the radius and ulna, at the proximal end of the humerus, while
_at the elbow joint there were certain irregularities which will be noted further
on. A reference to Fig. 2 will serve to explain my interest in the irregular bone
development shown in Fig. 1. One of John Hunter’s more important dis-
coveries was his realisation that the shafts of bones grew in length by a double
process; there was first the deposition of new bone in the cartilaginous growth
dise at the ends of the shaft, a process clearly recognised before Hunter’s
time; there was.in the second place a “‘modelling process” by which the new
bone thus laid down was pruned, reformed and incorporated as an intrinsic
architectural part of the cylindrical shaft. Hunter clearly recognised that
these two processes were independent operations. If Hunter’s teaching is
true then we ought to find disorders of growth in which deposition of new bone
goes on while the second or remodelling process is retarded or even completely
arrested. A survey of the skiagraphs of the first case of multiple exostoses
that came my way showed me that in this disorder the deposition process
goes on but the modelling process is retarded and aberrant. In multiple
exostoses, which is a disorder of youth and of adolescence, then, the modelling
process is profoundly retarded; in some instances almost arrested. The bony
excrescences or tumours, which serve as diagnostic marks for the clinical
recognition of the condition, are merely secondary results of the primary
disorder of growth for which I propose the name of Diaphysial aclasis.
For a complete set of skiagraphs of a second case I have to thank my
friend Capt. Lionel West. He sent to me, for the War Office Collection, full
records of a man aged 26 he had under his observation in the Military Hospital
at Prees Heath. In neither this case, nor the last, was a full family history
obtainable, not for lack of enquiry but because neither man had a very
full knowledge of his relatives. Capt. West’s case was in every way similar
to Capt. Annan’s, except that the epiphyses had completely united with the
shafts and there was a more definite arrangement of the cancellous trabeculae
in the direction of the lines of force. In Capt. West’s case, the man’s stature
was five feet (1524 mm.); in Capt. Annan’s case the exact height was not taken
but he was undersized. For a third case, also added to the War Office Collec-
tion, I am indebted to Dr Florence Stoney. In this case the man was aged 29
and the modelling process had been much less retarded than in the two younger
men. In Dr Stoney’s case a brother and four maternal uncles were affected
with the same disorder. A survey of recorded cases shows that about half
the subjects have one or more relatives similarly affected, and that the
disorder is Mendelian in its incidence. The skiagraphs of a fourth and very
instructive case were placed at my disposal by Mr W. Rowley Bristow of
St Thomas’s Hospital. One set of plates were taken in February, 1919, a
second set, exposed exactly as the first set had been, were taken in December
7—2
104 Arthur Keith
| | HY. | : i ;
Fig 3. Fig *. |
Mather. aer-29. Gregory. aet: 26.
Fig. 3. Skiagraph of the right knee of Dr Florence Stoney’s case. The arrest of modelling is much
slighter in degree than in Capt. Lionel West’s case (Fig. 4). In the latter case two areas of
exostosis are seen on the lateral aspect of the femoral shaft; between these areas periosteal
bone is being deposited. An exostosis also grows from the medial aspect of the proximal
end of the tibia. In both cases the proximal end of the fibula is thickened and ill formed;
in Fig. 4 there is ossific union between the proximal ends of the shafts of the tibia and fibula.
Changes accompanying Growth-disorders of Human Body 105
of the same year. The subject of the disease was a girl aged 16; by the super-
imposition of tracings from these two sets of plates I was able to determine
accurately the growth changes which had occurred in all the long bones of
this case in the preceding ten months. Mr Laming Evans was also good enough
Fig 5. Fig 6.
Fig. 5. The skiagraphic appearance of the distal ends of the left tibia and fibula of Capt. West’s
case. It will be observed that the lateral border of the trochlear surface of the astragalus
has been pushed between the epiphysial ends of the leg bones. The epiphyses, although
clearly differentiated from the shafts, are firmly united with them. There is a mutual inter-
locking between the outgrowths from the shafts of the tibia and fibula but no ossific union
between them. In the right limb the distal ends of the tibial and fibular shafts had grown
together and fused.
Fig. 6. Skiagraph of the distal end of a left femur showing a single cartilaginous capped exostosis.
There is no arrest of the modelling process. Single tumours or even several cartilage capped
exostoses are not necessarily symptomatic of the condition here named Diaphysial aclasis.
to give me access to records and skiagraphs he had made from four cases which
he has under observation, and of which he is to publish an account. Two of
his cases were particularly useful to me as they represented earlier stages
than the four I have enumerated above. Although the disorder is by no means
106 | Arthur Keith
rare, it is represented very sparsely in the medical museums of London. The
only skeletal representation is in the Museum of St Thomas’s Hospital where
there are preserved the limb bones of a subject of this disease. The dimensions
of the bones show that he was a man of small stature and their state, that he
was probably over 30 years of age. He committed suicide by throwing himself
in front of a railway train, and no family history was obtainable. I am
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STF THOMAS'S HOSP: CASE.
Fig 7. Fig 8.
Fig. 7. Vertical section of the proximal end of the right femur of the case preserved in the museum
of St Thomas’s Hospital. It will be seen that there has been an arrest of the modelling
process shown by the vertical depth of the neck, the low position of the trochanter minor
and the imperfect differentiation of the trabecular architecture.
Fig. 8. Exostoses on the outer aspect of the neck of the right femur.
indebted to my colleague Prof. Shattock for an opportunity of making a full
examination of the bones of this man. In recent medical literature records
can be found of about 800 cases!, but a survey of a selection of this literature
only served to show that the disorder is one which is remarkably uniform and
1 Some of the more recent records are the following:
McKail, J. Archives Radiology and Electro-therapeutics, 1917, vol. xxi. p. 286.
Cowie, Dr David Murray. Archives of Pediatrics, 1917, vol. xxxtv. p. 461.
Hess, Dr Alfred F. Ibid. p. 462. 0
Carman, R. D., and Fisher, A. O. Annals of Surgery, 1915, p. 142.
Nasse, D. “Ueber multiple cartilaginire Exostosen und multiple Enchondromata.” Berlin.
Sam. Klin. Vorirdge Chirurgie, N.F. No. 124, 1895, p. 209.
Bessel-Hagen, Prof. Fritz. “‘ Ueber Knochen- und Gelenkanomalien.” Langenbeek’s Archiv
f. Klin. Chir. 1891, vol. x11. p. 749.
Changes accompanying Growth-disorders of Human Body 107
characteristic and that the material I had in hand was sufficient to exemplify
all its predominant features.
We obtain some light on the nature of the disease named Diaphysial
aclasis when we note its distribution in the skeleton. All bones which are
formed entirely within cartilage are free from any disorder of growth. The
tarsal and carpal bones, the epiphyses of all the long bones, the vertebral
bodies and sternum are formed in aclastic individuals as in normal persons.
So are the bones formed in membrane—the bones of the cranial vault and of
the face. In the cases I have seen the facial bones are not robustly modelled—
there is a lack of supra orbital ridges aud the nose is short and pinched—but
there is no noticeable departure from the normal in their development. The
disease is confined to those elements of the skeleton where bone laid down
within cartilage comes to be covered by periosteal bone as in the shafts of
long bones. Hence this disorder of growth falls on the growing ends of the
shafts of long bones, where a core of bone formed within cartilage comes to
be encased in a sheath of bone formed beneath the periosteum. Where growth
is most extensive and most prolonged as at the distal and proximal ends of
the femur, tibia and fibula, at the distal ends of the forearm bones and proxi-
mal end of the humerus, the aclastic condition is most marked. It is also
particularly well seen at the growth line along the vertebral border of the
scapula and along the cristal border of the ilium. The outer and inner ends
of the clavicle being formed from both cartilage and membrane bone also
show an unmodelled formation.
In Fig. 9 there is represented a vertical section of the femur of a turtle to
show the relationship of the membrane or periosteal-formed bone to that
laid down in cartilage. We have here a diagrammatic representation of the
condition out of which the long bones of mammals have been evolved. The
cartilaginous extremities are devoid of separate epiphysial formations; there
ean be no question of an epiphysial line of ossification—only of a diaphysial
line at which the shaft increases in length (growth line in Fig. 9). This is also
true of mammalian long bones; the growth line has nothing to do with the
enlargement of the epiphysis, only of the shaft, and should therefore be called
the diaphysial line. Now the diaphysial line is made up of two distinct parts,
but hitherto we have fixed our attention on only one of these parts—the
cartilaginous part of the line in which endochondral bone is laid down. We
have omitted to note that the cartilaginous growth disc is surrounded by a
periosteal ring or ferrule where growth in length also takes place. The peri-
osteal growth ring represents the margin at which the covering of periosteal
bone extends itself over the growing core of cartilage-formed bone. In normal
development the cartilaginous core and periosteal proceed at an equal pace.
In achondroplasia, the arrest of growth falls on the cartilaginous core; the
periosteal ferrule outstrips and overlaps the cartilage-formed bone. In
Diaphysial aclasis the opposite is the case; the periosteal extension is arrested
and thus areas of cartilage-formed bone are exposed on the surface of the
108 Arthur Keith
shaft. The periosteum and the osteoblasts derived from the periosteum are
the main agents in the modelling of bone. Hence with the arrest of the peri-
osteal growth ring, the process of modelling becomes retarded and irregular;
the diaphysial cartilage thus exposed on the surface is free to expand in
abnormal directions.
Head.
4
Trochanler.
Membrane
bone.
AVS
J
At
BUH, fe ov
My i } Hthigs
. Ay
a Dr gem
Cartilage bone. fess tian ih
Ate ara, iting
5 AAG
Periosteumn: aM til
ae Hilit ft ary tat
Ve 7 A fsroary itt
ie f Ir Hy
NIL ¥ 1 j
a My 4. n
‘ : oe X& - *
Perichondrium\.“4jy}?
Fig 9. = Condylar Cartilage.
Growth line.
Fig. 9. Vertical section of the femur of a turtle (Chelone mydas) showing periosteal or membrane-
formed bone encasing the medullary cones of cartilage-formed bone. From a specimen in the
R.C.S. Museum.
In Fig. 10 a drawing of the skiagraph of the distal end of the left femur
of Dorothy D., aged 16 (Mr Bristow’s case), is reproduced. The dense bone
of the shaft, representing periosteal deposit, is seen to terminate quite abruptly
in an upturned edge. Below the upturned edge is an open cancellous network,
which I suppose to be endochondral-formed bone. The drawing represents
the condition in December, 1919; in February of that year an identical
skiagraph was taken; the diaphysial outline at that date is represented by a
stippled line in Fig. 10; it will be seen that new bone has been added not only
Changes accompanying Growth-disorders of Human Body 109
in the cartilaginous growth disc of the diaphysis (to a depth of 3-5 mm.) but
also along the whole of the medial surface below the upturned edge of the
dense periosteal bone. On the lateral surface there has been a certain degree
of absorption (see Fig. 10). Apparently the upturned periosteal margin of
bone had remained stationary; it had not descended towards the distal end
of the shaft during the period under observation. Yet when we compare this
skiagraph with those of the older cases shown in Figs. 1, 3, and 4, we must
presume that at the end of adolescence the modelling process does proceed
and that the exposed cancellous bone becomes irregularly covered by dense
bone of periosteal origin. It will be seen that the supposition that there is an
- arrest of development in the periosteal ring of the diaphysial growth disc
explains the appearances presented by the shafts of long bones in Diaphysial
Lhe hi -.-Periosteal
Mun bone
ti HA ,
Wit
hi i "|. Exposed
Mt) jt, Ha endochondral
4 Hl att 4 bone.
ih rn Ma | Aree of
Area of | : A, uf} \\) Hit} atrophy
deposition. £. AAA
Fig. 10. Distal end of the left femur of Dorothy D., aged 16, a subject of Diaphysial acIsis. The
stippled line indicates the outline of the skiagraph of the diaphysis taken ten months or
The area outside the stippled line represents the growth of the last ten months.
aclasis. The arrest in the extension of the periosteal ring permits the cartilage
of the diaphysial disc to become exposed on the surface of the shaft and thus
leaves it uncovered and free to give rise to irregular outgrowths or exostoses.
A covering of periosteal bone exercises a restraining or a controlling influence
on endochondral bone.
Unfortunately I have not had an opportunity of studying the microscopic
changes which occur in the diaphysial growth disc of the subjects of this
disorder. These dises, as seen in skiagraphs, are more irregular, more dentated
than in normal growth; there is a certain resemblance to the changes seen in
rickets. It is very possible that besides the arrest of extension of the periosteal
sheath, there is also an irregular grouping and division of the cartilage cells.
Indeed I am inclined to suspect that the primary disturbance may prove to
lie in the growth behaviour of the cartilage cells.
116: ; Arthur Keith
In about one-third of the cases reported—some 800 in number—there is
a dislocation of the proximal end of the radius—a result of unequal growth
between the bones of the forearm. In such eases, it will be found that the
ulna ends above the wrist in a thimble-shaped mass of cancellous bone. In
the two cases represented in Fig. 11 all trace of the distal epiphysis of the ulna
has gone; in one of Mr Laming Evans’ cases, a girl of 17, this epiphysis, although
separate and apparent, is clearly being absorbed. The disappearance of the
distal epiphysis of the ulna does not account for the arrest of the growth in
length of the diaphysis of that bone; it merely shows that there is a profound
disturbance of growth at the distal end of the ulna. The radius has a growth
dise at each extremity of its shaft. Prof. Digby! estimates that 25 per cent.
Detached
epicondyle.
Fig. 11. The upper figure represents a dislocation of the proximal end of the radius with detach-
ment of the lateral epicondyle in the right arm of Capt. West’s case, as a result of arrested
growth at the distal end of the ulna. The lower figure represents a corresponding dislocation
in the left arm of Capt. Annan’s case.
of its growth in length takes place at the proximal disc; 75 per cent. at the
distal. In the ulna, he estimates that the distal line is responsible for 81 per
cent. of the growth. A disturbance of the distal growth dise will therefore
affect the extension of the ulna much more than the extension of the radius.
In Fig. 12 are represented skiagraphs of the distal ends of the radius and ulna
of Dorothy D., aged 16. In her, there has been no dislocation of the proximal
end of the radius; the shortening of the ulna is decidedly greater in the right
arm than in the left. The stippled areas represent, in Fig. 12, the deposit of
bone during the previous ten months. At the distal end of both ulnae the new
deposit surrounds the cancellous extremities; it is as great at the sides of the
terminal shaft as in the terminal diaphysial line. I infer that the diaphysial
1 Journal of Anatomy, 1916, vol. L. p. 187.
- not yet mentioned, which causes a greater
Changes accompanying Growth-disorders of Human Body 111
growth, in place of being confined to the diaphysial line, has become spread out
over the surface of the cancellous extremity; the cartilaginous disc has been
spread out, as it were, over the sides as well as
over the terminal surface of the shaft. The
cartilaginous growth disc has become diffused.
But there is evidently some other circumstance,
degree of repression of growth in the ulna
than in the radius. We know that stresses
and strains have an influence on the activity
of bone corpuscles and I suspect that as the
radius is subjected to these strains and stresses
more than is the ulna, that the growth of the
latter bone suffers to a greater degree. In
Diaphysial aclasis there is a shortening of all
the long bones. In the St Thomas’s Hospital
ease the humerus is least affected; its total | eee me
length is 312 mm. on the right side, 299 mm. ge taney x ss opasaraaca arihae
on the left. The right radius is 199 mm., the of Dorothy D., aged 16 (Mr Bristow’s
left 191 mm. In proportion to the length of case). The stippled areas represent
the humerus the length of the radius ought to _ the bone deposited during the pre-
have been about 230mm. There has been a “US 2 months.
loss of about 15 per cent. in its total growth in length. In the ulna there is
a deficiency, as regards length, of 26 per cent. But even when we have taken
all of these factors into account there is still some factor militating against the
growth in length of the ulna in Diaphysial aclasis which remains to be dis-
covered. The fibula also tends to lag behind the tibia, but the union of
opposing exostoses and the consequent fusion of the terminal shafts prevent
any great discrepancy in their respective growths.
In the lower drawing of Fig. 11 it will be seen that a large exostosis grows
from the shaft of the ulna a short distance below its mid point. The root of —
this exostosis descends towards the distal extremity of the shaft. It is the
presence of the outgrowths from parts of the shaft, very remote from the
diaphysial growth dises, that has led clinicians to think that cartilaginous
exostoses cannot be a product of the cartilaginous growth discs. The youngest
subjects of this condition, so far reported, have been in their second year but
when we see how large a number have inherited this disorder of growth and
grasp the true nature of the disease we are justified in supposing that in every
case the condition, or a tendency to produce it, is already present at birth,
although it is not until the eighth or tenth year that it becomes manifest by
the painless development of bony outgrowths. In the majority of cases the
acute phase of the disease commences with the ripening of the genital glands.
Now the point at which an exostosis is situated in Fig. 11 corresponds to the
position of the distal extremity of the diaphysis of the ulna in the first or
112 ue Arthur Keith
second year after birth, The largest exostoses are always those which spring
from near the middle of the shaft and I regard them as parts or areas of
endochondral-formed bone detached from the growth dise while that structure
was still replete with the potential growth of infancy. Even the large exostoses
usually cease to grow when adult years are reached—when epiphyses become
fused with their respective shafts. We have, in the existence of mid-shaft
exostoses, evidence of the early onset of the disorder. In Diaphysial aclasis the
radius becomes a bent bow; the ulna serves as its taut string. In about one-
third of the cases the bow becomes unbent by a spontaneous dislocation of
the proximal end of the radius.
In Fig. 13 the distal ends of the left tibia and fibula of Dorothy D., aged 16,
are represented. In Fig. 18, A, the condition is shown in February, 1919; in
c Separation
line.
Cartilage ! hel Area of
dises >| pees if deposihon,
Fig. 13. A. The distal ends of the tibia and fibula of Dorothy D., aged 16 (Mr Bristow’s case)..
The cartilaginous growth discs are indicated by irregular black bands. The terminal diaphysis
of the tibia has expanded laterally and apparently fused with the terminal expansion of the
fibula.
' B. A drawing of the same parts ten months later. A line of separation now marks off
the lateral expansion of the tibia. The stippled area indicates the deposit of the previous ten
months.
Fig. 18, B, the condition in December of the same year is represented. The
stippled area represents the new bone added in that interval; it lies entirely
within the diaphysial line. In the earlier skiagraph the lateral expansion of the
terminal shaft of the tibia has apparently fused with the bone of the fibula,
but in the later skiagram a sharp separation has occurred between them. The
fibula has apparently undergone a slight dislocation laterally for the total
breadth, from the medial border of the tibia to the lateral border of the fibula,
has increased about 4mm. In Capt. West’s case, a man aged 26, there is a
medial outgrowth from the fibula which has pressed against the expanded
end of the tibia and caused a wide area of superficial absorption, the cup-
shaped area thus excavated being lined with a layer of indurated bone.
Each bone reacts in the subjects of Diaphysial aclasis in a characteristic
manner. The distal end of the humerus rarely shows more than a slight dis-
Changes accompanying Growth-disorders of Human Body 113
turbance of growth while its proximal end is almost the first site to give an
outward manifestation of the presence of the disorder. Prof. Digby estimates
that 81 per cent. of the length of the shaft of the humerus is added at the
proximal diaphysial line and we may therefore expect a much greater degree of
disturbance at this extremity. In Fig. 14 I give drawings from the skiagraphs
of the shoulder region of Dorothy D., aged 16. The terminal unmodelled part
of the shaft of the left humerus measures 64 mm. in length by 35 mm. in width
(as measured in the skiagraphs). The sleeve of dense periosteal bone ends quite
abruptly where the cancellous cylinder begins. The deposit of new bone,
Epiphysis. rae
Fig. 14. The proximal ends of the right and left humeri of Dorothy D.,faged 16 (Mr Bristow’s
case). The stippled areas represent the bone deposited during a period of ten months. The
diaphysial growth discs are represented by thick black lines.
represented by the stippled areas, has been almost entirely laid down in the
terminal diaphysial line (forming a stratum 6mm. in depth) but certain
deposits have also been added to the lateral and medial surfaces of the
terminal shaft. In the right humerus (Fig. 14) the modelling process, although
interrupted, has proceeded almost to the diaphysial line. Yet in spite of the
greater intensity of the modelling process in the right bone there has been
a heavy deposit of bone outside the terminal surface of the shaft. The recent
deposit on the lateral aspect is plainly an exostosis growing from the pectoral
ridge. It is also likely that the deposit on the medial surface is not laid down
over the dense casing of periosteal bone—as it appears to be in the skiagraph—
114 Arthur Keith
but is really of the nature of an exostosis or deposit. growing on the extensor
aspect of the shaft. There can be no doubt as to the irregularity of the process
of growth which is taking place at the proximal ends of the humeri nor of the
partial arrest of the modelling process.
The figures used to illustrate this paper represent the typical growth
lesions of the long bones. The clavicles, ribs, scapula and os innominatum
show corresponding defects and excesses of growth. Further observation
will probably reveal lesions in the base of the skull.
There is one other growth lesion which is very closely related to the disorder
named here Diaphysial aclasis. If the law which I have laid down that in
this disease every bone in the body which is made up by the union of endo-
chondral and periosteal elements exhibits aclasis and overgrowth be true,
then we should find the shafts of the metacarpal and metatarsal bones and
of the phalanges of the fingers and toes also showing similar disturbances. The
metatarsal and metacarpal bones do occasionally show a slight degree of the
disorder—particularly those of the fourth and fifth digits—but both meta-
carpals and metatarsals and their phalanges are usually quite normal in their
growth. In those cases however where the derangement is apparent before
the sixth year the long bones of the hand and foot are affected. On the other
hand these elements of the hand and foot are subject to another disorder,
also hereditary in nature and occurring in infancy and youth, namely multiple
enchondromata. These localised cartilaginous tumours arise within the shafts
of phalanges and metacarpal and metatarsal bones—particularly those of the
2nd and 3rd digits. All of these bones are peculiar in their order of ossification ;
the periosteal sheath of bone is laid down almost before the cartilage core has
commenced to ossify. I expect that a re-investigation of the developmental
processes attending the ossification of these long bones of the hand and foot
will throw light upon this bizarre anomaly of growth.
The conception of multiple exostoses as a disorder of growth is not new.
John Hunter recognised that it was “constitutionally interwoven with the
formation of bones in some people” (Palmer’s Edition, vol. 1. p. 533). Sir James
Paget expressed a somewhat similar opinion when he wrote of multiple
exostoses: ‘Indeed at this point the pathology of tumours concurs with
congenital excesses of development and growth” (Lectures on Surgical Patho-
logy, 3rd edit., 1870). Bessel-Hagen and Nasse (see references in footnote,
p- 106), who have written the best monographs on this disorder, are also
inclined to regard it as a growth disturbance. Ollier (Revue de Chirurgie, 1900,
vol. XxI. p. 39) has described under the name of Dyschondroplasia a condition
which is probably only an extreme condition of the disorder named here
Diaphysial aclasis.
When we seek to probe beneath the surface and search for the immediate
cause of this peculiar disturbance of growth we find no sure foothold on fact.
The condition of the various glands of internal secretion in those who are
the subjects of the disease has not been studied. Nor when observations are
Changes accompanying Growth-disorders of Human Body 115
made do I expect that any gross lesion will be found. Even in Achondro-
plasia no anatomical change in the structure of the thyroid has been noted
and yet from the similarity of the growth lesions in Achondroplasia to those
seen in cretinism there is a fairly certain basis for suspecting that a functional
defect of the thyroid is the immediate cause of the growth defects seen in
Achondroplasia. In certain respects Diaphysial aclasis is contrasted to
Achondroplasia and yet it seems to fall into the group of thyroid disorders,
for we find that while one defect of the pituitary gland may lead to dwarfism
another produces giantism. There can be no doubt that in Diaphysial aclasis
we have one of the most remarkable of all known disturbances of growth.
Summary. The disease known to clinicians as Multiple exostoses is a
definite disorder of growth and should be named Diaphysial aclasis to indicate
the nature of the growth disturbance. It is congenital in point of origin and
affects only those parts of the skeleton which are developed from both cartilage
and membrane. It is related to Achondroplasia and there is reason for
suspecting that it may be due to a disturbance in the function of the glands
of internal secretion—the thyroid gland being the one which is most likely
to be at fault. The study of this disorder helps us to analyse the normal
machinery of bone-growth.
FUNCTIONS OF THE LIVER IN THE EMBRYO
By J. ERNEST FRAZER, F.R.C.S. (ENc.),
Professor of Anatomy in the University of London
A srrancr statement was made by Harvey in the sixteenth chapter of his
immortal Ewercitatio Anatomica de Motu Cordis. He says here: “Hine in
Embryone pene nullus usus jecoris, unde. ..etiam in prima foetus conforma-
tione jecur posterius fieri contingit, et nos etiam in foetu humano observavimus
perfecte delineata omnia membra, imo genitalia distincta, nondum tamen
jecoris posita pene rudimenta....”
One cannot help wondering whether the meaning which appears here on
the surface really expresses Harvey’s intention, and that he meant to convey
the impression that the organ is a small thing and of no account in the earlier
months of development; for it does not seem possible that so acute an observer
would have been ignorant of the great relative size of the liver in these months.
No doubt, from the view-point which he occupied at the time, there seemed
to be no necessity for a large organ, which would account for the first sentence
quoted above; but, with a man of this calibre, it could not explain the second,
and one seems almost driven to assume that he was deceived by the condition
of his specimens and the friability of the liver—a very unsatisfactory explana-
tion.
The undeniable fact that the liver is of such great relative size in embryonic
life suggests that it performs some function then which is associated with its
size. The Galenical concept of the liver as the fount and origin of the blood
was seemingly laid to rest by Harvey, but, in a sense, it has stirred again,
in the qualitative, if not quantitative, blood-forming activities now known
to be at work in the organ. But this function does not account for the size
of the early liver. It goes on after the liver has altered its rate of growth,
and flourishes even after birth. Also the biliary functions of the gland are
not established before the relative maximum size is passed, and it is hard
to see any connection between them and the great embryonic growth. There
seems, in fact, to be only one thing in the life history of the embryo which
is directly associated with the greatest size of the liver, and which is coexistent
and coterminous with it: I refer, of course, to the extra-abdominal position
of the gut, terminating by its passage into the abdomen and its subsequent
growth there. This connection has often been recognised, and the liver has
been credited with the pushing of the intestine out of the abdomen at one
time, and, on the other hand, has been said to be the main power at work
in pulling it back again later on, but there has not been, so far as I am aware,
Functions of the Liver in the Embryo 117
anything more than general suggestions that these things may be so, nor
any coherent effort to show by what means they could be so. When working
with Dr Robbins on the rotation of the gut, I found myself adopting more
defined and, I think, reasonable views about the part played by the liver in
the matter. In the paper published at the time in this Journal I mentioned
these views shortly, in so far as was necessary for the purpose in hand: in
this communication I propose to give a fuller account of what, in my opinion,
this part may be considered to be,
For convenience, the subject may be considered under several different
headings. }
1. The state of the embryonic liver
As is apparent at once on examining sections, the liver of the embryo is
a loosely built organ, very vascular. It consists of solid material and a con-
siderable amount of fluid. The solid portion, leaving out of account blood
cells which vary directly with the amount of blood, is a fixed quantity. The
fluid constituent of the liver can be divided into that within the vessels and
that outside them. The former, the blood, can by its escape into its natural
extra-hepatic and extra-abdominal channels, lead to a rapid and sensible
diminution in the total bulk of the organ, the unchanged quantity of solid
constituent remaining. The liver grows by increase of its solid columns and
of the vascular spaces between them. It grows in correspondence with the
growth of the abdominal cavity, and fills up every available corner of that
cavity, lying beside the median mesenteric septum and the bursa omentalis. But
there does not seem to be any reason to suppose that in its growth it exercises
any pressure whatever on neighbouring structures: on the other hand, reasons
for thinking that it does not do so may be seen in the state of the bursa
omentalis, the bold transverse curve of the duodenum, the processes of the
aN _ Wolffian bodies, the thin-walled veins in the organ and outside it, ete. I am
not aware of any evidence of pressure being exerted by the growing liver,
_ and, during the examination of all stages, the impression has formed itself
in my mind that the organ in its growth might almost be likened to a very
viscid fluid slowly running, without pressure, and flowing into interstices
and filling up spaces: of course it is not a simple viscid fluid, but such an
idea will illustrate fairly well, in some ways, the conception I have formed of
its mode of growth and the way it acquires its form. It is instructive to
examine places where (as may be seen for instance here and there beside a
well-developed Wolffian body) a process of the liver has passed in through
some narrow chink or fissure, into a wider space, so that a small enlargement
is torn off at its narrow neck when the organ retracts on dehydration: in these
ceases there has plainly been extension of the liver without any flattening of
the structures bounding the chink, as if the liver had “flowed” into the recess
rather than pushed its way into it.
The conception of a liver growing in this way, composed of solid columns
with intervening spaces filled with fluid which is able to vary in amount,
Anatomy LIV i 8
118 | J. Ernest Frazer
entails certain corollaries. The growth goes on pari passt with the growth of
the belly cavity: but if the solid parts grow faster than the cavity, it follows
that the fluid parts must become relatively less, and vice versd. So, if we
accept the general truth of Jackson’s statements about the falling rate of
growth of the liver after the first part of the third month, it means that the
venous spaces in the organ at this time are comparatively large, and getting
relatively larger as the rate falls.
2. The mechanical bearing of this state
I have, so far, seen no reason to believe that the liver is in any way
responsible, through its increase in size, for the presence of the gut in the
umbilical sac. I have not been able to satisfy myself about the matter,
principally because my earlier specimens (under 5 mm.) are not sufficiently
well preserved to provide reliable data, but I have a decided impression that
the extra-abdominal position of the gut has more to do with the slow growth
of the belly-wall than with any intra-abdominal condition: that there is no
room in the abdomen at first for anything but the Wolffian bodies and the
umbilical veins: that this is due to the small size of the cavity from the small
extent of the walls: that consequently the lengthening intestinal bend is
effective only in the direction of the vitello-intestinal duct: and that the
formation of the dorsal mesentery, when its explanation is given, may
possibly throw more light on the umbilical position of the gut than will any
researches on the liver. Or, from a point of view a little different, it might
be said that the abdominal wall closes in behind the umbilical gut, and thus
this part of the bowel is not extruded from the belly, but lies outside it ab
initio. Whether these views turn out to be true or not, there is little doubt
that the gut is already outside the belly wall by the time the liver begins its
most effective growth, and, to my mind, this growth is called forth by, and
is an expression of the necessity for filling the space caused by, the increasing
area of wall—increasing too late to enclose the bowel within it. In other’
words, the liver growth would be more rightly looked on as an indirect conse-
quence of the external position of the gut, than as the cause of the gut
assuming this position. .
But, though it may not cause the extrusion of the bowel, it would seem
that the presence of the growing liver leads to the continued extra-abdominal
existence of the viscus. The organ grows pari passt with the cavity, which
it fills, so that the walls are supported by it against the external amniotic
pressure. This equalisation of pressure permits the other viscera, whether
inside or outside the belly, to live in “‘a state of rest” in their respective
situations,
There can only be inverse variations between the two constituents of the
liver mass, if this is to keep pace with the growth of the cavity: such variations
will naturally only be possible within limits. So long as the limits are not
exceeded, or perhaps too closely approached, the condition of equilibrium
Abe “tia ones eee gamer Calientes
Functions of the Liver in the Embryo 119
between the internal and external viscera will remain: if one could imagine
such a thing as the liver failing altogether to develop, while the abdominal
walls grew at their usual rate, it would not seem possible that the formation
of the intestinal coils could go on outside the cavity; for the cavity must be
filled, and, if the liver fails to perform this function, it can only be carried
out by the intestine. Looking at it conversely, the development of the coils
outside the belly is an indication that the liver growth fulfils efficiently the
task of occupying the available cavity and equalising the intra-abdominal
and extra-abdominal pressures.
8. The mechanical state towards the end of the first stage
Towards the end of the first stage, when the umbilical gut is nearly ready
_ to enter the abdomen, the rate of growth of the liver, i.e. of course, of its solid
_ parts, begins to fall behind that of the cavity. This was pointed out by Jack-
son some years ago (Anat. Record, 1909) and there can be little doubt, I think,
that his general conclusions are correct, although, as we shall see later, there
may be reason’ for modifying the details of his figures. As the rate of solid
growth falls, and as the mass must still fill the cavity, it follows that the
_ relative amount of blood in the organ must be increased: it is evident that,
the decreasing rate of solid growth persisting, there will be both actual and
relative increase in the amount of blood, and distension of its vessels. One
can imagine that at first this change in the relations between solids and fluids
would not make itself felt away from the liver, and that then any indications
of difficulty in keeping pace with the growth of the cavity might be met by
falling in of the walls to some little extent, but, if the process continues,
there must come a time when the vessels and the solid columns between them
are stretched to their utmost extent, and any further reply to the demands
of the growing cavity becomes impossible. Whether the process ever does
proceed so far as this or not, I have no means of deciding, nor does it really
much matter from our present point of view; it is sufficient to understand that
the liver now contains a large and unusual amount of fluid, and may be con-
sidered to be “stretched” to a considerable extent, a condition necessarily
associated with lessening of the tension inside the abdomen, compared with
that outside it and away from liver influence.
4, The necessary conditions associated with the entrance
of the gut into the abdomen
This movement of the intestine is rapid. As I conceive it, it is probably
only a matter of minutes. It is brought about by a relative rise in extra-
abdominal pressure, due to some fall in intra-abdominal tension. The mass
of gut and mesentery in the sac may perhaps offer at first some resistance to
the movement, aided by the small size of the aperture through which they
must pass, but when once the movement starts there is no reason why it
should not continue. The nature of the movement and its order have been
already dealt with in the previous paper, and need not detain us now.
g—2
120 J. Ernest Frazer
It is evident that the introduction into the abdomen of such a compara-
tively large mass as that which occupies the umbilical sac calls for provision
of space for special accommodation. This space must be provided as it is
required: it cannot exist as an unoccupied part of the cavity before the entry
of the intestines, for this would mean either a vacuum or a collection of fluid
which would change places, so to speak, with the gut, a supposition at variance
with the mechanical causes of the entry on the one hand, and, on the other,
with the conditions of both umbilical and abdominal regions as found in the
embryo. Moreover, it seems necessary to suppose that the provision of the
space must take place without the exercise of any force on the part of the
intestine: the gut cannot be thought to compress any organ or organs which
it finds in the abdomen, for this would mean that it makes its way against
resistance, a thing hardly conceivable.
I suppose that a common idea of what takes place might be expressed
by saying that the lessened growth of the liver and Wolffian bodies leads to a
fall in “intra-abdominal tension”’ which is met by the walls falling in below
the liver; then, when the gut comes in, space is provided by the bulging of
the slack of the walls. To my mind this conception is open, without considering
other points, to the fatal objection that it does not allow for the play to their
end of the factors causing the movement. Even if one were to admit—which
I would hesitate to do—that such elastic recoil were possible in these walls, a
little reflection will show that the exercise of this quality by the walls is not
compatible with a complete return of the intestine: the force supposed to be
leading to the return would decrease rapidly as the walls were relieved of
their inverted strain by the incoming bowel, a state of quiescence ought to
occur very soon, and it is impossible to conceive the movement going on to
a bulging of the walls, unless we postulate an insistence (on the part of the
bowel) on finishing the job when it has once started to enter the belly—a form
of vital activity hitherto unsuspected. For my part, I cannot help feeling
that the walls are incapable of playing any but a subsidiary part in the move-
ment, and that they are mainly passive so far as it is concerned, perhaps
indirectly aiding (as will be mentioned later) in the beginning of the movement,
but exercising no influence on its continuation or completion. ~
We might say, then, that the explanation of the conditions immediately
preceding, accompanying, and following the ventralisation of the bowel
must take account of the necessity for providing potential accommodation,
for converting this into actual accommodation as and when it is required, for
allowing this to take place without calling for any pressure from the bowel,
and for connecting all this with the mechanism which leads to the intra-
abdominal movement of the gut. In addition, the factors causing the change
of location must be capable of continuous action till the movement is com-
pleted.
Functions of the Liver in the Embryo 121
5. The réle of the liver in meeting these necessities
It has been pointed out above that the liver, if its rate of growth falls and
it yet fills the cavity, must be in what can be conveniently termed a “stretched”
state as the end of the first stage approaches. With certain and evident
reservations, it may now be likened to the lung in the adult thorax, a viscus
also in a “stretched” condition. The lung exercises a pull on the thoracic
wall which is increased as the thorax is enlarged: this is the same as saying
that the intrapleural pressure is further lowered. So long as the liver grows
pari passt with the belly its conditions differ from those of the lung, but when
it becomes “stretched,” it is comparable with that organ: it begins to exercise
a pull on the abdominal walls, and, as these enlarge, the intra-abdominal
pressure is lowered. If a tube were inserted into the pleura, water or air would
be drawn into that cavity through it when the thorax enlarges: in the case
of the abdomen there is already an umbilical tube connected with its cavity,
and its contents similarly tend to be drawn into the abdomen as the intra-
abdominal pressure falls: these contents are coils of gut and mesentery. The
immediate cause, then, of the ventralisation of the intestine is the relative
increase in external pressure arising as the result of lowered internal pressure,
due to the “‘stretched”’ state of the liver as the walls grow.
Also, as the pull of the lung would not be satisfied by the passage through
the tube of a few drops of water, but would lead to the taking in of a quantity
sufficient (if obtainable) to allow its collapse, so the retraction of the
“stretched” liver would continue in front of the entering intestines, without
pressure from them and merely in virtue of its own power of recovery of its
natural “unstretched” condition. This, it is hardly necessary to point out,
implies that the excessive blood occupying the dilated spaces is expelled from
the liver into the vena cava, so that the organ is reduced in size and the
original relation between solids and fluids restored. Thus it may be said that
the intestinal presence enables the liver to retract, and it is the tendency to
retraction, essentially inherent in its distended and “stretched” condition,
which initiates and carries on the movement of the bowel. Hence the liver
might be described as retreating before the intestine, without pressure, as a
lung retreats when some foreign substance begins to occupy the pleural sac.
Whether the tendency to retraction is wholly satisfied or not by the pres-
ence of the gut is, of course, a matter at present impossible to decide. The
rapid growth of the bowel after the event seems to point to an answer in the
negative, and it is conceivable that the dorsal shifting of the originally
- umbilical colon may indicate the same. The apparent rapidity of the move-
ment and its complete nature, with the great rarity of partial failure, also
point in the same direction, unless we are willing to admit a most accurate
and delicate adjustment between the retractile potentiality and the intestinal
mass.
Unfortunately, and in the nature of things, it is only possible to bring
122 J. Ernest Frazer
forward as assumptions the functions. which are claimed here for the liver.
Experimental proof of the assumptions is, of present necessity, lacking.
I hope that it may be possible to carry out some experimental observations
on other embryos when the opportunity serves, but, as nearly all my human
material reaches me-in formalin or alcohol, it has not been possible to use
it in this way. But the examination of ordinary prepared specimens yields
certain results which are of importance in this connection.
In the first place, there can be no doubt that the liver occupies all aveileble
space in the abdomen of the living or recent embryo. Reconstruction models
show this clearly: for example, the model of the liver of a 28 mm. specimen,
made for the original work, demonstrates by its markings all the organs with
which it was in contact before dehydration. In this way it can be shown
indubitably that, as in all other specimens after the youngest, it reached to
the extreme caudal limit of the abdominal cavity: yet the sections exhibit
the lower portion of the cavity as quite free from any trace of liver structure.
This is the usual and necessary concomitant of preparation. Dehydration
of the liver implies its contraction through the removal of fluid, and, as its
attachment is above, its retraction must show its effect mainly below. It
follows from this that, though the shape and relational markings are fixed
and preserved with a general fidelity, the bulk of the reconstructed organ is
less than it should be if it is to be taken as an absolute proportionate enlarge-
ment of the actual liver, and the ratio of its mass to the abdominal cubic
content is false without considerable correction. It was from this standpoint
that I took exception, earlier in this paper, to the acceptance of Jackson’s
measurements and ratios as calculations accurate in detail. My objection is,
of course, only to their acceptance without due correction for the effects of
dehydration, and does not apply to his general conclusions. I have tried to
avoid dehydration by making use of Salkind’s ‘‘lead gum” method, but this
was not successful in my hands and was abandoned owing to wastage of
valuable material: in other hands it might succeed and yield good results.
The shrinkage of the liver resulting from dehydration is very suggestive,
in that it shows how space can be provided in the abdomen by loss of fluid
from this organ. But the conditions under which fluid is removed in
this case differ widely from those that would be present if fluid were
taken out as blood, through the vessels. In -the first ease the alcohol
replaces the water in the vascular spaces, so that no collapse of these spaces
takes place, while its action on the solid columns is further modified by their
previous fixation: in the second case there is nothing to replace blood with-
drawn, so that, if it is withdrawn, the solid material round the spaces must —
fall in, and the total bulk of the liver must be decreased by so much. It would
seem, then, that the contraction due to dehydration would not be so marked
as that brought about by the withdrawal of a relatively small quantity of
intravascular blood, and the possibilities of this last method are, of course,
much greater; indeed, the maximum effect would be produced by complete
4,
Functions of the Liver in the Embryo 123
exsanguinification of the organ, a process which never occurs but which, if
it did occur, would probably lead to reduction to about half the original
bulk.
The following observation is of interest in connection with this aspect of
the condition. Two models were made from an embryo of a stage just pre-
eeding that in which ventralisation of the bowel might be expected to occur.
One was a “‘cast”’ of the abdominal space from which the liver had retracted,
care being taken to cut wide of the various structures there and not to include
any part of the space which seemed in any way to have come into being as
between two organs originally in contact, so that as far as possible only the
effect of liver contraction might be gauged: if any doubt arose, it was always
decided against the inclusion in the model of that part of the cavity concerned,
and in this way a cast was obtained which was not, I think, larger than the
liver space required, but was in all probability considerably smaller. The
second model represented the umbilical mass of gut and mesentery: to obviate
the shrinkage of these, the outline of the containing sac was taken in place
of its contents, as these had during life filled the sac, and in this way a mass
_model was obtained which might with great fairness be said to be approxi-
mately equal to—if not larger than—the bulk of the contents of the sac during
life. The bulk of each model was then found by displacement. The result
gave the ratio between the cavity and the umbilical mass as 28:31. As
already stated, the first measurement is probably too small, and the figures,
I think, would more truly be expressed as about of the same value, but the
interest of the observation really lies in the indication afforded by it of the
amount of contraction which occurs in the liver as the result of extraction of
fluid. It is evident that the necessary accommodation for the incoming intes-
tine could be provided, probably altogether, by shrinkage as the result of
removal of fluid from the solid columns, and hence it would seem that it
could be obtained easily by the more definite and complete retraction got by
withdrawal of blood from the liver vessels, if this withdrawal takes place:
if the withdrawal does not take place, there does not seem to be any mechanism
through which the liver can lessen its bulk, and lessening of its bulk is absolutely
necessary if the intestines are to find place in the abdomen.
These points just mentioned are important ones, as they bring forward
the fundamental facts on which comprehension of the mechanical conditions
depends: the abdominal cavity is fully “‘occupied” up to the entry of the gut,
it must be occupied during the passage, and yet accommodation must be
provided—and of all the structures which affect the cavity the liver is the only
one even remotely capable of fulfilling these functions.
If the views advanced in this paper are confirmed by further experience
and prove to be substantially correct, we have in them some explanation or
reason for the rapid rate of growth and size of the liver in the embryonic
period: it allows the abdomen to grow while the intestine develops outside
it, it supplies the means by which the intestines are brought into the belly,
124 J. Ernest Frazer
and it provides the accommodation for them therein, as and when it is wanted.
No suggestion is offered concerning the apparent necessity for the extra-
abdominal development of the gut; it is even conceivable that this position
of the bowel is required, for some deeper reason, to allow the liver to develop.
But, however this may be, there is in my mind no doubt about the mechanical
relationship between the two conditions, as set forth above. This way of
looking at the questions seems to me to offer the only completely satisfactory
solution of their problems, congruous with all the conditions present.
We might therefore divide the intra-uterine life of the liver into two main
stages: the embryonic, in which its functions, other than growth, might be
termed mechanical, and the foetal, after the ventralisation of the bowel, when
the processes of bile-formation and of other bio-chemical activities are
initiated.
The excessive development of the liver in its early stages has now some
sort of raison d’étre; it is otherwise apparently meaningless, for we see even
atrophy and degeneration of some parts at later stages. Moreover, not only
is the accuracy of the general statement quoted from the Evercitatio upset by
the fact that the liver reaches a great size in the early stages, but the reasons
advanced for this great size, if they are accepted, dispose of the particular
assertion contained in the first sentence of the quotation. There can be no .
question about the truth of the statement that the gut is extra-abdominal
and becomes intra-abdominal, nor that the mechanical conditions underlying
and allowing these states and changes call for explanation, and, as already
stated, the only completely satisfactory and satisfying explanation would seem
to be that which brings in the liver in the ways advocated in this paper.
ON THE DEVELOPMENT OF THE HYPOBRANCHIAL
AND LARYNGEAL MUSCLES IN AMPHIBIA
By F. H. EDGEWORTH, M.D.
Professor of Medicine, University of Bristol
Tue adult anatomy of the laryngeal muscles, nerves, and cartilages, in
Amphibia is now well-established, and especially by the work of Henle,
Fischer, Wilder, Gegenbaur, Géppert, and Driiner. An explanation of the
facts observed was sought for, and in 1892 the theory was put forward that
the laryngeal muscles are branchial in origin, their nerves branchial nerves,
and their cartilages modified branchial bars. A short history of the rise of
this theory and of its modifications forms a preface to this paper.
In papers published in 1916 and 1919 I showed that in Mammalia and
Sauropsida the laryngeal muscles, other than the Crico-thyroid of Mammalia,
are developed from the Constrictor oesophagi. In this paper evidence is
adduced that in Amphibia, similarly, the laryngeal muscles are developed
from the Constrictor oesophagi and are not derivatives of any branchial-arch
musculature.
The larynx in Amphibia comes into relation with certain hypobranchial
muscles, and a description of their development and morphology precedes
that of the laryngeal structures.
Many names have been employed by writers. A uniform nomenclature
has been used in the following paper, both in the historical account and in
the record of observations; and the following tabular statement shows its
relation to the names employed by previous writers.
Ventral muscles of the branchial arches.
In this paper:
Transversi ventrales :
Urodela:
Transversus ventralis iiiof Necturus Fischer Hyo-trachealis
and Proteus Wilder Hyo-laryngeus and Hyo-
Transversus ventralis iv of other trachealis s. Ph
Urodela branchialis iii or iv
Gegenbaur Hyo-trachealis
Géppert Hyo-pharyngeus s. Hyo-
trachealis
Driiner Interbranchialis iii or iv
Anura: larva
Transversus ventralis iv . Géppert Hyo-pharyngeus
Gymnophiona :
Transversus ventralis iv Géppert Hyo-pharyngeus.
126
Subarcuales recti and obliqui:
Urodela:
Subarcualis rectus i
Subarcualis obliquus ii of Nec-
turus and Proteus
Subarcuales obliqui ii and iii of other
Urodela
Subarcualis rectus iii of Necturus
and Proteus
Subarcualis rectus iv of other Uro-
dela
Anura: larva
Subarcuales recti i and ii
Subarcuales recti iii and iv
Gymnophiona:
Subarcualis rectus i
Subarcuales recti ii, iii and iv
In this paper
Urodela:
Henle (1839)
Fischer (1864)
Wilder (1892 and 1896)
Gegenbaur (1892)
Géppert (1894 and 1898)
Driiner (1901 and 1904)
Gymnophiona:
Henle
Goéppert
Anura: larva
Wilder
Géppert
Anura: adult
Wilder
Henle
Géppert
F. H. Edgeworth
Fischer, Mivart | Ceratohyoideus internus
Miss Platt, Driiner
Fischer Adductores arcuum
Miss Platt Constrictor arcuum
Driiner Adductores branchialium
Subarcuales obliqui
Ceratohypobranchialis (in Nec-
turus and Proteus)
Constrictor arcuum branchiarum
Fischer, Gegen- Constrictores arcuum
baur, Mivart,
Miss Platt
Driiner
Géppert
Driiner
Dugés
Schultze
Schultze
Fischer
Fiirbringer
Norris and Hughes
Fischer and
Goéppert
Subcerato-branchiales
Constrictores arcuum branchia-
lium
Subarcuales recti
Constrictores arcuum branchia-
lium
Ceratobranchial
Ceratohyobranchialis
Interbranchialis
° Ceratohyoideus externus
Ceratohyoideus
Ceratohyoideus internus
Constrictor arcuum branchi-
alium
Laryngo-tracheal skeleton
Whole cartilage
Cartilago lateralis
Cartilago lateralis
Cartilago lateralis.
Posterior part
Pars trachealis
Anterior part
Pars laryngea s.
arytenoid
Cartilago s. Pars
arytaenoidea
Seitenknorpel
Arytenoidea s.
C. lateralis
Arytenoidea s.
Stellknorpel
Pars arytenoidea
Cartilago lateralis s.
Pro arytenoidea
Cartilago s.
oe - trachealis
s. Cartilago lateralis
Tracheal elements
Pars cricotrachealis
Proc. trachealis
Cartilago arytenoidea Cartilago lateralis
Pars arytenoidea
Arytenoidea —
Arytenoidea _
Arytenoid and { Annulus
apical cartilage ( Processus bronchiales
C. arytenoideaand _ C. laryngo-trachealis
C. Santoriniana
C. arytenoidea and
C. Santoriniana
Pars crico-trachealis
f Pars cricoidea
; Partes tracheales
Hypobranchial and Laryngeal Muscles in Amphibia 127
Laryngeal muscles
Dorsal laryngeal muscle Laryngei Constrictor muscle
In this paper Dilatator laryngis Laryngeus dorsalis Constrictor laryngis
Laryngeus ventralis
Urodela :
Henle Dilatator aditus a Constrictor aditus
Dorso-larynge d Co adi
TsO- us an _ mstrictor aditus
uecker i Dorso-trachealis laryngis
Dorso-laryngeus and _ Laryngei Ring of Periarytenoi-
Wilder Dorso-trachealis s. deus dorsalis and
Dorso-branchialis v. ventralis
Gegenbaur Dilatator aditus — ~
Do h. f Laryngei Sphin: laryngi
_—s aryngeus . i phincter is
Géppert | Dorso-laryngeus and
Dorso-trachealis
Driiner Dorso-laryngeus Laryngei Constrictor aditus
: laryngis
Gymnophiona:
Henle Dilatator aditus M. interlateralis Constrictor aditus
Géppert Dila laryngis Lary. tralis 8 : laryngis
ilatator i ngeus ven - Sphincter i
f Fed sconce primase: (2).
Anura: larva
- Wilder Dorso- DUS 8. _ Sphincter laryngis
Dorso-branchialis v.
Dilatator laryngis a Sphincter Iaryngis
Anura: adult me < = a Seta
Henle {Samak des ei re des Compressor der
Stimmladeneingangs Stimmladeneingangs Stimmlade
bd Dilatator aditus Constrictor aditus Compressor {Sphincter
s. Dorso- laryngis s. | aditus { eels
Wilder bran V. 8. Periarytenoideus laryngis
: orancraaset nl ventralis
dorsalis |
Géppert Dilatator laryngis Hyo-laryngeus at {Sphincter
| anterior | posterior
In this paper Constrictor laryngis posterior
HISTORICAL ACCOUNT
Ventral muscles of the branchial arches
Anura. The Subarcuales recti of the larva were described by Dugés and
by Schultze.
Another muscle was described by Géppert (1894) in a 11 mm. larva of
Rana, arising from connective tissue surrounding the post-branchial body
and passing inwards towards the middle line. In older larvae the median
ends of the two muscles meet. He homologised this muscle with Transversus
ventralis iv of Urodela and, further, stated that it becomes the Constrictor
laryngis posterior of the adult—a muscle which arises from the processus
postero-medialis and passes inwards and forwards to meet its fellow in a
median raphé just in front of the Cartilagines laryngis.
Wilder, on the other hand, stated (1896) that the Constrictor laryngis
posterior develops at a late larval stage (one with rudimentary hind limbs)
128 F. H, Edgeworth
as a derivative of the ventral half of the Constrictor laryngis and is
not identical with the larval muscle described by Géppert, which probably
atrophies. G6ppert in 1898 adhered to his previous statement. Neither
investigator gave any figures in support of his opinion.
Differences of opinion between Géppert and Wilder in regard to Levator
arcus branchialis iv are mentioned later.
Gymnophiona. The Subarcuales recti and the Transversus ventralis iv
were described by Fischer and Géppert (vide infra).
Urodela.. The larynx, owing to certain developmental changes, which
will be described later, comes into relation with the Transversus ventralis
(iii in Necturus and Proteus, iv in Urodela with four branchial bars). The
linea alba, connecting the two halves of this muscle, underlies the pharynx
and anterior part of the larynx in Siredon, Salamandra, Triton, Necturus,
and Proteus; it underlies the larynx in Ellipsoglossa, and underlies the trachea
in Menopoma, Megalobatrachus max. and Amphiuma. Various opinions have
been expressed as to the morphology of this Transversus ventralis, Fischer
(1864) considered that it was part of a single muscle system—that of a Con-
strictor pharyngis. Wilder (1892) described the Dilatator laryngis and
Transversus ventralis as “‘extrinsic”’ laryngeal muscles. He homologised the
former with the dorsal segment of the fifth branchial arch of Selachians, but
could not determine whether the latter was homologous with the ventral
segment of the same arch or not. Gegenbaur (1892) homologised the Trans-
versus ventralis with the Constrictores areuum of the branchial skeleton
(called in this paper Subarcuales recti and obliqui). G6ppert (1894), accepting
Gegenbaur’s opinion, stated that the Transversus ventralis was the hindmost
member of a longitudinal series binding together the hyoid and the branchial
bars, though differing from the other members in that it has generally given
up its ventral attachment to skeletal parts. In Necturus and Proteus, where
no fourth branchial bar is present, the hinder part of the Transversus ventralis
and the Levator iii pass to an inscriptio tendinea separating them, whilst the
chief part of the former muscles passes over to Ceratobranchiale iii. In Megalo-
batrachus max., where the third and fourth bars are absent, the Transversus
ventralis and Levator iii meet in an inscriptio tendinea which forms an
anterior continuation of that in the territory of Levator iv. In land-living
forms such as Salamandra and Triton, no forward migration of the muscle
takes place, and, on atrophy of the rudimentary fourth bar, the Transversus
ventralis and Levator iv form a Cephalo-dorso-pharyngeus—a muscle-band
with an inscriptio tendinea. Wilder (1896) advanced the theory that, primi-
tively, there was a series of ventral transverse muscles attached to the visceral
bars—in the mandibular segment represented by the Intermandibularis
anterior, in the hyoid segment by the Intermandibularis posterior, and in the
branchial region by a series of Transversi ventrales. In Necturus and Proteus
the Transversus ventralis consists of Transversi ventrales iii and iv; in other
Urodela only iv is present. Embryology would show whether Transversi ven-
Hypobranchial and Laryngeal Muscles in Amphibia 129
trales i and ii are represented ontogenetically. Wilder made no reference to
Vertebrates other than Amphibia. Géppert (1898) accepted Wilder’s opinion
that the Transversus ventralis of Urodela other than Proteus and Necturus
represents a Transversus ventralis iv, but, against Wilder’s opinion concerning
Proteus and Necturus, stated that the muscle in those animals is an altogether
simple one in which no division is possible even in the embryo. Further, no
proof had been given that a Transversus ventralis ili as well as a Transversus
ventralis iv existed in Urodela with a fully developed branchial skeleton.
Driiner’s theory (1901 and 1904) of the segmental origin of the Transversus
ventralis of Urodela was different from that of Wilder and Géppert. He found
that the muscle is innervated by the N. recurrens intestinalis x, and not by
branchial arch nerves. He inferred from this that the muscle had migrated -
forwards from more posterior segments which once existed and was not
native to the segment in which it lay. His terms Transversus ventralis iii or
iv are thus purely descriptive and denote merely the bar of attachment. .
(It may be added that this theory was adopted in all cases of the hyoid and
branchial musculature of Urodela where the innervation does not harmonise
with the position of the muscle—the innervation being held to be a clue to
the derivation of the muscle elements. Géppert had expressed the same
theory in the statement that a muscle never changes its innervation in the
course of its phylogenetic development.) Driiner consequently described the
muscle in most Urodela as a Transversus ventralis iv. As regards Necturus
‘and Proteus, he stated that the muscle is homologous with Transversus
ventralis iv of Salamandra and Triton in position and form, i.e. is a Trans-
versus ventralis iv which has shifted forwards and become a Transversus
ventralis ili. In Megalobatrachus max. the muscle has shifted forwards another
segment and becomes a Transversus ventralis ii,
In regard to the corresponding Levatores arcuum, he stated that in
Necturus and Proteus there is no demarcation possible between a Levator iii
and a Levator iv, nor are there any remains of a gill-cleft. So that, unless it were
proved by ontogeny that such existed, it is possible that a Levator iv, cartilage,
and gill-cleft, have disappeared and that the insertion of the Levator into
the inscriptio tendinea behind Ceratobranchiale ii is due solely to a caudal
extension of Levator iii. In Megalobatrachus max. the Levator, which is
inserted into Ceratobranchiale ii and the inscriptio tendinea behind it, may
represent Levator ii, or ii and iii, or ii and iii and iv. Driiner, further, stated
that there is evidence in Salamandra and Triton larvae of at least one branchial
segment behind the fourth, between that and the Dorsolaryngeus. In Sala-
mandra there is a short inscriptio tendinea extending backwards from Cerato-
branchiale iv. Levator iv is separated into two portions, of which the anterior
is inserted into Ceratobranchiale iv and the posterior into the inscriptio. The
Transversalis ventralis is attached laterally, from before backwards, to
(a) Ceratobranchiale iv, (b) the inseriptio, and (c) the ligamentum branchio-
pericardiacum. Between portions (b) and (c), i.e. behind the fourth branchial
130 F.. H, Edgeworth
arch there is, in young embryos (size not stated), an epithelial connection
between the pharyngeal epithelium and the skin which represents a sixth
gill-cleft. Again, on the left side of a 25 mm. Triton larva the Levator arcus iv
consisted of two portions, inserted (a) into the cartilage, and (b) into the
inscriptio extending back from it; whilst on the right side there was in addition
a Levator v inserted at the junction of the inscriptio tendinea and the liga-
mentum branchio-pericardiacum. Between Levator iv and Levator v was
an epithelial connection between the epithelium of the pharynx and the
Plica omo-branchialis (which is formed from the fourth “ Kiemenblattchen”’
and the skin of the shoulder region). This lies at the position where a sixth
visceral-cleft would be expected and represents the remainder of it. The
‘position agrees with that found in Salamandra larvae.
In Siredon Levator arcus iv is inserted to Ceratobranchiale iv and an
inscriptio tendinea extending back from it. The Transversus ventralis arises
from ceratobranchiale iv, the inscriptio and the ligamentum branchio-pec-
torale. Further, the fourth branchial nerve gave off an inconstant, sensory
branch which passed under the ligamentum branchio-pectorale, lying behind
the position in which—on comparison with Salamandra and Triton larvae—
the sixth gill-cleft is to be sought. This is a rudiment of a R. posttrematicus v.
Once a small epithelial vesicle was found which was regarded as the remains
of gill-cleft epithelium. Also a fine nerve was given off from the R. pharyngeus
of the fourth branchial nerve, which was regarded as a R. pretrematicus vi.
There is thus in these larvae the remains of a sixth gill-cleft behind Cerato-
branchiale iv, and the Transversus ventralis has fourth and fifth branchial
elements. In Triton there is also a Levator v. The laryngeal structures—
cartilage, Dilatator laryngis, and laryngeal muscles—consequently do not
belong to a fifth branchial segment, as Wilder, Gegenbaur and Géppert sup-
posed, but to some more posterior segment, at least to a sixth, possibly to
one still further back.
Laryngo-tracheal skeleton
Anura. The laryngeal cartilages of Anuran larvae consist of a short rod
on either side of the larynx. The adult conditions have been described by
Henle and Wilder, and their development by Martens.
Gymnophiona. Géppert has described the condition of the laryngeal
cartilages in a late larva of Ichthyophis (vide infra).
Urodela. The laryngo-tracheal skeleton of Urodeles consists of a continuous
or interrupted cartilaginous or fibro-cartilaginous rod on either side of the
larynx and trachea’.
1 The pars trachealis cart. lat. is not present in Necturus where the short trachea is surrounded
by fibrous tissue only; it is present in other Urodela, cartilaginous in Siredon, Salamandra, Triton,
Ellipsoglossa and Proteus, fibro-cartilaginous with or without islands of cartilage in Menopoma,
Megalobatrachus max., Amphiuma and Siren. It is continuous with the pars laryngea in Menopoma,
Megalobatrachus max., Ellipsoglossa, Amphiuma, Siredon, Proteus and Siren. It is separated in
Salamandra and Triton (Driiner).
Hypobranchial and Laryngeal Muscles in Amphibia 131
Neither Henle (1839) nor Fischer (1864) discussed the derivation of these
structures.
In 1892 similar, but not identical, theories were independently advanced
by Wilder and Gegenbaur.
Wilder suggested that the pars laryngea is homologous with the fifth
branchial arch of Selachians and the inferior pharyngeal bone of Teleostei,
and for the following reasons: (1) Every form possesses either a fifth branchial
arch or a laryngeal cartilage in the same location typographically. No animal
possesses both. The sudden appearance of such well-developed hyaline
structures as the laryngeal cartilages and the sudden disappearance of other
well developed structures such as the fifth branchial arch are both unusual
phenomena and when considered together may well point to the theory.
(2) The fifth branchial arch in Selachians is supplied by X*. “This same
nerve follows the arytenoids and supplies this region throughout the
vertebrate realm under the name of Ramus recurrens.” (3) Another
example of former branchial arches entering the service of the larynx is
furnished by the thyroid cartilage, which develops from the second and third
branchial arches (Dubois). Wilder also stated that in Triton the pars trachealis
is developed from the connective tissue surrounding the trachea at a time
when the pars laryngea is an already-developed hyaline structure, and
regarded the laryngo-tracheal skeleton as derived from two sources—the
pars laryngea from a fifth branchial arch, and the pars trachealis which is
a new formation.
Gegenbaur suggested that the cartilago lateralis is homologous with the
fifth branchial arch of fishes, and for the following reasons: (1) There is a
similarity between the laryngeal muscles and the Mm. interarcuales ventrales
of the branchial skeleton. The Transversus ventralis iv is to be compared
with this musculature. (2) Amphibia show an atrophy of the branchial skeleton,
increasing caudally. The cartilago lateralis has still more diminished in size
and lost its union with the fourth bar—both phenomena have parallels in
the branchial skeleton. (8) The fifth branchial bar of Selachii (other than
Heptanchus and Hexanchus) shows signs of atrophy, and the inferior pharyngeal
bone of Teleostei—which is derived from the fifth branchial arch—is a structure
with many possibilities of modification. Wiedersheim (1886) had regarded
the pars laryngea as the primitive portion of the laryngo-tracheal skeleton,
to which the pars trachealis became secondarily united. Gegenbaur, however,
found that in Salamandra larvae there is a continuous cartilage extending
from larynx to bronchi, which subsequently separates into pars laryngea and
tracheal skeleton. The earlier stage corresponds to that of adult Proteus and
probably represents the ancestral condition.
Wilder, in 1896, abandoned his theory of an independent origin for the
tracheal elements, and accepted that of Gegenbaur, as did also Géppert
in 1894 and 1898.
Driiner (1901 and 1904) accepted the theory that the pars laryngea is
132 F. H. Edgeworth
homologous with a branchial bar—not, however, with the fifth, but with either
a sixth or a still more caudal one. This modification of Wilder’s and Gegen-
baur’s theories was occasioned by the discovery of certain structures (vide pp. 129,
130) behind the fourth bar and its muscles, which, he held, represented at least
one branchial segment between the fourth and that of the cartilago lateralis.
He stated that the transitory continuity of the laryngo-tracheal skeleton in
Salamandra is not present in Triton and Siredon where the tracheal portion
develops independently in the form of many cartilaginous islands, and is no
proof cf a single derivation. It is paralleled by the transitory fusion of the
various parts of the branchial skeleton. He consequently regarded the condi-
tion in Proteus (with a continuous laryngeal and tracheal skeleton) as rudi-
mentary rather than primitive; and adhered to the earlier opinion of Wilder
that the laryngeal and tracheal skeleton are distinct structures, and suggested
that the latter might be either derived from one or more branchial bars behind
the pars laryngea or be new formations.
The pars laryngea is not uniform in shape in Urodeles, and different
opinions have been advanced as to which is the most primitive form. In Siredon
and larvae of Triton and Salamandra it is a roundish rod-like structure. The
Dilatator laryngis is inserted to it, the Laryngeus ventralis and the Laryngeus
dorsalis when present! arise from the Dilatator laryngis by inscriptio
tendinea. In Necturus and Proteus the pars laryngea, pointed in front,
broadens to a flat plate, from the lateral edge of which a hook-like process
projects backwards. The hind end of the process is tied to the inner limb of
the plate by a ligament, which chondrifies in Proteus. The Dilatator laryngis
is inserted to the lateral edge of the cartilaginous plate and the hook-like
process, and the Laryngei dorsalis and ventralis arise from the upper and
lower surfaces.
G6ppert held that the form present in Necturus and Proteus is the more
primitive and that of Siredon and larvae of Triton and Salamandra is secondary,
owing to disappearance of the lateral part of the cartilage, with resulting
shifting of the origins of the Laryngei dorsalis and ventralis to the tendons -
of the Dilatator laryngis. Drier held the reverse opinion.
In Ellipsoglossa, Menopoma, Megalobatrachus max., and Amphiuma the
pars laryngea has an oblique direction, from dorso-oral to ventro-caudal.
The ventral ends meet and are tied together by connective tissue in the
ventral median line (in Amphiuma by a cartilaginous bridge). The cartilage
lies‘just beneath the mucous membrane and forms a support for the Rima
glottidis which partially separates the laryngeal cavity into an anterior part—
the vestibulum, and a posterior—the laryngo-tracheal cavity. In Menopoma
and Megalobatrachus max., there is a processus trachealis projecting back-
wards from the pars laryngea close to the mid-dorsal line.
1 The Laryngeus dorsalis arises from the tendon of the Dilatator laryngis in Triton, it is absent
in Siredon, whilst in Salamandra larvae it was stated by Géppert to be absent, by Driiner to be
present and to arise from the tendon of the Dilatator laryngis.
Hypobranchial and Laryngeal Muscles in Amphibia 133
Driiner held that this form of the cartilage is secondary to that present
in Salamandra, Triton and Siredon, and also that the processus trachealis is
due to the fusion of tracheal elements with the pars laryngea.
A theory of the cartilago lateralis, absolutely different from that of the
foregoing observers, was advanced by Wiedersheim (1904) from his investi-
gations of the larynx in Ganoids and Dipnoi. He suggested, from analogy with
Protopterus and Lepidosiren, that possibly the cartilago lateralis of Amphibia
was primitively a tendon-chondrification without any phylogenetic relation-
ship to the branchial bars.
Laryngeal muscles
Anura. Géppert (1894) described the laryngeal muscles of a 10mm.
larva of Ranaas consisting of as. Dilatatcr laryngis, Dorso-laryngeus and a Con-
strictor laryngis. The first named arises from the tissue lateral to the pharynx.
He was of opinion, from comparison with Urodela, that the Dilatator laryngis
had lost its constrictor action on the pharynx and become restricted in its
action to the larynx. The Constrictor laryngis consists of a simple paired ring
with median dorsal and ventral raphés, continuous ventrally with a Trans-
versus ventralis iv. He coacluded that it is homologous with the Laryngeus
ventralis of Urodela. In 1898 he modified this opinion and advanced the
theory that each half is homologous with the Laryngeus ventralis and the
Laryngeus dorsalis of Urodela.
According to Wilder (1896) there is in the larva no Levator arcus branchi-
alis iv, and at metamorphosis the Dilatatcr laryngis of the larva becomes
separated into a (dorsal) Petro-hyoideus iv and a ventral Dilatator laryngis.
According to Géppert (1894) a Levator arcus iv is present in the larva, and
gains a new insertion into the processus postero-medialis at metamorphosis,
forming the Petro-hyoidei posteriores or at least their hinder portion, and
the only change in the Dilatator laryngis of the larva is that it gains an
attachment to the processus postero-medialis.
Gymnophiona. The laryngeal muscles of a late larva of Ichthyophis were
described by Géppert (1894) vide infra.
Urodela. Fischer (1864) included the Dilatator laryngis and Transversus
ventralis iv in the muscle-system of a Constrictor laryngis, which appeared
to be a repetition of the Levatores arcuum.
Wilder (1892) regarded the Dilatator laryngis as homologous with the
dorsal segment of the fifth branchial arch of Selachii.
G6ppert (1894) regarded the Dilatator laryngis as a Levator arcus v
serially homologous with the Levatores of the branchial arches. This opinion
was accepted by Wilder (1896).
Driiner also regarded the Dilatator laryngis as serially homologous with
the Levatores arcuum, though of some segment behind the fifth branchial
(vide supra).
Wilder (1892) put forward the theory that the laryngeal ring of muscle
is a continuation of the ring musculature of the alimentary canal which the
Anatomy Liv 9
134 F. H, Edgeworth
developing respiratory tract carried with it when it arose as a diverticulum
of the former. Its first action was that of a sphincter and it gained relations
to the pars laryngea later.
Géppert (1894) argued, against Wilder’s theory, that there is a fundamental
difference between smooth and cross-striped muscle-cells; the former are
single cells, whilst the latter form a syncytium, and the relationship of the
two kinds of cells to nervous centres is quite different. In Siredon, ontogeneti-
cally, the Laryngeus ventralis is a derivative of the Transversus ventralis iv;
and in Triton larvae, although there is no direct proof of the origin of the
Laryngeus dorsalis, yet it stands in the closest relationship to the Dilatator
laryngis.
Wilder (1896) abandoned his theory of 1892, and homologised the
“intrinsic laryngeal muscles” (i.e. Laryngei and Constrictor) with a Trans-
versus ventralis v, which has become separated into dorsal and ventral
portions by the growth and fiattening out of the arytenoids—the homologues
of the fifth branchial bars.
Géppert (1898) abandoned his theory of 1894 that the Laryngeus ventralis
is derived from the Transversus ventralis iv, and stated that they are serially
homologous, the Laryngeus ventralis being the Transversus ventralis of a
fifth branchial branch and homologous with the Transversus ventralis v of
Acipenser and the Transversus ventralis posterior of Amia. The Laryngeus
dorsalis is possibly derived from the same source.
Driiner (1901 and 1904) was of opinion that the Laryngei and Constrictor
are homologous with a Transversus ventralis vi, or possibly with that of a
still more posterior segment which has migrated forwards to that of the
Dilatator laryngis and Arytenoid. The grounds for this opinion were derived
from its innervation. The Dilatator laryngis is innervated in all cases from ~
the N. intestino-accessorius X (with the addition, in Amphiuma and Siren,
of branches from the N. recurrens, and in Menopoma of a fine twig from the
nerve to the fourth branchial arch). On the other hand, the Laryngei and
Constrictor are innervated by the N. recurrens intestinalis X. The N. recurrens
intestinalis X is thus a collecting nerve in which the elements of at least two,
perhaps more, branchial segments are included, and of these at least one is
to be reckoned as being behind the segment of the Dilatator laryngis.
These observers have advanced various theories as to the primitive form
of the intrinsic laryngeal muscles in Urodela.
Wilder (1892) considered as typical the condition present in Siren and
Menopoma where the larynx is surrounded by a complete muscle-ring and
the arytenoids are partly enclosed by it and partly lie in its substance. In
1896, after publication of Géppert’s 1894 paper, he stated “I hardly feel like
considering the Sphincter of Salamandridae as more than a modification of
the original Laryngei and of thus considering the laryngeal ring of Triton as
essentially different from that of Siren or of Necturus.”
Géppert (1894) was of opinion that the primitive Urodelan condition is
Hypobranchial and Laryngeal Muscles in Amphibia 135
shown by Necturus and Proteus, where there are only Laryngei, attached to
a broad arytenoid, and that the Caducibranchiata (other than Amphiuma),
with a Constrictor and Laryngei attached to the tendon of the Dilatator
laryngis, represent a derivative condition due to a diminution in breadth of the
arytenoid. This was supported by observations on Siredon (in which no
Laryngeus dorsalis is found). In 13-5 mm. specimens he found a great number
_ of young muscle-elements dorsal to the already formed Laryngeus ventralis,
and in 18mm. specimens the primordium of the Constrictor was represented by
a small bundle of young muscle-elements dorsal to the Laryngeus ventralis with
its median end spreading towards the dorsal median line of the larynx. Similarly,
in 10mm. larvae of Triton alpestris he found the Constrictor being proliferated
from the Laryngeus ventralis. In 1898 he modified this opinion as regards
_ Tritom saying that he could now not exclude the Laryngeus dorsalis from
_ taking part in the formation of the Constrictor, and that the method followed
in Siredon was due to the absence of a Laryngeus dorsalis.
G6ppert regarded the Constrictor of Amphiuma as due to the lateral union
on each side of a Laryngeus dorsalis and ventralis.
Driiner regarded the condition of Siredon, Salamandra, and Triton—with
Laryngei and Constrictor—as the primitive one, and that of Necturus and
-Proteus—with Laryngei only—as secondary. Further, Wilder had stated
that, in Necturus, the first and last sections of a transverse series show con-
tinuous fibres of a circular cutline entirely enclosing the Laryngei and acting
as a Constrictor, and Driiner stated that in one case of Proteus he found the
rudiment of a Constrictor on one side.
OBSERVATIONS
Ventral branchial muscles
Anura. Ina7 mum. larva of Rana temp. there are four branchial muscle-
plates. That in the first branchial segment (fig. 1) has separated from the
pericardium and consists, from below upwards, of the primordia of the Sub-
arcualis rectus i, Marginalis i, and Levator i. The second, third and fourth
branchial muscle plates (figs. 2, 3) are continuous, ventrally, with the peri-
cardial wall. The fourth lies slightly posterior to the sixth gill-cleft.
In a 7} mm. larva the second, third and fourth branchial muscle plates
have separated from the pericardial wall. From the ventral ends of the
second and third, Subarcuales recti ii and iii have separated off. From the
ventral end of the fourth (figs. 5 and 6) Subarcualis rectus iv has separated off
and the (rudimentary) Transversus ventralis iv passes ventro-medially. Each
Subarcualis rectus extends forwards into the next segment.
In an 8 mm. larva Subarcuales recti i and ii have fused together forming
a muscle passing from Branchiale ii to the Hyale. The Transversus ventralis
iv (figs. 8, 9, 10) is better marked, passing towards the ventral aspect of the
laryngeal groove.
9—2
136 F. H. Edgeworth
In an 11 mm. larva (fig. 11) a muscle, passing from Branchiale i to the
Hyale, has separated from the forepart of the muscle passing from Branchiale
ii to the Hyale. The Subarcuales recti iii and iv have nearly fused together
(fig. 12), and, in a 12 mm. larva, form a muscle passing from Branchiale iv to
Branchiale ii. The Transversus ventralis iv has disappeared.
It is observable that the fourth branchial muscle-plate, before separation
from the pericardium, shifts a little backward so as to lie posterior to the
(rudimentary) sixth gill-cleft, and, when the fourth branchial bar becomes
formed in an 8 mm. larva, it passes backwards external and posterior to the
sixth gill-cleft.
Transversus ventralis iv is rudimentary and disappears early; it never
forms an independent muscle passing from Branchiale iv to the middle line.
It is also absent in larvae, of lengths from 10 to 12 mm. of Bufo lentig., Alytes,
and Pelobates.
Gymnophiona. The development of the ventral branchial muscles has
not yet been traced, but Fischer, Wiedersheim, Fiirbringer and Géppert have
partially described them.
In 3-5 and 5-9 cm. larvae of aitosias (figs. 28-25) all four branchial
bars are present, the third and fourth being fused at their ventral ends.
Copula i, s. Basihyale and Copula li, S. Basibranchiale i are present. Sub-
to the next sateiee one. The fonsinpets Sobarwanlis rectus i—is broader
than those behind, and, as it passes forward, divides into two portions, the
inner of which is inserted into the Hyale, whilst the outer is prolonged in
front of the Hyale and is inserted into the lateral edge of the Basihyale.
In a 7 em. larva of Siphonops (figs. 26-31) the third and fourth branchial
bars are fused, except at their dorsal ends, and there is no Basihyale. Sub-
arcualis rectus iv is absent. Subarcuales recti iii, ii and i are present. i is
single and inserted anteriorly into the Hyale. In the adult stage Subarcualis
rectus i persists, whilst ii and ili have degenerated into tendons.
The adult stages of Caecilia palmiri and Hypogeophis are similar to the
adult stage of Siphonops.
A Transversus ventralis i (not hitherto described) is present. in larvae of
Siphonops and Ichthyophis. In the former (figs. 26 and 27) its lateral end
is attached to Branchiale i and its median end to a short transverse aponeurosis
which connects it to its fellow. In Ichthyophis (fig. 24) its lateral end is
attached to Subarcualis rectis i, and its median end partially to Copula ii and
partially to a median raphé. The muscle is absent in the adult stages of
Siphonops, Caecilia palmiri and Hypogeophis.
There are no Transversi ventrales ii and iii in the larval stages of Siphonops
and Ichthyophis.
Transversus ventralis iv has been described iy Géppert, in a late larva of
Ichthyophis, as arising by two heads from the fused third and fourth branchial
bars and passing to an aponeurosis ventral to the trachea. In the younger
Hypobranchial and Laryngeal Muscles in Amphibia 137
larvae investigated I find that both heads arise from the fourth bar. In a
7 cm. larva of Siphonops the muscle arises from the nearly completely fused
third and fourth branchial bars by a single head.
_ The differences in the form of Subarcualis rectus i between Ichthyophis
and Siphonops are related to the presence in the former and absence in the
latter of Copula i s. Basihyale. The absence of a Subarcualis rectus iv in
Siphonops may be secondary and related to the greater degree of fusion of
‘the third and fourth branchial bars.
Urodela. In Menopoma seven gill-clefts are developed, and correspondingly
there are five branchial segments. In a larva of 15 mm. (figs. 33, 34) the sixth
and seventh gill-clefts cannot be distinguished from each other; they form a
lateral projection, with a slit-like Jumen, of the branchial endederm, 140u
long, which reaches the ectoderm. In a larva of 17 mm. (fig. 37) the projection
is 160u long, and on its ventral surface is a slight bulge, the first. indication
of the seventh gill-cleft. In a larva of 19 mm. the sixth gill-cleft has disap-
peared on the right side, leaving no trace, whilst on the left side the anterior
end of the sixth gill-cleft persists as an epithelial plug or stump continuous
with the branchial endoderm (fig. 43). Behind this, the seventh gill-cleft
reaches the ectoderm, on both sides (fig. 44). The distance between the
anterior end of the fourth and that of the fifth gill-cleft is 1704. On the right
side the distance between the anterior end of the fifth and that of the seventh
gill-cleft is 2804; on the left side the distance between the anterior end of
the fifth gill-cleft and the stump of the sixth is 180u, and the distance
between that and the anterior edge of the seventh gill-cleft is 110p.
The length of the third branchial segment (between the fourth and fifth
gill-clefts) is thus 170u, that of the fourth branchial segment is 180y, that
of the fifth branchial segment is 1104. The fifth branchial segment, which
does not contain any branchial muscle-plate, or branchial bar, or branchial
aortic arch, is thus shorter than the more anterior ones.
The seventh gill-cleft, which does not perforate, is present in larvae in
this stage up to one of 22 mm.; it has disappeared in larvae of 24 mm. without
leaving any trace. The stump of the sixth gill-cleft on the left side persists
in larvae up to the length of 28 mm. In one of 32 mm. it has become detached
from the endoderm.
Four branchial muscle plates are developed, in the first four branchial.
segments. In a larva of 15 mm. (figs. 32, 33) those in the first three segments
have become detached from the pericardial epithelium, whilst that of the
fourth branchial segment is still continuous with it. The primordium of the
hypobranchial spinal muscles forms a continuous column, and extends as
far forwards as the hyoid segment. In a larva of 17 mm. (fig. 36) the fourth
branchial muscle-plate has also become detached from the pericardial epi-
thelium. These muscle plates lie lateral to the branchial bars, which have
begun to develop. The ventral portions of the branchial muscle-plates form
the Subarcuales, and, in the fourth branchial segment, the Transversus
ventralis as well. The primordium of the hypobranchial spinal muscles has
138 F. H. Edgeworth
extended forwards to Meckel’s cartilage and separated into Genio-hyoid and
Sterno-hyoid. The hind end of the Genio-hyoid has grown backwards a little,
ventral to the Sterno-hyoid. In a larva of 18 mm. (fig. 38) (in which the
sixth gill-cleft is still continuous with the ectoderm) the Subarcualis rectus iv
has begun to grow forward. Its hind end is continuous with the lateral end
of the Transversus ventralis iv which has begun to grow transversely inwards
(fig. 39). In a larva of 19 mm. Subarcualis rectus i has grown forwards to the
second gill-cleft, Subarcuales obliqui ii and iii have grown forwards and down-
wards and meet, laterally to the Sterno-hyoid (fig. 42). The fourth branchial
bar now passes from the fourth branchial segment backwards, outside the
stump cf the sixth gill-cleft on the left side, into the fifth branchial segment,
and then upwards; i.e. on the total or partial atrophy of the sixth gill-cleft
it bulges backwards into the fifth branchial segment (figs. 48, 44). Corre-
spondingly, the hind end of the Subarcualis rectus iv and the lateral end of
the Transversus ventralis iv have shifted back into the fifth branchial
segment (figs. 48, 44). The front end of Subarcualis rectus iv has grown for-
wards into the second branchial segment. The Transversus ventralis iv has
now further developed, and passes transversely inwards to the middle line,
on the left side under, and behind, the stump of the sixth gill-cleft. In a larva
of 22 mm. the Urobranchiale has developed (see later, p. 141), and the hind
end of the Genio-hyoid has grown further back. In a larva of 24 mm., where
the seventh gill-cleft has disappeared, the hind end of Subarcualis rectus iv
and the lateral end of Transversus ventralis iv are relatively further back,
with the result that the anterior edge of Transversus ventralis iv is oblique
and lies, on the left side, posterior to the stump of the sixth gill-cleft (figs. 48,
49). The anterior end of Subarcualis rectus iv (a) reaches the first branchial
bar, whilst off-shoots (b and c) are given off to the second and third branchial
bars (fig. 51). The Subarcuales obliqui ii and iii unite and pass to the sheath
of the Sterno-hyoid.
There is little further change in the Subarcuales; in a 82 mm. larva the
ventral end of the second gill-cleft is shallower and the anterior end of Sub-
arcualis rectus i is attached to the Ceratohyale. Transversus -ventralis iv
gradually spreads backwards, forming a broad sheet; in a 34 mm. larva its
posterior edge underlies the Laryngeus ventralis. In the adult (Driiner) the
muscle underlies the trachea.
Miss Platt (1897) stated that in Necturus Subarcualis rectus i is developed
from the ventral end of the mesothelial tissue of the glosso-pharyngeal arch.
Subarcualis obliquus ii grows forwards from the mesothelium of the first
vagus arch near the point where this tissue joins the wall of the pericardium.
Subarcualis iii (a and b) arises as a single muscle from the wall of the peri-
cardium in the region where the mesothelium of the second vagus arch unites
with the pericardial wall.
She did not mention the Transversus ventralis iii, nor state how many
gill-clefts are developed, but the figures given show five.
My observations in regard to the Subarcuales of the first two branchial
Hypobranchial and Laryngeal Muscles in Amphibia 139
arches coincide with those above stated, but they are a little different in
regard to the number of gill-clefts and the development of the third branchial
muscle-plate.
cs In a larva of 12 mm. there are five gill-clefts—the sixth not being yet
_ developed. In a larva of 13 mm. the fifth gill-clefts are reduced to stumps
attached to the endoderm, on both sides, and the sixth gill-clefts have developed
_ and reach the ectoderm. The length of the third branchial segment (between
the fourth and fifth gill-clefts) is 120u, that of the fourth is 90u. In a larva of
15 mm. the sixth gill-clefts have disappeared leaving no trace. In a larva of
_ 18mm. the stumps of the fifth gill-clefts have separated from the endoderm,
and in one of 20 mm. the right one has disappeared.
In the larva of 12 mm. (fig. 57) the third branchial muscle-plate is con-
tinuous ventrally with the epithelium of the pericardium. In a larva of 13 mm.
(figs. 60 and 61) the third branchial bar passes backward from the third
branchial segment lateral to the stump of the fifth branchial cleft into the
fourth branchial segment and then upward. The third branchial muscle-
plate has separated from the endoderm, and its ventral end has developed
into the Subarcualis rectus iii and the Transversus ventralis iii. The former
grows forward from the fourth branchial segment laterally to the stump of
the fifth gill-cleft, the latter passes inwards, partly under the stump of the
fifth gill-cleft (fig. 60), and partly behind it (fig. 61). In the larva of 16 mm.
(figs. 67, 68), where the sixth gill-clefts have disappeared, the hind end of
the Subarcualis rectus iii and the lateral end of Transversus ventralis iii are
still further back, so that the front edge of Transversus ventralis iii is
behind the stump of the fifth gill-cleft.
Morphology of the ventral branchial muscles
Subarcuales. Anura. In larvae of Rana the Subarcuales recti are simple.
The only secondary changes are (1) Fusion of Subarcuales recti i and ii to
form a long muscle, and the subsequent separation of a slip from its anterior
half to form a muscle passing from the first branchial to the hyoid bar. (2) The
fusion of Subarcuales recti iii and iv to form a long muscle. The resulting
condition is also present in larvae of Bufo, Alytes, and Pelobates. The con-
dition of the Subarcuales in larvae of Aglossa has not yet been described.
Gymnophiona. The ventral branchial muscles in Siphonops and Ichthy-
ophis have been described above (page 136). These are the only larval forms
yet investigated.
Urodela. Subarcualis rectus i, as shown by Driiner, passes from the first
branchial bar, generally from Ceratobranchiale i to the Ceratohyale. In all
the larvae examined it was found that a delay occurs in the attachment of
the anterior end of the muscle to the Ceratohyale, it is for a time inserted
into the epithelium of the ventral end of the second gill-cleft, which forms a
groove in the floor of the branchial region, e.g. Menopoma (fig. 51). The
Subarcuales obliqui have been described by Fischer and Driiner. The latter
140 | F. H, Edgeworth
states that in Ellipsoglossa (adult), Megalobatrachus. max. (adult), Siredon,
Menopoma (adult), Salamandra and Triton larvae, the muscles pass forwards
and downwards, unite by their bellies or tendons, and are inserted into the
fascia of either the Rectus profundus or superficialis, and so act on the Uro-
branchiale.
Two exceptions to this general rule are described by Driiner. He stated
that in Necturus and Proteus (with only three branchial bars) only one muscle
—Subarcualis obliquus ii—is present, and that this, in Proteus, is inserted
on the fascia of the Rectus profundus, but in Necturus is inserted into Hypo-
branchiale i, i.e. in the latter is a Subarcualis rectus ii, In numerous embryos,
however, I find the muscle inserted into the fascia of the Rectus profundus
(fig. 66), i.e. it is a true Subarcualis obliquus ii. The other exception is that
of Amphiuma (adult), where Driiner stated that only one Subarcualis obliquus
is present, passing from Ceratobranchiale iii to Branchiale i and not to the
fascia of the Rectus.
I find that in Menopoma (larva) and Ellipsoglossa (larva) the common
tendon of Subarcuales obliqui ii and iii is inserted partly into the sheath of
the Rectus profundus and partly into the Urobranchiale.
The above can be summarised as follows: In Urodela, with exception of
Amphiuma (adult form), the Subarecuales of the second and third branchial
bars (or, in the case of Necturus and Proteus, that of the second bar) do not
grow forward to the next anterior bar, as in Anuran and Gymnophionan
larvae, but forward and downward, becoming Subarcuales obliqui, joining
together and passing into a tendon which has direct or indirect relations to
the Urobranchiale.
A Urobranchiale, either continuous with the branchial skeleton or as a
separate structure, has been described by Driiner in all the Urodela he
examined, with exception of Menopoma (adult), Megalobatrachus max. (adult),
Amphiuma (adult), and Ellipsoglossa (adult). In the larvae of Menopoma
and Ellipsoglossa, however, a Urobranchiale is present, as a structure either
separate or continuous with the branchial skeleton. In these two forms, there-
fore, the Urobranchiale disappears at metamorphosis or earlier (it has already
degenerated in a 40 mm. Menopoma), and this may also be the case in Megalo-
batrachus max. and Amphiumal!, for its development appears to be related to
the overlapping of the anterior end of the Sternohyoid s. Rectus cervicis by
the Geniohyoid—which is universal in Urodela. This overlapping is due to
a backward growth of the hind end of the Geniohyoid ventral to the Sterno-
hyoideus s. Rectus cervicis.
The development of the Urobranchiale is not uniform in Urodela. Stéhr
(1880) described it in Triton as due to division into dorsal and ventral portions
of an original primordium connecting together the median ends of the hyoid
and first two branchial bars. Miss Platt (1897) described a second Basi-
1In 45 mm. larvae of Amphiuma (Hay) the second Basibranchiale and Urobranchiale are
both absent.
ee ee ee ee ee
By she anc SS Sane sia
tS ce
Hypobranchial and Laryngeal Muscles in Amphibia 141
branchiale in Necturus as developing from cells on the anterior wall of the
pericardium. She inclined to regard it as a foreign element associated
secondarily with the branchial arches. Gaupp (1905) pointed out the homology
of this “second Basibranchiale” of Necturus with the Urobranchiale of
Salamandridae larvae, but added that it was not yet shown whether it
represents an independent Basibranchiale, which in Salamandridae larvae
develops in concrescence with the anterior Basibranchiale. .
I find that the hyobranchial skeleton of a 12 mm. larva of Ellipsoglossa
(figs. 71 and 72) is in a precartilaginous condition. The median ends of the
hyoid and first and second branchial bars are continuous ventrally with a
median rod which represents the first and second Basibranchialia. The
Urobranchiale is a ventral process of the second Basibranchiale.. In a 15 mm.
larva (figs. 73-76) chondrification has taken place; the Urobranchiale has
extended ventro-posteriorly, and the attachment of the second branchial
bars has spread along it.
The development of the Urobranchiale in Triton, Salamandra, and
Amblystoma, is similar to that in Ellipsoglossa.
In a 20 mm. larva of Menopoma (fig. 46) the Urobranchiale is a ventro-
posterior process of the precartilaginous second Basibranchiale. It has
separated from the second Basibranchiale in a 22 mm. larva, and is chondrified
as a separate structure in a 32 mm. larva (figs..53 and 54). This condition
persists in a 36 mm. larva. In a larva of 40 mm. it has degenerated into a
small clump of cells. In the adult it is absent (Driiner).
In Necturus no second Basibranchiale is developed. In an embryo of
16mm. (figs. 64-66) the Urobranchiale is a precartilaginous rod passing
ventro-posteriorly from its junction with the ventral ends of the first branchial
bars.
The Urobranchiale may thus be developed (1) as a ventro-posterior process
of the second Basibranchiale (Ellipsoglossa, Triton, Salamandra, Amblystoma),
(2) as a ventro-posterior process of the second Basibranchiale which separates -
off and subsequently chondrifies (Menopoma), (3) as a structure passing ventro-
posteriorly from the ventral ends of the first branchial bars, no second Basi-
branchiale being present (Necturus).
The attachment of the ventral end of the first branchial bar extends along
the Urobranchiale in Ellipsoglossa, Triton, Salamandra, and Amblystoma,
but does not do so in Necturus.
These phenomena suggest that some ancestral Urodelan stock possessed
a Urobranchiale as a ventral process of the second Basibranchiale, with no
extension of the ventral end of the first branchial bar along it—i.e. a condition
very like that of a 12 mm. Ellipsoglossa or 20 mm. Menopoma.
Subarcualis rectus iv has been described by Fischer and Driiner. The
latter states that it is present in the larval stages of Siredon, Salamandra and
Triton, and in the adult stages of Amphiuma and Menopoma: but is absent
in the adult stages of Siredon, Salamandra, Triton, Megalobatrachus max. and
142 FH, Edgeworth
Ellipsoglossa. My observations show that it is also present in the larval stages
of Ellipsoglossa and Menopoma.
It is a muscle that takes origin from the fourth branchial bar, passes
forward and separates into three slips (a, b, c) which are attached respectively
to the first, second and third branchial bars. In Siren only (a) is present.
In Necturus and Proteus there is a similar Subarcualis rectus iii which takes
origin from the third branchial bar, and is attached, (a) to the first, and (b)
to the second, branchial bar.
The forward extension of Subarcualis rectus iv in front of the third
branchial bar—to the second and first bars—is related to the secondary
function and position of Subarcuales ii and iii. (It is noticeable that this
secondary form of Subarcualis rectus iv also exists in Amphiuma (adult), and
that in Megalobatrachus max. (adult, with only two branchial bars) though no
Subarcualis rectus iv is present yet Subarcuales obliqui ii and iii and not
Subarcuales recti ii and iii are present (vide Driiner). These facts form
additional evidence in favour of the theory, suggested above, that a Uro-
branchiale exists in the larval forms of these Urodela also.)
There are thus five closely related phenomena in Urodela. (1) Backward
growth of the hind end of the Genio-hyoid ventral to the forepart of the
Rectus cervicis. (2) Formation of a Urobranchiale. (3) Formation of Sub-
arcuales obliqui li and i (Subarcualis obliquus ii in Necturus and Proteus).
(4) Forward extension of Subarcualis rectus iv (Subarcualis rectus ij in Nec-
turus and Proteus) to the first branchial bar. (5) Separation of a superficial,
ventral, portion of the Rectus cervicis, attached to the Urobranchiale.
No one of these secondary phenomena occur in Anuran and Gymnophionan
larvae, wheré the conditions are more primitive. (There is a small overlap
of the Genio-hyoid and Rectus cervicis in Rana temp. larvae, but it is due to
a backward extension of the former along the hypobranchial plate, and so of
a different character from that of Urodela. The anterior end of the Rectus
becomes attached to the Crista hyoidea (of Schultze), but this, as shown by
Gaupp, is a ventral process of Basibranchiale i, and so not homologous with.
- the Urobranchiale of Urodela.)
Transversi ventrales. Transversus ventralis i is present in larvae of Ichthy-
ophis and Siphonops, but not in Anuran or Urodelan larvae. 'Transversus
ventralis ii is not found in any Amphibia. Transversus ventralis ili is present
in Necturus, and probably in Proteus, but not in other Amphibia. Transversus
ventralis iv is present in larvae of Anura, Gymnophiona, and Urodela with
four branchial bars. In Rana the muscle is rudimentary and soon disappears.
In Ichthyophis it is attached to the fourth branchial bar, and, on the fusion
of this with the third, to the fused bar, by two heads in Ichthyophis, by one
in Siphonops. |
In Menopoma, at the stage when the sixth gill-cleft reaches the ectoderm,
the ventral end of the fourth branchial muscle-plate (attached to the peri-
eardial wall) and the primordium of the fourth branchial bar are in front of
-
Hypobranchial and Laryngeal Muscles in Amphibia 143
_ it and do not extend outside or behind it. When the gill-cleft is reduced to
stump, the fourth branchial bar passes outwards and backwards laterally to
the stump, then upwards and posterior to it, and correspondingly the pri-
mordia of the Subarcualis rectus iv and Transversus ventralis iv have migrated
posterior to the stump, and from this point grow forwards and inwards
respectively.
_ The whole series of events is due to an enlargement of the “branchial
basket,” whereby all the structures of the fourth branchial segment bulge
backwards behind the stump of the sixth gill-cleft.
_A similar series of events is observable in Rana, where—the sixth gill-cleft
being never more than a stump— it occurs relatively earlier, before the ventral
of the fourth branchial muscle-plate separates from the pericardial wall.
In Necturus a similar series of events occurs in regard to the third branchial
muscle-plate and the fifth gill-cleft. Only one Transversus ventralis is formed,
i.e. the third. Transversus ventralis iii or iv subsequently extends backwards
oneal a broad sheet which underlies, to a variable extent, the respiratory
tract (vide p. 128).
_ The above mentioned developments of Transversi ventrales may be
cites as follows:
d 3rd 4th branchial segment
x
-
coooP
ox oo
x
mae ee ree a | x
_ Necturus and Proteus es ee 0
Urodela with 4 branchial bars 0 x
The theory of Wilder (vide supra, p. 128) is supported by these facts.
It has to be remarked, however, that the Intermandibularis and Interhyoideus
are probably not serially homologous with the Transversi ventrales of the
branchial segments; and, further, that the phenomena in Necturus and
Proteus possibly admit of an explanation other than that of the persistence of
an ancestral feature which is lost in other Amphibia (vide infra, p. 147). His
theory, then, should be limited to the branchial region, and restated as follows:
primitively in Amphibia there was a series of ventral transverse muscles
attached to the branchial bars.
adduced as additional evidence in favour of the theory.
Summary of the characteristics of the ventral branchial muscles
_ The Subarcuales are developed by forward growth of the ventral ends
of the branchial muscle-plates.
__ In some primitive ancestral stock they probably formed a series of longi-
tudinal muscles, the Subarcuales each passing from its branchial bar to the
next in front.
_ In Anuran and Gymnophionan larvae few modifications occur. In Anuran
larvae Subarcuales recti i and ii unite, forming one muscle, and subsequently
144 F. H. Edgeworth
a lateral portion is separated from the anterior part and passes from the
Branchiale i to the Hyale; and Subarcuales recti iii and iv unite forming one
muscle. As regards Gymnophiona, in Siphonops larvae, where there is no
Basihyale, Subarcualis rectus i is single, whereas in Ichthyophis larvae, where
a Basihyale is present, Subarcualis rectus i separates into two muscles. In
Urodela, whilst Subarcualis rectus i remains single, considerable modifications
occur in the hinder subarcuales—probably associated with the backward growth
of the Genio-hyoid and the formation of a Urobranchiale. These changes are,
shortly, an insertion of Subarcuales ii and iii to the Urobranchiale directly or
indirectly, so that they form Subarcuales obliqui ii and iii (in Necturus and
Proteus ii only), and an extension forwards of the hindmost Subarcualis rectus
(fourth in Urodela with four branchial bars, third in Necturus and Proteus) to
Branchiale i.
*Transversi ventrales are formed by ingrowth from the ventral ends of the
branchial muscle-plates. Transversus ventralis i is present only in Gymno-
phionan larvae. Transversus ventralis iv (iii in Necturus and Proteus) is
formed in all Amphibian groups, though it is rudimentary and soon disappears
in Anuran larvae; it spreads backwards, forming a broad sheet, which in
part or wholly underlies the respiratory tract.
Innervation of the ventral branchial muscles
Anura. The account given by Strong is not detailed, but he states that
the Recurrens does not spread into the branchial region.
Gymnophiona. Norris and Hughes state that in Herpele (adult) the
Recurrens innervates the Transversus ventralis iv in addition to the laryngeal
muscles. In a 7 cm. larva of Siphonops, and in 3-5 and 5-9 cm. larvae of
Ichthyophis I find that the Recurrens innervates the same muscles as in
Herpele, i.e. it does not extend into the branchial region nor does it innervate
the Subarcuales recti and Transversus ventralis i.
Urodela. Driiner stated that Subarcualis rectus i is innervated solely
by the ix in Menopoma, Megalobatrachus max., and Necturus. It has an
additional nerve supply from the hinder branchial nerve or nerves and the
Recurrens intestinalis in other Urodeles. Subarcualis obliquus ii in Necturus
is innervated by the second branchial nerve, in Proteus by this and probably
also by the Recurrens. Subarcuales obliqui ii and iii in Ellipsoglossa and
Menopoma are innervated by the second and third branchial nerves, in Megalo-
batrachus max. and Siredon by these and the Recurrens, in Salamandra and
Triton by the Recurrens, in Siren ii by the second branchial nerve and iii
by the Recurrens. In Amphiuma the single Obliquus is innervated by the
second branchial nerve and the Recurrens.
Subarcualis rectus iv is absent in the adult forms of Ellipsoglossa, Megalo-
batrachus max., Siredon, Salamandra and Triton; in Menopoma (adult) a and b
are innervated by the second and third branchial nerves, c by the fourth
branchial nerve and the Recurrens; in Siredon (adult), Amphiuma (adult),
Hypobranchial and Laryngeal Muscles in Amphibia 145
Salamandra and Triton larvae, a is innervated by the second branchial nerve
and the Recurrens, b by the third branchial nerve and the Recurrens, ¢ by the
Recurrens; in Siren a (the only one present) is innervated by the second
branchial nerve and the Recurrens. Transversus ventralis iii of Necturus
and Proteus, and Transversus ventralis iv of other Urodeles, are innervated
_ by the Recurrens. Driiner, as stated above p. 129, inferred from these facts
that the Transversus ventralis ili or iv had migrated forward into the branchial
region, and that a similar though less marked migration had taken place in
_ the muscle-elements of the Subarcuales. Norris, holding with Driiner that
the nerves are the most conservative structures in the branchial region, and
“will thus constitute more reliable guides in the search for the primitive
relations in this region than will the branchial arches themselves,” states
that there is “‘a considerable usurpation by the Ramus intestino-recurrens of
territory of the ventral branchial region belonging originally to the post-
trematic rami of the branchial nerves.”
It is doubtful whether this statement implies a forward migration of
muscle-elements, as Driiner thought; or a forward extension of nerve-fibres,
the muscle-elements remaining constant.
_ But, however that may be, the phenomena of development show that
___ the Transversus ventralis iv and the Subarcuales are developed from the
_ ventral ends of the branchial muscle-plates.
. It may be inferred that the ventral branchial muscles are more conservative
_ than are their nerves.
_. Three processes appear to have occurred. (1) A disappearance of the
_ ventral motor branches of the branchial nerves, in increasing degree from
before backwards. (2) An additional or supplanting innervation by the
Recurrens. (3) In the case of the Subarcualis rectus iv an innervation by the
nerves of the branchial arches into which it grows—thus, in Menopoma,
_ Subarcualis rectus iv (a)—which grows forward to the first branchial bar—
is innervated by the second branchial nerve, (b)—which grows forward to the
second branchial bar—by the third branchial nerve, (¢)—which grows forward
to the third branchial bar—-by the fourth branchial nerve and the Recurrens.
Comparison of the innervation of the ventral muscles of the branchial
_ bars in Anuran, Gymnophionan and Urodelan larvae shows that the secondary
—additional or supplanting—innervation by the Recurrens intestinalis has
been developed within the Amphibian phylum, and to the greatest extent
in Urodela.
On the number of branchial bars and related muscles in Amphibia
Maurer (1902) described five gill-clefts and a post branchial body in Am-
phibia, and Driiner (1901) (vide supra, pp. 129, 130) six gill-clefts. Kingsley},
1 Kingsley names the clefts: (2) hyomandibular, (5) the first branchial, (c) the second branchial,
_ (d) the third branchial, in front of the fourth cartilaginous gill-arch, and then two pits behind this
arch—these, according to his statement are the fifth and sixth—according to the reckoning adopted
here, the sixth and seventh gill-clefts,
146 F. H, Edgeworth
however, had stated (1892) that in an embryo Amphiuma (size not stated)
there were two pits behind the fourth cartilaginous gill-arch, i.e. five branchial
segments. Marcus (1908) stated that in larvae of Hypogeophis seven gill-
clefts are developed (vide infra, p. 149), i.e. five branchial segments.
In Menopoma and Ellipsoglossa seven gill-clefts are developed, the last
two behind the fourth branchial bar and its muscles. No muscle-plate or
cartilaginous bar is developed in this fifth branchial segment.
The sum of this evidence suggests that five branchial bars with related
muscles existed in Amphibian ancestors, but that the fifth disappeared long
ago.
Driiner (vide supra, pp. 129, 130) came to the conclusion that Urodeles
originally possessed a greater number of branchial arches than four. The
evidence merits discussion. As regards the nerves found by him, it is possible
that they have relation solely to the sixth and seventh gill-clefts. As regards
the muscles, the phenomena of development do not bear out the theory that
the stump of the sixth gill-cleft separates a Transversus ventralis iv from a
Transversus ventralis v. Thus in Menopoma there is only one primordium
developed—that of Transversus iv. This, at first, lies solely in the fourth
branchial segment, then under the stump of.the sixth gill-cleft, then posterior
to it. The variation is due to the fact that, on the partial atrophy of the
sixth gill-cleft, the Transversus iv, the hind end of Subarcualis rectus iv, and
the fourth branchial bar, migrate into the fifth branchial segment; and, on
the atrophy of the seventh gill-cleft, still further back. There is a similar
progressive variation of the Transversus iv in relation to the sixth gill-cleft
in Ellipsoglossa, and of Transversus iii in’ relation to the fifth gill-cleft in
Necturus. The evidence, as regards muscle elements, is thus limited to the
discovery of a Levator arcus v on one side in one larva of Triton. I have not
seen this, however, in the many larvae of Menopoma, Ellipsoglossa, and
Triton crist. I have examined.
It is probable, therefore, that the case described by Driiner is an instance
of fluctuation, possibly of atavistic fluctuation, from the usual number of
_four branchial bars and related muscles in Urodela.
In support of these conclusions, it may be added that in Lysorophus—
a member of the ancestral Urodeles, from the Pennsylvanian deposits—
Sollas found only four branchial bars, the first three consisting of cerato-
branchial and epibranchial elements, and the fourth of a train of fragments.
The case of Necturus, with only three branchial bars and related muscles,
probably comes under a different category. All Amphibia, with exception of
Megalobatrachus max. (adult), Necturus and Proteus, have four branchial bars
and related muscles. Megalobatrachus max. has two branchial bars in the
adult state (Driiner), but only the early stages of larval development have
been published hitherto—by de Lange. In Necturus the development, described
above, permits of comparison with Menopoma.
In Menopoma seven gill-clefts are formed, all of which reach the ectoderm.
Hypobranchial and Laryngeal Muscles in Amphibia 147
_ The sixth disappears on the right side, whilst on the left side it forms an epi-
_ thelial stump continuous with the endoderm. This becomes detached later
on. The seventh disappears on both sides, without leaving any remnant. The
_ fourth (and last) branchial muscle-plate lies, at first, anterior to the sixth
- gill-cleft. No muscle-plate is developed in the fifth branchial segment.
In Necturus six gill-clefts are formed, all of which reach the ectoderm.
_ The fifth become detached from the ectoderm on both sides and form epithelial
_ stumps continuous with the endoderm. They become detached later on. The
sixth gill-clefts disappear on both sides and leave no trace. The third (and
last) branchial muscle-plate lies, at first, anterior to the fifth gill-cleft. No
_muscle-plate is developed in the fourth branchial segment.
| The differences in the ventral branchial muscles are as follows: (1) In
_ Menopoma there is a Transversus ventralis iv, and no Transversus ventralis iii.
In Necturus there is a Transversus ventralis iii, and no Transversus ventralis iv.
(2) In Menopoma two Subarcuales, i.e. the second and third, become Sub-
_arcuales obliqui ii and iii. In Necturus only one Subarcualis, i.e. that of the
second branchial arch, becomes a Subarcualis obliquus ii. (3) In Menopoma
-Subarcualis rectus iv extends forward to Branchiale i. In Necturus it is
_ Subarcualis rectus iii which extends forwards to Branchiale i.
_ There is so great a similarity between the muscles of the fourth branchial
_ segment in Menopoma and those of the third branchial segment of Necturus,
that it is improbable that the difference is due to transformation of the
_ characteristics of the third branchial arch musculature of Menopoma into
those of the third of Necturus, or conversely; nor is there any evidence of the
_ dropping out, or intercalation, of a branchial bar between the first and last.
_ This suggests that a common branchial muscle-plate has been separated
_ into four portions by the gill-clefts in Menopoma; whilst in Necturus it has
_ been separated into three portions by the gill-clefts.
No one branchial bar of Necturus, with its related muscles, is thus exactly
- homologous with any one branchial bar of Menopoma, and it is only possible
to speak of a collective homology.
_ Branchial segments may thus be reduced in number by at least two
processes, by a separation of the branchial area into a fewer number of seg-
ments without loss of any one individual segment, or by a loss of the ultimate
segment. The former is apparently what happens in Necturus and Proteus,
as compared with Menopoma and Ellipsoglossa. The latter is apparently
_ what happens in Amphibia generally, as compared with Dipnoi. In Dipnoi
there is a fifth branchial bar and related muscles. In Menopoma and Ellipso-
_ glossa there is an empty fifth branchial segment. In Rana there is no develop-
_ mental evidence of a fifth branchial segment. The existence in Necturus of
an empty fcurth branchial segment suggests that the mutation to three
_ branchial segments took place subsequent to the loss of a fifth branchial
_ bar and related muscles.
After formation of the full number of segments, the branchial region may
148 : F. H. Edgeworth
become shorter by fusion. Thus Sarasin showed that, in Ichthyophis, the
third and fourth branchial bars coalesce. Comparison of the 5-9 em, larva
of Ichthyophis with the, relatively later, 7 cm. larva of Siphonops suggests
that this is accompanied by fusion of Levatores iii and iv, and by disap-
pearance of Subarcualis rectus iv.
Development of the larynx and laryngeal muscles
Greil stated that in Urodelan and Anuran larvae the lungs are developed
from bilateral longitudinal grooves on the inner surface of the floor of the
_ oesophagus, forming with each other an angle of about 40°, open caudally.
These grooves develop at a period when only four gill-clefts are present; the
fifth and sixth being formed later, between the fourth and the primordia of
the lungs. The pulmonary grooves form pocket-like diverticula, which grow
backwards in the thickened splanchnopleure and develop into the primitive
pulmonary sacs. The pulmonary grooves are put into communication with
each other by a transverse or bifurcation groove. The ventral portion of the
wall of the oesophagus, in front of the bifurcation groove, forms by approxima-
tion of its walls the longitudinal laryngo-tracheal groove. It is continuous
posteriorly with the bifurcation groove. In Anura it becomes temporarily
closed by union of its walls, and is subsequently hollowed out into the laryngo-
tracheal groove. The pulmonary and bifurcation grooves are folded off on
their dorsal and caudal side from the oesophagus.
In Anura the sixth gill-clefts remain rudimentary and have no connection
with the ectoderm; in Bombinator they atrophy, in other Anura the ultimo-
branchial bodies are formed from their ventral portions. In Ranidae and
Bufonidae the lumen of the anterior part of the oesophagus becomes tem-
porarily obliterated and subsequently opens out—latér than does the laryngo-
tracheal cavity.
In Urodela (Triton, Salamandra, Siredon) the sixth gill-clefts, which are
also transitory, reach the ectoderm-bands which grow towards them and
fuse for a short distance. Rupture to the exterior does not take place. The
ultimo-branchial body is developed from the left sixth cleft.
Greil did not investigate the development of the laryngeal-muscles.
Anura. Ina7 mm. larva of Rana temp. (figs. 3, 4, 5), the laryngeal groove
extends from 75 behind the sixth gill-clefts, where it passes into the transverse
pulmonary groove, forwards to 15yu behind the sixth gill-clefts. Like the oeso-
phagus above, it has no lumen. The coelom extends dorsally on either side
of the transverse groove to the side of the oesophagus, but does not do so
laterally to the laryngeal groove. Many undifferentiated cells are visible on
either side of the oesophagus and laryngeal groove, proliferated from the
visceral layer of the coelom (figs. 4, 5).
In a 74mm. larva the laryngeal groove extends from 67y behind to the
level of the sixth gill-clefts. On either side of the laryngeal groove is seen
Oe
Hypobranchial and Laryngeal Muscles in Amphibia 149
the primordium of the laryngeal muscles, partially separated into the Con-
strictor and Dilatator laryngis (figs. 6, 7). It extends from 82u behind to
22u behind the sixth gill-clefts.
In an 8 mm. larva (figs. 8, 9, 10) the laryngeal groove extends from 604
behind to 7y in front of the sixth gill-clefts. There is a lumen in its ventral
part, continuous with that in the transverse groove. The laryngeal muscles
_ (figs. 9, 10) are fully formed, and extend from 127 behind to 15 behind the
sixth gill-clefts. The Constrictor meets its fellow dorsally and ventrally.
In an 11 mm. larva (figs. 13-16) the laryngeal groove extends from 22y
behind the sixth gill-clefts to 87 in front of them. The laryngeal muscles
extend from 195 behind to 22 in front of the sixth gill-clefts. The pri-
mordium of the arytenoid s. pars laryngea cart. lat. is visible within the Con-
strictor laryngis. The Constrictor oesophagi is visible lateral, and ventral, to
the forepart of the oesophagus.
The laryngeal groove is thus at first wholly posterior to the sixth gill-clefts,
and gradually extends forwards, so that finally its anterior end is a little in
front of them. The lumen in the transverse pulmonary groove extends for-
wards in the laryngeal groove, which opens by separation of its lips. There is
no trachea. The laryngeal muscles are formed in the splanchnic mesoderm
on either side of the laryngeal groove, and become fully developed behind
the sixth gill-clefts. In their subsequent growth they spread backwards and
forwards, so that the ventral part of the obliquely situated Constrictor
laryngis comes to lie a little in front of the sixth gill-clefts, i.e. in the fourth
branchial segment. There is no migration forwards of the laryngeal muscles.
The Constrictor laryngis posterior is not formed until metamorphosis
begins. In a 20 mm. larva (figs. 18 and 19) there are a number of oval cells in
the angle, open backwards, of the muscle-fibres of the Constrictor laryngis
diverging from the ventral raphé. In a later larva (fig. 20)—one with hind
legs just visible on the surface of the body—these cells have grown into muscle-
cells, which pass upwards and backwards forming the primordium of the
Constrictor laryngis posterior. These phenomena confirm the statement of
Wilder that the Constrictor laryngis posterior is a derivative of the Constrictor
laryngis.
Gymnophiona. In Ichthyophis five gill-clefts were mentioned by the
Sarasins. In Hypogeophis Marcus described seven gill-clefts, of which the
first six break through. The sixth totally atrophy. The seventh do not reach
the ectoderm and form the ultimo-branchial bodies which separate from the
hypoblast and develop into a small vesicle on each side. The primordium of
the lungs is first seen in stage 22 in which the fifth gill-clefts are already formed,
either as two lateral bulges ventral to the gut, of which the left disappears,
or as a right sided one—which (from the figure given) is apparently on the
level of the seventh gill-clefts. Marcus did not describe any later stages in
the formation of the larynx.
G6ppert stated that the laryngeal muscles of a late Ichthyophis larva
Anatomy LIV 10
150 F.. H. Edgeworth
consist of a Dilatator laryngis, a Constrictor laryngis, and a Laryngeus
ventralis. The first-named takes origin from the fourth branchial bar and is
inserted into the lateral process of the Cartilago laryngis; the Constrictor
laryngis consists of two half rings surrounding the Cartilago laryngis just
behind the attachment of the Dilatator; and the Laryngeus ventralis takes
origin from the lateral process of the Cartilago laryngis and passes down-
wards just in front of the Constrictor and meets its fellow in a ventral
median raphé. The existence of a Laryngeus dorsalis was doubtful.
These structures are all present, as described by Géppert, in earlier
Ichthyophis larvae, and in a late Siphonops larva. In both, however, the
existence of a Laryngeus dorsalis is certain (figs. 25, 29, 30).
In adult Siphonops the Laryngei dorsalis and ventralis have disappeared,
and the Constrictor is more developed. In adult forms of Hypogeophis and
Caecilia the Dilatator, Laryngei, and Constrictor are all present.
Géppert also described, in a late Ichthyophis larva, a Hyo-pharyngeus
internus, taking origin from the fourth branchial cartilage and from the
connective tissue lateral to the pharynx and passing round it to a median
aponeurosis between the pharynx and trachea and to the lateral side of the
trachea.
The muscle is present in younger Ichthyophis larvae and in larval and
adult Siphonops. In the 3-5 cm. larva of Ichthyophis the hinder part of the
muscle is overlapped by the anterior edge of the Constrictor oesophagi, and
in the Siphonops larva it is, though present, less developed—incompletely
separated from the Constrictor oesophagi and with no median raphé (fig. 31).
These phenomena suggest that the muscle is a separated portion of the
anterior edge of the Constrictor oesophagi which has gained attachments to
the fourth branchial cartilage.
Géppert described, as one of the laryngeal muscles in a late Ichthyophis
larva, fibres springing from the dorsal fascia and inserted into that covering
the anterior part of the ventral trunk-muscles.
It is not yet developed in 3-5 and 5-9 em. Ichthyophis larvae. In a7 em,
Siphonops larvae it is a slightly marked muscle lying just lateral to and behind
the fused third and fourth branchial cartilages and tendon of Levator iv,
with no dorsal or ventral attachment (fig. 31). In the adult Siphonops it forms
a well-marked muscle arising from the dorsal fascia just behind Levator iv,
and passing downwards outside the fused third and fourth branchial cartilages
to a median raphé just behind Transversus ventralis iv. These phenomena
suggest that the muscle in question is possibly a derivative of Levator iv.
There are, in Ichthyophis larvae and in larval and adult Siphonops, three
muscles arising in common from the dorsal fascia some distance behind
Levator iv—one passes downwards and inwards above the oesophagus, the
second passes downwards laterally to the oesophagus and is inserted into the
fascia on the medial surface of the Rectus and also to a median raphé which
is connected with the skin between the two Recti, whilst the third passes
Lee yea ‘ 2 ud
ee Le OS a ee a a re
Hypobranchial and Laryngeal Muscles in Amphibia 151
downwards and outwards lateral to the Rectus. The muscles do not appear
to have any genetic relation either to the Levatores or to the laryngeal
muscles.
Urodela. In a 15mm. larva of Menopoma (figs. 32-35) laryngeal and
transverse grooves are present, both continuous with the epithelium of the
branchial region and oesophagus. The front edge of the laryngeal groove is
40p in front of the anterior border of the sixth gill-cleft; it is 180m long,
extending back to the level of the hinder border of the (unseparated) sixth
and seventh gill-clefts, where it passes into the transverse groove. In a larva
of 17mm. (figs. 36, 37) the conditions are the same, but, owing to growth,
the laryngeal groove is 200 long. In a larva of 19 mm. (figs. 42-45) the length
a __ of the laryngeal groove is 3304 of which the posterior 30 and the transverse
groove have separated from the oesophagus. The anterior end of the laryngeal
groove is 40u in front of the stump of the sixth gill-cleft, and it passes into
the transverse groove 90u behind the border of the seventh gill-cleft. In a
larva of 22 mm. the length of the laryngeal groove is 330u, of which the
anterior 160y is attached to the epithelium. Its front end is 70u behind the
stump of the sixth gill-cleft, and 110, in front of the seventh gill-cleft. In a
larva of 24 mm. (in which the seventh gill-cleft has disappeared) the anterior
end of the laryngeal groove is 150u behind the stump of the sixth gill-cleft;
in one of 28 mm. it is 260 behind.
Two processes thus take place; a separation, from behind forwards, of the
transverse and hinder part of the laryngeal groove from the oesophagus,
and possibly a subsequent slight backward migration; but in a larva of 22 mm.
_ —the latest in which the seventh gill-cleft is present and demarcation of
_ thebranchial region from the oesophagus thus possible—the anterior end of the
_ laryngeal groove is in the fifth branchial segment and the larynx is situated
in the hindmost branchial segment and the forepart of the oesophagus.
In larvae of 15 and 18 mm. (figs. 32-35 and figs. 38-41) the epithelium of
the pericardium and pericardio-peritoneal ducts, underlying the laryngeal and
transverse grooves, is thickened and proliferating cells which spread up round
those grooves. In a larva of 19 mm. (fig. 45) these cells have increased in
number and spread dorsally round the oesophagus. Those immediately
round the laryngeal groove are undifferentiated, whilst the Constrictor
oesophagi and Dilatator laryngis are slightly marked out by the cells being
long-oval in shape. In a larva of 22 mm. (fig. 47) the Constrictor oesophagi
and Dilatator laryngis are quite distinct from the surrounding splanchnic
mesenchymatous cells. The Dilatator laryngis has spread upwards, its dorsal
end being lateral to the spinal musculature. In a larva of 24 mm. (fig. 50)
the Laryngei are visible in front of the lower end of the Dilatator. In one of
28 mm. (fig. 52), the Constrictor laryngis is visible behind it and the pri-
mordium of the arytenoid is distinguishable.
Ina 12 mm. larva of Necturus the front end of the laryngeal groove is in
the third branchial segment, 50 in front of the fifth gill-cleft; its length is
10—2
152 F. H. Edgeworth
170u. In a larva of 18 mm. the front end of the laryngeal groove is in the
fourth branchial segment, 30u behind the stumps of the fifth gill-cleft, its
length is 704, and it passes into the transverse groove at the posterior edge
of the sixth gill-clefts. In a larva of 15 mm. the front end of the laryngeal
groove is 100u behind the stumps of the fifth gill-clefts, and in one of 17 mm.
150u behind. In subsequent stages the stumps of the fifth gill-clefts have
become detached from the endoderm.
In larvae of 12 and 13 mm. (figs. 57-59, and 60-62) the splanchnie layer of
the coelomic epithelium round the laryngeal and transverse grooves is thickened
and proliferating cells which spread round these grooves and the oesophagus.
In a larva of 15 mm. (fig. 63) the primordia of the Constrictor oesophagi and
Dilatator laryngis are visible in this splanchnic mesoderm. In a larva of 17 mm.
(fig. 69) the Dilatator is more marked and its upper end has spread up laterally
to the spinal musculature. The Laryngei are formed; their lateral ends are
continuous with the Dilatator laryngis and do not arise from the primordium
of the arytenoid. In a larva of 20 mm., the trachea has developed, 80m in
~ length, and the Dilatator tracheae has separated from the Dilatator laryngis.
In a larva of 42 mm., as shown by Géppert, the Laryngei arise from the ary-
tenoid.
Morphology of the larynx and laryngeal structures in Amphibia
On reviewing the above observations it is clear that, in the Amphibia
examined, the transverse groove lies behind the ultimate gill-cleft, in the
oesophageal region. The laryngeal groove extends forward into the ultimate
(Rana) or penultimate (Menopoma, Ellipsoglossa, Necturus) branchial seg-
ment. In the latter three animals, the front end of the laryngeal groove
subsequently migrates slightly backwards into the ultimate segment.
The transverse groove and hinder part of the laryngeal groove are constricted
off from the oesophagus. The larynx thus comes to lie in the ultimate branchial
segment and the forepart of the oesophagus. The front end of the larynx
subsequently lies at steadily increasing distances behind the remains of the
penultimate gill-cleft or -clefts, but as this occurs after loss of the ultimate
gill-clefts its meaning is doubtful. It may be simply a growth phenomena
and not indicate any real backward migration. The oesophageal and laryngeal
muscles and the laryngeal cartilages are differentiated from cells which are
proliferated from the splanchnic layer of the coelomic epithelium—pericardium
and pericardio-peritoneal ducts. The cells spread round the oesophagus and
larynx. The oesophageal and laryngeal muscles become differentiated among
these cells. Although, phylogenetically, the laryngeal muscles: may be re-
garded as derivatives of the Constrictor oesophagi, in actual development they
are not budded or split off from it, but the two sets of muscles develop con-
currently in close proximity in the splanchnopleure sheath of the oesophagi.
Comparison of the various laryngeal muscles leads to the following con-
clusions. Dilatator laryngis. In Anuran larvae the Dilatator arises from the
Hypobranchial and Laryngeal Muscles in Amphibia 153
connective tissue ventro-lateral to the oesophagus and passes inward and
forwards to the arytenoid. In the adult, the origin of the muscle becomes
attached to the processus postero-medialis. In Gymnophiona (larva and adult),
the muscle arises from the ventral part of the fourth branchial cartilage, and
_ is inserted into the arytenoid. In Urodela the origin of the muscle extends
_ upwards round the spinal musculature to the dorsal fascia (hence the name
“Dorso-laryngeus”’ often applied to it).
_ Géppert, who (vide p. 133) was of opinion that the Dilatator is serially
homologous with Levatores arcuum branchialium, thought that its form in
_ Urodela is primary and that the conditions in Anuran larvae and in Gymno-
_ phiona are secondary.
But, as shown above, the Subarcuales of the branchial bars are more
_ primitive in Anuran and Gymnophionan larvae than in Urodela, and the
_ Dilatator is developed by upward extension from a primordium ventro-
_ lateral to the forepart of the oesophagus. It follows that there is no a priori
_ probability that the form of the Dilatator in Urodela is primitive and the
phenomena of its development are against such a view. It is possible then
_ that its form in Anuran larvae is the primitive one, and that those in Urodela
_ and Gymnophiona represent two divergent secondary conditions.
Constrictor laryngis and Laryngei. In Anuran larvae a Constrictor laryngis
_ is developed, encircling the arytenoid posterior to the insertion of the Dila-
‘tator. In Gymnophionan larvae Laryngei and a Constrictor are present,
the former in front and the latter behind the insertion of the Dilatator.
In Urodelan larvae, other than Necturus, Proteus, and Siren, Laryngei and
a Constrictor are present, the former in front and the latter behind the insertion
of the Dilatator. In Necturus, Proteus, and Siren, Laryngei only are present—
a Constrictor is not developed.
Driiner stated that in Salamandra and Triton the Laryngei disappear
at metamorphosis. The same is also true of Siphonops.
, Géppert held that the Constrictor is proliferated from the Laryngei
ventrales in Siredon, where there is a slight overlap of these muscles. But in
Menopoma there is no overlap and, though the Laryngei are developed at an
_ earlier stage, yet there is no indication that the Constrictor is developed from
It would appear then that the Laryngei and Constrictor are independent
laryngeal constrictor muscles, of somewhat different form, developed in
_ front of and behind the insertion of the Dilatator.
It is not known whether the absence of Laryngei in Anura is a primitive
or a secondary feature. On comparison with Dipnoi (see later), it would
appear that probably a Constrictor is, phylogenetically, the older structure.
_ The absence of a Constrictor in the Perennibranchiata, Necturus, Proteus,
and Siren, is probably to be explained by the occurrence of its development
at a somewhat later stage than the Laryngei, taken in association with the
theory of Boas that the Perennibranchiata are persistent larval forms—
154 F. H, Edgeworth
Urodela which no longer have a metamorphosis. Menopoma would be similar
if development ceased at the stage of 24 mm.
Géppert (vide p. 132) held that the form of the arytenoids, and the attachment
of the Laryngei to them, in Necturus and Proteus represents the primitive
condition. But the developmental phenomena appear to negative such a view
and to show that, as Driiner thought, the condition is secondary to a more
primitive one, in which, as e.g. Triton, the arytenoids are narrower and the
Laryngei take origin from the Dilatator.
In Siren (vide Driiner) there are, in front of the Dilatator, Laryngei,
arising partly from the arytenoid and partly from the Dilatator, but no
Constrictor. There are, however, outside the Laryngei, sphincter fibres,
which have no homologues in other Amphibia. The condition needs embryo-
logical investigation—possibly the sphincter fibres are proliferated or separate
from the Laryngei. »
From the slightly different innervation of the Dilatator laryngis and of
the Constrictor laryngis and Laryngei Driiner inferred (vide supra, p. 134) that
these muscles have been derived from different segments. This is not borne
out by developmental phenomena. Further, in Anura and Gymnophiona all
the laryngeal muscles are innervated by the N. recurrens. The phenomena
in Urodela are simply due to a slightly earlier giving off of the branch for
the Dilatator from the N. intestino-accessorius, and have no morphological
importance.
Cartilago lateralis. Anura. Martens (1895) stated that in Rana temp.
there is no continuous cartilago lateralis which afterwards separates into
cartilago arytenoidea and C. laryngo-trachealis, but that these elements are
separate from the first, the arytenoid developing during metamorphosis, and
the four elements which fuse to form the annulus shortly afterwards.
I find that the arytenoid is present in a 12 mm. larva, in a precartilaginous
condition, quite distinct from the surrounding mesoblast. There is no trachea
at this stage, and during the rest of larval life the larynx immediately bifur-
cates into the two bronchi (fig. 17). In a larva during metamorphosis, at the
stage when the tail has shrunk to half its original length, the trachea develops
and the elements of the annulus appear. They are continuous with the dorsal
end of the obliquely placed arytenoid by precartilaginous tissue (figs. 21 and |
22),
Gymnophiona. In a 8-5 cm. larva of Ichthyophis the trachea is already
formed. There is a precartilaginous arytenoid, which anteriorly is circular in
shape, then broadens (with attachment of the Dilatator laryngis to its outer
edge, and the Laryngei above and below) and then contracts. It is continuous
posteriorly with a cellular sheath, thicker dorsally than ventrally, round the
trachea. In a 5-9 cm. larva the arytenoid has chondrified and is continuous
with a cellular sheath round the trachea. In this sheath are incomplete ring-
shaped patches of cartilage.
In a 7 cm. larva of Siphonops the conditions are similar to those of the
Hypobranchial and Laryngeal Muscles in Amphibia 155
_ 5-9 em. Ichthyophis larva (fig. 31). In the adult, with the disappearance of
the Laryngei, the lateral projection of the arytenoid also disappears and its
hind end is continuous with the first tracheal ring.
. Urodela. A precartilaginous arytenoid is present in a 10 mm. larva of
Triton cristatus. It is chondrified in a larva of 12mm. No trachea is present in
larvae up to a length of 28 mm. and correspondingly there is no pars laryngea.
_ A trachea, 135 in length, has developed in a larva of 38 mm. (figs. 77 and 78).
Behind the arytenoid, and continuous with it, is a cellular mass lateral to
_ the trachea. This cellular mass is chondrified as the trachea bifurcates into
_ the bronchi. Later on, as described by Driiner, there are many cartilaginous
islands along the trachea, and subsequently, as described by Gegenbaur, a
_ continuous arytenoid and tracheal skeleton—the cartilago lateralis.
Similarly, in Salamandra, the first cartilage developed in the tracheal
sheath is found at its bifurcation into the bronchi, in a 25 mm. larva.
__ Ina 28 mm. larva of Menopoma there is no trachea, the larynx immediately
bifurcating into the bronchi. A precartilaginous arytenoid is present, with
_ flat internal and convex external surface, and its posterior end ventral to its
anterior end (fig. 52). In a larva of 32 mm. a trachea, 120y in length, has
_ developed. This is not accompanied by any forward migration of the larynx
telative to the branchial skeleton; by it the bifurcation of the respiratory
_ tract is carried further back. The arytenoid is chondrified and has a slight
_ lateral process at the insertion of the Dilatator laryngis. The arytenoid is
_ continuous with a cellular sheath lateral to the trachea (fig. 55). In a larva
_ of 34mm. the primordium of the processus trachealis has developed in the
_ eellular tracheal sheath, dorsal to the posterior end of the arytenoid (fig. 56).
Ina 40 mm. larva this process is continuous with the arytenoid. In the adult
(Driiner) many cartilaginous islands have developed in the tracheal sheath.
In a 17 mm. larva of Necturus (Fig. 69) the arytenoid is present as a pre-
cartilaginous mass of cells extending laterally to the larynx, but not suffi-
_ ciently far for the Laryngei to arise from it. They are continuous laterally
_ with the Dilatator laryngis. In a 42 mm. larva, as shown by Géppert, the
arytenoid is broader and the Laryngei arise from it. There is no trachea in
larva up to a length of 18 mm. In one of 20 mm. (fig. 70) a trachea, 80 long,
has developed. Lateral to the trachea is a sheath of connective tissue, which
_ is continuous anteriorly with the arytenoid.
: It follows from the above that the simplest and probably the most primitive
_ form of the arytenoid is a roundish rod, surrounded by the Constrictor laryngis
and with a Dilatator laryngis attached to its anterior end. This is present in
Anuran larvae. In Gymnophionan and Urodelan larvae the arytenoid is
_ relatively longer, in relation to the presence of the Laryngei. The condition,
in Necturus and Gymnophionan larvae, of a broad plate with Laryngei arising
_ from it, is probably secondary to a simpler condition such as is present in
_ Triton. In this connection it is of interest to see that in Siphonops the ary-
___ tenoid becomes roundish in outline on the atrophy of the Laryngei.
156 F. H, Edgeworth
The development of the pars trachealis cartilaginis lateralis is related to
the formation of a trachea which develops at the end of the larval stage in
Rana, during larval life in Menopoma, Amblystoma, Triton, Siphonops
and Ichthyophis, and in the 20 mm. stage of Necturus. The pars trachealis
is formed as a non-chondrified backward prolongation of the pars laryngea
s. arytenoid. It may persist in this condition, e.g. Necturus, or may subse-
quently chondrify in tracts of more or less complete rings. In Triton and
Salamandra the cartilage is first developed at the bifurcation of the trachea.
The above discussion shows that further embryological investigations are
needed—in particular it would be well to know the condition of the branchial
skeleton and ventral branchial muscles in the larvae of Amphiuma? and
Cryptobranchus jap., the development of the sphincter laryngeal fibres in.
Siren, and the development of the ventral branchial muscles, larynx and
laryngeal muscles in Gymnophiona.
On the phylogenetic history of the laryna, trachea, and laryngeal muscles
Schmidt (1918), who investigated the development of the larynx in
certain Reptiles, was of opinion that the lungs of Polypterus, Amphibia, and
Amniota, like the swimming bladder of Lepidosteus and Amia, develop in the
same native soil (‘“‘Mutterboden”), and that, on the other hand, the trachea
with the larynx of Amniota, and possibly also that of Amphibia, are phylo-
genetically a later formation, the development of which begins with pulmonary
- respiration.
The larynx of Dipnoi and Polypterus lies in the ventral wall of the gut —
behind the branchial region. Its musculature was described by Wiedersheim
(1904) and Géppert'(1904). They came to the conclusion, though without any
embryological evidence, that it is developed from pharyngeal musculature
and that it represents musculature of atrophied branchial arches.
Neumeyer (1904) and Kellicott (1905), independently, showed that the
larynx of Ceratodus is developed in the ventral wall of the gut at some distance
behind the branchial region. Greil (1913) confirmed their observations, and
also showed that the free mesoderm cells round the gut and larynx become
spindle-shaped and develop into smooth muscle cells, which form a mantle
round the gut and larynx.
Kerr (1910) stated that in Lepidosiren and Protopterus the lung-rudiment
is developed, in stage 32, as a mid-ventral bulging from the pharynx at the
level of cleft vi. His figures show that its connection with the gut migrates
backwards, so that in stage 35 it is distinctly posterior to the level of the
6th gill-clefts, i.e. is in the oesophageal region. In Lepidosiren, Agar (1907)
stated that the ventral and lateral parts of the “‘Constrictor pharyngis” of
Wiedersheim are formed from mesenchymatous cells, budded off from the
inner walls of the pericardio-peritoneal ducts, and are thus of splanchnic
origin. The dorsal part of the muscle is of somatic origin, being derived
1 In larvae younger than the 45 mm. stage investigated by Hay.
Hypobranchial and Laryngeal Muscles in Amphibia 157
from myotome Y. He did not investigate the development of the laryngeal
muscles, but comparison of his figures with those of Wiedersheim suggests
_ that they are differentiated from the ventral, splanchnic, part of the “Con-
strictor pharyngis.”
_ Wiedersheim employed the term “ pharynx”’ to denote the portion of the
entary canal corresponding to atrophied branchial arches. In Lepido-
, however, there is no embryological evidence that the territory sur-
rounded by the pharyngeal constrictor represents a region of atrophied
ial arches—so that the name is hardly justified. The term “pharyngeal
constrictor” in Dipnoi might perhaps be replaced by that of “‘ oesophageal
ctor,” though with the reservation that in Lepidosiren and probably
rotopterus there is an added constituent from a myotome to its dorsal
portion, which is absent in Ceratodus and Amphibia. In this and previous
papers the name “pharyngeal” is used as synonymous with “branchial.”
In this latter sense it may be said that there is no pharyngeal constrictor
ogg in Mammals.
_ The larynx in Dipnoi is thus developed either in the oesophageal region,
or in that of the posterior branchial clefts, and migrates backwards. This
variation is similar to that which obtains in Amphibia. On comparison of the
gures given by Kellicott in Ceratodus with those of Kerr in Protopterus, it
s seen that whereas in Ceratodus the larynx immediately bifurcates, in
Protopterus there is a portion of the respiratory tract anterior to its bifurca-
tion. In Amphibia it is the laryngeal groove which, in part, may be situated in
e branchial region; the bifurcation groove is posterior to it. If this is so,
n the primitive larynx, or what corresponds to it, i.e. the bifurcation
ve, is situated in the oesophageal region both in Dipnoi and Amphibia,
whilst the laryngeal groove—a later development—is formed in front, and in
part in the branchial region.
_ Wiedersheim held that Protopterus and Lepidosiren, in contrast to Cera-
todus, have developed in the direction of Amphibia. The Dilatator laryngis
of these two Dipnoi, however, lies on the inner side of the Constrictor laryngis
is not homologous with the Dilatator laryngis s. Dorso-laryngeus of
nphibia which lies on the outside. _
_ On comparison with Dipnoi, the new features in the larynx of Amphibia
are (1) Formation of a laryngeal groove in front of the transverse groove,
forward into the hinder portion of the branchial region. It is
possible, however, as suggested above, that there is a laryngeal groove in
Lepidosiren and Protopterus. (2) Formation of a Dilatator laryngis on the
outside of the Constrictor oesophagi. (3) Formation of Laryngei in Urodela
and Gymnophiona. (4) Formation of an arytenoidea. (5) A, late, formation
of a trachea, with extension of the arytenoid along it. It is thus possible that
the features which are common to Dipnoi and Amphibia are (1) Formation
_ of a transverse groove, or its homologue the larynx in Dipnoi, in the floor of
the oesophagus. (2) Derivation of the laryngeal musculature from a pri-
158 F, H, Edgeworth
mordium common to it and the Constrictor oesophagi. The only muscle which
possibly may be common to Dipnoi and Amphibia is a Constrictor laryngis,
which is present in Lepidosiren and Protopterus?.
In Amniota, as in Amphibia, the transverse groove is devidesl a behind
the branchial region in the floor of the oesophagus, and the laryngeal groove
is formed progressively forward into the branchial region. The differences
from Amphibia are that the laryngeal groove extends into a more anterior
branchial segment and that the separation of the respiratory epithelium
extends relatively further forward so that the larynx lies entirely in the
branchial region. Correspondingly, the primordium of the laryngeal muscles
separates from that of the Constrictor oesophagi, migrates forward into the
branchial region and there develops into the laryngeal muscles. This method
is secondary and related to the secondary position of the larynx.
In Sauropsida the muscles consist of a Dilatator and a Constrictor laryngis
which are homologous with those of Amphibia. In a few Reptiles Laryngei
are developed. These, like the Constrictor, lie posterior to the insertion of
the Dilatator, are modifications of the Constrictor and_not homologous with
the Laryngei of Urodela and Gymnophiona.
In Mammals the laryngeal muscles consist of a Dilatator, Interarytenoid
and Laryngeus ventralis. The Dilatator is homologous with that of Amphibia
and Sauropsida and, as in the latter, arises from the Cricoid cartilage. The
Interarytenoid represents the dorsal half of a Constrictor. Both the Interary-
tenoid and Laryngeus ventralis lie in front of the insertion of the Dilatator.
Apparently, therefore, they are homologous, not with the Constrictor of
Sauropsida and Amphibia, but with the Laryngei of Urodela and
Gymnophiona.
Recurrent laryngeal nerve. As the laryngeal muscles are not branchial in
origin, their motor nerve—the recurrent laryngeal—is not a branchial nerve.
It may be regarded as a specialised oesophageal branch of the vagus. In
Gymnophiona and Urodela, and markedly in the latter, it extends to the
ventral branchial muscles, supplementing or supplanting branchial nerves.
The phylogenetic history of the recurrent laryngeal nerve is obscure. No
nerve was described by v. Wijhe or Beauregard in Ceratodus, nor by Hyrtl
in Lepidosiren. Pinkus described, in Protopterus, a fine twig extending from
the N. intestinalis to the mucous membrane of the pharynx and larynx, and
a R. muscularis and recurrens—a strong branch from the vagus ganglion
which passes down on the outside of the “‘ Constrictor pharyngis”’ and divides
into two branches, one of which passes forwards and sinks into the tongue
muscles, whilst the other innervates the “Constrictor pharyngis.” This last
branch was also described by Agar. Neither observer states whether twigs
from this R. muscularis to the Constrictor oesophagi can be traced into the
1 It is to be noted that Greil’s investigations of the larynx of Ceratodus did not extend beyond
the 18 mm. stage and that Wiedersheim aid that the state of his material left much to be desired.
So it is possible that Ceratodus, too, has a Constrictor laryngis.
Hypobranchial and Laryngeal Muscles in Amphibia 159
laryngeal muscles. But, whether this be so or not, it is probable that the
_N. laryngeus recurrens of Amphibia, Sauropsida, and Mammalia may be
regarded as being derived from a homologue of this nerve.
Laryngeal and tracheal cartilages. The arytenoid s. pars laryngea cartilaginis
lateralis of Amphibia is developed within the Constrictor laryngis or within
this and the Laryngei, and like them is differentiated from cells proliferated
“from the splanchnic layer of the coelomic epithelium. It does not, therefore,
_ represent a fifth, or a more posterior, branchial bar. Its development is
probably, as Wiedersheim suggested, dependent on muscle action, It is
possibly related to the new development of a Dilatator laryngis in Amphibia.
The tracheal skeleton s. pars trachealis cartilaginis lateralis is a backward
prolongation of the arytenoid and related to the development of a trachea.
In Sauropsida the ventro-median surface of the Constrictor laryngis may
become attached to the hyo-branchial skeleton, but this does not enter into
* the formation of the larynx.
In Mammalia a thyroid cartilage is formed, derived from two (separate
in Monotremes, fused in Marsupials) branchial bars, or from one branchial bar
(Eutheria), and the Crico-thyroid muscle is additionally formed from the
Constrictor pharyngis, with an innervation from the superior laryngeal
nerve. In Monotremes, however, there is a Thyreo-cricoid muscle, innervated
by the recurrent laryngeal nerve.
_ I have, in conclusion, the pleasure of thanking Prof. Watasé for larvae
of Ellipsoglossa, J. Pearson, Esq., for larvae of Ichthyophis, Dr Harmer for
specimens of Caecilia and Hypogeophis from the British Museum, Prof. J. P.
Hill for the loan of sections of an adult Siphonops, and the Bristol University
Colston Society for defraying the expenses incurred.
LIST OF FIGURES
Pirates I—XV
: The figutes are from transverse sections, unless otherwise stated. The lowest number, from
any series, denotes the most anterior section.
Rana temp. Figs. 1-22.
Figs. 1-5. Larva 7mm. long. 1 through Ist and 2nd branchial muscle-plates.
SS 2nd and 3rd_séi,, =
eee 4th ”
ea the laryngeal atapwe.
are the transverse groove.
Figs. 6 and 7. Larva 7} mm. long. bt ie
”
Figs. 8-10. Larva 8mm. long. 8 through 6th ere
9 and 10 through the laryngeal groove.
ania 11-16. Larva 11 mm. long. 11 through hypobranchial plate.
12 ne the third branchial bar.
13 and 14 through the laryngeal groove.
15 through the transverse groove.
16 ~=,, ~+~the oesophagus and larynx.
Fig. 17. Larva 12 mm. long, through larynx and bronchus; the section is slightly oblique, so that
it cuts both larynx and one bronchus.
)
160 F. H. Edgeworth
Figs. 18 and 19. Larva 20 mm. long, through larynx. .
Fig. 20. Larva with the hind legs just visible, through larynx.
Figs. 21 and 22. Larva with tail shrunk to half its original length, through trachea.
Ichthyophis glutinosa. Larva 5-9 em. long. Figs. 23-25. 23 through basihyale, 24 through Trans-
versus ventralis i, 25 through larynx.
Siphonops braziliensis. Larva 7cm. Figs. 26-31. 26 and 27 through Transversus ventralis i.
28 through Subarcuales recti ii and iii. 29 and 30 through larynx. 31 through trachea.
Menopoma s. Cryptobranchus allegheniensis. Figs. 32-56.
Figs. 32-35. Larva 15mm. long. 32 through 3rd branchial segment.
32) Damier 4th %
34_—C(«, 6th gill-cleft.
BD ras transverse groove.
Figs. 36 and 37. Larva 17 mm. long. 36 through 4th branchial segment.
Or ks 7th gill-cleft.
Figs. 38-41. Larva 18 mm. long, sagittal sections. 38 is the most external.
Figs. 42-45. Larva 19mm. long. 42 through Subarcuales obliqui ii and iii.
43 ~(, Transversus ventralis iv.
44 5, 7th gill-cleft.
45 larynx.
Figs. 46 and 47. Larva 22mm. long. 46'through Urobranchiale, 47 through Dilatator laryngis.
Figs. 48-50. Larva 24mm. long. 48 and 49 through Transversus ventralis iv.
50 through Laryngei.
Fig. 51. Larva 24 mm. long, sagittal section.
Fig. 52. Larva 28 mm. long, through larynx.
Figs. 53-55. Larva 32 mm. long. 53 through Urobranchiale.
54 just behind Urobranchiale.
55 through trachea.
Fig. 56. Larva 34 mm. long, through hinder part of larynx.
Necturus maculatus s. Menobranchus. Figs. 57-70.
Figs. 57-59. Larva 12 mm. long. 57 through 3rd branchial segment.
BS 654; laryngeal groove.
BO: transverse groove.
Figs. 60-62. Larva 13 mm. long. 60 through stumps of 5th gill-cleft.
teaver 4th branchial segment.
62, laryngeal groove.
Fig. 63. Larva 15 mm. long, through laryngeal groove.
Figs. 64-68. Larva 16 mm. long. 64-66 through 1st branchial bars and Urobranchiale, 67 and
68 through Transversus ventralis iii.
Fig. 69. Larva 17 mm. long, through Dilatator laryngis and Laryngei.
Fig. 70. Larva 20 mm. long, through Dilatator laryngis and Dilatator tracheae.
Ellipsoglossa s. Hynobius nebulosus. Figs. 71-76.
Figs. 71 and 72. Larva 12 mm. long, through 1st branchial bars and Urobranchiale.
Figs. 73-76. Larva 15 mm. long, through Urobranchiale.
Triton cristatus. Figs. '77 and 78.
Larva 33 mm. long, through trachea and bronchi.
ABBREVIATIONS IN FIGURES
Roman numerals _..._ cranial nerves
Branch iiiandiv ... fused branchialia iii and iv (in Gymnophiona)
br. muse. pl. ... ... branchial muscle plate
br.i-hyale... ... muscle passing from Ceratobranchiale i to hyale, in Rana
br. ii-hyale ... gt : 5 Ceratobranchiale ii to hyale, in Rana —
br. aor. arch. ... ... branchial aortic arch :
cerato br.iv ... ... cerato branchiale iv
cer. hy. ext. ... ... M. cerato-hyoideus externus
const. oesoph. ... ... M. constrictor oesophagi
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_ Hypobranchial and Laryngeal Muscles in Amphibia 161
const. lary. ©... ... M. constrictor laryngis
const. lary. post. |... M. constrictor laryngis posterior
dil. lary. «- «+ M. dilatator laryngis
dil. trach. ... ... M. dilatator trachealis
gen. gloss. .... --- M. genio-glossus
gen. hy. én ..- M. genio-hyoideus
‘gen. hy. lat. ... --. M. genio-hyoideus lateralis
gen. hy. med. ... ... M. genio-hyoideus medialis
Géppert’s m. ...._...._ muscle described by Géppert
hyophary. int.... --. M. hyo-pharyngeus internus
hypobr. pl. ... --. hypobranchial plate
inter. hy. ais ... M. interhyoideus
intermand.... --. M. intermandibularis
lary. dors. _... .. M. laryngeus dorsalis
lary. vent... ... M. laryngeus ventralis
lary. gr. sem .-. laryngeal groove
LT ee ae ... M. Levator arcus branchialis
_ Marg. i ee ... M. marginalis of first branchial i,
oesoph. aa ++» oesophagus
omo-hum.-maxillaris ... M. omo-humero-maxillaris
pars lary. c. L. ... ... pars laryngea cartilaginis lateralis
peric. p.c. ... .-. pericardio-peritoneal canal
pri. annulus ... .«-» primordium of annulus
wt eryten 5 a ” arytenoid cartilage
pri. const. oesoph. ... by M. constrictor oesophagi
pri. dil. lary. ... Ae: “ M. dilatator laryngis
pri. hypobr. sp. m. ... va hypobranchial spinal muscles -
pri. proc. trach. oe ee processus trachealis
rec. intest.n. ...._-...._N. recurrens intestinalis
rect. superf. ... _.... _M. rectus superficialis
subare. obl.... .-. M. subarcualis obliquus
thyr. gl. ste ... thyroid gland
trans. gr. eee --. transverse groove
trans. vent. ... .-. M. transversus ventralis
tend. of rect. ... --- tendon of M. rectus
vent. aor. ne --- Ventral aorta
vent. pr. basibra. ... ventral process of first Basibranchiale
urobranch. ... --- Urobranchiale
LITERATURE
W. E. (1907). “The development of the anterior mesoderm, and paired fins with their
nerves, in Lepidosiren and Protopterus.” T'rans. R. Soc. Edin. Vol. xiv.
UREGARD, H. (1881). “Encéphale et nerfs craniens du Ceratodus Forsteri.” Jour. de [anat.
et de la physiol. de Vhomme et des animaux.
Lance, D. (1916). Studien zur Entwicklungsgeschichte des Japanischen Ricsensalamanders
_ (Megalobatrachus maximus Schlegel). Leiden.
UNER, L. (1901 and 1904). “Studien zur Anatomie der Zungenbeim-, Kiemenbogen-, und
_ Kehlkopf-musculatur der Urodelen.” 1. Teil, Zool. Jahrb. Abt. f. Anat. u. Ontog. Bd xv.
1. Teil, ibid. Bd xrx.
s, A. (1834). Rech. s. Postéol. et la myol. des Batraciens a leurs différents dges. Paris.
oRTH, F. H. (1916). “On the development and morphology of the pharyngeal, laryngeal,
and hypobranchial muscles of Mammals.” Quart. Jour. Micr. Sc. Vol. txt. Part 4.
—— (1919). “On the dite comme of the laryngeal muscles in Sauropsida.” Jour. of Anat.
_ Vol. tiv. Part 1.
162 F. H, Edgeworth
Gavrp, E. (1905). “‘Die Entwicklung des Kopfskelettes.” Hertwig’s Handbuch, Bd un. Abteil 2.
GEGENBAUR, C. (1892). Die Epiglotiis. Leipzig.
GOppERT, E. (1894). “Die Kehlkopfmusculatur der Amphibien.” Morph. Jahrb. Bd xxu. Heft ii.
—— (1898). “Der Kehlkopf der Amphibien und Reptilien.” 1. Theil. Amphibien. Morph.
Jahrb. Bd xxvi. Heft ii.
—— (1901). “Beitrige zur vergleichenden Anatomie des Kehlkopfes und seiner Umgebung
mit besonderer Beriicksichtigung der Monotremen.” Jenaische Denkschr. v1. Semon. Zool.
Forschungsreisen, 11.
—— (1904). ‘‘Der Kehlkopf von Protopterus annectens.” Festschr. Ernst Haeckel.
Gruit, A. (1904). “Ueber die sechsten Schlundtaschen der Amphibien und derer Beziehungen
zu den supraperikardialen (postbranchialen) Kérpern.”’ Verhand. d. Anat. Gesell. Anat.
Anzeig. Bd xxv.
(1905). “Ueber die Anlage der Lungen, sowie der ultimobranchialen (postbranchialen,
supraperikardialen) Kérper der Anuren Amphibien.” Anat. Hefte, 89, Bd 29.
(1905). “Bemerkungen zur Frage nach dem Ursprunge der Lungen.” Anat. Anzeiger,
Bd xxv.
—— (1913). *‘Entwicklungsgeschichte des Kopfes und des Blutgefasssystems von Ceratodus
forsteri. Zweiter Theil.” Semon’s Forschungsr. Bd. I.
Hay, O. P. (1890). “The Skeletal Anatomy of Amphiuma during its earlier stages.” Jour. -
Morph. Vol. tv.
HENLE, J. (1839). Vergleichend anatomische Beschreibung des Kehlkopfes mit besonderer Beriicksich-
tigung des Kehlkopfes der Reptilien.
Hyrtt, J. (1845). Lepidosiren paradoxa. Prag.
Ketuicorr, W. E. (1905). “‘The development of the vascular and respiratory systems of Cera-
‘todus.” New York Acad. of Sc. Memoirs, Vol. 1. Part 4.
Kerr, J. GrawAM (1910). ‘On certain features in the Development of the Alimentary Canal in
Lepidosiren and Protopterus.”” Quart. Journ. Micr. Sc. Vol. rv.
Kriyastey, J. 8. (1892). “The head of an embryo Amphiuma.” Amer. Naturalist.
Marovs, H. (1908). Beitrdge zur Kenntnis der Gymnophionen. 1. Ueber das Schlundspaltengebiet.
Archiv f. mikrosk. Anat. u. Entwick. Bd 71.
Mirrens, M. (1895). ‘‘Die Entwickelung der Kehlkopfknorpel bei einigen unserer einheimischen
Anuren Amphibien.” Anat. Hefte, Bd rx.
Maurer (1902). ‘Die Entwickelung des Darmsystems.” Hertwig’s Handbuch, Bd 1. Teil 1.
Nevumeyer, L. (1904). ‘‘Entwickelung des Darmkanales bei Ceratodus Forsteri.” Denkschr. Med.
Nat. Gesell. Jena, Bd tv.
Norris, H. W. (1913). “‘The cranial nerves of Siren lacertina.” Jour. of Morph. Vol. xxtv. No. 2.
Norris, H. W. and Miss Hucuzs (1918). “The cranial and anterior spinal nerves of the Caecilian
Amphibians.” Jour. of Morph. Vol. xxx1.
Pryxvs, F. (1895). ‘Die Hirnnerven des Protopterus annectens.” Morph. Arbeit. Schwalbe, Bd rv.
Sarasry, P. and F. (1890). Ergebnisse naturwissenschaftlicher Forschungen auf Ceylon, Bd a.
4 Heft.
Scumipt, V. (1913). “Ueber die Entwickelung des Kehlkopfes und der Luftrohre bei Rope
Anat. Hefte, 146 Heft (48 Bd H. 3).
ae apm Pee eereeee pe eh elena Eee OTT
ftie tie ae aed
Pets costed De etn
ae oe hes
ee
=
Scuuurze, F. F. (1892). ‘“‘Ueber die inneren Kiemen der Batrachierlarven.” Abhand. d. K. ae
Preuss. Akad. d. Wissen. zu Berlin.
Sottas, W. J. (1919). Structure of Lysorophus as exposed by serial sections. Read Roy. Soc.
May 22.
Srrone, O. S. (1895). “The Cranial Nerves of Amphibia.” Jour. of Morph. Vol. x.
vAN WiJsHE, J. W. (1882). “ Ueber das Visceralskelett und die Nerven des Kopfes der Ganoiden und
von Ceratodus.” Niederl. Arch. f. Zool. Bd v. H. 3.
WiepersHer, R. (1904). “Ueber das Vorkommen eines Kehlkopfes bei Ganoiden und Dipnoern .
sowie tiber die Phylogenie der Lungen.”’ Zool. Jahrb. Suppl. vit.
Wivper, H. H. (1892). “Studies in the phylogenesis of the larynx.”” Anat. Anzeiger, Bd vii. 18 Heft.
(1896). “The Amphibian Larynx.” Zool. Jahrb. Abt. f. Anat. u. Ontog. Bd rx.
CARDIAC AND GENITO-URINARY ANOMALIES
IN THE SAME SUBJECT
By ALEXANDER BLACKHALL-MORISON, M.D., F.R.C.P.
AND ERNEST HENRY SHAW, M.R.C.P.
F . S., male, 38 years of age, was admitted into the Great Northern Central
Hospital on March 6, 1919. The previous history obtainable was of “heart-
trouble” for three years and “pain in the head” for four weeks. Two nights
previous to admission, the headache was severe and on awaking from sleep,
ptosis of the left upper eyelid was observed. There was also a history of a
‘severe cold with cough and some haemoptosis in 1916.
| On March 7, the mental condition is noted as having been “strange” and
_ the patient is stated to have become cyanosed at times. On the 8th he is
described as “deranged,” restless and complaining of headache. The heart
‘examined at this date is stated to have shown a loud, “flapping”’ first sound
and a systolic bruit not conducted outwards to the left. The pulse rate is
stated at the same time to have been “slow,” regular and feeble. There was
complete oculo-motor paralysis of the left eye, but no motor or sensory
disturbance was notable elsewhere. There was some stiffness of the left leg
and an exaggerated knee-jerk in the same limb. The urine was free from
albumin and sugar.
On March 10th signs of intracranial pressure were marked and the visiting
_ physician examined him on the afternoon of that day. The patient was found
to be delirious and incapable of answering any questions. The oculo-motor
signs described were well-marked. On examining the heart, one was struck
_ by the peculiarity of the auscultatory signs. The apical systolic bruit was not
audible in the left paravertebral groove and so marked was the accentuation
_ of the first sound, that it could be described by no other term than as a loud
smack. The condition of the patient precluded more detailed examination
and he died the same day.
On post mortem examination, the deceased was found to have tuberculous
meningitis, and the lungs showed several small cavities at the pulmonary
apices and scattered tuberculous foci in the lower lobes. The heart and
genito-urinary organs showed abnormalities to be described more fully. The
following description of the heart is given by Dr Alexander Blackhall-Morison:
The right ventricle is dilated and hypertrophied, the thickest portion of
the wall having a diameter of 5cm. The chamber measures 9 x 7 cm. The.
columnae carneae are decidedly hypertrophied and especially so is the mass
running downwards and outwards from the base of the posterior cusp of the
164 A. Blackhall-Morison and FE. H. Shaw
pulmonary arterial valve (Pl. XVI, fig. 1). These cusps are themselves normal.
The transverse measurement of the pulmonary arteryis6em. Theendocardium
below the pulmonary valves is opaque. The tricuspid orifice is dilated, easily
admitting three fingers and measuring 5 cm. transversely and the same antero-
posteriorly. The internal or septal cusp is fleshy, sessile and of no valvular .
value. The anterior cusp measures 4 x 5 cm. and is attached in its normal
position. The posterior cusp at its right boundary coalesces with the right
limit of the anterior cusp, but is attached abnormally low in the ventricle
and its left portion is divided into two pieces. A large, tough, umbrella-like
flap is attached to the ventricle close to its apex and a second smaller portion
is, like the internal cusp, fleshy, sessile and of no valvular value. The right
auricle measures 8 x 6 cm, and is hypertrophied. This chamber is also dilated.
The foramen ovale and venous entrances are normal and the aie sinus
is provided with a well-developed Thebesian valve.
The left auricle is normal, as usual opaque in lining and smooth i in oul
The left ventricle measures 7 x 6 cm. and its wall at its thickest 2 em.
The mitral and aortic cusps are normal. The mitral orifice measures 74 em.
transversely and the aortic orifice 5 em. There are two coronary arteries and
the base of the aorta is slightly atheromatous.
The anatomical point of chief interest in the cardiac conditions described,
as bearing upon clinical diagnoses, has reference to the abnormal tricuspid
segments. The very strikingly exaggerated loudness or accentuation of the
first sound of the heart was manifestly due to the impact of blood in systole
upon the redundant tricuspid segments. The effect reminded one of the
sudden slap of a loose sail rendered taut ‘by a gust of wind. The great audi-
bility of the sign may also in a less degree have been due to the superficial
position of the ventricle affected, for, dextral signs caused by organic valvular
disease are for this anatomical reason more pronounced than those arising
in the deeper left ventricle. An indirect anatomico-physiological interest
likewise attaches to this case as elucidating the chief cause of the accentuated
first sound in mitral stenoses. Of this a variety of explanations has been offered,
‘but this case strongly supports the view that that diagnostic sign is chiefly
attributable to the impact of ventricular blood in systole on the more or less
fixed aortic segment of the mitral valve. Dr Ernest Henry Shaw gives the
following description of the genito-urinary anomalies in the case:
Congenital absence of one kidney with abnormal development of ureter
of same side (fig. 2).
The specimen consists of the bladder with the vesiculae seminales and
portions of the vasa deferentia, and the malformed ureter of the left side.
The bladder is normal in size and its wall is natural in thickness. Internally
a rounded prominence is seen to the left of the trigone about # in. in diameter.
It is formed by a thin layer of tissue which is easily depressed by the finger
into a large sac in and behind the bladder wall. No ureteral opening is visible
on the left side. A ridge of firm muscular tissue runs down from the promi-
ee eee eee nt
os
se
Plate XVI
Right ureter
Left ureter
Fig. 1. R.V. right ventricle. P.A. pulmonary artery. S.c.
septal cusp of tricuspid valve; a.c. anterior cusp‘and
.c. posterior cusp of the same. L.V. left ventricle.
-v. pulmonary vein. L.A.ap. left auricular appendix.
—Right ureter
Right vas deferens
Right vesicula
Sseminalis
Cardiac and Genito-Urinary Anomalies in Same Subject 165
nence and becomes continuous with the verumontanum. The orifice of the
right ureter is seen in its usual position and is natural in size.
On the posterior aspect a large sacculated cavity is seen in the left wall of
he bladder and from this the ureter emerges. The left seminal vesicle is large
and dilated to form a bilobed cyst, at the bottom of the cyst a rod is passed
through a small hole into the large cyst at the lower end of the ureter. The
left vas is much dilated below and then suddenly contracts to a narrow hollow
rod as it enters the base of the prostate.
The left ureter begins below as a large thin walled sacculated tube which
ru ns upwards in a convoluted manner and gradually becomes narrower.
Towards the upper end it gives off a narrow branch about two inches long and
further up a second branch about one inch long. Both branches are hollow
and end blindly. The ureter ends above in a small cystic mass and from the
upper part of this two strands of tissue taper away.
_ The vesiculae seminales and vas deferens on the right side are natural.
ureter is a little enlarged.
The left ureter was filled with turbid yellowish fluid which contained many
eells of various shape and size, granular material, and a large number of
spermatozoa. The latter were mostly small and ill-formed, but many were
quite normal in size and shape. On injecting formalin solution into the dilated
ureter it first passed into the left seminal vesicle which became distended, it
then issued from the cut end of the vas deferens. A channel of communication
between the ureter and vas was thus clearly proved. The hole between the
ureter and seminal vesicle suggests that the channel is linked up by this
n. There is no communication between the left ureter and the bladder
.
_ The small cystic mass at the upper end of the ureter may represent a
udimentary kidney. Microsccpically the cysts and some small tubes are
lined with columnar epithelium.
_ The right kidney weighed 15 oz. and appeared to be normal. —
The specimen appears to be valuable from a developmental point of view.
supports the theory of the origin of the ureter being formed by an offshoot
from the Wolffian duct (vas deferens). The lateral branches of the upper part
suggest the formation of the calicyes found in the normal kidney. The dilata-
of the ureter is due to pressure by the accumulation of seminal fluid, and
the tube may be said to form a huge seminal vesicle. The formalin solution
did not escape from the ejaculatory duct and it is not possible to tell from the
__ present state of the dissection whether this tube is present or if it is patent.
Anatomy tiv ll
ON THE PARATHYREOID DUCT OF PEPERE AND ITS
RELATION TO THE POST-BRANCHIAL BODY
By Dr MADGE ROBERTSON,
From the Physiological Laboratory, University of Glasgow
Iw certain mammals the extraordinary mixture of the thyreoid with the
organs developed from the gill clefts and of these with one another has led
not only to misunderstanding of the results of physiological experiments, but
also to confusion in the interpretation of the morphological relationships of
the various structures.
The elaborate paper by Mrs F. D. Thompson (Phil. Trans. B, vol. 201)
illustrates this from the morphological side, while the earlier conclusions of
Swale Vincent and of Forsyth on the functional identity of thyreoids and
parathyreoids indicate the danger from the physiological aspect (Alnason
and Swale Vincent, Transactions of the Royal Society of Canada, 1917, p. 121).
In the cat the mix-up is very striking. Not only are the two ordinary
parathyreoids found in connection with each lobe of the thyreoid but thymus
tissue is generally present in close relation to both, while parathyreoid nodules
occur in the thymus in about 50 per cent., according to the observations of —
Harvier.
The development and structure of the thyreoid, parathyreoid and thymus
have been very fully investigated but the relation and significance of the post-
branchial body in mammals are still obscure.
The structure seems to have been first observed by Sandstrém when he
described the parathyreoids. Pepere (Arch. Ital. de Biol. 48-49) calls it the
“narathyreoid duct,”’ although as will be shown it is not necessarily connected
with these structures.
In the routine study of a large series of thyro-parathyreoid structures
removed from cats and dogs by Professor Noél Paton and Dr Leonard Findlay
in their investigation on Tetania Parathyreopriva (Q. J. of Exp. Phys. vol. x.
p. 208, 1917) and of several thymus glands the presence of a structure closely
corresponding in character with this post-branchial body has been found in
connection with the parathyreoid and thymus nodules of the thyreoid and
also in the thymus.
The tissues were fixed in picro-formalin, cut serially in paraffin and stained —
in haemalum and eosin.
In 88 cat thyreoids examined in serial section I found it present in all,
while in the thyreoids of 11 dogs it was found in 8.
In the thymus glands of two dogs and one cat ay Steenareany, examined a
similar structure was present.
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Parathyreoid Duct of Pepere 167
This body varies greatly in size, shape and character. It is essentially of
the nature of a multi-loculated cyst, with duct-like channels extending from
_ it in various directions.
_ Generally part of it lies deep in the thyreoid, and it here frequently has
the appearance of a much enlarged thyreoid vesicle, filled, not with the pink
staining colloid of the thyreoid, but with a homogeneous material staining
of a blackish blue colour.
At other parts the walls are thicker, with more fibrous tissue around them,
and they form partial septa giving a multi-loculated character.
__ The epithelial lining shows marked variations. Sometimes a single layer
flattened epithelium is present, sometimes the cells are columnar and some-
es they are ciliated (Plate XVII, Fig. 1). Sometimes there are several layers
of horny-looking flattened cells, which occasionally completely fill the lumen.
In many of the loculi and channels this epithelium can be seen breaking down
and becoming necrotic often ize amass of homogeneous debris (Plate XVII,
Figs. 2, 3, 4).
Certain features are common to the duct in all its forms.
(1) The channels have origin in the breaking down of epithelial cells of
a type quite distinct from those of the parathyreoid and thyreoid and easily
_ Fecognisable in the midst of either of these. The epithelial cells of the “duct”
are larger than those of the thyreoid or parathyreoid, they stain as a rule
more faintly, and they are sometimes peculiarly clear and almost refractile
appearance.
_ (2) There is associated always with the ducts at some stage of their course,
and frequently throughout the whole of their course, a greater or less amount
f lymphoid tissue closely resembling thymus. Mixed with the round lymphoid
cells are many spindle shaped cells such as have been described by Dudgeon
(Journal of Path. and Bact. 1905, p. 173) as occurring in the thymus in atrophy.
_ (8) The duct-like structures are almost always in some part of their course
in close connection with one or other of the parathyreoids.
_ (4) They contain a large amount of homogeneous necrotic material
obviously derived from broken down epithelial cells, and differing, as a rule,
_ in its staining properties from the colloid of the thyreoid vesicles.
_ (5) They all appear to end blindly, and must therefore be closed sacs—
smaller or greater— and not ducts.
_ (6) The tissue round about them is not specially vascular and they do
- not seem to come into any very close relationship with blood vessels. :
_ Inthe thymus a similar structure repeats all the variations which it showed
in the thyreoid. An epithelial lining of tall columnar cells with a very definite
basement membrane is however more frequently seen, and sometimes the
_ lumen of the duct is filled with lymphocytes or the products of their degenera-
_ tion rather than with epithelial cells.
; In one case this structure occupied a considerable part of the atrophic
thymus and showed the most diverse forms of cells in the lumina.
11—2
168 ‘Madge Robertson
It occurs most often in the fibrous stroma dividing the gland into lobules, or
in fibrous tissue towards the periphery of the gland (Plate XVIII, Figs. 1 and 2),
but also in the medullary portion of a lobule. Small pieces of parathyreoid
tissue are sometimes seen in the neighbourhood of the duct. Parathyreoid
tissue was found in two out of the four thymus glands examined complete
(one dog and one cat).
The most interesting feature of the duct in the thymus is the fact that
Hassall’s corpuscles can be seen quite definitely to be budded off from the
epithelium of its walls (Plate XVIII, Figs. 3 and 4) and they frequently form
the terminations of some of its loculi.
This structure is so distinctive and so different from the parathyreoid or
thymus tissue lying near it that its independent nature is strongly suggested.
It is of course possible that it is derived from the degeneration of the epithelial
connection of these two structures with the gill clefts, but on the other hand
its close resemblance to the post-branchial body as described in elasmobranchs,
urodela, frogs, reptiles and birds by Mrs Thompson (loc. cit.) strongly suggests
its identity with this.
In Chrysemys Picta she describes it as follows: “‘It is in close relation to
the parathyreoid. It consists of a number of vesicles of varying size and shape
though they tend to be spherical. The vesicles are of two distinct types, some
large, with very low epithelium staining very deeply—others smaller, with
cylindrical epithelium. Some of the vesicles contain a material which appears
to be true colloid.”
In birds the post-branchial body is described as consisting of three parts—
the first composed of compact epithelial cords, the second of spherical vesicles
lined with cubical epithelium which may be ciliated, and the third of true
parathyreoid tissue and thymus.
In the pigeon she says “‘the post-branchial body has an extraordinarily
complicated structure. It is obviously of epithelial origin and nature. It is
composed largely of structures which at first sight resemble small arteries
but whose walls are made up entirely of concentrically placed spindle shaped
cells, and projecting into the lumen are irregular cells lining the tubules.
The rest of the body appears to be built of structures identical with the various
well known forms of Hassall’s corpuscles of the thymus.”
In the fowl, she says “the post-branchial body is represented by a group i
of 8-10 vesicles lined with a low cubical epithelium, embedded in a constricted
off-portion of the elongated thymus. In the thymus nodule there is also a
structure which must be put in the same category. This is a much infolded
vesicle of large size lined with columnar ciliated epithelium.”
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Journal of Anatomy, Vol. LIV, Parts 2 & 3 Plate XVII
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Columnar
~~" ciliated
epithelium
Fig. 1. Duct lined in part with columnar ciliated
epithelium. x 100.
Fig. 2. Very large thin walled duct loculi. x 100.
ie” eres
Fig. 3. Epithelial cells. | Duct channel filled with
homogeneous epithelial
debris. x 100.
Fig. 4. Well defined duct channel containing some
epithelial debris. x 300.
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Parathyreoid Duct of Pepere 169
SUMMARY
_1. There is in the thyreoid, parathyreoid and thymus glands of cats and
dogs a structure cyst-like in some of its forms, and duct-like in others and
often of considerable complexity.
_ 2. In a series of 33 thyreoids of cats examined in serial section this
structure was found to be present in all. In all thyreoids of dogs examined
serially it was found in all but three.
In four thymus glands—three dogs and one cat—examined in serial
etion it was present in three—two dogs and one cat.
_ 8. The lumen of the structure appears to be formed by the breaking down
of large epithelial cells. Sometimes in the thymus it seems to be formed rather
by the disintegration of lymphoid cells.
4, By the breaking down of these cells, epithelial and lymphoid, a homo-
geneous material is formed frequently filling the duct channels and loculi.
This material sometimes stains pink with haemalum and eosin like the colloid
the thyreoid vesicles, but more frequently takes a dark bluish black colour.
5. The structure corresponds very closely in appearance with the “ post-
branchial’? body described in fowls and pigeons (and various lower animals)
by Mrs F. D. Thompson, and it is suggested that it may be the representative
I desire to express my thanks to Professor Noél Paton for much kind
assistance in the preparation of this paper.
_ The work was done under a grant from the Medical Research Committee
which my thanks are due.
DESCRIPTION OF PLATES
Pirate XVII
Fig. 1. Duct lined in part with ciliated epithelium.
Fig. 2. Very large, thin walled, duct loculi.
Fig. 3. Duct channels developing in lymphoid nodes in a capsule of thyreoid by breaking down of
Fig. 4. Duct channel in capsule of parathyreoid containing degenerating epithelium.
Pirate XVIII
Fig land 2. Duct in fibrous tissue capsule of thymus.
Fig. 3. Duct in centre of thymus lobule. Hassall’s corpuscle forming by proliferation of cells of
wall. Lymphocytes and epithelial cells in lumen of duct.
Fig. 4. Duct in centre of thymus lobule. Hassall’s corpuscle budded off at lower corner of duct
channel.
NOTE ON ABNORMAL MUSCLE IN POPLITEAL SPACE
By Pror. F. G. PARSONS
Pror. Parsons showed, at the December Meeting of the Anatomical
Society, an abnormal muscle, in the roof of the popliteal space, of which an
illustration is given. It was supplied by the external popliteal nerve and ~
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ip
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Ext. Pop. N.
Inner Head
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Ext. Saph, Vein. Ext. Saph.N.
Fig. 1. Dissection of popliteal space showing abnormal muscle described in the text.
Prof. Parsons was inclined to regard it as a conversion of the fascia lata of
the thigh inte muscle, especially as he had noticed that most of the fibres
of the fascia in that region run transversely. He produced specimens to show
that other structures which are usually fibrous may be converted into muscle. —
i Ngo Ta es
LEVEL OF EXTERNAL AUDITORY MEATUS 4]
By Pror. F. G. PARSONS
‘Tue accompanying dioptographic tracings of the relation of the external
auditory aperture in the soft parts to the bony external auditory meatus were
shown by Prof. F. G. Parsons in order to help the solution of the problem as
_ to the allowance which should be made for the soft parts when the auricular
Prersod
: Fig. 1. Vertical coronal sections of the external auditory meatus to show variations in the
Bus relationships of the soft parts to roof of meatus.
_ The four tracings showed that the skin opening is always below that in
_the bone, but that its distance below varies from 3 to 8 mm.
Until further material is available it will, therefore, be wise to allow an
average of 5 mm. for the lower level of the soft meatus, and 4mm. for the
_ thickness of the scalp on the vertex of the head.
NOTE ON RECURRENT LARYNGEAL NERVES
By Pror. F. G. PARSONS
Pror. F. G. Parsons showed, at the December Meeting of the Anatomical
Society, some dissections of the recurrent laryngeal nerves which he had been
asked to make by some of the surgeons of St Thomas’s Hospital. The points
to which he drew special attention were (1) that the nerve, especially on the
right side, does not lie in the groove between the trachea and oesophagus,
but some little distance away, and may therefore be met with sooner than
the operator expects. :
(2) That the nerve on the left side gives off a very large branch to com-
municate with the cervical sympathetic.
(8) That on reaching the thyroid gland the nerve is very closely applied
to the posterior part of the internal surface of that structure, lying between it
and the trachea and, higher up, between it and the cricoid cartilage. So
closely is it attached to the irregular surface of the gland in this region and so
obscured is its course just here by arteries and lymphatic glands that the
complete removal of the gland without injuring it must be a task of the
greatest difficulty.
The relation of the nerve to the inferior thyroid artery is unreliable. A little
distance below the gland the main inferior thyroid artery usually passes
behind the nerve, just as it passes behind the sympathetic, though this
relation is not constant to either structure. When the gland is reached the
nerve often becomes the most posterior structure, passing between branches
of the artery. The specimens incidentally showed that the right recurrent
laryngeal nerve has only a course of about three inches.
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HYPERTROPHY OF THE INTERSTITIAL TISSUE
3 OF THE TESTICLE IN MAN
By T. RUSSELL GODDARD
INTRODUCTION
_ Ar the time of the outbreak of war I was engaged in Cytological research
_ upon the germ cells. Col. C. J. Bond, C.M.G., F.R.C.S., knowing this, very
__ kindly supplied me with a number of retained testicles, removed by operation
from young men who presented themselves for enlistment in His Majesty’s
~ Forces.
After a preliminary examination of the slides made from this material,
it occurred to me that a comparison of the interstitial tissue found in these
organs, with the same tissue in the normal organ in advanced age, might be
interesting and perhaps illuminating. It appeared possible that such @ com-
parison might supply some further points of interest having a bearing upon
_ hypertrophy of interstitial tissue, in relation to atrophy of the seminal
_ epithelium.
Shortly after this time I myself joined the army, and consequently the
_ work of examination and preparation of this paper have been delayed until
now.
MATERIALS AND METHODS
My material consisted cf five retained testicles removed by operation from
_ young men whose ages ranged between 19 and 25 years. The organs were
found in various positions above the abdominal ring. In all cases they were
smaller than the normal testicle; three of them were roughly about the size
_ of a blackbird’s egg, one somewhat smaller, whilst the fifth was nothing more
_ than a collection of gland tissue along the vas deferens and seminal ducts.
Immediately after removal they were fixed in Bouin’s Picro-Formol, first
being opened with a scalpel to allow easier access of the fixing fluid. After
remaining about 18 hours in the Picro-Formol, they were washed out in
70 per cent. alcohol, and then transferred to 80 per cent. alcohol. The material
was then passed through 90 per cent. alcohol, absolute alcohol, cedar-wood
oil, xylol, and embedded in paraffin wax having a melting point of 52°C.
Serial sections were cut 8y thick on an ordinary Cambridge Rocking Micro-
tome. The sections were stained on the slides by Heidenhain’s Iron-Alum
Haematoxylin, and alcoholic eosin was used as a plasma stain.
I also secured at the same time two normal testicles for comparison and
control, one from a boy aged 17, and the other from an old man aged 78. In
the case of the boy the organ was removed and fixed in Bouin’s Picro-Formol,
a few hours after death. In the case of the old man the organ was removed
174 T. Russell Goddard
by operation, and preserved in 7 per cent formol. The methods employed
in making the slides were the same as those used in the case of the retained
organs. :
THE RETAINED TESTICLES ~
General Description
Each testicle is invested with a tunica albuginea of normal thickness. The
seminiferous tubules are as numerous as they are in the normal organ, but
their diameter is somewhat smaller. Large intertubular areas of fibrous
stroma are quite infrequent, the organs usually being tightly packed with
seminiferous tubules. The individual organs examined vary slightly in this
respect.
The seminiferous tubules in no instance exhibit any signs of spermato-
genesis. The seminal epithelium in all cases is atrophied, the tubules being
tightly filled with degenerating cells. The size and shape of these cells and their
nuclei vary slightly in different individuals. In some cases the cells are roughly
spherical, and in these the nuclei are also spherical. In others, the cells and
their nuclei are elliptical. The cytoplasm is clear and very finely granular.
Interstitial Tissue
In all the retained organs examined, the interstitial tissue is found to be
extremely well developed. In fact, more so than in the normal organ during
active spermatogenesis. Large areas are found in the intertubular stroma,
which are tightly packed with the cells of Leydig, more commonly known
as interstitial cells. These cells are large and irregular in shape, the cytoplasm
is clear and finely granular, and stains strongly with eosin. Lying in the eyto-
plasm near the nucleus is usually a well-defined attraction sphere containing
a double centrosome. The nucleus is large and spherical, having a sharply-
defined nuclear membrane. One, two, or three large and deeply staining
chromatic nucleoli are found, and scattered irregularly throughout the linen
meshwork are numerous chromatin granules. Occasionally a plasmosome is
present.
NORMAL TESTICLE (Man aet. 78)
General Description
The seminiferous tubules are not so numerous, and are more widely
separated by interstitial tissue, than is the case in the organs from young men.
The testicle is well supplied with blood vessels. The tubules are lined with
seminal epithelium, but present marked signs of decreased activity. The
majority of the cells are primary spermatocytes in the resting stage. Many of
the cells are atrophied, and present an appearance similar to that of the cells
found in the seminiferous tubules of the retained organ. Spermatozoa are
found in some of the tubules.
Interstitial Tissue
Large areas are met with between the tubules, which are tightly packed
with interstitial cells. The nuclei are large and take the stain deeply, having
Hypertrophy of Interstitial Tissue of the Testicle in Man 175
a sharply defined nuclear membrane. They contain one, two, or three large
nucleoli, and numerous chromatin granules dispersed irregularly throughout
the linen meshwork. Occasionally oxyphil granules are present. Most of the
cells contain an attraction sphere enclosing a double centrosome. The cyto-
plasm is finely granular and stains deeply with eosin. All the interstitial cells
observed show pronounced signs of activity. The shape of the cells appears
to be arbitrary, and dependent upon how tightly packed they are in the
intertubular tissue. The interstitial cells are much more numerous in this
testicle than they are either in the normal testicle from the boy, or in the
retained organs. Large areas tightly packed with them are frequently observed.
SUMMARY
1. In all the retained organs examined, there was complete atrophy of
the contents of the seminiferous tubules.
2. In all cases there was a marked hypertrophy of the interstitial tissue,
in some instances more pronounced than in others.
8. In the case of the normal testicle removed by operation from the old
man aged 78 years, the contents of the seminiferous tubules exhibited signs
of diminished activity.
4. The interstitial tissue of this organ exhibited a very pronounced hyper-
trophy.
CONCLUSIONS
The first part of this paper, that relating to the retained testicles, corro-
borates the work of other observers. The latter part dealing with the condition
_ of the interstitial cells in old age in man, is, so far as I am aware, new and
interesting. It is unwise, to say the least, to formulate any hypotheses upon
the evidence of one individual. However, I intend to carry out further
investigation upon the subject, and by examining a number of testicles from
old men, I shall be able to decide whether this condition is normal in advanced
age or not. If this condition is normal, it seems highly improbable that the
increased activity of the interstitial cells has any connection with an increased
development of secondary sex characters. Rasmussen has apparently found
a parallel case in the rodents. In a paper published in 1917 he states that in
the Woodchuck (Marmota monaz), which is sexually active only in the spring,
interstitial cell growth seems more uniformly related to the later and regressive
stages of spermatogenesis, than to the initial stages. However, he says that
there is evidence of variability even in regard to these. On the other hand,
Tandler and Grosz have shown that in other animals which undergo seasonal
changes in sexual activity, increased development of interstitial cells imme-
diately precedes that of the seminal epithelium. However, from the work
that has been done upon the subject, it appears usual to find increased
activity of the interstitial cells when the seminiferous tubules are either
’ decreasing in activity, or completely inactive. In addition this condition has
been produced experimentally by ligature of the vas deferens. It appears
176 T. Russell Goddard
that the seminal epithelium and the interstitial tissue are closely inter-related,
and that increased activity of the latter is influenced by diminished activity
or atrophy of the former. For what physiological reason, in the existing state
of our knowledge, it seems impossible to decide. It cannot in all cases mean
an increased secretion of hormones.
DESCRIPTION OF PLATE XIX
Figures 1 to 6 are from photomicrographs made with a Zeiss camera, a Zeiss apochromatic —
oil-immersion objective of 2 mm. focus and N.A. 1-30, and compensating ocular No. 4. The light
was obtained from a Graetzin lamp and passed through a Watson holoscopic oil-immersion sub-
stage condenser. Figures 7 to 9 were photographed through a Zeiss A objective of ? in. focus
and N.A. -20. In all cases the camera extension was 50 cm. The magnification was obtained from —
a stage micrometer graduated to read one-hundredth parts of a millimetre. hee of this
scale were taken under both combinations and are included in the plate.
Interstitial cell from normal testicle (Boy aet. 17).
Idem. Nuclei as large as this are rare in this testicle.
. Group of Interstitial cells from one of the retained testicles.
Fig. 4. Interstitial cells from retained testicle. A double centrosome will be seen lying in the
cytoplasm below the nucleus in the centre of the figure.
Fig. 5. Giant cell and nucleus from normal testicle (Old man aeft. 78).
Fig. 6. Group of Interstitial cells from normal testicle (Old man aet. 78).
Fig. 7. Seminiferous tubules. from normal testicle (Boy aet. 17). Small islands of Interstitial
cells are shown between the tubules.
Fig. 8. Seminiferous tubules from one of the retained testicles. The intertubular spaces are tightly
filled with Interstitial cells. The contents of the tubules are atrophied.
Fig. 9. Seminiferous tubules from normal testicle (Old man aet. 78). Large areas of Interstitial
cells are shown between the tubules. The contents of the tubules exhibit signs of dienisiehen
activity.
Fig. 10. Photograph of stage micrometer showing magnification of Figs. 1 to 6.
Fig. 11. Photograph of stage micrometer showing magnification of Figs. 7 to 9.
1 2
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wo bo
THE ORA SERRATA RETINAE
By G. F. ALEXANDER, M.B., Cu.B. (Ep.)
Tue above name is a sadly mistaken one for the serrated border of the
Retina, being wrongly in the plural: a better one would surely be Limbus
-Serratus. But why is the mouth or border of the Retina, i.e. where this
_ membrane ends at the Ciliary Body, serrated? I do not think any explanation
: has hitherto been forthcoming other than that it “grew so.” The Ciliary
_ Body is universally described as consisting of a posterior zone termed the
_ Orbiculus Ciliaris or Pars Plana on account of its being smooth, and an anterior
_ zone bearing the Ciliary Processes or Pars Plicata. The great mistake, however,
_ has been perpetuated in describing the posterior zone as smooth for it is not
so, as a careful examination will reveal the following, viz., from the posterior
aspect of each Process there continues backwards to the border of the posterior
zone a slightly elevated prolongation of its posterior border as a ridge or
_ Subsidiary Process, highest in the centre and tapering on each side into con-
tinuity with the flat internal wall of the Ciliary Body, which thus consists of
series of sulci between the elevations given by the Main and Subsidiary
Processes. A further interesting feature of the Subsidiary Processes is that
each consists of a number of low r parallel radial ridges. Now before the Retina
by the hexagonal pigment cells continuing as the outer layer, and its
supporting fibres as the inner layer, of its Pars Ciliaris (the transition of these
nucleated fibres into the epithelial cells being the exact counterpart of that
the epithelial cells of the lens capsule into the lenticular fibres), it passes
or a short distance over the Orbiculus, and this overlying hem through
being raised upwards by the Subsidiary Processes is thrown into a series of
elevations and depressions and thus acquires a serrated appearance.
NOTE ON THE OCCURRENCE OF CILIATED
EPITHELIUM IN THE OESOPHAGUS OF A
SEVENTH MONTH HUMAN FOETUS
By F. H. HEALEY, B.Sc.
From the Physiological Laboratory of the University of Birmingham
Dorrie the summer of 1918 a recently dead, well nourished, seventh
month, female foetus was sent to the department and appeared perfectly
normal. Portions of various organs were removed and fixed in 10 per cent.
formalin for class purposes; among these were the oesophagus, trachea and
stomach.
The oesophagus was divided transversely into three segments and the
cardio-oesophageal junction opened longitudinally, pinned flat on a cork
and fixed in that position. The tissues were then treated in the usual way,
finally embedded in paraffin and sectioned. Various staining agents were
used including haematoxylin, eosine, van Gieson, methyl blue and iron
haematoxylin. .
On examination it was at once seen that the mucous membrane of the
oesophagus presented a remarkable feature, namely, that superimposed upon
the usual stratified squamous epithelial lining were patches of ciliated cells
varying in extent and in position; sometimes occupying the crests of the folds
and sometimes the sulci between them. On the whole they were more numerous
in the upper end of the tube than lower down, but some were still visible even
to the orifice of the tube into the stomach.
The ciliated patches were well defined and did not project above the
general level of the epithelium, the stratified epithelium being pitted to receive
them. There was also a marked absence of mucous glands in the submucous
coat. Apart from these peculiarities the structure of the oesophagus was
quite normal.
The ciliated cells on examination proved to be of the ordinary columnar
type, measuring 14-5 x 9-8 and presenting flagellae 6-8 in length. These
were implanted upon well-marked basal segments, from which depended the
usual rootlets.
To determine the extent of the patches serial sections 10u in thickness
were cut from the middle third of the oesophagus and mounted serially on
slides.
Definite patches were selected and their course followed throughout the
series. The number of ciliated cells and the breadth of the patch in microns
were recorded for each section. By this means the patches were found to
run mainly in a longitudinal direction and might be better, described as
Occurrence of Ciliated Epithelium in Human Foetus 181
strips than as patches. They showed branchings and bifurcations at different
levels; the branches also had a longitudinal arrangement. Some strips were
very short, running through only a few sections, others were of greater length,
Ried through 60 or 70 sections.
Drawing of Strip. Yon = 10 pb
0 ror T T Sars | T
10 ~
r :
a I branching
20F- “4
» &£
PE "
a
F 30- 2% branching]
eee
y = 4
E J
S 40-- —
=
SOE = 2
2 ae :
3 +}
60F- -
E
7Oe- Se
~ l L l L i i |
No. of section Breadth of main part Breadth of bifurcation
2 304 _
8 50u ssi
ll 60u 35-2u
18 59u 34-64
20 87-8u —
First bifurcation joins main part
21 74-4u i
30 53u —
32 . Sip ; 65u
42 45u 60u
50 42-6u 6lu
60 36u 69n
65 94u ~
Second bifurcation joins main part
69 24u
Distance between first bifurcation and main part at section 11 =100z
” second 2. ” ” 32= 62u
oe Liv 12
182 F. iH. Healey
The dimensions and configuration of a typical strip are set forth in the
preceding table and drawing. It measures 690 in total length, bifurcates
twice, one branch being much longer than the other, and the strip varies in
breadth from three to ten cells.
Sections from the trachea of the same foetus were then examined to ascer-
tain whether the ciliated cells might not, by some accident, have been derived
from its mucous membrane; but the trachea proved perfectly normal and its
epithelium quite unabraided. The cells therefore could not have been de-
squamated from the air passages. This was done only as a precautionary
measure, there being no reason to suppose that they were derived from any
other locality, because they were sunk in little depressions in the squamous
epithelium and exhibited no dislocation and besides, the cells were quite
healthy, without the slightest sign of degeneration.
Examination was next made of the transverse sections of the oesophagus
of the following human embryos kindly placed at my disposal by Prof.
Peter Thompson of the Anatomical Department:
3 mm. long
5mm. ,,
Tm i,
11-25 mm. long
16 mm. long,
but no trace of ciliated epithelium could be found in the oesophagus of any
of them. (I have to thank Dr Yates of the Middlesex Hospital for his kindness
in examining the 11-25 mm. embryo for me.)
Sections in the collection in the Physiology Department were also ewasned
but in none of them could any trace of cilia be found in the oesophagus.
They included:
Foetal Sheep
12th day Rabbit embryo
Mouse embryo 1 cm. long
” 2cm. ,,
Bat embryo
Foetal Hedgehog
New born Kitten
5th day Chick.
The condition under examination seems therefore to be a rare one and is not
without interest from both an embryological and a pathological standpoint.
Considered embryologically the phenomenon is not so surprising, because
the trachea and the oesophagus are developed from the same portion of the
primitive foregut, i.e. the part between the developing pharynx proximally
and the future stomach caudally ;—the oesophagus being the dorsal part of
the original tube and the trachea the ventral part. Originally they were both
lined by the endoderm of the alimentary canal, but at a later stage, this
endoderm in the trachea develops into the ciliated epithelium of the adult,
while that of the oesophagus becomes stratified squamous. In the oesophagus
of the foetus under consideration, there are strips of ciliated epithelium which
ee ee F: pi
a. SSE eee y yor
SR ee ay ee See ea et eae eee Wr eee
Occurrence of Ciliated Epithelium in Human Foetus 183
are obviously not disintegrated epithelium from the trachea superimposed
_ on the normal epithelium of the oesophagus, because (a) the structure of the
_ trachea is quite normal, the*epithelium being intact. (b) The strips in the
oesophagus are not simply superimposed but are directly continuous on
_ either side with the squamous cells. Hence the question arises as to whether
the oesophagus is ciliated normally at an early stage in its development,
_ afterwards losing its ciliated epithelium, such a condition being possible
_ because of the occurrence of epithelioma in the adult oesophagus.
It thus remains to be demonstrated that at an early stage in the develop-
_ ment of the oesophagus it is a ciliated tube like the trachea, the embryonic
_ endoderm cells becoming ciliated cells which only persist for a short time,
and then disappear entirely, leaving the ordinary squamous epithelium.
_ If this is so, then in the present case only parts of the ciliated epithelium
have disappeared, some persisting in the form of strips. But since in no embryo
‘ examined could any trace of cilia be found in the oesophagus, its occurrence
_in this foetus is probably an abnormality, and in the normal development of
_ the oesophagus no ciliated epithelium is ever present.
_ This foetus is also of interest to the Pathologist. New growths in the
adult may possibly be due, in part at any rate, to such abnormalities, which,
_ though perfectly normal low down in the animal scale, only occasionally
: occur in higher forms and may be looked upon as vestigial remains, which,
according to some pathologists, may afford a suitable nidus for the develop-
_ ment of cancer and other malignant growths.
f
5
®
12—2
oF atta EI ON ACRE IN ST EID Ie ORE
THE RELATIVE POSITIONS OF THE OPTIC DISC
AND MACULA LUTEA TO THE POSTERIOR POLE
OF THE EYE
By JAMES FISON, M.A., M.D. (Canras.),
Harrogate
Many years ago I noticed in the third volume of L. Testut’s Traité
@ Anatomie Humaine (4° édition) what I at first took to be mere printers’
errors in the description of the macula lutea and the optic disc. They occur
in the following passages:
“La tache jaune...occupe exactement le péle postérieur de l’ceil. Elle
est située par conséquent un peu en dehors et un peu au-dessus de la papille
optique.”
“Elle (la papille optique) revét l’aspect d’un petit disque...située a
3 millimétres en dedans, et 4 1 millimétre au-dessous du péle postérieur
de l’ceil.”’
I soon saw, however, that this was not a misprint of “au-dessous”’ for
“‘au-dessus”’ and vice-versd, for in three illustrations (one of them a coloured
plate) the macula is shown above the level of the centre of the optie dise.
The coloured plate bears the legend: “La rétine, vue 4 ophthalmoscope,
ceil gauche, image droite.” In reality it shows the reversed image of the
right eye. In the description of the sclera the following passage occurs:
‘Elle (ouverture postérieure) est située 4 8 millimétres en dedans et a 1 milli-
métre au-dessous de ce pdle (péle postérieur)”’; and in a figure, showing the
back view of the eye, the entrance of the optic nerve is placed well below the
horizontal meridian.
In the latest edition of Testut and Jacob’s Traité d Anatomie Topographique
some corrections have been made. The description beneath the coloured
plate—the same plate as that found in the Traité d Anatomie Humaine—is
as follows: “La choroide et la rétine vues a l’ophthalmoscope, ceil gauche,
image renversée.”’ Here the correction has not gone far enough, for it is a
reversed image of the right eye that is represented and not the left. But in
subsequent figures of this region, in all of which the macula lutea is on a higher
level than the optic disc, there is no mention of the reversed image.
In the text the optic disc is described as being ‘“‘A 3 millimétres en dedans
et 4 1 millimétre au-dessus du péle postérieur de l’ceil,” and the macula “qui
occupe exactement le pdle postérieur de l’ceil” as being “‘un peu au-dessous
de la papille.”’ But, when the sclera is under consideration, Testut states that
the posterior opening of the sclera is “A 8 millimétres en dedans et a 1 milli-
métre au-dessous de ce péle (pdle postérieur),”’ and the figure on the same
-
The Optic Disc and Macula Lutea 185
page (the same as that in the Traité d Anatomie Humaine) bears out this
wrong description.
If such inconsistent statements and inaccurate illustrations could be
found in Testut’s works I expected to find other anatomists also at fault
in their articles on the Eye; for Testut is justly regarded as one of the
greatest living anatomists, and his works are not infrequently referred to
in English treatises on Human Anatomy and Surgical Anatomy. In the
eleventh edition of Quain’s Elements of Anatomy, in three separate passages, the
head of the optic nerve is said to be on a lower level than the horizontal
meridian of the eye. One of these passages reads as follows: “‘About 3 mm.
inside the yellow spot and about 1 mm. below the level of a horizontal line
_ through the posterior pole of the eyeball is...the optic disc.” Two figures
show the macula above the level of the centre of the optic disc, and facing
one of these is a large coloured plate of the fundus with the macula in its
normal position below this level.
In the twentieth edition of Gray’s Anatomy, Descriptive and Applied the
optic nerve is said to enter the eyeball “3 mm. to the nasal side and a little
below the level of the posterior pole” ; while, in the picture of the posterior half
of the left eye, the optic disc is shown in its correct position above the level
ofthe macula.
Similar descriptions to those found in Gray’s Anatomy occur in the fourth
edition of Cunningham’s Teat Book of Anatomy. In a curiously worded
passage, after stating that the macula lutea is at the posterior pole of the eye,
the optic disc is said to be on a lower level than the posterior pole; and some
pages later this statement is repeated. But in a picture of the fundus the
optic disc is seen on a higher level than the macula.
In the fifth edition of his Manual of Practical Anatomy Cunningham
states that the optic nerve enters the eye 3 mm. to the nasal side of, and 1 mm.
below, the posterior pole; and Testut’s figure is reproduced showing the entrance
of the optic nerve into the eye, as seen from behind, with the nerve below the
horizontal meridian.
A. M. Buchanan, in his Manual of Anatomy, states in three places that the
optic nerve entrance is below the level of the posterior pole.
Two passages in The Anatomy of the Human Eye by Arthur Thomson
clearly state that the point of entrance of the optic nerve is below the level
of the posterior pole of the eye.
Similar statements relating to the relative positions of the optic nerve
and posterior pole, together with misleading pictures, occur in the works on
Human Anatomy of George A. Piersol and of Spalteholz, in Maximilian Salz-
mann’s work on the Anatomy of the Eye, and in the Surgical Anatomy of
C. R. Whittaker.
In A Treatise of Human Anatomy by H. Morris, the article on the Eye was
written by R. Marcus Gunn, at that time Senior Surgeon at Moorfield’s Eye
Hospital. Here there is no mention of the optic disc being below the level
186 James Fison
of the posterior pole, and no picture giving a wrong impression as to the
relative positions of the optic dise and the macula. The statement made by
Testut that the macula is at the posterior pole is found here also—‘‘at the
posterior pole of the eye a small spot (fovea centralis) exists.”
Improper statements in works on Human Anatomy as to the relative
positions of the macula lutea and the optic dise are inexcusable—the ophthal-
moscope will reveal in a moment the truth to anyone who cares to verify his
statements. Inconsistencies between the figures and the text are equally
reprehensible.
Conflicting statements regarding the posterior pole of the eye can however
be readily explained, for there is more than one possible axis of the eye.
In most, if not all, of the works on Anatomy already referred to there is
evidence of confusion of thought in this matter. A notable example of this
occurs in Buchanan’s Manual of Anatomy (1914). On page 1383 we find
“The centre of the corneal segment is called the anterior pole, and the centre
of the sclerotic segment is known as the posterior pole. The sagittal (antero-
posterior) axis, or axis of vision, of the eyeball is represented by a line con-
necting the anterior and posterior poles.” On page 1384, “Posteriorly the
eyeball receives the optic nerve, which pierces the sclerotic coat at a point
about } inch to the inner side of, and about 33, inch below, the posterior pole.”
Again on page 1384, “‘It (the optic entrance) is situated, as stated, at a
point about 4 inch to the inner side of, and about 4; inch below, the posterior
pole of the eyeball.’’ On page 1395, “The internal surface presents in the line
of the visual axis of the eyeball, the macula lutea or yellow spot, where vision
is most distinct.”
The last statement is a perfectly true one, if by visual axis is meant the
line of vision, which is, however, by no means the same thing as the axis of
vision defined on page 1383. On the other hand if “visual axis” and the
“axis of vision’? on page 1883 are the same axis then the posterior pole is at
the yellow spot, and all the statements about the optic disc being below the
posterior pole are manifestly false.
There appears to be a general agreement amongst anatomists to describe
an anterior pole of the eye as being the centre of the front of the cornea,
a posterior pole as being the centre of the posterior curvature, and the line
joining the poles the sagittal axis.
Testut’s definition of the poles is more cautious. He says: “‘ Les poles sont
- les deux points de la surface extérieure de l’ceil que traverse le diamétre antéro-
postérieur de cet organe: le péle antérieur correspond au centre de la cornée
transparente; le pdle postérieur est situé au point diamétralement opposé,
un peu en dehors de V’orifice d’entrée du nerf optique.”” Elsewhere Testut
is definitely committed to the statement that the macula is exactly at the
posterior pole.
Maximilian Salzmann is more cautious still. He says that the midpoint
of the cornea forms the anterior pole of the eyeball, and that diametrically
The Optic Dise and Macula Lutea 187
opposite this is the posterior pole “in der nicht weiter anatomisch charak-
terisiert ist, also nur durch Konstruktion oder Messung gefunden werden
kann. Die Verbindungslinie beider Pole ist die geometrische Achse des
Augapfels.” He points out that an optic axis, in the strict mathematical
sense, only exists very rarely—the foci of the three principal refracting surfaces
generally lying on a line which is by no means a straight one. He then goes
on to state that the line of sight is very different from the geometrical axis,
for the fovea, he says, lies to the temporal side of and below the posterior
_ pole. Later on he says that the midpoint of the head of the optic nerve is
about 3 mm. to the nasal side of, and 1 mm. below, the posterior pole. Unfor-
tunately no details of measurements of so and so many normal human eyes
are given either by Testut or Salzmann to convince one that Testut is right
in stating that the yellow spot is exactly at the posterior pole of the sagittal
axis, or that Salzmann is right in saying that the fovea is below the posterior
pole. I have not been able to find any anatomist who quotes his authority
for stating that the optic dise and macula bear such and such a relation to
the posterior pole of the eye.
Doubt as to the propriety of stating that the macula is situated at the
posterior pole has evidently arisen in the mind of the author of the article
on the Eye in Gray’s Anatomy, Descriptive and Applied. In the eighteenth
edition (1913) we read: “Exactly in the centre of the posterior part of the
retina...is...the macula lutea.” In the twentieth edition (1918) this has
become “Near the centre of the posterior part of the retina is. ..the macula
lu 2? :
It seems to me most probable that anatomists have in their minds the
researches of Helmholtz and Tscherning on the optic axis. These observers
_ showed.that the optic axis (i.e. the line passing through the nodal point and
_the centre of rotation of the eyeball) cuts the region of the posterior pole
_ on the inner side of the yellow spot and slightly above it. But the optic axis
_is, by definition, a different axis from the anatomical sagittal axis, and the
confusion of one with the other is certain to lead to wrong descriptions.
Moreover this statement of Helmholtz, confirmed by Tscherning, does not
mean that the optic disc is below the level of the posterior pole, for the optic
disc is itself slightly above the level of the macula.
Would it not be wise to avoid this morass of conflicting statements by not
using the posterior pole as an anatomical landmark, when it has no charac-
teristics of a landmark? It-would be simpler and more accurate to make the
yellow spot the central landmark for this region, and state the plain truth
that it is situated in the region of the posterior pole of the eyeball.
The centre of the optic disc will usually be found to be at about the level
of the upper edge of the macula. Often the optic dise occupies a still higher
position, more rarely the centre of the dise and centre of macula are on the
same level. I have only once seen the centre of the disc below the level of
the macula. It is certainly an exceedingly rare position.
188 James Fison
REFERENCES
Txstut, L. Traité danatomie humaine. 4° Edition (1899); 6¢ Edition (1911-12).
Txstut, L. et Jacon, O. Traité d’anatomie topographique. 3° Edition (1914).
Quatin’s Elements of Anatomy. 11th Edition (1909).
Gray, H. Anatomy, descriptive and applied. 18th Edition (1913); 20th Edition (1918).
CunninGHAM, D. J. Textbook of Anatomy. 4th Edition (1917).
—— Manual of Practical Anatomy. 6th Edition (1918).
Bucuanan, A. M. Manual of Anatomy. (1914.)
THomson, ArtHuR. The Anatomy of the Human Eye. (1912.)
PrersoL, GrorGE A. Human Anatomy. (1907.)
SpaLtTEHouz, W. Handailas d. Anatomie d. Menschen.
WHITTAKER, CHARLES R. A Manual of Surgical Anatomy. 2nd Edition (1914).
SaLzMANnn, Maxrimitian. Anatomie u. Histologic d. menschlichen Augapfels im Normalzustande.
(1912.)
Morais, Sir H. A Treatise of Human Anatomy. 2nd Edition (1898); 4th Edition (1907); 5th
Edition (1915).
Handbuch d. physiol. Optik. 2te Aufl. S. 108.
Zischr. f. Psychol. u. Physiol. d. Sinnesorg. Hamburg u. Leipzig, 1892. Bd. m, S. 475.
RAs Sli eS eae yd: Ca MON EES To > UI ee ee Ry. ae le on oe eee,
THE MICROSCOPICAL STRUCTURE OF THE ENAMEL
OF TWO SPARASSODONTS, CLADOSICTIS AND PHAR-
SOPHORUS, AS EVIDENCE OF THEIR MARSUPIAL
CHARACTER: TOGETHER WITH A NOTE ON THE
VALUE OF THE PATTERN OF THE ENAMEL AS A
TEST OF AFFINITY
By J. THORNTON CARTER,
Research Assistant in the Department of Zoology, University
of London, University College
Tue question of the existence of any relationship between the Creodonts
and modern carnivorous Marsupials is one which, owing to the close resem-
blance in their dentitions, has attracted much attention from palaeontologists.
The form and pattern of teeth afford valuable data in establishing such
relationships, but closely similar dentitions may be evolved in creatures of
widely divergent ancestry as in the case of the Dog and the Thylacine. Con-
sequently, any essential character which enables an investigator to state
definitely from the examination of a fragment of a tooth, as to the precise
relationship of its possessor, is of great value.
Such a character exists in the structure of the enamel of the teeth of
Marsupials. The late Sir John Tomes in a classical paper (1) demonstrated the
fact that with one exception—the Wombat—all recent Marsupials possess
_ enamel on their teeth characterized by the presence of tubes continuous with
__the dentinal tubes. These enamel tubes are occupied by an organic fibril,
the tube being merely the channel in which the fibril lies surrounded by the
_ enamel without the intervention of an intermediate substance.
In 1906, Sir Charles S. Tomes published a paper entitled “On the Minute
Structure of the Teeth of Creodonts, with especial reference to the suggested
resemblance to Marsupials’’ (2), in which he employed this distinctive character,
__ first demonstrated by his father, in the endeavour to find whether the structure
of the enamel in these fossil forms disclosed any evidence as to their Didelphian
__ or Monodelphian affinities, but states that “in the interpretation of the occur-
rence of this character a different value appears to attach to negative and
positive results: if we find no tubes at all in the enamel we shall, I think, be
quite justified in saying that no near affinity with the Marsupials can exist.
On the other hand, if-we find rudimentary traces of this penetration, we shall
not be justified in attaching great importance to it as an evidence of Marsupial
affinity, though if we find an abundant penetration we shall have a character
which, so far as is known, is peculiar to Marsupials and to Hyrax.”
Tomes prepared sections from teeth of Hyaenodon, Mesonyx, Pachyoena,
Oxyoena, Sinopa, Didymictis, Cynodictis and Borhyoena.
190 J. Thornton Carter
The explorations of Ameghino have led to the discovery in Patagonia of
a number of forms—Cladosictis, Procladosictis, Pseudocladosictis, Amphipro-
viverra, Perathereutes, Acyon, Prothylacinus, Borhyoena, Pseudoborhyoena,
ete. from the Santa Cruz and Casa Mayor formations, and Proborhyoena and
Pharsophorus from the Deseado formation—which exhibit in a large number
of characters a most marked resemblance to existing polyprotodont Marsupials.
Scott (3) writes: ‘“‘The differences are of three kinds: (1) there are no
vacuities in the bony palate; (2) the milk dentition is less reduced, the canines
and one or two premolars being changed; (3) the enamel of the teeth in the only
genus (Borhyoena) which has been examined microscopically, resembles in its
minute features that of the placentals and lacks the Marsupial characters.
Though by no means unimportant, these differences are altogether out-
weighed by the thoroughly marsupial nature of all other parts of the skeleton,
and I cannot but agree with Dr Sinclair in including them with the Tasmanian
Thylacine.”’ ‘
Dr Sinclair’s memoir (4) constitutes the most authoritative and exhaustive
account yet published dealing with these fossil Thylacinidae, in which family
he placed most of the forms included by Ameghino in his sub-order, Sparas-
sodonta. He writes: ‘“‘In connection with the question of the descent of the
Patagonian and Tasmanian Thylacines from a common ancestor it may be
interesting to notice that certain large Carnivorous Marsupials from the
Pyrotherium beds (Ameghino, 1897) named by Ameghino, Proborhyoena and
Pharsophorus retain the metaconid in the lower molars whilst the premolar
formula is unreduced. The loss of the metaconid in the Thylacinidae separates
them sharply from all other carnivorous marsupials. It is possible that these
two genera mentioned, in which this cusp is retained, will be found to occupy
an intermediate position between the Thylacinidae and Dasyuridae, but
until they are better known it is unsafe to attempt generalizations of so broad
a character.”
As Scott mentions, the enamel of one only of these extinct Thylacinidae
has been examined: this was done by Tomes who prepared sections from a
fragment of a tooth of Borhyoena, now regarded as a Sparassodont, but
included by him amongst the Creodonts. His description states ‘‘ Borhyoena.
In this genus we find the absence of penetrating tubes and we can distinctly
recognize the carnivorous pattern in the course of the prisms. But apparently the
prisms are a little straighter than in recent Carnivora, or at least in recent
Felidae. It is not, however, possible to speak very positively as to their
greater simplicity, as I had only a fragment of a tooth at my disposal, and the
sections I was able to get were small, and may not have included any of the
thickest parts of the enamel where, as has already been noted, these characters
are to be found most marked. However, there is ample evidence to say that the
enamel of Borhyoena is essentially of the Carnivorous type and bears no more
resemblance to Marsupials than does that of other Creodonts.”’ (The italics are
mine. )
The conclusions of Tomes, though negative, in so far as he found no evidence
Enamel of Sparassodonts, Cladosictis and Pharsophorus 191
of “‘penetration” of the enamel by tubes, have been of considerable weight
with palaeontologists in their estimation of relationship of the Creodonts and
_ of the Sparassodonts, but the evidence of the Marsupial affinities of the Pata-
gonian forms is so overwhelming that Mr D. M. S. Watson, Lecturer in Verte-
,brate Palaeontology at University College, suggested that I should examine
the enamel of Pharsophorus (from the Deseado formation of Patagonia,
Oligocene).
Dr C. W. Andrews, F.R.S. (British Museum, Natural History) very kindly
gave me one of the cheek teeth from which I have been able to prepare a
number of sections. All of these preparations disclose the typical Marsupial
character of the presence of “tubes” (¢) in the enamel (e). It will be seen
(Plate XX, fig. 1) that the enamel prisms leave the dentine surface at an angle —
of about 45° and pursuing an almost straight course, run outwards until but
a short distance from the free surface where there is a slight change of direction.
Mr Watson also obtained for me from the American Museum of Natural
History, through the generosity of Dr Matthew, a portion of the crown of a
cheek tooth of Cladosictis (from the Santa Cruz formation of Patagonia,
Miocene) from which I have prepared several sections. In each of these also
the characteristic Marsupial structure of the enamel obtains (Plate XX, fig. 1).
The enamel in my sections of the tooth of Cladosictis is peculiarly refractile
making it difficult to obtain a clear photomicrograph showing the direction
of the enamel prisms but the course which they pursue is somewhat similar to
that seen in illustration of the enamel of Pharsophorus (Plate XX, fig. 1). The
tubes of the enamel in these sections are very markedly spiral in their course
and, by careful focussing, can be followed through most of the thickness of the
enamel, but naturally this does not show very clearly in a photomicrograph
which reproduces but one plane.
_ IT have had no opportunity of examining the enamel of Borhyoena (frag-
ments are scarce and but two complete skulls have been found) but its affinities
are so’ close to the specimens examined that I have little doubt that, with
_ a sufficiency of material, the presence of tubes in the enamel will be demon-
strated!.
As C. S. Tomes states: “‘The examination of fossil teeth presents greater
difficulties than those of recent teeth. Structurally the enamel is always well-
: preserved, but it has in the process of mineralization, often hecome unduly
transparent, so that careful illumination is even more essential in deciphering its
structure. And the teeth are often exceedingly brittle and friable, so that it is
difficult to get good sections....The dentine, however, being richest in organic
1 Since this paper has been in the hands of the printers I have received a considerable portion
of the crown of a cheek tooth of Borhyoena from which I have prepared twelve sections of the
enamel with the adjacent dentine. These sections range from the tip of the cusp to the neck of
the tooth and in all there is penetration of the enamel by “tubes” which in some cases pass from
the dentine through the greater thickness of the enamel.
__ Over the apex of the cusp the pattern of the enamel is somewhat complex, the prisms running
_ in groups or sheaves, but in all other parts of the crown of the tooth their course is almost
straight, passing out from the dentinal surface at an angle of about 60°. (1. v. 1920.)
192 J. Thornton Carter
matter, is often very badly preserved so that sometimes all structure has
disappeared: a fact which handicaps the observer in tracing the passage of
tubes from it, and sometimes leaves him only able to look for characteristic
appearances of tubes in the enamel itself. Moreover, many of the teeth being
rare, only small bits of damaged teeth were available for examination, so that
it was not always possible to select the plane in which a section was most
desirable: one had to take what one could get.”
In the examination of a considerable number of fossilized teeth I have
encountered the same obstacles as did Tomes and have learned to appreciate
the difficulties which exist in arriving at a definite conclusion as to the presence
or absence of certain characters. One fortunate section may disclose these
characters, but when negative results only are obtained, the one safe course
seems to be to withhold an opinion until an abundance of material is available.
In his examination of the teeth of Creodonts, Sir Charles Tomes employed
in addition to the Marsupial character of “penetration” of tubes, another
criterion in the general pattern assumed by the enamel prisms. He writes:
‘A general character of marsupial enamels is the simplicity of the course pur-
sued by the enamel prisms, each prism pursues as a rule an almost straight
course from the dentine to the enamel surface, and where marked curvatures
do occur, all of the contiguous prisms pursue the same course so that no patterns .
are produced by neighbouring prisms crossing one another. Where, however,
the tubes are very abundant, the enamel prisms can hardly be seen at all, and
we have to take the tubes as indicative of their course.”
Of Carnivora, he writes: “...The enamel patterns of Carnivora are fairly
constant. As one.would expect from analogy, they are not quite identical in all:
thus in the Dog group they are simpler, and where the enamel is thin they
become quite straight. Where, however, the enamel is thicker, the patterns
are easily identifiable as similar to those found in, for example, the Felidae,
though the curvatures are less pronounced....”’
In Hyaena “It will be noticed that no prisms in this, the thicker portion
of the enamel, pursue a straight course and that all do not pursue the same
course. They are, however, grouped into bundles or sheaves of prisms pursuing
an approximately parallel course, whilst towards the exterior of the enamel all the
bundles become parallel and straight. They are thus interwoven with one another
in a way that is not found in any known Marsupial.’”’ (The italics are mine.)
Taken in conjunction with other anatomical characters, I regard the
presence of tubes in the enamel as a precise test of Marsupial affinity, but I
think too much importance must not be attached to the pattern of the enamel
in determining affinity between members of different orders, however useful
such a test may be when applied to members of the same order, for I agree
that in the case of most recent Carnivora, in those areas where the enamel is
thick, a general sort of pattern is produced by the interweaving of groups of
prisms.
In Cynodictis, however, which is not a Creodont but one of the Fissipedia
and therefore a true Carnivore, Tomes found that ‘“‘the enamel prisms are
i
<
‘
.
indicative of their course.
*
Enamel of Sparassodonts, Cladosictis and Pharsophorus 193
almost straight and no decussation, or only the faintest trace of decussation
of the prisms of different planes is to be seen. It resembles chiefly the enamel
of Didymictis and differs in respect of its greater simplicity from that of other
Creodonts examined and from recent Carnivora. My sections of Cynodictis
embrace the whole tooth, so that there is no question as to the greater com-
plexity of pattern existing in any other part of the tooth.”
Of Didymictis, one of the Miacidae, of the Palaeocene and lower Eocene,
a Creodont family ancestral to the Fissipedia, but so highly specialized in its
Carnivore characters that Scott (op. cit. p. 557) is of opinion it should be regarded
as a true Carnivore, Tomes writes: ‘“‘the enamel prisms are parallel and pursue
a course only slightly curved. The typical carnivorous pattern is not to be
found, nor is there any trace of it, so that of the Creodonts examined this and
Cynodictis stand alone in this respect.”
Here then we find that in an early true Carnivore and in a form ancestral
to it the typical pattern which Tomes régards as characteristic of Carnivore
enamel is absent.
In Borhyoena, now regarded by Sinclair, Scott, Andrews and others as an
undoubted and highly specialized predaceous, polyprotodont Marsupial,
Tomes in his sections distinctly recognizes “the carnivorous pattern in the
course of the prisms....However there is ample evidence to say that the enamel
_ of Borhyoena is essentially of the Carnivorous type and bears no more resem-
blance to that of Marsupials than does that of other Creodonts.”
: In connection with other investigations I have examined a large number
of teeth of representatives of most genera of Marsupials: in some cases a head
has been taken and sections prepared from every tooth for the purpose of
comparing the structure obtaining in different members of the same dental
series, and I may state that the pattern of the enamel in recent Marsupials
is not so simple as the description given by Tomes, and quoted earlier in this
paper, would lead us to suppose.
In Plate XXI, fig. 1, is reproduced a photomicrograph from a section of the
enamel of Dasyurus where the prisms are seen to be “grouped into bundles or
_ sheaves of prisms pursuing an approximately parallel course...interwoven with
_ one another in a way” which Tomes states “‘is not found in any known Mar-
supial.”’
__ A photomicrograph taken from a section of the apex of one of the cheek-
teeth of Macropus ruficollis is reproduced in Plate XXI, fig. 2, where it is seen
_ that, contrary to Tomes’s assertion, the prisms in Marsupial enamel may cross
one another, producing a pattern.
Tomes also states that “when the [enamel] tubes are very abundant the
- enamel prisms can hardly be seen at all and we have to take the tubes as
” From his investigations on the development of
Marsupial enamel (5) he arrived at the conclusion that the tubes lie in the axes
_ of the prisms, his view being that in development each enamel cell is furnished
with a prolongation of its cytoplasm which extends through the whole thickness
of the forming enamel, and that calcification proceeds centripetally in these
194. J. Thornton Carter
processes, in some cases leading to a complete obliteration with a resulting solid
prism, whilst in others calcification does not proceed so far and the resultant
uncalcified prolongation of the enamel cell constitutes the “tube” which,
therefore, is confined within the limits of one prism.
Were this view of development correct the tubes would be indicative of the
course of the prisms: but the difficulties encountered in interpreting the struc-
ture of enamel are made evident when it is found that eminent authorities differ
in their views as to the position occupied by the tubes in the enamel. As stated
above, Tomes considers them to lie within the prisms whilst Mummery (6) is
convinced that they invariably lie in the interprismatic material, his view
being that spaces exist between the prisms of the forming enamel and that the
dentinal fibrils insert themselves into these areas.
Tomes states ((7), pp. 51, 52) that von Ebner considered that “the tubes in
Marsupial enamel do not lie in the rods themselves but in their interspaces,
and he gives a figure of a transverse section in which all but one of the tubes
appear to do so. Leon Williams has photographed some transverse sections
of marsupial enamel in which three-fourths of the tubes appear clearly to be in
the substance of the rods. The remaining fourth appear as though they were
between them.”
I have a number of preparations, some of which have been reduced to a
thickness of 54, which agree with the appearances seen in Leon Williams’s
photographs.
Reference to Plate XXI, fig. 3, will, I think, demonstrate clearly that the
course of the enamel tubes and their occupying fibrils is not associated with or
dependent upon the direction of the prisms; they may proceed parallel with
the prisms, lying in the interprismatic area: or they may lie within the substance
of the prisms: or they may proceed at right angles to or tangentially across
groups of prisms.
The facts stated above and demonstrated in the illustrations figured in
Plate XXI, lead me to attach restricted value to the pattern of the enamel as a
determining character in deciding affinity.
I have been able to examine the enamel of one Creodont only, the highly
specialized Hyaenodon, for which tooth I am indebted also to Dr Andrews,
but the sections obtained from this lead me to think that a re-examination of
the microscopic structure of enamel in the more primitive Creodonts, should be
undertaken.
In Hyaenodon Tomes “found no trace of penetration by tubes” but my
sections do disclose such a penetration as may be clearly seen in Plate XXII,
figs. 1 and 2 (t), where the tubes, though infrequent, extend some distance
into the enamel.
The general pattern of the enamel is shown in Plate XXII, fig. 3, whichis from
a photomicrograph of a section which had been etched to bring out the pattern.
So it is seen that in a Creodont this pattern which Tomes regards as
characteristic of Carnivora can exist together with that peculiarly Marsupial
character of the “‘ penetration” of the enamel by tubes.
Eo erlcer
Journal of Anatomy, Vol. LIV, Parts
d
2
oe
D
v
Plate XX
Plate XXI
Journal of Anatomy, Vol. LIV, Parts 2 & 3
ee
j
, ‘g s+,
BIA A
v
“Ne
>
3"
Sages,
Ce Nia
Fig. 3.
Se Oe:
any
Reeser a
Enamel of Sparassodonts, Cladosictis and Pharsophorus 195
The result of this investigation is to demonstrate that the two genera
of Sparassodonts examined possessed typical marsupial enamel and thus the
points of difference in the skeletal characters between these extinct Thylaci-
nidae and recent carnivorous marsupials become reduced to two only.
Further, the demonstration of the fact that recent marsupials may, in the
structure of their enamel, disclose patterns which have been regarded as
essentially typical of Carnivora, and that Hyaenodon possessed enamel which
exhibits a “penetration” by tubes, may be regarded as additional evidence in
favour of the common origin of the Marsupials and the early Monodelphia.
In the ultimate solution of this problem the evidence afforded by the minute
_ structure of the teeth may prove a deciding factor.
In conclusion I desire to express my thanks to Mr D. M. S, ‘Watson for
asking me to undertake this work; to Dr C. W. Andrews, F.R.S., and to
Dr Matthew for entrusting me with such rare and valuable material: and to
Mr F. J. Pittock, of the Zoological Department of University College, for taking
the beautiful microphotographs reproduced in the illustrations.
To Professor J. P. Hill, F.R.S., I owe a constant and increasing debt of
gratitude for affording me facilities to carry on research under his inspiring
direction and with the invaluable advantage of his advice and criticism.
DESCRIPTION OF PLATES
REFERENCE LETTERS
d. dentine; ¢. enamel; p. prism; ¢. tube.
PLate XX
_ Fig. 1. Cladosictis. Section of a tooth showing the pegaiare-gpuchind of the enamel (e) by tubes (¢)
continuous with the dentinal tubes (dé). Microphotograph x 320.
Fig. 2. Pharsophorus. Section of a cheek tooth presenting the tubes in the enamel (e) con-
tinuous with the dentinal tubes. Microphotograph x 360.
Pirate XXI
Fig. 1. Dasyurus. Section of enamel from a cheek tooth showing the prisms arranged in bundles.
Section etched to bring out the pattern. Microphotograph x 280.
Fig. 2. Macropus ruficollis. Section of apex of a molar tooth showing the pattern produced by the
crossing of groups of prisms. Etched. Microphotograph x 160.
Fig. 3. Macropus. tion of enamel, etched with acid, showing that the tubes (t) do not neces-
sarily follow the direction of the prisms (py). Microphotograph x 320.
Puate XXII
gh Sam 1 and 2. ee apiro Sections of a tooth showing the presence of tubes in the enamel.
- Fig. 3. “gg yomeee mag ects of tooth which has been etched to bring out the pattern of the
arrangement of the enamel prisms. Microphotograph x 120.
REFERENCES
(1) Tomes, Sir Jony. “On the Structure of the Dental Tissues of Marsupial Animals, etc.”
Phil. Trans. vol. cxxx1x. 1849.
(2) gree Sir C. 8. “On the Minute Structure of the Teeth of Creodonts, with especial reference
resemblance to Marsupials.” Proc. Zool. Soc. 1906, vol. 1.
(3) Soors, . W. B. History of the Land Mammals in the Western Hemisphere. Macmillan Co.
New York, 1913.
(4) Suycuarm, Dr W. J. Reports of the Princeton University Expeditions to sien. teas vol. rv.
Part m1.
(5) Tomes, Sir C. 8S. “On the Development of Marsupial and other Tubular Beatie, etc.” Phil.
Trans. yol. CLXXxIx. 1898.
(6) ha penile Dr of H. “On the Nature of the Tubes in Marsupial Enamel, etc.” Phil. Trans.
vol. cov. 191
(7) Tomes Sec. 8 A Manual of Dental Anatomy. 7th edition, 1914.
A CYCLOPS LAMB (C. RHINOCEPHALUS)
By REGINALD J. GLADSTONE, M.D., F.R.C.S.,
AND C, P. G. WAKELEY, M.R.C.S., L.R.C.P.,
University of London, King’s College
"Tue occurrence of one-eyed monsters has excited the wonder and curiosity
not only of the men of our own period but also of the ancients. Among the
latter Homer stands out pre-eminently, and his tale of the adventures of
Ulysses, and his fellow-travellers, with the giant Polyphemus, has fascinated
and stimulated the imagination of all students of mythology.
The questions which these ancient lays suggest, are:
1. Is there any foundation in fact, for the classical myths of a race of
giant cyclopes living apart from the world in insular seclusion?
2. Is it possible for human cyclopes to reach maturity and have normal
vision?
It seems probable that the idea of a race of one-eyed monsters has arisen
from the occasional birth of such among animals and men; and that the
myths which have grown out of this idea have gradually evolved in the
imaginations of the poets and historians of the past, rather than that they
have been evolved, as it is alleged by seme, upon a basis of allegorical construc-
tion; or that they are explainable on the assumption that there were races
who fought with helmets, constructed with a single opening in front, which
gave rise to the appearance of a single eye.
Among the records of mammalian cyclopean monsters we have not found
any mention of such having survived their birth by more than a few hours
er days}.
From a cursory examination of published cases, the explanation of the
early death of these monsters appears to be due to the difficulty which is
experienced by the young in suckling. In those cases in which the cyelopic
defect is combined with a high degree of “‘agnathia”’ (10), this would of course
be impossible, owing to the pharynx ending blindly, and having no com-
munication with the mouth or nasal cavities. The young would thus quickly
die from suffocation. But there are a large number of cases such as the speci-
men which forms the subject of this paper in which the mouth cavity com-
municates freely with the pharynx. In the majority of these cases, however,
the nasal cavities are completely shut off from the pharynx (fig. 4), which
ends in a blind recess at the base of the skull. The young would thus be
1 Regnault has figured a case of a cyclocephalic foal which was said to have lived for about —
4 months. Geoffroy Saint-Hilaire however, who quotes the case, believes that the history is not
authentic, and that the case ought not be taken into consideration.
A Cyclops Lamb (C. Rhinocephalus) 197
_ prevented from breathing during the act of suction, and the process of
suckling would have to be carried out by alternate respiratory and suction
movements. Under these circumstances it is not surprising that the vast
majority if not all cases of cyclopia occurring in mammals should not survive
their birth by more than a few days.
It has been shown by Geoffroy St Hilaire@3), however, that cyclops
monsters, whether human or occurring in domesticated animals, such as the
sheep, horse, pig, dog or cat, do not survive their birth by more than a few
hours, some being described as dying suddenly in convulsions in less than
twenty minutes after birth. This he attributes to the same cause as that which
results in the very early death of the anencephalia, namely a grave defect
in the development of the brain. It is, therefore, only in the lesser degrees
of deformity which are unaccompanied by defect in the growth of the brain,
and in which both the mouth and nasal cavities communicate with thé
pharynx that it would be possible for the individual to survive. In fact not
the true cyclopes in which there is a single median eye, but those cases in
which there is merely an approximation of the eyeballs, without any marked
defect in the development of the nasal chambers.
With regard to the possibility of a cyclope possessing normal vision, we
find that in nearly all the published cases in which a dissection has been made
of a median eye, that the interior of the eyeball is almost completely filled
with choroid, and no mention is made of either retina or vitreous. Moreover,
the lens has been found double, or if single, it has usually shown indications
of its composite nature. It is extremely improbable, therefore, that if it were
possible for a human cyclope to reach maturity, he would possess normal
vision.
The specimen of cyclops lamb (figs. 1 and 2) which forms the subject of
this paper, belongs to the class described by Geoffroy St Hilaire, as C. Rhino-
cephalus. The name indicates the presence in this variety of a trunk-like
appendage, or proboscis. This contains the rudiments of the olfactory portions
of the nasal chambers, and projects upward from the frontal region above
a single orbital cavity.
Viewed from in front fig. 1, there may be noted (1) the proboscis (3-5 cm.
in length) turned upwards and backwards over the frontal region. Its
external opening shows an indication of bilateral subdivision into right and
left nostrils. At its base a pointed process of bone somewhat triangular in
form could be felt projecting upwards from the centre of the supraorbital
margin. In the subsequent dissection of the head, this proved to be the
premaxillae fused one with the other and displaced upwards above the
eyeball. Below the proboscis is (2) the composite median eye, which occupies
a rhombic area corresponding to the fused right and left palpebral apertures.
The lateral angles of this area are formed by the external canthi. The right
and left upper eyelids are continuous with one another at the superior angle,
and the lower lids unite at the inferior angle. In the middle is a vertical
Anatomy LIv 13
198 R. J. Gladstone and C. P. G. Wakeley
(yy
je
it a les
; ce \
hy Ww
Fig. 2. O. Rhinocephalus, viewed from the side.
;
:
:
.
A Cyclops Lamb (C. Rhinocephalus) 199
fold of conjunctiva which represents the fused “plicae semilunares,” and
which lies between two corneae. These are situated one on each side in the
anterior wall of a single median eye, the transverse diameter of which con-
siderably exceeds the vertical. Below the orbit is (3) a short upper lip, and
projecting beyond this (4) the tip of the tongue, which is turned upwards
towards the eye. Below this again is (5) the lower lip, which projects forward
(see fig. 2) a short distance beyond the upper lip.
On making a dissection of the bones of the skull (fig. 3), it was seen that
the root of the proboscis is supported on its under part by the premaxillae
which are united with each other in the middle line, and displaced upward.
_ Their basal or palatine parts together form the median part of the roof of
the common orbital cavity. Laterally they are connected by fibrous tissue
to the frontal and nasal bones. Dorsally the root of the proboscis is formed
by the two nasal bones, which are very much shortened. Behind they
oe Nasal
Pre aicualts.
2 “~"~Z ygomolic
~~Lachrymal
~~-Moxilla
Fig. 3. Lateral view of skull.
articulate with the frontal bone, while anteriorly they are united with the
premaxillae by membrane. The single orbital cavity is wider in the transverse
diameter, than a normal right or left orbit. This is owing to the participation
of the outer and middle parts of both orbits in the formation of a single large
median cavity. The median walls of the orbits formed usually by the sphenoid,
ethmoid and lachrymal bones are absent. The lachrymal bones having been
displaced downwards, form part of the floor of the orbital cavity, and the
central part of the infra-orbital margin; while the ethmoid is displaced upward,
and forms part of the skeletal basis of the “ proboscis.”
- The orbital margin is formed above by the basal or palatine parts of the
premaxillae, and supra-orbital margins of the frontal bones; laterally by the
13—2
200 R. J. Gladstone and C. P. G. Wakeley
external angular processes of the frontal and the malar bones; below by the
infra-orbital processes of the malar bones, and the two lachrymals. The single
optic foramen is continuous on each side with the superior orbital or sphe-
noidal fissure,
The upper jaw is markedly shortened and is composed of the alveolar
portions of the maxillae only; the premaxillae taking no part whatever in
its formation. In it are contained the normal number of teeth, viz.: three
premolar and three molar,
Lachr ymal sac
Nasal
Maxillary Sinus
Ee uslachiay Tube
& ay
\
\ Prermolar
Fig. 4. Median section of head.
The anterior part of the lower jaw, which is unopposed by the premaxillae
is curved upward. In it one can recognise three incisor, and one canine,
anteriorly, and the normal number of premolar and molar teeth behind.
The remaining parts of the skull as viewed from the lateral aspect appear
normal.
On making a longitudinal section of the head and neck (fig. 4), the cavity
of the proboscis was seen to lead down from the single 8-shaped opening formed
by the right and left nostrils into a large tubular space which extended to the
root of the proboscis. Here the inner membrane appeared to be continuous
A Cyclops Lamb (C. Rhinocephalus) 201
on each side of the crista ethmoidalis with the dura mater of the anterior
fossae of the skull. The interior of the proboscis was partially subdivided
into right and left nasal cavities by an irregular septum formed by rudiments
of the mesethmoid and vomer. Laterally there were some nodular projections
representing the ethmoturbinals. The apparent openings in the region of the
cribriform plate leading from the cranial cavity into the trunk were occupied
by three flask-shaped evaginations of the dura mater. These were connected
by nerve fibres with the olfactory lobes.
Below the anterior cranial fossae the section passed through the orbital
cavity in the middle of which was the single eyeball. The cavity of this was
almost completely filled by choroid, but contained in addition two lenses,
of which the right was the larger. In correspondence with these there were
two anterior chambers, the iris and the cornea of the right side being larger
than on the left. On the floor of the orbit were the two lachrymal sacs; that
on the left side was prolonged downwards and forwards into a narrow tube
which ended blindly; on the right side the duct was complete, and opened
into the lower part of the right nasal cavity, beneath an overhanging ridge
which appeared to be the maxilloturbinal. It was evident therefore that the
nasal chambers were divided into two parts; an upper or olfactory part
lying above the orbit, and contained within the proboscis, and a lower
maxillary part, represented on the right side only, and closed both in front
and behind. In the remaining part of this region the saw had passed through
bone; the section having traversed parts of the fused maxillae, lachrymal,
palate and pterygoid bones. Anteriorly by breaking away the bone overlying
it, an alveolus containing the first left premolar tooth was exposed; and by a
similar method the cavity of the left maxillary air sinus was opened up. The
nasal region was limited behind by a well defined sloping border which was
formed by the posterior margins of the fused internal pterygoids. This
constituted the anterior boundary of the naso-pharynx, which was thus
entirely cut off from the nasal cavities. The lateral walls of the naso-pharynx
were closely approximated, its transverse diameter thus being greatly lessened.
The lower orifice of the Eustachian tube and a pharyngeal recess were visible
on each side. The pharynx was continuous with the buccal cavity through
a slit-like opening bounded laterally by the anterior pillars of the fauces, The
anterior part of the roof of the mouth was absent, the premaxillary portion
having been displaced upwards above the orbit. The upper lip appeared to
be formed by the labial portions of the embryonic maxillary processes only,
the central portion which is normally formed from the medial nasal processes
being displaced upward from this region into the proboscis. The roof of the
mouth was thus considerably shortened, and the tongue which protruded
beyond the upper lip was bent sharply upward towards the eye.
A median longitudinal section through the brain, showed that the cavity
of the third ventricle was almost completely obliterated, by fusion of the
optic thalami, and that there was a complete absence of the corpus callosum.
202 R. J. Gladstone and C. P. G. Wakeley
A single optic nerve passed forwards from the optic chiasma to the posterior
pole of the eyeball. The remaining cranial nerves were seen to occupy their
normal situations with the exception of the IV nerve which appeared to be
absent, :
On removing the roof of the orbit, we were able to recognise the right
and left levator palpebrae superiores muscles, lying superficially on each side
of the median plane, and fused by their medial borders. Beneath were the
superior recti also fused. The superior oblique, and internal recti muscles
were absent, and only traces of the inferior oblique and inferior recti muscles
could be recognised. The lateral recti were present, and well developed. Branches
of the third nerve, and the sixth nerve supplied the muscles described above,
and the supra-orbital and lachrymal branches of the ophthalmic nerve were
present.
ETIOLOGY
The cause of “‘cyclopia,”’ and the frequently associated defect “‘agnathia”
has been investigated by many authors and experimental embryologists,
more especially Meckel(17), Geoffroy St Hilaire(3), Huschke, Dareste(),
Born, Spemann (25), Driesch(6), Fischel(7), Stockard (26) and E. Schwalbe (24),
and a considerable number of theories have been advanced in explanation
of the condition. The more important of these have been summarised by
Ernst Schwalbe in his work entitled, Die Morphologie der Missbildungen
des Menschen, und der Tiere, Teil 111. It will therefore be unnecessary to do
more than record certain conclusions, which we have come to, from a study
of the specimens which we have examined.
In the description of a specimen of a cyclops and agnathic lamb published
by one of us in 1910(10), it was pointed out that a distinction may be drawn
between those cases of cyclopia which occur in double- and those which occur
in single-monsters. As a type of the former, which illustrates the condition
best, we may select the well-known class cephalothoracopagus disymmetros.
In these monsters there is a composite head which has the appearance
of having been formed by the fusion face to face of the heads of two separate
embryos with one another; there being two completely separated bodies,
having their ventral aspects opposed, and each bearing the normal complement
of upper and lower limbs. The condition, however, as has been shown by
EK. Schwalbe, appears to be due not to fusion of two embryos, but to an
extensive posterior dichotomy of a single embryo. In the dichotomy every-
thing but the most anterior part of the cephalic end of the medullary plate
is involved. The two partially separated heads have grown in contact with
one another, so as to produce a large double-head, on the opposite sides of
which are two composite faces. The right and left halves of each face are
formed from the opposed halves of each head. As the longitudinal axes of each
head are seldom in line with one another, but join at an angle, one face is
often more completely developed than the other, namely the one corresponding
to the side on which the axes would unite so as to form a projecting angle,
A Cyclops Lamb (C. Rhinocephalus) 203
whereas on the opposite side corresponding to the receding angle, the compo-
site face is imperfectly developed, the lateral parts of the face being approxi-
mated and the central parts defective or absent. On this side a single composite
eye, and external auditory meatus may be present, and the nose and mouth
rudimentary or absent. Here the growth of the two partially separated heads
has been interfered with by contact of one head with the other; thus, the mouth
and nose, and the nasal halves of the eyeballs remain undeveloped, whereas the
outer parts of the two faces are free to grow. The single eye is thus formed
by the temporal halves of the right and left eyes belonging respectively to the
right and left foetuses grown forward in continuity with one another, the
nasal halves being suppressed; not by a right or left eye belonging to a single
head, as might occur if an irregular fusion had taken place between the heads
of two separate individuals.
The formation of the single composite eye in these monsters furnishes
we believe an explanation of the mode of development of cases of cyclopia
occurring in single-monsters, namely, a defect in that part of the medullary
plate from which the floor of the third ventricle and adjoining parts of the
lamina terminalis and optic vesicles are developed, and involving also the
overlying surface ectoderm and mesoderm. This would allow the temporal
halves of the optic vesicles, to grow forward in continuity with one another
so as to form a single composite eye, and it would prevent the normal union
of the fronto-nasal process, with the maxillary processes. The degree of the
deformity will naturally vary with the extent of the primary defect in develop-
ment; and the parts which are affected, will vary with the exact site of the
original defect, and also with the stage of development at which the defect
in growth takes place.
The cause or causes of this defect in growth of the central parts of the face,
which gives rise to the different degrees of cyclopia and allied defects, is a
difficult question which we do not propose to deal with in this paper; we may
mention however that the mechanical effect exerted by the pressure of the
head-fold of the amnion appears to be disproved, as a general cause, by the
frequency with which the defect appears in anamnia, and by the symmetry
of the parts, which is such a marked feature of the monophthalmia.
Recent experiments by American investigators on fish and amphibian
embryos indicate that the condition arises from some interference with the
general nutrition of the growing embryo, which acts more especially on certain
parts, at a particular period of development. It was found, for instance by
McClendon (is), that a large percentage of fundulus embryos were cyclopic,
when reared in water in which the carbonic acid content of the water was
considerably above that found in normal pond water, and he got the same
results with embryos grown in water in which was dissolved varying propor-
tions of magnesium and other salts. The number affected and the degree of
the deformity varied with the strength of the solution, and he also found
that different effects followed the use of the deleterious salt at different periods
204 R. J. Gladstone and C. P. G. Wakeley
of development. Similar results were obtained by Stockard (26) who, in addition
to magnesium salts, employed alcohol, ether, chloroform and ehloretone in
varying strengths. It may be presumed therefore that certain parts of the
embryo in which growth is especially active at a particular stage in develop-
ment, would be especially susceptible to the action of the poison, and would
suffer more than others if the general nutrition were interfered with. If this
assumption is correct, the principle involved is applicable to all classes of
vertebrate animals, whether the defect in nutrition is produced by a faulty
condition of the water in which the embryos of fishes or amphibia are reared;
or with reptiles and birds the nutrition of the embryo in incubated eggs is
interfered with by varying the condition of the air supplied, e.g. with regard
to temperature and degree of moisture. And in the placentalia the same
cause will act through varying conditions of the maternal blood circulating
through the placenta or of the liquor amnia, or, finally, as a result of endo-
metritis, or a diseased condition of the placenta itself, causing impairment
in the nutrition of the embryo.
It may be worth while to point out here, that the special action of chemical
substances circulating in the blood, at a later stage of development, on the
growth of particular parts, such as the long bones, or the nasal and maxillary
regions of the face, may be discounted in this connection; e.g. the supposed
action of the thyroid and pituitary secretions on these parts in adolescent and
adult subjects in certain forms of gigantism and acromegaly. For in the more
extreme forms of cyclopia, and in the allied condition of agnathia, it is probable
that the defect in development, occurs at a very early stage in development
(Schwalbe and Spemann) before either the thyroid or pituitary glands have
become recognisable as definite organs; and in the less marked forms of
deformity which occur, from a faulty development taking place at a later
stage, e.g. “hare lip,” these organs though existing as epithelial pouches
would, presumably, not yet be functional.
The theory that the defective development of a particular part or organ,
may be due to faulty nutrition of the embryo as a whole, rather than to local
and mechanical causes, if true, is of great importance as an explanation of
the frequent association in a single individual of one defect in development
with another; e.g. spina bifida, with “‘hare lip”’ and cleft palate. The general
condition which would have interfered with the union of the medullary folds
or neural laminae, would also have prevented the union of the embryonic
medial nasal processes with the maxillary. The theory also serves as an
explanation of the frequent occurrence of congenital deformities of varying
types in children born at succeeding pregnancies from the same mother,
A general cause such as chronic alcoholism, syphilis, or the imperfect elimina-
tion of urea from the system may obviously act prejudicially on the general
development of the embryo, and with varying states in the health of the -
mother, more at one period of development than another. It would however
also exert a more especially prejudicial action on particular organs during
A Cyclops Lamb (C. Rhinocephalus) 205
certain critical stages in their development, e.g. in the development of the
nose and mouth, the period at which union of the palatal processes, with one
another and with the nasal septum takes place during the eighth week of
intra-uterine life.
We thus see that a connection is established between such apparently
widely separated types of deformity as cyclopia or agnathia, and bilateral
or single facial cleft, cleft palate or hare lip; all of which may be regarded as
variations in degree of deformity between the more extreme, and less extreme
instances of defective development. The different stages connecting these
malformations are well illustrated in the classification of the varying degrees
of cyclopia by Bock (1), and in an important article by the Japanese author,
Inouye (13), on the development of the premaxilla, and its bearing on the
malformations grouped under the term “facial cleft.” The different grades
in defective development of the lower jaw, leading up to complete agnathia
is too large a subject to deal with in this article, and we propose therefore
to describe these in a subsequent paper.
Viewed from the practical standpoint, the dependence of these deformities
on defective nutrition due to a general or constitutional cause, serves to
emphasize the importance of careful constitutional treatment of women
during pregnancy, and more especially the early stages, when the more critical
phases of development are taking place.
SUMMARY
The study of this specimen, and allied conditions has served, we believe, to
establish the following general conclusions:
1. Cyclopia when occurring in mammalia are as a general rule incapable
of surviving their birth by more than a few hours or days; this is owing to
interference, by associated defects in the development of the mouth, pharynx
and nasal cavities, with the acts of respiration or suction, and frequently
owing to grave defects in the development of the brain.
2. A cyclopic eye is imperfectly formed, and therefore blind.
8. The cyclops eye both in single and double monsters is formed from
the lateral portions of the common rudiment of two eyes which have grown
forward in continuity with one another, the central parts being defective.
4. A cyclops eye is not formed by the fusion of two more or less fully
developed optic cups but from a continuous area of the neural ectoderm
which has failed to undergo the normal development into separate right and
left optic vesicles. Varying degrees of the condition ranging from a single
eye contained in a single orbital cavity, to only a slight approximation of
the two eyes, may be explained by a more or less complete failure in the growth
of the central parts of the common primordium from which the two optic
vesicles are normally developed. If the defect in growth affects the whole
of this area, there will be neither eyeball nor optic nerve, and the condition
206 R. J. Gladstone and C. P. G. Wakeley
may be accompanied by varying degrees of approximation of the external
auditory meatuses leading up to a single median tympanic membrane and.
agnathia.
- Two lenses contained within a single eyeball, will be due to two separate
ectodermal invaginations into the mouths of an optic vesicle which is only
partially subdivided, and there will be two corneae and two irides. If a single
lens is found in a cyclops eye, it will be formed from a single ectodermal
invagination and it will correspond to the outer halves of two lenses, which
will be developed in continuity with one another over the brim of a composite
optic cup. A constriction in the median plane has sometimes been observed
in such double-lenses indicating their mode of origin. In other words as
expressed by Schwalbe, a double-structured lens in a single eye does not
prove that the rudiments of the lens are secondarily united, but the condition
may be explained on the assumption that a certain degree of doubling of the
optic cup has led to the development of two lens components.
5. As pointed out by Spemann and Schwalbe, the very great regularity
of the double structures in these monsters, would be incomprehensible if the
fusion theory were correct. If fusion were to take place one would expect
with much greater probability considerable deformation due to opposed
lateral pressure.
6. Cyclopia, and the various stages leading up to the compen oodles:
when occurring in a single monster, is, we believe, due to a “general” rather
than a “local” or “mechanical” cause, such as pressure of the head-fold of
the amnion, or too early union of the medullary folds, preventing inrolling
of the intervening ectoderm to form the nasal halves of the two optic cups
(Dareste).
7, Itis possible, that a deleterious condition (acting) generally may affect
one part more than another at a particular stage of development, owing to
certain organs which are passing through a critical phase in their development
being specially susceptible to such influences at that stage in their growth.
Also owing to inequality in the rate of growth of certain parts of the embryo
as compared with others any general interference in the growth of the embryo
at a particular time would have a greater effect on the more rapidly growing
parts than it would on those which at the time are growing less rapidly.
REFERENCES TO LITERATURE
(1) Boox, E. Klin. Monatsbl. f. Augenh. Stuttgart, 1889, xxvu. 508.
(2) Bramwextt, B. ‘Photographs of case of cyclopaean monstrosity.” Edin. Med. J. 1880-1,
xxvi. 550, 1 pl.
(3) Cxavs, G. Arb. a. d. Zool. Inst. d. Univ. Wien, 1892-3, x. 283-356.
(4) Crate, B. Edin. Med. J. 1886-7, xxxi1. 193-197, 1 pl.
(5) Darestx, C. “Mode de formation de Cyclopie.” Ann. d’Oculistique, 1891, 171-182.
(6) Drreson, H. Analytische Theorie der organischen Entwicklung, Leipzig, 1894.
(7) Fisonen. Verhandl. d. Deutschen Path. Gesellsch. v. 5, 1903, 225-356.
(8) Gatxours, J. F. Boston Med. and Surg. J. 1880, om. 135 and 495.
(9) Gauppr, E. Anat. Hefte, 1911, xia. 311.
A Cyclops Lamb (C. Rhinocephalus) 207
Guapstong, R. J. “A cyclops and agnathic lamb.” Brit. Med, J. 1910, m. 1159.
Hacker, V. “Die Keimbahn von Cyclops, neue Beitrage zur Kenntniss der Geschlects-
___ gellen-Sonderung.”” Arch. f. mikr. Anat. Bonn, 1897, xirx. 35-91, 2 pl.
Hirst, B. OC: Hirst and Piersol, Human Monstrosities. Young, Pentland, Edin. and London,
1892, 113-128.
Ivovyr, M. Anat. Hefie, 1912, xiv. 481, and xtvr. 1.
JENKINSON, J. W. Experimental Embryology, 1909, 275.
‘Lewts, W. H. Amer. J. Anat. ut. 1904; J. Exper. Zool. 1. 1905.
MatHerse, A. “Description d’un monstre cyclopien rhinocéphale.” Bull. Soc. Anat. de
Paris, 1879, 4 8. rv. 115-117.
( | Mecxen, J. F. Handbuch der pathologischen Anatomie, Halle, 1812-18.
McCienvon, J. F. Amer. J. Physiol. 1912, xxrx. 289.
Putsatrx, C. Journ. d Anat. et Physiol. Paris, 1889, xxv. 67-103.
Prersot, Georce A. v. Hirst, B. C.
Pratno, G. Boston Med. and Surg. J. 1917, cuxxvi. 332.
Rapaup. Bull. Sci. de la France et de la Belgique, xxxvu. 436.
Samt-Hiaree, J. G. Histoire générale et particuliére des Anomalies de l Organisation chez
? Homme et les Animauz, Paris, 1832-1837.
Scuwase, E. Die Morphologie der Missbildungen, Teil m. 29-32.
Sremann. Arch. f. Entwicklungsmech. xt. 225, xvi. 553.
Strockarp, C. R. J. Exp. Zool. 1907, tv. 165; Amer. J. Anat. 1909, v1. 286, 1910, x. 369.
THE ANATOMY OF A SYMELIAN MONSTER
By T. B. JOHNSTON, M.B., Cu.B.,
Professor of Anatomy, University of London, Guy’s Hospital Medical School
‘Tue number of recorded cases of monsters of the type to be described in
this paper is not so large as might reasonably be expected, and no really
satisfactory theory has been propounded to explain their occurrence.
The foetus which forms the subject of this note was born during the early
part of the eighth month and belonged to the class of Symeles (Saint-Hilaire (1)).
The head, arms and upper part of the body were well developed and,
outwardly, normal, but the lower limbs were united to one another almost
------Unbilical Cord
--- 2 Persistent Cloacal Tubercle.
-\----False Rrineum.
---Patella.
Fig. 1, Ventral view of lower half of Symelian Monster.. The thighs are partially fused, the
knees are directed laterally, the tibiae are anterior and the plantar aspect of the foot is
directed forwards.
down to the knees, and both were rotated laterally (fig. 1). In addition, the
buttocks did not show the usual prominence. The fused limbs possessed an
unusual degree of mobility on the trunk. The hip-joints were practically
fixed but the movement occurred in the lumbar region, where, as will be
described later, an unusual joint was present.
No genito-urinary or anal apertures were present and the only representa-
tive of the external genital organs was a small, median, conical elevation,
situated on the ventral aspect about midway between the umbilicus and the:
apparent perineum (fig. 1). It strongly suggested a penis, but it was imper-
forate and had no trace of a prepuce. On microscopical examination it was
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The Anatomy of a Symelian Monster 209
found to consist of a core of connective tissue with a complete covering of
skin, in which there were numerous hair follicles. No trace was found of an
urethral plate and there were no vestiges of preputial folds.
The umbilical cord was normal in position and appearance, but it contained
only two vessels, viz. the umbilical vein and a single umbilical artery.
It may be here stated that the degree of fusion of the lower limbs was
less in the present case than in any other I have been able to trace, including
the case recorded by Katz(14).
A summary of the abnormal conditions found in the various systems is
given below, but detailed description is restricted to those points which appear
to have an important bearing on the production of this type of monster.
Fig. 2. Posterior view of the pelvis and sacrum. The sacrum is much reduced, and the ischia
are fused in the regions of the ischial spines and in the regions of the tuberosities. The
acetabula look backwards as well as downwards and laterally.
Osseous System. In this system, the anomalies were confined to the
vertebral column, the ribs, the sternum and the innominate bones.
There were seven cervical, thirteen rib-bearing vertebrae and one lumbar
vertebra. The sacrum was very rudimentary and consisted of three partly
ossified vertebrae and a small cartilaginous nodule, which was all that repre-
sented the fourth and fifth pieces of the sacrum and the coccyx. As will be
seen from fig. 2, a condition of spina bifida was present.
The bodies of the vertebrae showed few striking changes but neighbouring
laminae were sometimes fused to one another, as were neighbouring transverse
processes. The single lumbar vertebra had no vertebral arch and a large joint
cavity was interposed between it and the sacrum. This accounted for the
210 T. B. Johnston
unusual degree of movement between the lower limbs and pelvis, on the one
hand, and the vertebral column, on the other. A similar condition has been
recorded by Gebhard (2), but, as the lumbar vertebrae and the lumbo-sacral
joint were normal in many of the cases described by other authors, the con-
dition must be regarded as. secondary. It represents an abnormal type of
the normal flexion of the foetal limbs “in utero” and is probably to be
attributed to limitation of movement at the hip-joints.
Neighbouring ribs, like the laminae and transverse processes of the
thoracic vertebrae, showed a marked tendency to fuse, but only the dorsal
portions were affected, the ventral portions remaining separate. There were
thirteen ribs on the right side, and fourteen on the left side.
The innominate bones were separated posteriorly by the rudimentary
sacrum. The ischia were fused to one another in the regions of the spines and
again in the regions of the tuberosities, As a result, the greater sciatic fora-
mina were thrown into one, and, at a lower level, a small median opening
represented the fused lesser sciatic foramina. Median sagittal section showed
that the pubes were fused to one another from the symphysis down to the
ischia.
Muscular System. The psoas major, the glutaeus maximus, the piriformis,
the gemelli and the obturator internus muscles all showed varying degrees
of abnormality, but the most interesting anomaly was found in the biceps
femoris. On both sides the short head was normal, but the long head, on
the left side, arose from the fused tuberosities extending to the right of the
middle line. On the right side, the long head was absent, but, in view of the
fact that the long head of the left side was innervated both by the left and
right sciatic nerves, it may be concluded that, in reality, it had fused with
its fellow. On the other hand, the two semitendinosus muscles were quite
separate, while the semimembranosus muscles, though quite independent at
their origins, were partially, blended for a short distance and then separated
again. we
Nervous System. Owing to the condition of the vertebral column, the
spinal medulla was in two portions. The upper part ended opposite the lowest
rib-bearing vertebra, while the lower part lay in the unclosed sacral canal.
The cervical and brachial plexuses were normally constituted, but, while
there were thirteen intercostal nerves on the left side, there were only twelve
on the right side. The lowest intercostal nerve, on each side, gave origin to
the subcostal nerve and the upper root of the genito-femoral nerve.
There were no recognisable lumbar nerves, but there were three sacral
nerves. S 1 was a large nerve, which gave origin to the lower root of the
genito-femoral, the lateral cutaneous nerve of the thigh, the femoral and the
obturator nerves and, in addition, sent a communicating branch to § 2.
The latter, further strengthened by a branch from S 3, formed the sciatic
band, while the remainder of S 8 constituted the posterior cutaneous nerve
of the thigh.
The Anatomy of a Symelian Monster 211
Circulatory System. The only striking anomalies discovered were found
in the abdomen. There was, as is usual in these monsters, a single, median
umbilical artery, directly continuous with the abdominal aorta. The common
iliac arteries were therefore indistinguishable, but the external iliaes arose
by a common trunk from the dorsal aspect of the single median artery and
almost at once separated, being normal in the remainder of their course so
far as could be traced. Their common trunk gave off a few small branches
to the rudimentary pelvis and a single gluteal artery on each side.
The inferior mesenteric artery was absent.
There were no striking anomalies present in the veins.
Abdominal Viscera. The stomach, the duodenum and the rest of the
small intestine were normal, as were the liver, spleen and pancreas. The large
intestine ended blindly in the region of the spleen, and was considerably
umbilical artery.
Fig. 3. Structures on the posterior abdominal wall, showing the single, median, umbilical artery
distended with meconium. It was supplied, in its whole extent by the colic
branches of the superior mesenteric artery.
The suprarenal glands were normal. ;
The kidneys were absent, but occupying their position on the posterior
abdominal wall were two flattened, partly lobulated structures which extended
downwards as far as the iliac crests (fig. 3). Microscopical examination showed
that these structures contained a tube, but the characters of its epithelial
lining could not be determined owing to imperfect fixation. The wall of the
tube contained a thick layer of unstriped muscle, and, in some sections what
looked very like degenerated glomeruli were observed. I believe that this
structure is a remnant of the mesonephros and its duct.
The ureters and bladder were absent.
The ovary lay in the iliac fossa. It had a normal relationship to the uterine
tube and the meso-salpinx, but the uterus, as such, was absent. The uterine
tube passed backwards and medially and became continuous, on each side,
212 TT. B. Johnston
with a small nodule which lay near the abdominal aorta (fig. 3). This
nodule, on section, consisted of a strong muscular wall containing a tube
in its centre. On microscopical examination, it was possible to identify the
lining epithelium of the tube as being columnar in character, but it was
impossible to determine whether or not it had been ciliated. These nodules
represent the unfused Mullerian ducts.
The ligament of the ovary was, in the absence of the utertis, directly
continuous with the round ligament and, after traversing the inguinal canal
(fig. 3), terminated in the subcutaneous tissue over the pubis.
As already indicated, the colon was absent below the left colic flexure.
To sum up, the most striking anomalies were the following:
(a) Partial fusion of the skin, fasciae and muscles of the thighs.
(b) Fusion of ischia and pubes.
(c) Presence of a single, median, umbilical artery.
(d) Rudimentary condition of the sacrum, absence of coccyx and disap-
pearance of four lumbar vertebrae.
(e) Absence of terminal portion of colon.
(f) Absence of kidneys, ureters, bladder and urethra.
(g) Vestigial character of external genitalia.
(h) Presence of femoral, obturator nerves, etc., despite the aiaante of
the lumbar nerves and the lumbar part of the spinal cord.
(¢) Partial fusion of vertebral arches and ribs, asymmetrically.
(k) Innervation of the long head of the left biceps femoris by both sciatic
nerves.
In monsters of the type just described, the most striking deformity is the
fusion of the lower limbs and it was the fact that the degree of fusion is subject
to great variation that led Saint-Hilaire (1) to suggest the following grouping:
(1) Symeles, in which fusion has not affected the feet; (2) Uromeles, in which,
in addition to fusion of the limbs, the feet are fused into one; (3) Sirenomeles,
in which the two limbs fuse to form a stump, no foot being present. This
subdivision, however, is not of great value as it only takes account of one of
the features constantly found in these monsters.
A complete review of the earlier literature on the subject was given by
Manners-Smith (4) in 1895. Since then, Mall(5) has shown that “ pathological
embryos, experimental monsters and human monsters at term form a class
by themselves, inasmuch as they are produced from normal ova through
causes which lie in their environment.” This observation at once discounts
the views as to the origin of the Symelian and allied monsters put forward
by Gebhard (2), Vrolik (6) and others. Saint-Hilaire’s(1) view, which Manners-
Smith (4) felt compelled to fall back on, is unsatisfactory in that, although
one naturally agrees with the statement that, given the opportunity, sym-
metrically developed structures tend to fuse with one another, it fails to
suggest any reason for the origin of the conditions favourable to fusion.
The Anatomy of a Symelian Monster 213
As a result of the varied conditions found in this group of monsters,
anomalies, which, though interesting in themselves, are relatively unimportant
because inconstant, have frequently been described in great detail, whereas
anomalies, which are of great importance because they are constant, have
frequently received scant attention. It is only by a close study of the constant
features that one can hope to arrive at the exciting cause of the malformation.
The following list has been drawn up from a study of the available literature.
(1) There is always present a single, median umbilical artery in direct
continuity with the abdominal aorta.
(2) There is always some degree of fusion of the lower limbs. This
_ condition varies from that found in the present case to that found in Sireno-
meles (Moorhead (12), etc’).
; (3) There is always some degree of suppression at the caudal end of the
vertebral column.
‘ (4) There is always some degree of interference with the development
of the cloaca and the external genitalia.
(5) So far as has been discovered, the head, neck, upper limbs and thoracic
viscera are usually normal.
Of these features, I believe that the first is the most worthy of consideration.
Its constancy was early noted but its importance has been, to a large extent,
3 overlooked. Solger(7), whose views are quoted by Manners-Smith(4)—I have
been unable to obtain his original paper—pointed out that the single umbilical
artery was not the persistent member of a pair but was formed by fusion of
the two umbilical arteries. When they are first recognisable in the human
embryo, the umbilical arteries are represented by arterial plexuses spreading
over the sides of the caudal end of the yolk-sac, connected dorsally at several
points with the tailward continuations of the aortae. Fusion of these two
oe plexuses caudally would result, firstly, in the production of a single, median,
umbilical artery continuous with the abdominal aorta, and, secondly, in the
formation of an obstruction to the tailward growth of the hind-gut and to
the development of the cloacal membrane. This arrangement would be in
keeping with the described conditions of the structures whose development
is dependent on the growth of the hind-gut and the formation of the cloacal
membrane, since the large intestine ends blindly, and the bladder, urethra,
anal orifice and external genitalia are awanting in these cases.
It is perfectly clear that the converse of this proposition might be stated,
namely that failure of the hind-gut to develop would permit the umbilical
arteries to meet and fuse. Consideration, however, of cases described by
Gebhard (2) and Manners-Smith (8) leads to the view that the failure of the cloacal
development is secondary to the arterial fusion, and that the precise stage in
the embryo at which this fusion is completed is open to some slight variation.
Gebhard) found a band of connective tissue passing from the ventral
aspect of the blind termination of the large gut in company with the umbilical
artery to the umbilicus, It contained a tube which communicated dorsally
Anatomy LIv 14
214 qa. Bo ohnston
with the large gut and which Gebhard identified, as I think correctly, as the
*‘allantoisstiel.”” The persistence of the allantois in this case may be regarded
as being due to the fact that the arterial fusion occurred or was completed
at a slightly later stage than in the majority of cases.
Manners-Smith (8), in his third case, records that the rectum was present,
but that it ended blindly both above and below and it received the deferent
ducts. Further a small urinary bladder was present, but it possessed no
openings into it or out of it. The conditions present in this case are very
suggestive and they indicate, to my mind, that fusion of the umbilical arteries
was not completed till the cloaca had reached a stage of development similar
to that seen in the human embryo of 4-25 mm. vertex-breech length, figured
by Felix (9). It is obvious that, since the deferent ducts open into the rectum,
the urorectal septum has not been responsible for the subdivision of the cloaca
and I believe that fusion of the umbilical arteries, completed at a stage such
as has been suggested, would account for the conditions found in this case
quite satisfactorily.
On the other hand, the case recorded by Abramov and Rjesanov (3)
presents a difficulty which is not easy to explain. They record the presence of
a tail-like process in the sacral region, traversed by a canal, which opened to
the exterior near the end of the tail and was connected to the dorsal wall of the
large gut. The bladder and external genitalia were absent and there was the
usual single, median, umbilical artery. The authors regard the external
opening on the tail as the anus, but, from the description given by them, it
is certain that the orifice does not represent the true anus. Unless the
connection with the large gut was an artefact produced by the metal sound
used to explore the canal in the tail, then, whether it be a patent neurenteric
canal or a true portion of the gut, the fusion of the umbilical arteries cannot
have been complete. It should be stated that the authors, relying on a case—
not a Symelian monster—described by Weigert(10), identify the umbilical
artery as a persistent omphalo-mesenteric artery. Weigert’s description is far
from convincing and there is little doubt that the artery, identified by him
as a persistent omphalo-mesenteric artery and held by him to be identical
with the single umbilical artery of Symelian monsters, was in reality the right
umbilical artery, the left umbilical having failed, as it sometimes does.
The fusion of the lower limbs is a condition referable to a slightly later
stage than that at which the fusion of the umbilical arteries takes place and
it can only occur in the absence or reduction of the structures which normally
intervene between them, i.e. the cloaca and the caudal end of the vertebral
column. Manners-Smith’s (8) case, quoted above, shows that the latter is the
more important factor. Narrowing of the tail end of the embryo due to
reduction of the vertebral column is to be regarded as probably due to
deficiency in the vascular supply. Such a narrowing causes approximation of
the lower limb buds, post-axial border to post-axial border and, in high degrees
of fusion, it is found that the fibulae fuse with one another, while the tibiae
The Anatomy of a Symelian Monster 215
remain separate. The degree of fusion of the limbs apparently depends on
whether the two limb buds at their first appearance possess a common post-
axial border or whether, originally separate, the post-axial borders meet at
the bases of the buds as they enlarge with the elongation of the limbs. In
any case, it is certain that the degree of fusion is determined very soon after
the appearance of the buds. As a result of fusion, the limbs are anchored to
one another and normal rotation fails to occur.
Under normal conditions, the sclero-blastema does not appear in the lower
limb bud until the embryo has reached a length of 9 mm. (Bardeen(11)) and
at that stage the sacral and the upper two coccygeal vertebrae are already
laid down, Further, before the ischial and pubic processes are recognisable,
the vertebral column has elongated considerably. It is clear, therefore, that
the failure of development of the vertebral column must precede the fusion of
the lower limbs and this developmental failure, as already indicated, probably
has its cause in vascular deficiency.
Whether this latter is attributable in any way to the fusion of the umbilical
arteries, or whether both are referable to some still earlier common cause, it
is impossible to say without further evidence and that evidence can only be
obtained by the careful examination of further cases. The most that can be
‘said at present is that the single median umbilical artery and the reduction
at the lower end of the vertebral column are the true primary anomalies, and
_ that the fusion of the limbs and the failure of the bladder, etc., to develop are
subsidiary to them.
It is not my intention to discuss the numerous other interesting anomalies
which were found in this monster, since, as I have shown, they cannot be
regarded as throwing any light on the general condition.
In conclusion, I desire to express my indebtedness to Professor Arthur
Robinson, through whose kindness the specimen came into my possession.
BIBLIOGRAPHY
(1) Sanmyt-Hiarre, G. Traité de T ératologie, Brussels, 1838.
(2) GesHarp,C. “Ein Beitrag zur Anatomie der Sirenenbildung.” Archiv fiir Anatomie
und Physiologie, 1888, pp. 164-194.
(3) Axsramov, S. and Ryzsanov, M. “Ein Fall von Sirenenbildung.” Virchow’s Archiv fiir
pathologische Anatomie, Bd 171, pp. 284-297.
(4) Mannens-Smiru, T. “A description of two Symelian Monsters.” Journal of Anatomy and
Physiology, vol. xxx. pp. 169-183.
(5) oe F. P. “Pathology of the Ovum.” Keibel and Mall’s Manual of Human Embryology,
vol. 1.
(6) Veowtk, A. J. Tabulae ad illustrandam embryogenesia hominis et mammalium, 1849.
(7) Soxreser, B. “Ueber Sirenen.” Inaug. Diss., Wiirzburg, 1872.
(8) Mannenrs-Smiru, T. “Some points in the Anatomy of a Sirenomelian Monster.” Journal
of Anatomy and Physiology, vol. xxx. pp. 507-512.
(9) Fest, W. “The development of the Urino-Genital Organs.” Keibel and Mall’s Manual
of Human Embryology, vol. 1. p. 875, 1912,
. 14-2
216
(10)
(11)
(12)
(13)
(14)
(15)
T. B. Johnston
WerceErt, C. “Zwei Falle von Missbildung eines Ureter und einer Samenblase mit Bemer-
kungen iiber einfache Nabelarterien.” Virchow’s Archiv fiir pathologische Anatomie,
Bd 104, pp. 10-20.
BARDEEN, C. R. “Morphogenesis of the Skeletal System.” Keibel and Mall’s Manual of
Human Embryology, vol. 1.
Moorunap, G. “The Anatomy of a Sirenomelian Monster.” Journal of Anatomy and
Physiology, vol. Xxx1x. pp. 450-461.
Brentneton, R. C. “Dissection of a Symelian Monster.” Journal of Anatomy and Physio-
logy, vol. xxv. pp. 202-209.
Katz, A. “Monstre symélien et pseudencéphale.” Bull. de la Soc, Anat. de Paris, 1902,
pp. 410 and 411.
Rue, H. “Ein Fall von Sirenenbildung.” Virchow’s Archiv fiir pathologische Anatomie, .
Bd 129, pp. 381-400.
SPO ne a ate at Pee
SEXUAL DIMORPHISM IN RANA TEMPORARIA,
AS EXHIBITED IN RIGOR MORTIS
By F. A. E. CREW, M.B.,
Assistant in the Natural History Department of the University of Edinburgh
Ix December last I had occasion to separate the males from the females
among the frogs which had been killed and distributed for the Practical Zoology
class in the University of Edinburgh. Eighty-five common frogs (Rana
_temporaria) had been killed, half an hour before I saw them, by immersion in
liquid chloroform, and had been placed in the water of the dissecting-dishes.
I anticipated no difficulty in recognising the sexes, for in specimens of a
size suitable for dissection, the sexual differences are fairly obvious even on
casual inspection. The male presents a general appearance: of ‘maleness,’
suggesting sturdy compact strength; the limbs, and particularly the fore-limbs,
are massive with well-developed muscles; the trunk is squarish in outline,
and the abdominal muscles are so thick that through them the viscera cannot
be identified; and the skin of the back and flanks is comparatively smooth.
The female, on the other hand, is much more slightly built and her limbs are
more slender and not nearly so muscular; through the thin abdominal wall
the pigmented ovaries can be seen distinctly, during a great part of the year,
and at all times, the development of the internal reproductive organs is suffi-
cient to produce a bulging of the flanks and a suggestion of fullness of the
abdominal cavity; and during the breeding-season the skin of the back and
flanks becomes roughened in consequence of the development of the temporary
papillae. In December, however, these are not sufficiently developed to
produce this typical roughness.
But for my decision as to which were males, I meant to depend upon the
presence of the finger-pad. Upon the palmar surface of the innermost finger,
the index, of the male frog, is found a cushion or tubercle, which takes the form
of a rounded, oval swelling, black or deep-brown in colour, during the breeding-
season, and grey at other times.
But a rapid inspection of the frogs at once indicated that this test was
inapplicable, for, as they lay in the stiffness of death, about half their number
had assumed an attitude in which the palms of the hands were tightly hidden
from view and could not be exposed without fracture of bones and tearing of
muscles. These were collected and examined. The attitude of every one of the
whole forty was identical in every particular, and every one was undoubtedly
amale. The other forty-five were collected and compared, and it was seen that
they were female, one and all, and that the attitude assumed by them was
similar in every case; and further it became clear that in rigor mortis there was
=
218 F. A. FE. Crew
such a difference in the attitudes assumed by the male and by the female,
that the sex could be told at a glance. Further consideration showed that this
difference in attitude depicted in a most striking way the sexual dimorphism
that exists in the common frog. '
The finger-pad undoubtedly marks the male, and the roughened back
denotes the female; but the most notable external differences which distinguish
the sexes, are those which depend upon the underlying differences in the degree
Fig. 1. The upper row are females, the lower, males.
of development of three muscles, which to the male are of supreme importance
during the breeding-season. These muscles are the rectus abdominis, the flexor
carpt radialis, and the abductor indicis longus, and in the male they attain
a considerable degree of development, being always of a much greater size
than the same muscles of a female of the same age. During the breeding-season
they become even larger still in the case of the male, and it is to these muscles,
that the differences in appearance, which the sexes exhibit, both in life and
during rigor mortis, are due.
Sexual Dimorphism.in Rana Temporaria 219
I. M. rectus abdominis
On either side of the middle line of the abdominal wall, and separated from
its fellow of the opposite side by the fibrous linea alba, is found this long flat
muscle, broadest in its middle part, which arises by a narrow strong tendon,
from the inferior border of the pubis, and runs forwards to divide at the level
of the second of the five inseriptiones tendineae, counting from behind forwards,
into two portions. The outer portion forms the portio abdominalis of the
m. pectoralis, whilst the inner portion is continued as the rectus abdominis,
which, narrowing as it approaches the pectoral girdle, divides so that the
median fibres are inserted into the cartilaginous plate of the xiphisternum,
and the rest are continued into the m. sternohyoideus.
The m. pectoralis covers the ventral surface of the pectoral girdle and
consists of three portions, of which the largest and strongest is the portio
abdominalis, which is the direct continuation of the outer portion of the
m. rectus abdominis. This portion is inserted into the median surface of the
crista ventralis humeri. The m. sternohyoideus has two origins, an inner, from
the upper surface of the inner extremity of the coracoid and from the pars
cartilaginea and pars ossea sterni, and an outer, which is the direct continuation
of the m. rectus abdominis in front of the fifth inscriptio. The muscle passes
forwards on the upper surface of the coracoid and of the clavicle, and during
its course its direction abruptly changes from the horizontal to the vertical
as it dips to pass between the two insertions of the m. geniohyoideus to become
inserted into the lower surface of the hyoid and its posterior cornu.
The action of the m. rectus abdominis, when both girdles are fixed, is to
shorten and tense the abdominal wall, and so to compress the viscera, thus
assisting to evacuate the excretions from the cloaca and bladder, and the
products of the internal reproductive organs from the seminal vesicles or
oviducts and from the cloaca. When neither girdle is fixed, contraction of the
muscles of both sides working in unison, will produce flexion of the vertebral
column. The m. pectoralis adducts the arm, bringing it across the chest, and
at the same time rotates it inwards. The m. sternohyoideus is a depressor of the
hyoid. The action of the m. rectus abdominis and its continuations is countered
by that of the extensor group of muscles of the dorsal aspect of the vertebral
column, particularly the m. longissimus dorsi, ileolumbaris, dorsalis scapulae,
latissimus dorsi and geniohyoideus.
Il. M. flexor carpi radialis
The site of origin of this muscle upon the humerus is marked, in the case
of the male, by a well-defined crest, the crista medialis, near the epicondylus
medialis. This crest is not present in the female, whilst in the male its great
development is made necessary by the much greater size of the muscle,
Narrowing as it courses down the forearm, the muscle is inserted into the
median prominence of the os centrale. Its action is to flex the forearm and wrist
_ but it is particularly concerned with the movement of the hand and wrist
220 F. A. EB. Crew
lateralwards to the thumb-side, and so plays an all-important réle during the
sexual act. In the male, this large muscle becomes even larger during the
breeding-season, but at all times it is bigger and more powerful in the male
than in the female.
Ill. M. abductor indicis longus
This muscle arises from the lateral surface of the os antibrachii (caput —
inferius); from the epicondylus lateralis humeri (caput superius); and from the
radius (caput breve), and passes obliquely down the forearm and over the wrist-
joint to be inserted into the metacarpal of the second digit which serves as
a thumb. In the male, this metacarpal is much stronger and stouter than in
the female, and on its inner aspect a ridge is developed to provide for the
insertion of this muscle, which becomes much enlarged during the breeding-
season. The action of this muscle carries the second digit lateralwards away
from the rest of the hand, and causes it to press firmly against the chest of the
female during the sexual act.
As for the rest of the muscles, it is found that those of the male are some-
what larger than those of the female of the same size, but not sufficiently so
to be at all indicative of the sex. The angle which the legs make one with the
other is bigger in the female than in the male, but its size varies too much
to permit a generalisation such as this to be regarded as a sex-difference.
Combined and full action of these three muscles, the much greater develop-
ment of which is a male characteristic, will cause the body to assume the
following attitude. The head will be flexed upon the chest and the floor of
the mouth depressed (m. rectus abdominis and. sternohyoideus). The vertebral
column will be flexed and the abdominal wall concave and tense (m. rectus
abdominis). The arms will be adducted and rotated inwards, so that they will
be brought across the chest (m. rectus abdominis and pectoralis). The forearms
will be flexed and pressed against the chest-wall (m. flexor carpi radialis).
The wrists will be flexed (m. flexor carpi radialis). The index finger will be
abducted strongly (m. abductor indicis longus). So that the palms of the hands
will be held together, the fingers interlocked, and the index finger held well
away from the rest of the hand.
And this is the very picture that the males presented as they lay in rigor
mortis, whilst the attitude of the females demonstrated, that in them, there
was no special degree of development of any particular muscles, although it did
seem that the ventral muscles were weaker than the dorsal, for the attitude
assumed was one of general extension. _
There is nothing remarkable in the fact that, in a case such as this, where
the sexual dimorphism rests on differences in the degree of the development
of some certain muscles, the differences in the external appearances of the
sexes will be most strikingly depicted in the attitudes of rigor mortis. For
during this phase of tonic contraction, when the interaction of opposing
muscles is deciding the posture which the body shall adopt, such muscles as
Sexual Dimorphism in Rana Temporaria 221
the three described above, will exert an overwhelming force, swamp all
opposition, and dictate what this attitude will be.
In the case of the frog, this illustration of the sexual dimorphism is par-
ticularly striking, and it would appear that only the cloak of familiarity could
have screened from others the picture which revealed itself to me by chance.
It seems probable that, if in December this difference in attitude in rigor
Fig. 2. Male and female forms contrasted.
1 =the continuation of the m. rectus abdominis which constitutes the portio abdominalis of the
m. pectoralis.
2=the continuation of the m. rectus abdominis which constitutes the greater part of the
m. sternohyoideus.
3=the left forearm and hand of the male. This shows the great size of the muscles of the
forearm, particularly of the m. flexor carpi radialis; and the position of the index finger.
mortis is exhibited, it will occur at all times of the year, It is entertaining to
wonder if, in the human, certain trades, which call out a predominating
development of certain groups of muscles, cannot be told by the attitude of
the body in rigor mortis, and if in other species, sexual dimorphism is as well
portrayed as in the case of the frog.
In figure 1, it will be seen that the upper row is of females, and the lower
one of males, Figure 2 shows a male and a female dissected to demonstrate the
difference in the degree of development of the muscles,
THE CONSTRICTOR MUSCLES OF THE BRANCHIAL
ARCHES IN ACANTHIAS BLAINVILLII
By EDWARD PHELPS ALLIS, Jr,
Menton, France
Ix my work on “‘The Homologies of the Muscles related to the Visceral
Arches of the Gnathostome Fishes” (Allis, 1917), I came to the conclusion
that there must have been, primarily, some overlapping of the constrictores
superficiales in the branchial arches of Acanthias, and that if that condition
persisted, and if the innervation of these muscles was as given by Vetter (1874),
Tiesing (1895) and Ruge (1897), these muscles would present typical examples
of a muscle derived from one segment of the body and innervated by the nerve
of another segment.
I have since then received some specimens of Acanthias blainvillii, and
have had the muscles and their innervation traced by my assistant, Mr John
Henry. The drawings are by Mr Jujiro Nomura, and the veins, arteries and
nerves are, because of the reproduction in black and white, shown considerably
enlarged. This is particularly true of the terminal branches of the nerves,
which are, of course, very delicate.
When the skin of this fish is removed in the branchial region, it leaves a
thin subdermal fascia-like layer of connective tissue, which is loosely attached
to the inner surface of the skin and is closely applied to the outer surface of the
constrictor muscles. Enclosed within this tissue there is a series of dorso-
ventral veins, which are connected by others which run longitudinally or
diagonally. The anterior one of the dorso-ventral veins arises from the superior
jugular vein, and runs downward along the line between the larger, posterior
portion of the constrictor superficialis dorsalis of the hyal arch and an anterior
portion of that constrictor which is inserted on the hyomandibula. At the
ventral end of the latter muscle the vein turns posteriorly and then anteriorly
along the dorsal and ventral edges of the large triangular aponeurosis that lies
between the dorsal and ventral portions of the constrictor of the hyal arch
and is described by both Vetter and Marion (1905), and then turns downward
along the posterior edge of the muscle Csv, of Marign’s descriptions, between
it and a band-like muscle bundle that is called by Marion the muscle Csv,,,
and falls into the inferior jugular vein. The next posterior vein arises from
the superior jugular, runs downward along the dorsal aponeurotic line related
to the first gill opening, passes along the posterior edge of that opening, and
then onward along the corresponding ventral aponeurotic line, and falls into
the inferior jugular. The next three posterior veins have similar origins and
similar relations to the aponeurotic lines related to the second, third and fourth
ee
Constrictor Muscles in Acanthias Blainvillit 223
gill openings, and each falls, ventrally, into the inferior jugular. Posterior
to these five veins there is a sixth one which arises from a dorsal longitudinal
commissural vein, described immediately below, and runs downward along
the hind edge of the muscle Csd, until it reaches the dorsal edge of the fifth
gill opening, where it turns outward on the dorsal surface of the base of the
pectoral fin. Approximately parallel to that part of this vein that lies in the
base of the pectoral fin, but lying on the ventral surface of that fin, there is
another vein which leaves the fin approximately at the ventral edge of the
fifth gill opening, and from there runs downward along the hind edge of the
muscle Csv,, and falls into the inferior jugular; these two veins, together, thus
forming a vessel similar to those related to the anterior gill openings, excepting
in that it does not arise from the superior jugular and that it is interrupted
as it runs around the hind edge of the gill opening to which it is related.
Posterior to this vein a seventh one arises either from the base of the superior
jugular vein, or from the sinus venosus, and is distributed to the pectoral fin,
this vein having the appearance of being a serial homologue of the more
anterior ones but not being connected ventrally with the inferior jugular.
These several veins are all connected with each other by a dorsal longitu-
dinal commissure which runs posteriorly along the ventral edge of the musculus
trapezius and then across the external surface of the shoulder-girdle, the sixth
vein of the series arising from this commissure and not from the superior
jugular. Ventral to this dorsal commissure, about half way between it and the
gill openings, a second longitudinal commissure connects the posterior six
veins. Immediately dorsal to the gill openings still another longitudinal
commissure extends from the second to the sixth vein; and dorsal to this
commissure the posterior five veins are connected with each other by a number
of other commissural vessels which have a dorso-posterior, and hence diagonal
course. Ventral to the gill openings the second to the sixth veins are connected
with each other by a ventral longitudinal commissure which lies along the
ventral edge of the muscle-sheet formed by the constrictores superficiales of
the several arches.
Accompanying each of the dorso-ventral veins related to the five gill
openings, but lying internal to them and the enclosing tissue, directly upon the
related linear aponeuroses, there are dorsal and ventral arteries the origins
of which will be given later. Each of the dorsal arteries extends downward
almost to the dorsal edge of the related gill opening, the ventral arteries each
extending upward, posterior to the related gill opening, to its -dorsal edge,
but not apparently there connecting with the dorsal artery.
When these veins and arteries, and the related tissue, have been removed,
the constrictores superficiales are exposed, these muscles forming what appears
to be a practically continuous muscle-sheet crossed by the four well-known.
aponeurotic lines, which extend dorsally and ventro-mesially from each of the
first four gill openings.
_ The dorsal portion of the constrictor of the mandibular arch was not
224 | Edward Phelps Allis, Jr
examined. The ventral portion consists of a musculus intermandibularis and,
posterior to it, on either side, a sheet-like muscle (Csv,), which has its origin
on the mandible and its insertion on a median aponeurosis common to it and
its fellow of the opposite side. These two muscles form a continuous sheet
innervated by branches of the ramus mandibularis trigemini, and hence are
parts of the constrictor superficialis of the mandibular arch, as Marion, who
describes them both, concluded. Vetter. did not find an intermandibularis in
this fish, and he calls the sheet-like muscle the muscle Csv,, thus assigning it
to the hyal arch,
Beneath the muscle Csv,, there is a second sheet-like muscle, most of the
fibers of which have their origins on the ceratohyal but a few posterior ones
on the hyomandibula. The fibers of the muscle radiate somewhat, the anterior
ones running antero-mesially and the posterior ones postero-mesially. All these
fibers are inserted on a deeper portion of the median aponeurosis that gives
insertion to the superficial muscle Csv,, the anterior fibers not extending as far
mesially as the posterior ones, This deeper muscle is innervated by branches
of the ramus hyoideus facialis and hence is, as Marion states, a part of the
constrictor of the hyal arch. It is accordingly an interhyoideus, and may be
so referred to. Superficial to its posterior portion there is a narrow muscle- .
bundle which is the muscle Csv,, of Marion’s descriptions. It arises on the
outer surface of the musculus adductor mandibulae, runs postero-mesially
along the hind edge of the muscle Csv,, and is inserted on a posterior portion of
the median aponeurosis that gives insertion to the latter muscle and the inter-
hyoideus. This muscle bundle has the appearance of being a posterior portion
of the muscle Csv,, but it is innervated by branches of the ramus hyoideus
facialis, the branch that innervates it running forward internal to the bundle,
outward along its anterior edge, hetween it and the muscle Csv,, and then
posteriorly across the external surface of the bundle on to the external surface
of the muscle Csv,. At the point where it turns posteriorly, a sensory branch
is given off, which runs anteriorly and anastomoses completely with a terminal
branch of that branch of the ramus mandibularis trigemini that innervates
the muscle Csv,, this relation of these nerves thus being as in Amia and many
of the Teleostei. This muscle bundle is thus a part of the constrictor of the
hyal arch, and not, as Marion concluded, of the mandibular arch. It apparently
corresponds to the musculus depressor rostri of the Batoidei, but as that term
is here inappropriate it may be called the muscle Csv,,.
‘Corresponding to these two parts of the ventral portion of the constrictor
of the hyal arch, the anterior fibers of the dorsal portion of the constrictor
form a band-like muscle which has its origin in the fibrous fascia that covers
the outer surface of the trunk muscles, and running ventro-anteriorly has its
insertion mainly on the hyomandibula but partly also on the palatoquadrate,
these two parts of this muscle being found as distinctly separate muscles in
one of two specimens that were examined. This muscle is the homologue of
the levator hyomandibularis of the Batoidei, and may be so designated.
Constrictor Muscles in Acanthias Blainvillii 225
The remainder of the constrictor of the hyal arch forms a large flat muscle
sheet, Cs,, which fills the space between the hind edges of the dorsal and
ventral muscles above described and the articular ends of the palatoquadrate
and mandible, anteriorly, and the first gill opening and the related linear
aponeuroses posteriorly, and extends, both dorsally and ventrally, beyond the
latter aponeuroses. The larger part of this muscle is cut into dorsal and ventral
portions by the large triangular aponeurosis, above referred to, that extends
posteriorly from the articular ends of the palatoquadrate and mandible. This
aponeurosis lies directly upon the branchial rays of the hyal arch, has quite
certainly been formed in relation to them, and has its counterpart in the
several aponeurotic lines formed where the fibers of the musculi interbran-
chiales of the branchial arches cross the branchial rays of the related arches,
Posterior to the pointed hind end of this aponeurosis, between it and the anterior
edge of the first gill opening, the fibers of Cs, have a dorso-ventral course and
are inserted dorsally on the dorsal linear aponeurosis related to the first gill
opening and ventrally on the corresponding ventral aponeurosis.
Anterior to these dorso-ventral fibers of Cs,, the dorsal and ventral fibers
of the muscle may be said to arise, respectively, from the dorsal and ventral
edges of the large triangular aponeurosis, and they are connected, across the
aponeurosis, by ligamentous lines in relation to which small isolated muscle
bundles may be found. The dorsal fibers run dorso-posteriorly, the anterior
(proximal) ones lying parallel to, and in contact with, the hind edge of the
levator hyomandibularis. An important bundle of the anterior fibers of the
muscle pass, because of their dorso-posterior direction, dorso-anterior to the
dorsal end of the aponeurotic line related to the first gill opening. These fibers
become tendinous at their dorso-posterior ends and are there gathered into
a muscle-head which either passes ventral to the ventral edge of the anterior
end of the musculus trapezius, or perforates that edge, and is inserted in the
fascia that covers the trunk muscles. Posterior (distal) to these fibers, an
equally important bundle separates into superficial and deeper layers. The
deeper layer is inserted on the linear aponeurosis related to the first gill
opening, none of them apparently having their insertion on the underlying
extrabranchial. The superficial layer passes external to that aponeurosis,
between it and the overlying vein, and is enclosed in a loop of the related
artery, to be later described. The fibers of this layer then continue dorso-
posteriorly, lying directly upon the anterior (proximal) fibers of the muscle
Csd,, and toward their dorso-posterior ends unite with the latter fibers to
form a muscle bundle which contracts to a tendinous muscle-head and per-
forates the ventral edge of the musculus trapezius dorsal to the dorsal end of
the linear aponeurosis related to the second gill opening, and has its insertion
in the fascia that covers the trunk muscles. Posterior (distal) to these fibers,
the remaining fibers of this part of the muscle all have their insertions on the
linear aponeurosis related to the first gill opening.
The ventral portion of Cs, is strictly comparable to the dorsal portion.
226 Edward Phelps Allis, Jr
Its anterior edge lies parallel to, and in contact with, the hind edge of the
muscle that I have called the muscle Csv,,, but not in contact with that edge
of the musculus interhyoideus, lying somewhat posterior to it and, in one of
two specimens examined, being connected with it by a number of separate
muscle strands which lie internal to the muscle Csv,,.
A few anterior fibers of Csv, separate ventrally from the remainder and
are inserted on the median aponeurosis that gives insertion to Csv,,. This
bundle corresponds to that dorsal bundle of the muscle that perforates the
ventral edge of the musculus trapezius dorso-anterior to the dorsal end of the
linear aponeurosis related to the first gill opening, and also to what Vetter calls
the deeper portion of the constrictor superficialis of Heptanchus. The next
posterior fibers of Csv, separate into superficial and deeper bundles, the
latter one having its insertion on the linear aponeurosis related to the first gill
opening, and the superficial bundle passing external to that aponeurosis,
between it and the related vein, and enclosed in a loop of the related artery,
and being inserted, with the underlying fibers of the muscle Csv, in tissues along
the lateral edge of the musculus coracoarcualis, the posterior fibers even
passing across the linear aponeurosis related to the:second gill opening.
The dorsal and ventral superficial bundles of Cs, are, as above stated,
respectively enclosed in a loop of the artery related to the dorsal and ventral
linear aponeurosis of the first gill opening. The dorsal artery arises from the
dorsal longitudinal commissure of the efferent branchial arteries, and runs
outward along the dorsal extrabranchial of the first branchial (glossopharyn-
geal) arch until it reaches the dorso-anterior edge of the dorsal superficial
bundle of Cs,. There it separates into two parts, one of which runs ventrally
internal to the bundle and the other external to it, the two branches uniting
at the ventro-posterior edge of the bundle. There a branch is sent downward
along the external surface of Cs,, and goes to dermal tissues, the remainder
of the artery running downward along the linear aponeurosis related to the
first gill opening. The ventral artery arises from the ventral longitudinal
commissure of the efferent branchial arteries, and forms a loop around the
ventral superficial bundle of Cs, similar to the one formed by the dorsal artery
around the dorsal superficial bundle. Each of these loops is connected by a
commissural branch with a similar loop formed in relation to the superficial
bundle of the muscle Cs,, and that loop with similar loops formed by the arteries
related to the third and fourth aponeurotic lines, dorsal and ventral longitu- _
dinal commissures thus being formed. Each superficial muscle bundle is
indented where it is crossed by the related vein and artery, this indentation
being slight for the ventral muscle but more marked for the dorsal one, the
fibers of the latter muscle being partly cut through and the nerves that supply
them pinched so that they are markedly thin at these points. The nerves and
muscle fibers are certainly here injured by the pressure of the blood vessels,
and as the muscles of this arch, and similar ones in the more posterior arches,
vary greatly in size in different specimens, in some being reduced to only a few
Ee gL LS eee ee ee aye ee ee eS OT
Constrictor Muscles in Acanthias Blainvillit 227
strands, or even wholly absent, the conditions would seem to show that these
superficial bundles are in process of abortion.
The dorsal and ventral aponeuroses on which the fibers of the several
constrictor muscles have their insertions lie directly beneath the related blood
vessels, as above stated, and along the antero-lateral edge of the gill pouch
next posterior to the gill opening to which the aponeuroses are considered to be
related. The dorsal and ventral aponeuroses of each arch lie parallel, and
slightly anterior to, the extrabranchials of their arch, those extrabranchials
thus lying in the roof of the next posterior gill pouch. The aponeuroses each
extend beyond the related extrabranchial and each passes posterior to the gill
opening to which it is considered to be related, * dorsal aponeurosis extend-"
ing ventrally beyond the dorsal edge of that gill opening, and the ventral one
_ extending dorsally beyond its ventral edge. The dorsal and ventral extra-
branchials do not either of them extend to the corresponding edge of the gill
opening. It thus seems certain that the aponeuroses were not developed
primarily in relation to the extrabranchials but to the antero-lateral edge of
the gill pouch next posterior to the arch to which the aponeuroses belong.
In the action of respiration this pouch was continually expanding and con-
tracting, and as it expanded it must have exerted pressure on the muscle that
passed over its antero-lateral edge and so have given rise to an aponeurosis,
the pressure of the blood vessels that overlie the ee doubtless con-
tributing to its formation.
In the glossopharyngeus, or first branchial arch the primitive muscle-mass
was first separated into adductor and constrictor portions in the manner
explained in an earlier work (Allis, 1917). The distal (posterior) fibers of the
constrictor portion then turned posteriorly both at their dorsal and ventral
ends, and where they crossed the extrabranchials of their arch linear aponeu-
roses were developed, these aponeuroses lying external to those portions of the _
extrabranchials that lie distal to their sharply bent-in proximal ends. The
aponeuroses accordingly started from the dorsal and ventral ends of the
original constrictor, at points intermediate between their distal (posterior)
and proximal (anterior) edges, and they cut the constrictor portion of the
muscle of each arch into the so-called interbranchialis and constrictor super-
ficialis. The fibers that were cut by the aponeuroses were, necessarily, primarily
inserted on them, but they later Acquired, in part, insertion also on the under-
lying extrabranchials. The fibers that lay wholly distal or proximal to the
. aponeuroses were not cut by them, and hence retained their full lengths.
The distal fibers of the interbranchialis accordingly have their dorsal
attachments either on the aponeurosis that cuts this muscle out of the original
constrictor, or on the underlying part of the dorsal extrabranchial of the arch.
Proximal (anterior) to these fibers, the fibers are inserted mostly in fibrous
tissues that surround the superior jugular vein, the distal ones lying upon
the bent-in dorsal end of the extrabranchial of the arch and doubtless there
being in part attached to it. These fibers all run ventrally, in a curved course,
228 Edward Phelps Allis, Jr
and have their insertions on the ventral aponeurotic line related to the muscle,
and on the underlying portion of the ventral extrabranchial of the arch, and
they are crossed by a number of aponeurotic lines developed in relation both —
to the branchial rays of the arch and the posterior efferent artery, the rays
lying against the posterior surface of the muscle and the artery posterior to
the rays. The tips of the median and next ventral rays of the series perforate
the muscle and project posteriorly along its anterior surface. In the ventral
half of the muscle a large proximal portion of the fibers have their origins on
the ceratobranchial of the arch, and hence do not form a ventral continuation
of the fibers of the dorsal half of the muscle. These fibers lie proximal (anterior)
to the ventral end of the ventral linear aponeurosis, and are inserted mostly
on the bent-in ventral end of the ventral extrabranchial of the arch, but at the
bend of that cartilage an important bundle crosses it, and passing ventro-
posterior to the coracobranchialis of the second arch, and dorsal to the
coracohyoideus, is inserted in fibrous tissues near the median line. At the
proximal edge of the muscle, a superficial bundle of fibers separate from the
underlying ones and is inserted on the ventral end of the ventral extrabranchial
of the hyal arch.
The posterior efferent artery of the arch lies, as above stated, posterior
to the branchial rays, and certain branches of it are sent outward along the
posterior surface of the musculus interbranchialis, and others, which perforate
-that muscle, outward along its anterior surface. Certain of these branches
reach the posterior (distal) edge of the muscle and there fall into the dorsal
and ventral arteries that lie along the external, and hence anterior surfaces
of the aponeuroses related to this muscle. The distal portions of these dorsal
and ventral arteries thus apparently owe their origin to the anastomosis,
with each other, of certain of the branches of these radial branches of the
posterior efferent artery of the arch. Other branches of the efferent arteries
anastomosé with branches of the dorsal and ventral longitudinal commissures
of the efferent arteries, and so form the basal portions of the dorsal and
ventral arteries. The arterial loops that encircle the dorsal and ventral
superficial bundles of the constrictor superficialis of the hyal arch would then
be, in part at least, of glossopharyngeal origin.
The constrictor superficialis of the glossopharyngeus arch, the muscle Csg,
is formed of those fibers of the primitive constrictor of the arch that were left
after the interbranchialis had been cut out of it. The distal (posterior) fibers
have a dorso-ventral course between the first and second gill openings, and are
inserted, both dorsally and ventrally, on the linear aponeuroses related to the
second gill opening. The more proximal (anterior) fibers, both dorsal and
ventral, arise either from the aponeuroses related to the first gill opening, or
from the underlying parts of the extrabranchials of this arch, the dorsal fibers
running dorso-posteriorly, and the ventral ones postero-mesially, and most of
them having their insertions on the aponeuroses related to the second gill
opening. The most proximal (anterior) fibers of the dorsal half of the muscle
Constrictor Muscles in Acanthias Blainvillii 229
pass, because of the direction in which they run, dorso-anterior to the dorsal
end of the aponeurosis related to the second gill opening, and, as already
stated, they unite with the overlying superficial bundle of Csd, to form a
muscle bundle which becomes tendinous and perforates the ventral edge of the
trapezius to acquire insertion in the fascia that covers the trunk muscles.
These fibers of the muscle Cs, thus correspond to that bundle of the nguscle
Cs, that passes dorso-anterior to the dorsal end of the aponeurosis related to
the first gill opening and has its insertion beneath the anterior end of the
ventro-anterior edge of the trapezius. Immediately distal (posterior) to this
bundle of the muscle Cs,, a bundle of superficial fibers separates from the
deeper ones, passes external to the aponeurosis related to the second gill
opening, internal to the related vein and through a loop of the related artery,
and, uniting with the underlying fibers of the muscle Csd,, perforates the
ventral edge of the trapezius and acquires insertion in the fascia that covers
the trunk muscles; this bundle thus corresponding strictly to the dorsal
superficial bundle of the muscle Cs,. In the ventral half of Cs,, the origins
and insertions of the fibers are strictly similar to those in the dorsal half
of the muscle, but the proximal fibers are not gathered into muscle heads, per-
sisting as a sheet-like muscle which is inserted in fibrous tissues along the
lateral edge of the musculus coracoarcualis.
The interbranchialis and constrictor superficialis of this arch are both
innervated, in all their parts, by branches of the nervus glossopharyngeus
which run outward along the anterior surface of the interbranchialis, traverse
the related linear aponeurosis, there passing internal both to the related vein
and the dorso-ventral arteries, and then run posteriorly along the external
surface of the constrictor superficialis. No branches of this nerve could be
found going to the overlapping superficial bundles of the constrictor of the
hyal arch, those bundles being supplied only by branches of the nervus facialis.
In the first vagus (second branchial) arch there are interbranchialis and
constrictor superficialis muscles strictly comparable to those in the glosso-
pharyngeus arch. In the ventral half of the muscle there are certain isolated
bundles of the constrictor superficialis which run posteriorly external to the
aponeuroses related to both the third and fourth gill openings and have their
insertions on the shoulder-girdle along with the fibers of the muscle Cs,._ In
the second vagus (third branchial) arch the conditions are also similar, ex-
cepting that in this arch, in the two specimens examined, no dorsal fibers of
the constrictor superficialis separated from the deeper ones to form the super-
ficial bundles found in the anterior arches. There was, nevertheless, in the
related dorso-ventral artery, a loop strictly similar to those that, in the more
anterior arches, enclose the superficial bundles.
In the third vagus (fourth branchial) arch, the interbranchialis does not
differ from those in the more anterior arches, nor does the constrictor super-
ficialis, excepting in the manner of its insertion. There is no aponeurotic line
related to the fifth gill opening, that line being replaced by tissues that line
Anatomy LIy 15
230 Edward Phelps Allis, Jr
the anterior edge of the shoulder-girdle, and the fibers of the constrictor of
this arch are in part inserted in that tissue but in large part traverse it and
have their insertion on the posterior wall of the fifth gill-pouch. A dorsal
bundle of the muscle forms a tendinous head and perforates the trapezius,
as in the anterior arches, but is inserted on the internal surface of the shoulder-
girdle instead of in the fascia related to the trunk muscles.
The conditions in the adult of this fish thus seem to show, quite con-
clusively, that the constrictor superficialis of a given arch primarily over-
lapped externally, to a certain extent, those of the next posterior arches, and
that it retained its primitive innervation throughout its entire length. Later,
these overlapping portions of the muscle were largely suppressed, remnants
of them however persisting arid being innervated by the nerve of their own
arch, and not, as stated by earlier authors, by the nerves of the arches to which
the underlying fibers belong. The suppression of the larger part of these over-
lapping fibers was probably largely due to their having become functionally
supernumerary as soon. as the linear aponeuroses related to the deeper
muscle had become fully developed, for that deeper muscle was evidently
primarily the more important one, and also lay nearer the source of its nerve
supply. The efficiency of a given nerve must evidently have been impaired
when it was crossed and somewhat pinched by an aponeurotic line, and while
each nerve had, of necessity, to continue beyond the aponeurotie line that
separates the interbranchialis and constrictor superficialis portions of the
muscle of its own arch, that necessity did not exist at the second line, and
the nerve and muscle accordingly both tended to abort beyond that point.
: LITERATURE
Auuis, E. P. jnr (1917). “The Homologies of the Muscles related to the Visceral Arches of the
Gnathostome Fishes.”’ Q. J. M. S. vol. uxm. London.
—— (1918). “The Muscles related to the Branchial Arches in Raia clavata.” Journ. Anatomy,
vol. uo. London.
Marion, G. E. (1905). “Mandibular and Pharyngeal Muscles of Acanthias and Raia. Tuft’s
College Studies, vol. 11, No. 1. Mass.
Ruas, G. (1897). “Uber das peripherische Gebeit des Nervus facialis bei Wirbelthieren. Fest-
schrift Gegenbaur, Bd. 11. Leipzig.
Trustne, B. (1895). “Ein Beitrag zur Kenntnis der Augen-, Kiefer-, und Kiemenmuskulatur der
Haie und Rochen.” Jen. Zeitschr. fiir Naturwiss. Bd. xxx. Jena.
Verrer, B. (1874). “Untersuchungen zur vergleichenden Anatomie der Kiemen- und Kiefer-
musculatur der Fische.” Jen. Zeit. f. Naturwiss. Bd. vu. Jena.
DESCRIPTION OF PLATES
Piates XXITI—XXV
Te. 1. Lateral view of the head of Acanthias Blainvillii, with the skin removed in the branchial
region to show the veins enclosed in the subdermal tissue. x 3.
Fig. 2. The same with subdermal tissue and enclosed veins removed, showing the constrictores
superficiales related to the branchial arches. One of the superficial bundles of these muscles
cut and turned upwards. x 4.
} Journal of Anatomy, Vol. LIV, Parts 2 & 3 Plate XXIII
: 230°
¥V vi cy uh
Fig, 2.
Journal of Anatomy, Vol. LIV, Parts 2 & 3 Plate XXIV
230°
7
|
e
2.
=:
F
Tos
Cad +Csd.
Csqucsd :
Tp Csd | .
Pp 6 Csd+Csd Cs Lh
Fig. 3.
Cy dva gel Cg Cev ¢ :
est i + oy ne Imd
Pa fice | Me ted Sate}
Or
; OS
kG °
[Le
4
pod
Ae
\
¢
;
¢
j
"a ve ck A
Rez
Suk oe a i
Res rent
aS
ie S aes
Constrictor Muscles in Acanthias Blainvillit 231
Fig. 3. Portion of the same showing the musculus trapezius and the insertions of the superficial
bundles of the constrictores superficiales. x }.
Fig. 4. Ventral view of the same, showing the veins related to the branchial arches on one side,
and the constrictores superficiales and related nerves and arteries on the other. ~ 4.
Fig. 5. The same, the muscles C’sv, and Csv,, cut on one side of the figure and turned backward
so as to show the underlying musculus interhyoideus. Parts of the constrictores superficiales
cut and removed so as to expose the underlying extrabranchials. x 4.
Fig. 6. Antero-lateral vein of the musculus interbranchialis and constrictor superficialis of the
first vagus arch. x 1}.
INDEX LETTERS
BR ... .-- Branchial ray. :
Cs,_6 .-- Mm. constrictores es acts 2-6.
Csd._, ..- Mm. constrictores superficiales dorsales 2-6.
Csd,,—Csd,, Superficial bundles of Mm. constrictores superficiales dorsales 2-5.
Csd,,+Csd, Superficial bundle of Csd,, together with the underlying fibers of Csd,.
Csd;, +Csd, ” 2° Csd;, ” ” oe ” 2 Cad,.
Csd,, + Csd; 2? Cad, > 2? ” ” ” ”? Csd;.
Csv,_, --- Mm. ‘oompiriotesen superficiales ventrales 1-6,
Car .-- Ventral bundle of constrictor superficialis of hyoid arch.
a, --- Commissural veins connecting the dorso-ventral veins of the branchial arches.
dva... ... Dorso-ventral arteries.
eall .-. Efferent branchial artery of the 2nd branchial arch.
EBRI-IV _ Extrabranchial cartilages of branchial arches 1-4.
geI-V _... Gill-clefts 1-5.
Tbr, ... M. interbranchialis of Ist vagus arch.
Thy ... ... M. interhyoideus.
Imd... .-. M, intermandibularis.
Lhm .-. M. levator hyomandibularis.
_ Spe N. facialis.
ngl .. N. glossopharyngeus.
NY, .. Ist vagus nerve
NV, . --. 2nd vagus nerve
Tp . M. trapezius.
- ee ... Dorso-ventral vein related to the hyoid arch.
vI-V --- Dorso-ventral veins related to the branchial arches 1-5.
15—2
THE TIBIA OF THE AUSTRALIAN ABORIGINE
By W. QUARRY WOOD, M.D., F.R.C.S. (Ep1n.)
Demonstrator in Anatomy, Edinburgh University
Tue tibia from the anthropological point of view is one of the most inter-
esting of the long bones. Not only does it vary in length to a remarkable
degree, but it presents numerous features which differ considerably in their
degree of development in the primitive races as contrasted with the modern
European. In addition, there is a distinct resemblance in many cases between
the features of the tibia in primitive races and in the tibiae of prehistoric
men. Naturally, under the circumstances, many observations have been made
on the tibiae of various races with the result that material for comparison is
generally abundant. The Australian tibiae, however, have not received any
marked attention. So far as I have been able to discover, there is no syste-
matic and complete anthropometric examination of the bone on record. In
1889 Arthur Thomson, in describing the appearances produced in the tibia
by the attitude of squatting, referred to 14 Australian bones. Klaatsch of
Breslau in 1910 noted the resemblance between the Australian tibia and that
of Homo Aurignacensis. Apart from these and a few other references to
isolated features, the tibiae of native Australians remain practically un-
described.
The account which follows is based upon the examination of the Australian
tibiae in the collection of the Anatomical Museum of the University of
Edinburgh. In all there are 236 tibiae in good condition. They were collected
in various parts of Australia, but mainly in the Northern Territory by
Dr W. Ramsay Smith, Permanent Head of the Department of Public Health
of South Australia, whose enthusiastic devotion to science has never received
any adequate acknowledgment, and they were presented by him to the
University Anatomical Museum in order that they should be examined and
_ described when the opportunity occurred.
GENERAL TECHNIQUE
The methods of examination are based on those recommended by Rudolf
Martin in his Lehrbuch der Anthropologie. A short account will be given at
the commencement of each section of the procedure adopted.
LENGTH OF THE TIBIA
Technique. Length of Tibia:—1. From the articular surface of the lateral.
condyle to the tip of the medial malleolus. This measurement was taken by
Hepburn’s Measuring Board.
ae
iS
ah Sat cain,
Nie ae a oa a a Re able ca C
Ee er at re
a
The Tibia of the Australian Aborigine 233
la. Greatest Length of Tibia or Spino-Malleolar Length:—The distance
from the tip of the intercondyloid eminence to the tip of the medial malleolus.
1. Length of the Tibia for comparison with the living:—Taken from the
mid-point of the margin of the articular surface of the medial condyle to the
tip of the medial malleolus.
2. Joint-surfaces distance:—The distance from the centre of the articular
surface of the medial condyle to the least prominent point on the distal
articular surface. It was obtained by means of the Parallelograph.
The average length of the 236 tibiae examined, measured from the articular
surface of the lateral condyle to the tip of the medial malleolus, was 380 mm.
The longest bone gave the remarkable figure of 446 mm. The shortest tibia
in the series was 316 mm. in length.
In 2000 white American tibiae Martin found that the average length was
365 mm. in the male and 345 mm. in the female, or 355 mm. when the sexes
are taken together. In other races the length varies from that of the short
tibia of the Aino, which measures on the average only 331 mm. in the adult
male, to that of the tibia of the Alamann, which reaches an average length
of 373 mm. in the male and 342 mm. in the female, or 357-5 mm. when the
sexes are taken together. It is evident, then, that the tibia of the Australian
aborigine is longer than that of any other race yet investigated?. This fact
becomes all the more remarkable when the other dimensions of the bone are
examined,
The average spino-malleolar length was 386 mm., giving an increase of
6 mm. as the height of the intercondyloid eminence. References to the size
of this process are very sparse in the literature. Klaatsch considers that a
small intercondyloid eminence is a characteristic feature of the Orang-
Aurignac type of tibia. I compared the size of the process in 20 European
bones and found it in the latter to measure 5-1 mm., so that there is very
little difference between the European bone and the Australian in this respect.
The length of the medial malleolus seems also to have received very little
attention. Klaatsch lays stress on the great length of the malleolus in the
Spy tibia and considers it of great importance as a feature of difference between
the Spy tibia and the Aurignacian. In the Australian bones the average
length was 13-8 mm., in a model of the Spy tibia in the University. Anatomical
Museum it was 19 mm., and in 118 Scottish tibiae measured in the Anatomical
Department it was only 7-6mm, The distinct difference in length of the
process in the Australian and in the Scottish tibiae would seem to indicate
that the length of the medial malleolus is worthy of more consideration for
purposes of racial diagnosis than it has received.
The relation of the length of the tibia to the body-height is a factor which
varies more than in the case of any other of the long bones. Topinard has
published figures which prove this conclusively. Thus, in New Caledonians
1 Martin’s figures were published in 1914. I have not observed any larger 5 Pg in the
literature since that date. ‘
234 W. Quarry Wood
the proportionate length was 23-8, while in the Samoyede the tibia is only
20-8 per cent. of the body-height, a difference of 8 per cent. In females the
extremes are even further apart, variations of as much as 4-2 per cent. having
been described by Topinard. The tibia is, therefore, of comparatively little
value in calculations of the body-height. In the present series complete
skeletons were not available, but for the purpose of a rough estimation of
the relationship, the body-heights which are given by Spencer and Gillen for
natives of Central Australia were employed, these being the only figures at
hand. :
Spencer and Gillen found the average height of 30 aborigines to be
163-2 cm. If we take 380 mm. as the average length of the tibia, the relation-
ship between length of tibia and body-height works out at 23-3. This is
perhaps sufficient to indicate, when taken in conjunction with the comparisons
of the measurements of length, that the Australian tibia is near the top of
the scale when considered in relationship to body-height. The highest pro-
portion described so far—as mentioned above—is the 23-8 of the New Cale-
donian.
Karl Pearson has worked out formulae by which the body-height may be
calculated from the length of the various long bones. The formulae which
he gives for the tibia are: S = 78-664 + 2-3767' for male bones and
S = 74-774 + 2-852T for female bones. In the Australian bones the sex is
not stated in the majority of the specimens. If we presume, for purposes of
a rough estimation, that there were equal numbers of male and female tibiae,
the average living stature would work out at 166-55 cm., a little higher than
the figure taken from Spencer and Gillen. If we take 166-55 cm. as the body-
height the relationship of the tibia to the living stature works out at 22-8,
still a ratio which is high in comparison with other races.
An asymmetry as regards the length of the two tibiae has long been
recognised. In 93 pairs of bones from the present series, the two tibiae were
equal in only 7:6 per cent. of cases; the right was the longer in 49-4 per cent.,
and the left in 43 per cent.
In concluding the consideration of measurements of length, it may be
mentioned that, when the measurement was taken from the mid-point of the
medial margin of the medial condyle to the tip of the medial malleolus, the
average length was 877 mm. Therefore, when measurements are made in the
living subject, it is necessary, at least in the Australian aborigine, to make
an addition of 8 mm. so as to obtain the true length of the bone.
DIMENSIONS OF THE EPIPHYSES
Technique. The epiphyses were measured in both the transverse and the
sagittal directions. The Greatest Breadth of each was obtained by means of
the Measuring Board. The Sagittal Diameter of the proximal epiphysis was —
measured at the level of the tubercle. That of the lower was taken as the
distance between the anterior and posterior borders in the mid-line of the
i aren
The Tibia of the Australian Aborigine 235
bone and was measured always at right angles to the long axis of the shaft.
In addition, the smallest transverse diameter of the proximal epiphysis at
the level of the tubercle was taken. It was measured with callipers as the
distance between the lateral and medial margins at that level. The sagittal
measurements were also made with callipers.
The dimensions of the epiphyses of the tibia have not received in the past
all the attention which they merit, but in the few instances in which they
Fig. 1. The proximal aspects of a European and an Australian tibia of approximately the same
length. The greater breadth and more massive character of the European epiphysis are clearly
demonstrated. The two bones were photographed at the same distance from the camera.
have been carefully worked out, very pronounced race differences have been
found to exist. If the breadth of the epiphyses alone is considered, very
interesting results are obtained. In the present series, with an average length
of 380 mm., the average breadth of the proximal epiphysis was 69 mm. and
of the distal epiphysis 45mm. For comparison with these figures and to
illustrate the importance of measurements of epiphyses, the following table,
which, with the exception of the Scottish and Spy measurements, is taken
from Martin, is worthy of consideration.
236 W. Quarry Wood
Length of tibia Proximal epiphysis Distal epiphysis
WISE = ses oat 365 mm. 72:7 mm, 51-7 mm.
Scottish ... aes S02 3; 74 iM —
Fuegian ... aE S38. 55 765, 61-2. ,,
Aino Bs wes 339 ,, male 73°7 ,, male 50-6 ,, male
319 ,, female 67:4 ,, female 45:4 ,, female
Japanese... 333 ,, male 74:3 ,, male 50°38 ,, male
309 ,, female 66:8 ,, female 45:4 ,, female
Spy ve oe 326-43 82 58 3
Senoi ae was 325.2° male 64. » male 43°5 ,, male
319 ,, female 62:5 ,, female 40:5 ,, female
The Australian tibia is longer than any of the above and yet has the
narrowest epiphyses except in the case of the very short tibia of the male
Senoi, and in the females of the Senoi, Japanese, and Aino in whom the tibia
is at least 60 mm. shorter. The huge epiphyses of the Spy tibia, the measure-
ments of which are taken from a cast in the University Anatomical Museum,
correspond to the thick clumsy diaphysis of that bone.
The sagittal diameters of the epiphyses correspond in a general way to
the transverse. That of the proximal epiphysis in the Australian tibiae was
43 mm., that of the distal 34mm. As similar measurements in other races
were not available for comparison, I made the same measurements in 40
Scottish tibiae. The figures from these were 44-7 and 387-9.
DIMENSIONS OF THE DiaPHysiIs
Technique. The diaphysis was measured in the sagittal and the transverse
diameters. The sagittal measurement was taken between the crest and the
mid-point of the posterior surface by means of callipers:
(1) At the middle of the Spino-Malleolar length.
(2) At the level of the nutrient foramen.
(8) At the point where the popliteal line cuts the medial border.
The transverse diameter, i.e. the distance between the medial and interosseous
borders, was measured at the same three levels.
The circumference of the diaphysis was measured by means of a narrow
tape measure:
(1) At the middle of the bone.
(2) At the level of the nutrient foramen.
(3) The smallest circumference was estimated also, and was found to
be situated usually in the distal third about the level at which the crest
begins to disappear.
The average sagittal diameter at the —_ levels was (1) 2-9 em., (2) 3-3 em.
and (3) 3:1 em. The average transverse diameter at these levels was (1) 2 ¢m.,
(2) 2-2cem., and (3) 2:1em. The average circumference at the three levels
mentioned was (1) 8-1 cm., (2) 8-9 em. and (8) 7 em.
To indicate the relationship of the thickness of the tibia to its length, it
is customary to employ the following index:
Smallest circumference of diaphysis x 100°
Greatest length
The Tibia of the Australian Aborigine 237
The average index in the Australian bones worked out at 18. In the
majority of other races this index is about 20, The smallest index recorded
appears to be that of the Negro, which is 19-8 (Martin). The tibia of Spy
and Neanderthal forms a marked contrast in this respect to the Australian
tibia, the index for the Spy tibia being 26-2 and for the Neanderthal tibia 24.
Fig. 2. A typical Australian tibia compared Fig. 3. One of the longest and one of the
with a European bone of the same length. shortest of the Australian specimens.
The Australian bone is more slender, both These were photographed at the same
as regards the diaphysis and the epi- distance from the camera as the bones in
physes. Note the articular facets on the Fig. 2.
anterior aspect of the distal epiphysis and
on the anterior border of the Australian
specimen. The difference in the appear-
ance of the area on the lateral condyle
for the attachment of the ilio-tibial tract
is well brought out.
It may be mentioned here that, as Klaatsch has noticed in the Zeitschrift fiir
Ethnologie, the Australian tibia shows many points of resemblance to the
Aurignacian tibia, especially with regard to the slender character of the
diaphysis and the epiphyses, and differs widely in many respects from the
Spy and Neanderthal bones.
238 W. Quarry Wood
From the measurements recorded so far it will be seen that the shape of
the Australian tibia is quite characteristic. It is an extraordinarily long and
slender bone with small epiphyses, differing distinctly in these features from
the tibia of any other race which has been investigated. A typical specimen
is illustrated in Fig. 2.
PLATYCNEMIA
For estimation of the degree of platycnemia in the tibia, the formula
which is most commonly employed is
Transverse diameter at level of nutrient foramen x 100
Sagittal diameter at same level
Hrdlicka has objected that these measurements are affected by the degree
of development of the linea poplitea and by variations in level of the nutrient
foramen, and recommends that they should be taken instead at the middle
of the bone. Accordingly, the measurements were taken, in the present
investigation, not only at the level of the nutrient foramen, but also in the
middle of the bone and at the point where the linea poplitea cuts the medial
border, a third point which is reeommended by some observers. It may be
stated at once that the first level—i.e. at the nutrient foramen—which has
been adhered to by Manouvrier, Broca and others, was found to be the most
satisfactory of the three. The measurements at the middle of the bone and
at the junction of the linea poplitea and the medial border fail to indicate the
true degree of platycnemia since, in the majority of cases, they lie below the
level at which the modification in shape of the tibia is well marked. Thus,
the average index of the Australian bones at the level of the nutrient foramen
was 65-2, at the middle 68-7, and at the junction of linea poplitea and medial
border 67-7. These figures show clearly that to demonstrate the full degree
of platyenemia the measurements should be taken at the level of the nutrient
foramen, the level which gives the lowest cnemic index. It should be men-
tioned also that the third level—at the junction of linea poplitea and medial
border—was found to be by no means constant, whereas the degree of de-
velopment of the linea poplitea and the level of the nutrient foramen were not
found to vary to any serious extent. :
Manouvrier, in his classical work on platycnemia, adopted the following
grouping when considering the cnemic index:
Index below 54-9... ... hyperplatyenemic
» between 55 and 62-9... platyenemic
me om 63 and 69-9... mesocnemic
» over 70 cs ... euryenemic
The average European tibia, which on section resembles an equilateral
triangle, has an index of about 70. In bones with a lower index, the tibia
appears to be somewhat flattened from side to side, having the appearance
on section of an isosceles or a scalene triangle. The average index of the
Australian bones was 65:2. The highest index was 86-2 and the lowest 50.
The Tibia of the Australian Aborigine «289
Of the total number of bones, only 7 were hyperplatycnemic, 74 were platy-
enemic, 114 were mesocnemic, and 41 were euryenemic. The degree of platy-
cnemia in the Australian aborigine may therefore be described as moderate.
It corresponds to what is met with in such races as Polynesians, Andaman
Islanders, American Indians, and Malays. The most marked degree of
platyenemia is met with in the Aino whose index is 59-3 (Koganei). The
index for the Cro-Magnon tibia is 64-5, while that for the Spy tibia is 85-8
and for the Neanderthal bone 71-3.
Manouvrier was the first to point out that the apparent flattening of
platyenemic bones has for its object the provision of a larger surface of origin
for the tibialis posterior, and that the essential cause of the peculiar shape of
the tibia is a hypertrophy of that muscle. The hypertrophy in man is mainly
due to the indirect action of the muscle, the action which comes into play
when the foot is fixed on the ground and which immobilises the proximal end
of the tibia so that it may support the weight of the body. This action is
especially important when the knee is somewhat flexed, as in running or
leaping. The resulting platyenemia is therefore more marked in races who
live in rocky uneven country and who follow the chase. It is naturally absent
in children and comparatively slight in women. Havelock Charles has shown
that hypertrophy of the tibialis posterior and platyenemia are produced also
by the attitude of squatting in races like the Punjabis who live on a level
plain and who are not exposed to the factors above mentioned. The condition
is also met with in modern European tibiae and in these is most likely due to
occupations such as that of a hill-shepherd, where the cause is the same as
in savage races, or that of a miner, where the prolonged adoption of a squatting
attitude will act in the same way as in the Punjabis.
The explanation of Manouvrier has been criticised especially by Hirsch
and by Klaatsch. Hirsch attempted to explain the condition of platyenemia
by purely mechanical influences. He considered it to be an adaptation in
the shape of the bone to resist forces which tend to bend it in a sagittal direc-
tion, such forces coming into play especially in running or jumping when the
knee is flexed. He denied absolutely the influence of muscles on the external
shape of the bone. The theory of Hirsch has already been completely refuted
by the work of Fick, Guérin, Vallois, and others, and does not require further
discussion.
Klaatsch objected to the theory of Manouvrier on the ground that it does
not explain the absence of platycnemia in the Spy tibia, which was certainly
exposed to the conditions producing platycnemia, and stated also that the
essential change in platyenemia is not an increase in the antero-posterior
diameter owing to the increase in the area of origin of the tibialis posterior
but is, in reality, a diminution in the transverse diameter of the bone.
Manouvrier explains the absence of platycnemia in the Spy tibia as the
result of the remarkable shortness and thickness of the bone. The tibialis
posterior already had a sufficient area of origin and no further increase in
240 — W. Quarry Wood
the sagittal diameter of the tibia was required. The statement with regard
to the relationship of the sagittal and transverse measurements has been
made also by Derry. Derry founded his statement on the examination of
between four and five hundred predynastic Egyptian tibiae. Unfortunately,
he gives almost no measurements, having apparently merely inspected the
bones, therefore the value of his conclusions cannot be properly estimated.
The examination of the Australian tibiae supported Manouvrier’s views
in every respect. They show that the principal change in platycnemia is not
a simple transverse flattening of the bone, as Klaatsch and Derry have
asserted. Manouvrier himself showed that the weight of platyenemic bones
is equal to that of euryenemic, The average transverse diameter of the
Australian bones at the level of the nutrient foramen was 22 mm. In a con-
siderable number of the platycnemic specimens the transverse diameter was
actually above this figure, so that the factor which caused a lowering of the
cnemic index was an increase in the sagittal diameter alone. The average
sagittal diameter of the specimens with an index below 70 was 35 mm., while
in those with an index of 70 or over the average sagittal diameter was only
32 mm., which shows clearly enough that in tibiae with a tendency to platy-
cnemia the sagittal diameter is actually increased and the change is not due
merely to a diminution in the transverse diameter.
Mere inspection of the area of origin of the tibialis posterior in the platy-
cnemic bones showed that this area was much larger than in euryenemic.
To demonstrate the increase I measured the breadth of the origins of the
tibialis anterior and posterior at the level of the nutrient foramen in the
platycnemie specimens and contrasted them with similar measurements in
12 euryenemic European tibiae. In the platyenemic bones the figure for the
tibialis anterior was 22-3 mm. and for the posterior 18-3 mm., a difference of
4mm. In the euryenemie bones the figures were 26mm. and 14-7 mm., a
difference of 11:3mm. These figures show that the tibialis posterior has a
much bigger area of origin relatively to the tibialis anterior in platyenemic
bones than in euryenemic. The measurements given and the appearances of
the muscular impressions on the platyenemic bones of Australian aborigines
afford strong confirmation of Manouvrier’s explanation of the cause of platy-
cnemia.
THE OUTLINE OF THE TIBIA AT THE LEVEL OF THE NUTRIENT FORAMEN
Technique. With the tibia clamped in the vertical position a tracing of
its shape on transverse section was obtained by means of the Perigraph.
Hrdlicka has made a special study of the outline of the tibia. He sub-
divided tibiae into six types according to their shape on transverse section.
In the Australian bones five of Hrdlicka’s types were represented. It was
possible to obtain a tracing from 226 specimens only, the remainder being
rejected on account of mutilations. An inspection of the tracings showed
ee te
The Tibia of the Australian Aborigine 241
that six groups could be defined and tracings illustrating the six varieties of
outline are shown in Fig. 4.
No. 1 shows an outline which corresponds more or less to an equilateral
triangle and therefore to the usual outline of a European tibia. Of this
variety there were only 17 examples. No. 2 shows a rare form of tibia in which
the lateral surface is distinctly hollowed out, probably to afford a larger area
- of origin to a powerful tibialis anterior. Only four examples of this type
occurred. No. 3 was much the most common variety and 160 of the tibiae
could be allotted to this group. The special feature of this group is the sub-
OG
4 2 6
Fig. 4. The six types of outline occurring in the Australian tibiae. In No. 1, A= Anterior border,
B=Interosseous membrane.
division of the posterior aspect into a postero-medial and a postero-lateral
surface. It was shown by Manouvrier that this change in the outline of the
tibia is due to a powerful development of the tibialis posterior and is the
appearance usually found in platyenemic bones. No. 4 shows an outline in
which the medial border is rounded off and the whole posterior half of the
outline is more or less uniformly convex. Hrdlicka states that this variety
of outline is practically limited to female tibiae. Twenty-seven of the tracings
belonged to this group. The bones from which they were taken were mostly
small and slender and probably of the female sex, supporting Hrdlicka’s
242 W. Quarry Wood
observation. The fifth tracing shows a more or less oval outline, and of this
type there were only eight examples. Hrdlicka states that this form is asso-
ciated with marked platycnemia, that it is rare in Europeans and North
American Indians but common in Negroes, The average cnemic index for
the eight Australian bones was 58-4 which confirms the statement with regard
to platyenemia. No. 6 illustrates a variety of tibia which is not included in
Hrdlicka’s types but which was described by Manouvrier. It shows that the
origin of the tibialis posterior lies, in these bones, in the same plane as that
of the tibialis anterior, while that of the flexor digitorum longus looks directly
backwards. This form of tibia occurred in ten of the Australian bones,
RETROVERSION AND RETROFLEXION
In the European the tibia is usually straight in its whole extent. By the
term Retroversion is meant here the condition in which the diaphysis is straight
Fig. 5. fad=Inclination angle of the tibia.
ghd = Angle of retroversion. de=Tangent to
the superior medial articular surface, a is
the mid-point of this surface, and 6 is the
mid-point of the inferior articular surface.
baf is the physiological axis. c is the mid-
point of the lateral surface 2 cm. below the
tubercle and bcg is the morphological axis
of the tibia.
.b
in its whole length but the proximal extremity is tilted slightly backwards.
This retroversion of the proximal extremity is best expressed by the angle
between the tangent to the articular surface and the axis of the diaphysis—
the Angle of Retroversion. It is of some importance also to consider the angle
which is formed by the same tangent and the physiological axis of the bone,
the physiological axis being indicated by a line between the mid-points of
‘the articular surface of the medial condyle and of the inferior articular surface.
This second angle differs slightly from the first and is known as the Angle of
Inclination. :
By the term Retroflewion is meant a rather uncommon condition in which
bare
eT a ee Tae Le a en eee
BN ght ie all dade
The Tibia of the Australian Aborigine 243
the upper half of the diaphysis is distinctly bent backwards so that a pro-
nounced posterior concavity of the bone results.
Technique. In measuring the angles of retroversion and inclination, the
tangent to the superior medial articular surface was obtained by fixing a
slender steel rod over the middle of the articular surface by means of a little
putty. The bone was clamped in a horizontal position with the lateral surface
- upwards, in such a way that the steel needle was parallel to the marble slab
underneath. The physiological axis was easily obtained from the mid-points
of the articular surfaces by means of the parallelograph. A difficulty arose
with regard to the morphological axis. Martin recommends a line drawn
through two points, one of which is the mid-point of the inferior articular,
surface and the other the mid-point of the lateral surface 1 or 2 cm. below the
tubercle. The boundaries of the lateral surface are the anterior border and
the interosseous crest, so that the mid-point of the lateral surface should lie
mid-way between these. But in many bones, and especially in those which
are platyenemic, the interosseous crest curves very distinctly forwards
towards its upper end. The result is that the lateral surface is considerably
narrowed towards its upper end and the mid-point is carried further forwards
than it would be in bones in which the interosseous crest is straight in its
whole length. In tibiae with such a curvature at the upper end of the inter-
osseous crest the axis of the diaphysis, marked in the manner indicated above,
is inclined slightly forwards at its proximal end and the angle of retroversion
is made to appear a little greater than it really is. After a consideration of
various methods, including the method employed by Manouvrier, I decided
that the method recommended by Martin was the least liable to error and I
have adhered to that procedure throughout the investigation.
Retroversion was first described by Collignon in 1880. He attributed it
to an attitude of incomplete extension of the knee-joint and regarded it as
a legacy from a simian ancestor. Manouvrier showed conclusively, however,
that retroversion is not only not inconsistent with the erect attitude but is
actually an advantage in the extended position of the joint, especially in the
Spy and other prehistoric forms in whom the lumbar curvature was pre-
sumably less developed than it is in modern races. He then set himself to
formulate a fresh explanation for the existence of this character. He believed
that it was due to the method of walking with the knee en flexion by the
inhabitants of hilly countries. These people find that the least fatiguing
method of walking over hilly and irregular country is to walk with the knees
slightly flexed. The gait is well seen in hill-shepherds in this country. The
arguments brought forward in proof of this theory are very convincing, but
the work of Havelock Charles has shown than another explanation is the true
one. He demonstrated the change in a well-marked degree in the tibiae of
Punjabis who live in a plain as flat as Holland and whose gait is as erect as
that of a Guardsman. He believed that the retroversion was due to the habit
of extreme flexion of the joint in the act of squatting, acting from the earliest
244 W. Quarry Wood
childhood. The ligamentum patellae is attached to the diaphysis. In complete
flexion of the joint the tension of the ligament on the anterior aspect of the
epiphysis will have a tendency to bend it backwards. He showed that the
squatting posture, which is adopted by natives of Eastern and savage races
during many hours of the day, both at work and during leisure, has a profound
effect on the conformation of the tibia.
Charles showed also that retroversion was present in the Punjabi infant
and regarded it as a character inherited from ancestors in whom it had
persisted or been acquired as the result of the squatting
attitude. The association with the retroversion of the
.foetus of other features which result from the squatting
attitude, namely, additional facets for the talus and
convexity of the lateral condyle, favours this conclusion.
G. Retzius showed that retroversion is present also in
the foetus and child of modern European races.. The
change is most marked about the sixth month and rather
diminishes towards the end of pregnancy. By the end
of the first year of life the condition has almost dis-
appeared in the European child. Hultkrantz explains
the disappearance of the retroversion in the infant by ©
the enforced extended position in which it lies. Retzius
believes that this condition in European infants is a
reminiscence of the earlier stages of their history and
not simply the result of mechanical conditions during
intra-uterine life, as has been suggested by Hueter.
Klaatsch agrees with the opinion of Retzius.
I found well-marked retroversion in the tibiae of
one or two Australian infants which I was able to
examine. In the 236 adult bones the average Angle of
Retroversion was 17° and the average Angle of Inclina-
tion 13°, which form a marked contrast to the angles Fig. 6. A calls saad
of about 7° and 5° which are usually found in modern example of retroversion
Europeans. In comparison with other modern savage @™ % Australian tibia.
races the Australian angles are very high. The only races having a greater
degree of retroversion are the Fuegians and the Californians, the retro-
version angle in both of these being 20° and the inclination angle in the
former being 16-5° and in the latter 15°. It seemed of importance, then, to
discover if, in a race with such a well-marked degree of retroversion, the
habitual attitudes correspond to that which is suggested by Charles as the
cause of the condition. In the works of Spencer and Gillen on the Native
Tribes of Central and Northern Australia there are numerous photographs
illustrating the postures which the aborigines commonly adopt when in repose.
The attitude of squatting, which is common to the majority of savage races,
is sometimes adopted, as is also the “sartorial” or tailor position, but the most
A BS ad yea Cec Sara
———
es
a
The Tibia of the Australian Aborigine 245
common posture differs from these and is very characteristic. The position
is illustrated in Figs. 7 and 8. The individual sits with the knees acutely
Fig. 7. In the central figure in this photograph the position of the foot in the common
resting attitude can be seen. It is turned under the buttock in such a way that the buttock
rests on its medial border.
Fig. 8. Another photograph illustrating the attitude of exaggerated genuflexion which is the
common posture of rest in the Australian aborigines. Both photographs are reproduced from
the works of Spencer and Gillen by permission of Macmillan and Co.
flexed and directed straight forwards. The thigh is in contact with the calf
and the weight of the body is transmitted through the thighs to the back of
the leg and thence to the ground through the whole length of the leg proper
Anatomy LIv 16
246 W. Quarry Wood
and through the feet. The position of the feet varies. In the majority of cases
they are placed underneath the buttocks at a right angle to the leg and with
the great toes directed towards each other or overlapping. The person actually
sits on the medial borders (see Figs. 7 and 9) of the feet or even on the sole of
the foot, the lateral borders or the dorsum of the foot resting on the ground
(see Figs. 9 and 10). In other cases the buttocks rest on the heels and the foot
A=buttocks
B=right foot
C=left foot
Fig. 9. This photograph shows both feet crossed under the buttocks, the weight of the body
being transmitted to their medial borders. Enlarged from Spencer and Gillen by permission
of Macmillan and Co.
A=buttocks
C=left foot ‘
B=right foot
Say
Fig. 10. In this photograph, which is)from the same source as Fig. 9, it will be seen that the
whole weight of the body is resting on the sole and medial border of the right foot. This
demonstrates the remarkable degree of rotation of the foot which is possible in aborigines.
may be either acutely dorsiflexed at the ankle-joint or may be plantar-flexed
so that the dorsum of the foot rests on the ground. It is interesting to notice
that the attitude adopted by the females corresponds to that described by
Dr St John Brooks and quoted by Arthur Thomson with reference to Zulu
girls. They sit with the buttocks and one thigh on the ground, with the
knees flexed, and the legs directed to the opposite side. Occasionally the
inclined forwards, as in running downhill
amount of bending of the diaphysis takes
The Tibia of the Australian Aborigine 247
females take up the position of extreme genuflexion which is the common
resting position of the males. It is obvious that in these positions there is the
same tension on the ligamentum patellae as in squatting and the effect on
the position of the proximal epiphysis is the same.
Retroflexion. Retroflexion of the tibia is a change which has received
_ comparatively little attention. Manouvrier pointed out that the proximal
extremity lies normally behind the pro-
longation of the axis of the diaphysis and
that there is therefore a constant tendency
to backward bending of the diaphysis. This
tendency will be greatest when the tibia is
or leaping. The tibia in ‘certain subjects is
unable to resist the strain and a certain ©
_ place. He found that the change occurred
most commonly in platyecnemic races and ©
that the individuals presenting it were ~
_ usually robust and muscular.
Klaatsch emphasises the importance of
distinguishing between retroversion and re-
troflexion. He believes that the two changes.
are dependent on different states of erectness
of the tibia. He noticed in European tibiae
a slight concavity of the anterior border,
_ the starting-point of the concavity being
at the same level as the commencement of
_ the backward bend in a retroflexed bone. See
_ He found retroflexion especially marked in fig. 11, An example of retroflexion
the Veddah tibia. He suggests that races in an Australian tibia.
presenting this feature may represent an ;
intermediate stage between the race of Spy and the modern European or, on
the other hand, that the European tibia may represent a line of development
_ jn one direction and the retroflexed tibia development in another, both having
originated from the same starting-point. The common ancestral form is
presumed to have resembled the Spy tibia, which is not so strongly retro-
flexed as the Veddah, but much more so than the modern European tibia.
To verify the observation of Klaatsch I examined a series of 118 European
tibiae and found in the majority of cases the appearance he described. In
most bones it was not so much a concavity of the anterior border as a gradual
slope upwards and forwards to the tubercle. In the Australian tibiae retro-
flexion was not common. It was present in only 31 of the 236 specimens and
in only 9 was it well marked. The curve in the majority of cases commenced
at the junction of the proximal and middle thirds of the diaphysis. I was
16—2
248 W. Quarry Wood
able to verify the observation of Manouvrier that retroflexed bones are robust
and show well-marked muscular impressions. The average cnemic index for
the 31 retroflexed specimens was 64-9, so that a marked degree of platyenemia
was not present. Indeed, four of the bones had an index of over 70.
CONVEXITY OF THE ARTICULAR SURFACE OF THE LATERAL CONDYLE
In modern European tibiae the surface of the lateral condyle is often very
gently convex from before backwards. In savage races, as was first pointed
out by Arthur Thomson, this convexity is
very much greater. He attributed ittothe —"™__
habitual adoption of the attitude of squat-
ting. He pointed out that in flexion of the
knee-joint the lateral meniscus moves back- “ — OT:
wards to a certain extent. In the extreme
flexion associated with the squatting posi- en
tion this backward movement is much facili-
tated by an increased convexity of the
articular surface of the lateral condyle. yo
Thomson made his observations by moulding
a strip of soft lead across the centre of the
articular surface of the lateral condyle in PA 5
the antero-posterior direction. From this
he was able to make a tracing. He then Fig. 12. A reproduction of Thomson’s
arranged the tracings into five groups ac- 0 ae sae a pie de
cording to the degree of curvature which surface of the lateral condyle.
they displayed. In the present investigation
I was able to obtain tracings from 218 bones with the Perigraph, an easier
and more accurate method.
The average curve in the present series corresponded to 2-3 of Thomson’s
scale, the figure which he himself gave for Australian tibiae being 2-5. A few
bones showed as much curvature as his fourth type. In other races the average
curvature varies from 1-5 in the European to 3-2 in the North American
Indian. A curvature of 2-5 to 2-7 is common in many modern savage races.
Although the explanation of Thomson as to the cause of the curvature is
undoubtedly correct in the majority of cases, it may be pointed out that it is
not the attitude of squatting alone that produces the condition. The curvature
is well marked in the Australian but, as has been mentioned, the common
attitude of rest in this race is not that of squatting, but an exaggerated
kneeling position. In this position extreme flexion of the knee is also present
and acts in the same way on the proximal end of the tibia.
A tracing taken transversely across the middle of the articular surface
showed a gradual upward slope towards the intercondyloid eminence from
about the centre of the condyle, a feature which, as was pointed out by
Humphry, adds very considerably to the antero-posterior convexity of the
m= C€ ~a»~7- fF
The Tibia of the Australian Aborigine 249
medial portion of the articular surface. The lateral part of the articular
surface, as shown by this tracing, was practically flat.
There is no constant relationship between the degree of convexity and
the degree of retroversion. The average angle of inclination from a series
with a high convexity was much the same as that from a series with a low
convexity. The same remark applies to the relationship to platyenemia. In
a group of 25 tibiae in which the convexity was 8 in 22 cases and 4 in 8 cases,
according to Thomson’s scale, the cnemic index varied from 51-9 to 86-2,
the latter being the highest index of the whole series. This last specimen
with the high index had a convexity of 8. The average index for the group
was 65-9 which differs very little from the average of 65-2 for the whole
series. This bears out the generally accepted view that, though the convexity
of the lateral condyle and platyenemia are commonly associated, they are
dependent on essentially different causes, the former to habitual posture and
the latter to hypertrophy of a muscle.
ARTICULAR FACETS ON THE ANTERIOR MARGIN OF THE DisTAL EPripuysis
In European tibiae the anterior margin of the distal epiphysis is usually
sharp and well defined, but in most primitive races it presents an articular
facet towards the fibular side. The facet is directly continuous with the
distal articular surface. A similar facet will be found on the neck of the
talus which fits exactly into the tibial facet when the two bones are articulated.
Arthur Thomson, who first described this condition, attributed it to the
extreme dorsiflexion at the ankle-joint in the act of squatting. Havelock
Charles described also a second facet of a smaller size and occupying a more
medial position. He found the medial facet present in 47 per cent. of
Punjabis, while the lateral facet was present in 64 per cent.
In the Australian bones I found the lateral facet present in 190 out of
the 236 bones (see Fig. 14). The medial facet was rarely present. It occurred
alone only twice and in association with the lateral facet in three specimens.
_ The difference in frequency in the occurrence of the medial facet in Australians
and Punjabis is probably to be explained by the difference in the habitual
attitudes of the two races. The lateral facet is sometimes found in European
tibiae. In 118 European bones I found it in 20 specimens. The medial facet
was present in two specimens. To explain these appearances in European
bones Regnault has attempted to assign them to modifications in the shape
of the articular surfaces. The work of Lane and others, however, has shown
that they are much more likely to be due to factors which come into play
as the result of the occupation of the individual. Heredity having determined
the general shape of the bone, the development of the peculiarities in the adult
' bone is due to the assumption of attitudes at work, as in the occupation of
a miner, which correspond very much with the squatting posture and are
associated with marked dorsiflexion at the ankle-joint.
Variations in the shape of the medial condyle have been described by
250 : W. Quarry Wood
different observers. Havelock Charles found that in Punjabis the articular
surface is never horizontal in the transverse direction, as in Europeans, but
slopes considerably downwards and medially from the intercondyloid eminence.
He attributes this modification to the squatting position. I did not find this
change present in the Australian bones, in which the articular surface was
as horizontal as in the European. In view of the difference in the habitual
attitudes of Punjabis and Australians, the absence of this variation is not
surprising. ;
Martin makes the statement that in primitive races the medial condyle
seems to lie relatively lower and more inclined medially than in the European,
owing to which the whole articular surface is sloping slightly from the lateral
to the medial side. This appearance was not present in the Australian bones,
and in several specimens the proximal epiphysis was slightly tilted in the
opposite direction so that the medial condyle was at a slightly higher level
than the lateral.
TORSION OF THE TIBIA
Although torsion has long been recognised, it was not until comparatively
recently that its importance, especially with regard to the origin of man, was
fully understood. P. le Damany and Klaatsch deserve the greatest credit for
the work they have done in connection with this feature. Le Damany showed
that the condition is absent in infants and is mainly due to the habit, which
we instinctively acquire, of turning the point of the foot laterally to improve
the base of support when standing. By the fifth or sixth year the angle of
torsion has attained approximately the value which it will have in the adult.
He found also that in most cases the torsion is greater in the right tibia than
in the left and pointed out that prehistoric tibiae are twisted like those of
our contemporaries and to the same degree.
Klaatsch pointed out the significance of the fact that in the higher anthro-
poids the torsion of the tibia is in the opposite direction to that of man and
the improbability of the positive angle of man having developed from the
negative angle of the anthropoids.
Technique. To measure the angle of torsion, a steel rod was fixed trans-
versely over the mid-points of the articular surfaces of the two condyles to
indicate the transverse axis of the proximal epiphysis. The transverse axis
of the distal epiphysis was indicated in a similar manner. The tibia was then
clamped in the vertical position so that the two axes crossed as nearly as
possible at the centre of the two epiphyses. The two axes were then easily
marked on paper by the Parallelograph and the angle measured.
The angle of torsion is about 19° in modern Europeans. In the lower
races it varies from 14° in the Japanese and 18° in the Negro to 28° in the
Malay. The low degree of torsion in the Japanese is probably due to their
manner of walking. In the Australian bones the average angle of torsion
was 17°. This figure is next to the Japanese when compared with other
modern races. In searching for an explanation of this low degree of torsion
The Tibia of the Australian Aborigine 251
I convinced myself by the examination of a large number of photographs
from the works of Spencer and Gillen already referred to, that in standing
the Australian aborigine turns his toes laterally to a lesser degree than the
European. Another factor which probably tends to diminish the amount of
torsion is the habit of resting in the kneeling position previously described,
with the feet turned medially under the buttocks so that the toes point to-
wards each other. Klaatsch makes the statement that Australian females
stand with their feet practically parallel with the median sagittal plane of
the body which is in conformity with the appearances depicted in the above-
mentioned photographs.
Le Damany made the observation that the angle of torsion was usually
greater in the right tibia than in the left and suggested that the difference
was connected with right-handedness. In the present series the reverse con-
dition was present. In 86 pairs of tibiae the left angle was the greater in 70
cases, the right in 15, and the two angles were equal in only one pair of bones.
On working out the average angle on the two sides I was much impressed by
the marked difference; the average angle of the right tibiae in the 86 pairs
was 12°6°, that of the left was 21°6°. Unless the Australians are left-handed,
a point on which I have no information, I have no explanation to offer for
this striking difference.
An IMPRESSION ON THE ANTERIOR ASPECT OF THE LATERAL CONDYLE
While examining the Australian bones I was struck by a prominence on
the anterior aspect of the lateral condyle. The prominence bears an ovoid or
circular impression about 7 to
10 mm. in diameter, flattened or
slightly concave, with a smooth
surface of dense compact bone—
almost having the appearance of
an articular facet. The impression
was almost constantly present; in
236 specimens it was absent or
poorly marked in only 43. cases.
On examining European tibiae I
found a similar impression, which
has been noticed by Professor
Thomson, occasionally present. In Fig. 13. The proximal extremity of an Australian
118 European bones it was dis- tibia showing the facet on the lateral condyle.
tinctly present in 20 and faintly marked in other 8.
The question arose as to whether this was a pressure facet or due
to some other cause. The first idea that suggested itself was that it might
be connected with the peculiar attitude of extreme genuflexion that the
aborigines take up when resting. In this position one can quite easily
demonstrate that there is a considerable degree of pressure on the lateral
252 W. Quarry Wood
condyle, though the pressure is mainly borne on the tubercle of. the tibia.
Against this explanation is the fact, which an examination of pathological
specimens at once reveals, that although adventitious facets are of common
occurrence where two bony surfaces are in contact they practically never
result from pressure applied to a bone through the skin. Examination of
the skeleton of a foot from a case of talipes equino-varus in a man aet. 50
demonstrated this clearly. Although the man had walked on the lateral
border of his foot for nearly 50 years, the bones presented no appearances
like the one under discussion.
The other possibility that suggested itself was that the impression might
be produced by the attachment of an anatomical structure. A similar smooth
dense surface is produced by the ligamentum patellae where it is attached
to the tubercle of the tibia, or, less typically, by the tendo caleaneus where
it is attached to the calcaneus. The only structure attached in this neigh-
bourhood likely to produce such an impression is the ilio-tibial tract. In
European bones the tract is usually described as being attached to a hori-
zontal ridge on the antero-lateral aspect of the lateral condyle. In order to
verify this description I dissected the attachment of the ilio-tibial tract in
six specimens. I found that the attachment extends forward from the tibio-
fibular joint on to the anterior aspect of the lateral condyle. It is closely
blended below with the attachment of the capsule of the knee-joint though
the two structures can be separated at a higher level. The anterior portion
of the tract extends distally on to the anterior aspect of the condyle and is
attached to the area’under discussion. This anterior portion constituted the
strongest part of the tract. In European bones the area of attachment gives
the appearance of a flat triangular surface bounded in front by a faint eleva-
tion and below by the ridge indicating the line of attachment of the deep
fascia of the leg. The surface of the bone in this area was rough and similar
in appearance to the neighbouring parts.
Apparently in the Australian bones the facet is due to the attachment of
an unusually well-developed ilio-tibial tract. It may be presumed that the
active conditions of life which cause platyenemia will throw an increased
strain on the tract and conduce to its powerful development. It will be of
interest in future investigations to observe if this appearance is present in
other primitive races.
SomE Minor PoINntTs IN CONNECTION WITH THE DistTAL EpapHysis
Martin has referred to variations in the general shape of the distal
epiphysis in connection with the tibia of the natives of Tierra del Fuego. He
found the distal epiphysis more flattened from before backwards than in
Europeans; the anterior aspect was slightly concave while the posterior
surface was strikingly flat, with no indication of a groove for the tendon of
the tibialis posterior. In the Australian bones, apart from the generally
slender character of the epiphysis, there was no striking difference in shape
The Tibia of the Australian Aborigine 253
Fig. 14. A is the distal extremity of a European tibia, B and C are the extremities of Australian
bones. The articular surface of the medial malleolus terminates in the European bone in
a sharp anterior border, in the Australian specimens it is continued on to the anterior aspect
of the malleolus. Note also the facet on the anterior border of the distal extremity in the
Australian bones.
Transverse diameter of A =5-2 cm.
os ns » B=4-5 cm.
we oe » C=415 cm.
Fig. 15, The same appearances as in Fig. 14 demonstrated by photographing the distal articular
surface. The two bones on the left are Australian and the two on the right European.
——
254 W. Quarry Wood
from the epiphysis of the European tibia, The anterior aspect was gently
convex and the groove for the tibialis posterior was, as a rule, well marked.
The medial malleolus, however, showed in many eases a distinct difference
from that of the European bone. As has been already mentioned, its average
length is almost double that of the European malleolus, and it shows a more
distinctly conical shape. When looked at from the front, the malleolus fre-
quently presented an appearance which I have not seen described in the
literature. The anterior border was somewhat everted or bevelled, so that
there was an extension of the articular surface on to the anterior aspect. This
additional articular facet is illustrated in Figs. 14 and 15.
It varied in the degree of its development in different cases but was well
marked in 26 specimens. In other bones, in which there was no. facet on the
anterior border of the malleolus, the malleolus was markedly oblique, the
whole process being bent in the medial direction. Both of these changes are
probably related to the attitude of the foot in the positions of rest. The
foot of the Australian aborigine seems to have an extraordinary degree of
A A
B B
Fig. 16. Tracings taken in the transverse direction at the mid-point of the medial malleolus
in an Australian and a European tibia. In the European bone—on the right—the articular
surface B is slightly concave and terminates in front in a sharp border A. In the Australian
specimen the anterior border of the articular surface is rounded off so that it extends on to the
anterior aspect of the malleolus.
mobility at the ankle-joint, and the resting position in which the lateral .
border of the foot is placed on the ground and the toes are turned medially—
which has been referred to repeatedly—would tend to bring the talus into
firm contact with the malleolus. In some cases, as a result of the strain on
the malleolus, the whole process becomes bent medially, while in others the —
anterior border of the malleolus becomes bevelled off so as to permit the
talus to be slightly rotated in the medial direction around a vertical axis.
Klaatsch describes a feature on the distal epiphysis which he calls the
Praefibular Process. This consists of a prolongation of the anterior border
of the incisura fibularis so as to form a somewhat peg-shaped process. The
articular surface extends on to the lateral aspect of the process, the articular
area on this projection being separated from the rest by a definite border.
He found it especially well marked in the Australian tibia. Examination of
the present series supported this observation, the process being commonly
present and showing a very definite extension of the articular surface on to
its lateral aspect.
_ “auto-intoxication,
toxin from the alimentary canal. That such a prolonged intoxication should
The Tibia of the Australian Aborigine 255
PATHOLOGICAL CONDITIONS ILLUSTRATED IN THE AUSTRALIAN TIBIAE
A review of all the Australian tibiae in the Anatomical Museum revealed
very few examples of disease. Two specimens, however, showed undoubted
evidence of arthritis deformans of the knee-joint. The most important factor
in the causation of this disease in civilised races is generally regarded as an
*” in the form, in most cases, of absorption of a soluble
take place in a race like the Australians, who lead an active life under natural
conditions, is difficult to believe. It would therefore seem possible that certain
_ types, at least, of the disease are dependent rather on an organismal infection
of the affected joint or joints than on any prolonged derangement of meta-
~ bolism.
One pair of bones showed signs of advanced syphilitic disease. A few
specimens showed the presence of small sequestra in the diaphysis surrounded
by an area of osteoporosis. These were most likely due to tuberculosis.
Several specimens illustrated the condition which Stirling has termed “‘cam-
__-poenemia.” The bones affected by this condition are very long and are
markedly curved with the convexity forwards. The diaphysis is considerably
_ thickened and the bone shows a marked degree of torsion, usually to about
half a right angle. The appearance of these bones suggests a resemblance to
_ the condition known as Paget’s disease or Osteitis deformans, or to a con-
_ dition resembling rickets in the adult. It may be that the bones become
_ softened and bent during a period of malnutrition, such as those to which
a race like the Australian aborigines is continually being exposed, and are
restored to their former rigidity when the bad time has passed, preserving
the deformity which has developed during the period of malnutrition.
SUMMARY AND CONCLUSIONS
1. Length of the Tibia. The average length of the 236 tibiae examined,
measured from the articular surface of the lateral condyle to the tip of the
medial malleolus, was 380 mm. The longest tibia was 446 mm. and the shortest
316mm. The average length is greater than in any other race yet investi-
gated. The intercondyloid eminence is well-developed and slightly longer
than in European tibiae. The medial malleolus is longer than in European
tibiae but considerably shorter than that of the Spy tibia. The Australian
tibia is very long in proportion to the average body-height. The tibiae of the
two sides are nearly always asymmetrical as regards their length; they were
equal in the present series in only 7-6 per cent. of cases, the right tibia being
more often the longer of the two.
2. Dimensions of the Epiphyses. The slender character of the epiphyses
of the Australian tibiae is very striking, especially when considered in relation
to the great length of the bone. The average transverse diameter of the
proximal epiphysis was 69mm. and of the distal epiphysis 45mm. The
corresponding sagittal diameters were 43 mm. and 84mm. These measure-
256 W. Quarry Wood
ments are much smaller than those recorded for any other race, with the
exception of a few examples with very short tibiae.
3. Dimensions of the Diaphysis. The average sagittal diameter at the
middle of the tibia was 2:9 em.; at the level of the nutrient foramen it was
3-3.cm.; and at the point where the popliteal line cuts the medial border, it
was 3-lcem. The average transverse diameter at these levels was 2 cm.,
2-2cm., and 2:1cem. The average circumference at the middle of the bone
was 8:1 cm.; at the level of the nutrient foramen it was 8-9 em.; the smallest
circumference was 7 cm. The Index of Massiveness or relation of thickness
to length is lower than in any other race on record.
4. Platycnemia. The average cnemic index for the series was 65-2. The
Australian tibia therefore occupies an intermediate position in this respect
when compared with that of other races. Examination of the specimens with
well-marked platyenemia confirmed in every respect the view that the
essential cause of the change is hypertrophy of the tibialis posterior.
5. Outline of the Tibia at the Level of the Nutrient Foramen. The most
common appearance of a transverse section of the Australian tibia is that in
which the posterior aspect is subdivided into a postero-lateral area for the
tibialis posterior and a postero-medial area for the flexor digitorum longus.
A type of platyenemia in which the surface for the tibialis posterior lies in
the same plane as that for the tibialis anterior, which is very rare in other
races, occurred with comparative frequency.
6. Retroversion and Retroflexion. In the Australian tibia the average
Angle of Retroversion was 17° and the average Angle of Inclination was 13°.
These angles are very high in comparison with those of other races. The
high degree of retroversion is due to the marked genuflexion in the common
attitude of rest, and not merely to the attitude of squatting. Retroflexion is
not of frequent occurrence in the Australian tibia. The bones in which it
is present are strong and well-formed, so that it is probably not due to yielding
of the bone to forces tending to bend it in the sagittal direction.
7. Convewity of the Articular Surface of the Lateral Condyle. The average
degree of this change in the Australian tibia corresponds to 2-3 of Thomson’s
scale. Like retroversion it is due to habitual acute flexion of the knee-joint
in the common attitudes of rest, which are not’ necessarily squatting attitudes,
There is no constant relationship between the degree of convexity of the
condyle and the degree of platyenemia.
8. Articular Facets on the Anterior Border of the Distal Epiphysis. The
lateral facet is almost constantly present; the medial rarely occurs. These
facets are due to habitual extreme dorsiflexion at the ankle-joint in the
postures of rest.
9. Torsion of the Tibia. The average angle of torsion in the Australian
tibia is 17°. This low figure probably depends partly on the method of walking
and partly on the position of the feet in the common attitudes of rest. There
is a very striking difference between the angles on the two sides, that on the
The Tibia of the Australian Aborigine 257
left being usually much greater than that on the right. This is the converse
of what is found in most other races.
10. An Impression on the Anterior Aspect of the Lateral Condyle. The
majority of Australian tibiae present a well-marked circular or ovoid smooth
_ facet, flattened or slightly concave, on the anterior aspect of the lateral
eondyle. This is occasionally, but much less frequently, present in the Euro-
pean tibia. It is produced by the attachment of a powerfully developed
Tractus [lio-tibialis.
: 11. Minor Points in Connection with the Distal Epiphysis. The medial
- malleolus not infrequently shows an extension of the articular surface on to
_ its anterior aspect. In other cases the medial malleolus is bent in the medial
direction. These changes are probably due to the position of the foot in the
_ common attitudes of rest. The Praefibular Process of Klaatsch is commonly
present in the Australian tibia.
REFERENCES
_Cuar.es, H. C. K. (1893). “The Influence of Function as Exemplified in the Morphology of the
Lower Extremity of the Punjabi.” Journal of Anatomy and Physiology. London, vol. XxXvmI.
pp. 1 and 271.
Cottienon (1880). “Descriptions des ossements fossiles humains.” Revue d Anthropologie.
eo Paris, vol. rx.
-Dezry, D. E. (1907). “Notes on Predynastic Egyptian Tibiae.” Journal of Anatomy and
_ Physiology. London, vol. Lx, p. 123.
Hrescu. Die mechanische Bedeutung der Schienbeinform. Berlin.
‘Hrpuicxa, A. (1899). “Study of the normal tibia.” Proceedings of the 11th Annual Session of
_ the Association of American Anatomists, p. 61. Amer. Anthrop. vol. 1. p. 307.
Huerer, C. (1862). ‘“Anatomische Studien an den Extremitatengelenken Neugeborener und
Erwachner.” Virchow’s Archiv, Bd. xxv. und Bd. xxv1.
‘Kuaartscn, H. (1899). ‘‘Die fossilen Knochenreste des Menschen und ihre Bedeutung fiir das
_ Abstammungs Problem. Ergebnisse der Anatomie und Entwickelungsgeschichte.” Merkel
und Bonnet, Bd. rx.
_ — (1900). “Die wichtigsten Variationen am Skelet der freien unteren Extremitat. Ergebnisse
__ der Anatomie und Entwickelungsgeschichte.” Merkel und Bonnet, Bd. x.
-—— (1901). “‘Das Gliedmassenskelet des Neanderthalmenschen. Anat. Anz. Bd. xrx. Erz.-H.
: 121.
hy (1910). “Die Aurignac-Rasse und ihre Stellung im Stammbaum der Menschheit.” Zeitschrift
fiir Ethnologie, Heft 3 and 4.
Kocaner (1894). “Kurze Mitteilung itiber Untersuchungen von Aino-skeleten.” Archiv fiir
Anthrop. Bd. xx.
Manovvetrer, L. (1887). “La platyenemie chez ’homme et chez les singes.” Bulletins de la
Société & Anthropologie de Paris, T. x. Sér. m1. p. 128.
—— (1888). ‘Mémoires sur la platyenemie chez ’homme et chez les anthropoides.”” Mémoires
et Bulletins de la Société d Anthropologie de Paris, Sér. 1. T. m1. p. 469.
— (1893). ‘Etude sur la retroversion de la téte du tibia et l’attitude humaine 4 l’époque
/ quaternaire.” Mémoires et Bulletins de la Société d Anthropologie de Paris, Sér. 11. T. 1v. p. 219.
Marti, Rupotr (1914). Lehrbuch der Anthropologie. Jena.
Pearson, Kart (1899). “On the Reconstruction of the Stature of Prehistoric Races.” Phil.
Trans. Roy. Soc. vol. cxcm. p. 169. .
Rerzrvs, G. (1900). “Ueber die Aufrichtung des foetal retrovertierten Kopfes der Tibia beim
Menschen.” Zeitschrift fiir Morphologie und Anthropologie, Bd. 1. p. 166.
_ SPENcER and GiLLEN (1899). Native Tribes of Central Australia. Macmillan & Co., London.
—— (1904). Northern Tribes of Central Australia. London.
Spencer (1914). Native Tribes of the Northern Territory of Australia. London.
Tormarp (1885). Eléments ¢ Anthropologie Générale, pp. 1040-1041.
MODELS OF THE HUMAN STOMACH SHOWING ITS
FORM UNDER VARIOUS CONDITIONS
By A. E. BARCLAY, M.A., M.D. (Cams.)
Wiiru the advent of the opaque meal and X-ray method of examination
of the alimentary tract, it at once became evident that the time-honoured
diagrams and descriptions of the stomach were seriously at fault. There were
many points, even in the gross anatomical appearances, which were incom-
patible with the shadows seen by means of X-rays. This was hardly to be
wondered at, considering that the old descriptive anatomy was written from
observations on post-mortem and preserved specimens, corrected to a certain
extent by operative appearances, which, owing to the anaesthetic, the prone
position and various other factors were hardly a true picture of the living
functioning stomach. There is little to be gained by reviewing the literature
on the subject, the fruitless discussions as to unnatural biloculations and the
varied appearances of excised stomachs which were due to formalin or other
factors. To-day I do not think that any anatomist will raise his voice in
protest when a radiologist describes the stomach as <‘J” shaped, “‘cow’s
horn” shaped, or any other shape; for thought progresses, and it is realised
that the radiologist sees the living anatomy, and it is for the radiologist, or
those who have efficient X-ray installations at their disposal, to say what is
and what is not the shape of the living stomach—the day of the description
of dead specimens as essentially representing the conditions of life has gone
for ever. As a radiologist who has examined well over 7000 living, functioning
stomachs; I claim to speak with some authority, and yet, in spite of such an
experience in the screen examination of both normal and pathological patients,
it is with no little diffidence that I send forth these models as representing
the normal stomach. |
The essential fact in understanding the normal stomach is that one must
think of it as a living muscle; that it is a sensitive organ, that it is perhaps the
most sensitive muscular organ in the whole body.
In the early days of gastric work, one used to record atony of the stomach
in one’s. notes as a pathological condition, till various object lessons taught
one otherwise: for instance, a sudden dropping of the lower border was the
first sign that a patient was going to faint. This was noted fairly frequently
in the early days during the prolonged examinations that were necessary. The
sudden banging of a door, or an unexpected touch by the screen on the patient’s
chin brought about the same result. Sometimes we recorded a marked atonic
condition one day, only to find that it had gone when he came for re-examina-
tion and was less apprehensive. One could write at length on this subject,
but my only object in mentioning it is to emphasise the point that in making
models of the normal stomach I am doing something which is quite contrary
Models of Human Stomach under Various Conditions 259
to nature, i.e. attempting, for teaching purposes, to give a standard picture
of a living organ which may alter enormously and yet be within the bounds
of normality. If those who use these models will bear this in mind and will
impress this fact on their students, they can be used with safety for teaching
purposes. If, however, they are used as standards for descriptive purposes,
perhaps even with measurements and capacities, etc., they will but perpetuate
- in a new form those cast-iron descriptions which were simple and easy for
a student to learn, but which gave a habit of mind in clinical work that was,
to me at any rate, a great obstacle to gaining an understanding of the things
__ which one saw in the living anatomy when one came to study it by means of
X-rays. The effect of this descriptive teaching of anatomy runs into the
clinical medicine books—surely the student who has never seen a stomach
filled with opaque food must imagine a dilated stomach as something resemb-
ling a distended football bladder, whereas, being a potential cavity, the normal
stomach is canalised, i.e. “dilated”’ with quite a small quantity of food and
gradually distends as more food is taken, the walls being contracted on the
contents at all stages. The “dilated”? stomach is one found in everyday life
after a full meal has gone into a perfectly normal, well-toned stomach. What
‘is always described as a “dilated stomach,” is found in the dyspeptic who
_ eats very little, and is simply an atonic stomach, one in which the tone being
defective, the food goes to the bottom and hangs at the lowest part of the
sac. In the middle portion, the walls are actually in contact—the cavity is
certainly not dilated. ‘‘ Dilatation” can occur in such a stomach, but the
quantity of food to produce such a result would make the most experienced
gourmond feel very unhappy. This one instance should be sufficient to make
the teacher of anatomy hesitate before he imprints on the student’s mind
a cast-iron picture of living organs—it requires a re-education for the student
_to grasp the essential motility and adaptability of the living alimentary tract
and his powers of observation and deduction will be hopelessly at sea until
_ he appreciates these facts.
The best method of teaching the anatomy of the living stomach is by
_ demonstrations to small numbers in a good X-ray department, but woe
betide that demonstrator who thinks that because the laboratory boy is
healthy, his stomach is one that is quite normal and will correspond to the
models—the demonstrator may be badly “‘let down”’ if his laboratory boy is
a little nervous, or finds the food distasteful and nauseous. A true idea of the
normal stomach can only be obtained by a long experience of a large number
of examinations, and it is only in view of my very large experience, that I
venture to write this description for a journal of a science in which I make
no pretensions to be an expert.
In the foregoing I have endeavoured to indicate the fact that the hcleiatah
is a “fluid” organ, if one may use the term in this sense. It may be displaced
across the abdomen by a collection of gas in the colon; it is easily pushed
upwards by pelvic tumours, pressure on the abdomen, etc., and in spite of
260 A. HE. Barclay
quite gross displacements it may give not the slightest sign that the distortion
is causing any embarrassment of its functions. How some of the ladies
existed who “tight-laced,’’ and thus nipped atonic stomachs in the middle, is
a problem which, when this fashion recurs, will be worth studying. The fact
that this did happen, and that there are survivors to tell the tale, is sufficient
to show how wonderful is the adaptability of that organ which, in my student
days, I regarded as a retort in which various test-tube experiments were
always in progress. .
The nearest approach to a fixed point is the cardiac orifice, and since this
is incorporated with the diaphragm, and as the fundus of the stomach extends
into the left dome, perhaps one should begin with this structure.
The levels given as the results of X-ray findings are from observations in
the upright position. So far as my records go they are not materially altered
(4 to 2 inch) by the change to the recumbent position.
I give below a table of levels gathered for me by Dr J. B. Higgins from
various works on Anatomy.
Cardiac
Right Left orifice Pylorus
Quain ... fe eee iv .. 8thD.V 9th D. V 10th D. Vo 12th D. V
Text-Book of Anatomy, Gray so BU DY. 8-9hD.V 10thD.V IstL.V
Text-Book of Anatomy, Cunningham 8th D. V 9th D. V llth D. V —
Manual of Anatomy, Buchanan... 8th D.V 9th D. V llthD.V istL.V
Practical Anatomy, Fagge ws aa _ llth D. Vist L. V
Practical Anatomy, Cunningham ... 7th D. V 8th D. V 10th D. V —
(on forced respiration)
Surface Markings, Rawlings... .. 78th D. V 8th D. V 1lthD. V IistL.V
Symington’s Atlas... ‘he sis 10th D. VV 10-11th D.V_ 11th D.V_ Ist, 2nd L. V
Todd’s Clinical Anatomy... ... 9-10th D. V —_ llth D. V 2nd, 3rd L. V
NG a si .. 10-l1thD. Vs 11th D. V 12th D. Vs 3rd L. V
I wish it to be very clearly understood that I am not quoting these figures
in any way in disparagement of the great anatomists whose data I am giving.
I am quoting them simply to drive home the lesson that the anatomy of the
living and of the dead are two very different things and, to the medical
student at any rate, it is the anatomy of the living that is of value,
The disparity in the figures is very striking (except in Todd’s Clinical
Anatomy in which his figures were taken from X-ray findings) and is of
course due to post-mortem effects. If the figures had been taken from
subjects who had died and been preserved in the upright position, an exactly
opposite disparity would have resulted, for, tone having disappeared, the
action of gravity would have made the diaphragm and all the viscera sag
into the abdomen, the stomach and intestines hanging by their attachments
or resting on the pelvic floor, with the lower abdomen comparatively bellied
out and the upper abdomen comparatively sucked in.
The ziphi-sternal notch corresponds to the mean level of the diaphragm
in a large proportion of normal subjects but is not sufficiently constant for
a definite landmark.
Models of Human Stomach under Various Conditions 261
The level of the umbilicus is usually given as the 3rd L. V. Radio-
graphically it is almost invariably about the lower level of the 4th L. V.
As to the models themselves. They are not taken from any one subject,
but are compiled reconstructions, founded on experience. For the purposes
of the work however I made a series of special examinations several years
_ ago, taking plates in five positions, i.e. (1) standing postero-anterior, (2) stand-
_ ing sideways, (3) lying on back, (4) lying on right side, (5) lying on left sjde,
with a number of normal subjects, whose good nature and scientifie interest
I willingly acknowledge. On these plates I outlined those portions of the
stomach which-contained either bismuth or air and filled in the intervening
gaps to the best of my ability. In the normal empty stomach one had to rely
on rapid glances as the patient took a watery suspension of barium, watching
the way in which the rugae were outlined and various other points, before
one ventured on making a model of an organ which had to be reconstructed
almost entirely from deduction as to the manner in which it filled.
__ Whe outlined plates were then placed on a viewing box and pantograph
_ tracings, reduced to one-fifth, were made on cards so that the whole of the
_ records of each position could be seen at a glance. Small size plasticine
models were then constructed and these served my own purpose for demon-
stration. Professor Stopford suggested that they would be more useful
natural size and accordingly this has been done.
I do not know of any other models of the normal stomach based on X-ray
_ findings except Jefferson’s, which were made chiefly from the cinemato-
_ graphic diagrams published by Groedel. The only attempts to indicate the
_ shape of the normal stomach in the right and left lateral positions that I
_ have come across are in Forssell’s admirable book?. I did not see these till
after I had made my models and it is interesting to note that our ideas on ~
the subject correspond so closely.
THE MODELS
In this description I am purposely avoiding all reference to other viscera,
since the radiologist is unable to see these sufficiently clearly to make accurate
_ observations. Most of the viscera of importance from a diagnostic point of
_ view however are comparatively fixed, and we know their positions.
In the series I have included a model of an atonic stomach—one in which
the condition is very pronounced. Atony is responsible for such extraordinary
changes in the X-ray appearance of the stomach and may be such a transitory
condition that it cannot be regarded as a pathological state. Rather it is a
physiological relaxation of muscle tone. In order to give the contrast I have
also included a model of gastroptosis.
In each case, when speaking of the full stomach, I do not mean a dis-
tended organ but one that is comfortably filled by about three-quarters of a
pint of food.
1 Archiv und Atlas der Normalen und Pathalogischen Anatomie, 1913.
Anatomy LIV 17
262 A. EH. Barclay
In order. to avoid complicating the models, I have left out all suggestion
of peristaltic waves.
In the upright position the angle of inclination of the stomach from the
fundus downwards is approximately 80 degrees. This was the figure arrived
at after 100 consecutive observations. In some subjects however there is
practically no angle at all, the organ simply hangs straight down. These are,
for,the most part, the atonic stomachs found in tall thin women with flat
abdomen and poor lumbar curvature. In others there is as great an angle as
60 degrees. These rarer cases are the very hypertonic stomachs met with in
short stout men, with rather marked lumbar curvatures, and in whom the
I. 2 IA. ZAs
Fig. 1. Model of normal empty stomach in upright posture, as seen on its anterior or ventral
surface.
Fig. 2. Model of normal stomach moderately filled in upright posture, as seen on its anterior or
ventral surface.
Fig. 1 a. Model of normal empty stomach in upright posture, as seen on its left or convex
border.
_ Fig. 2 4. Model of normal stomach moderately filled in upright posture, as seen on its left border
or greater curvature.
The drawings are designed merely to show the form of the stomach under the various con-
ditions mentioned in the text; no attempt has been made to represent their relationship to the
sagittal median plane of the body.
abdominal fat is well developed. These are the extremes, but a very large
proportion of patients, especially with so-called “‘normal”’ stomachs, exhibit
an angle of about 30 degrees.
There is usually a slight angle in the stomach itself as it comes forward
over the kidney. In some subjects, nearly always men, this angle is quite
sharp, the upper portion being at an angle of perhaps 70 degrees while the
lower two-thirds of the organ drop practically straight down. In these cases
the manner in which the stomach fills is peculiar: the upper cup fills first
and appears to spill over into the lower part, the “cup and spill type” I
always call it. It is a curious angle and is often associated with duodenal
lesions, It is certainly due to a spasmodic contraction, but the mechanism
Models of Human Stomach under Various Conditions 263
that produces the deformity is not at all easy to understand. Sometimes this
angulation is so pronounced that a definite hour-glass contraction is produced.
In children, the stomach is relatively shorter and wider in proportion to
the length of the body. Whereas in the adult the stomach reaches the
umbilicus, in children up to about four years of age it only comes half way
and does not reach the umbilical level till near puberty.
The hypertonic stomach does not differ essentially from the normal—it
is proportionally shorter and wider and the pylorus and first part of the
duodenum pass more or less transversely, or even downwards, into the second
part of the duodenum.
(1) The normal empty stomach. (Standing position.)
The cardiac end of the stomach naturally varies in size according to the
quantity of air contained in it. When there is no fluid at all the air gives
a round clear area, but if there is, as is usual, just a little secretion present,
the air space will be the arc of a circle with the lower margin a straight fluid
line.
The construction of this model is almost entirely from deductions, since
the empty stomach cannot be seen. Jefferson! studied the canalisation of
the empty stomach and found that the liquid food passed down the lesser
.curvature. He attributed this to the very marked band of oblique fibres that,
curving over the cardiac orifice, runs down on either side of the lesser curva-
ture, forming more or less the “‘canalis gastricus”’ described by Lewis. These
observations I have confirmed, but whether Jefferson’s explanation is correct
or not I cannot say. My own impressions are rather in the direction that it
is simply the fact that the lesser curvature route is the straightest in the line
of the action of gravity that causes fluid to take this route. It is quite certain
however that there is no definite channel] down the lesser curvature in the
empty stomach, as can readily be shown by giving a spoonful of solid food,
as solid as the patient can swallow, and following this up by a watery sus-
pension of barium, when the watery fluid will most likely take an outer course
down between the rugae, which can usually be seen as separate shadowy lines,
some seven or eight in number, running straight down to the lowest part of
the stomach.
The pyloric end cannot be studied until sufficient food has been given to
fill it. Therefore this is constructed entirely from deductions from the way
in which it fills.
(2) The normal full stomach. (Standing position.)
As filling takes place, the increased capacity is obtained almost entirely
by a widening of the tube. In the model the cardiac end is rather wider than
normal, suggesting that the patient has swallowed a fair quantity of air with
the food—a perfectly normal act up to a point.
1 Archives of the Roentgen Ray, May 1915.
264 A. H. Barclay
It will be noted that with moderate quantities of food the capacity is
obtained not by increase in the length but almost exclusively by lateral
expansion. The organ maintains its contents in tubular form and this tube
widens out as more food is taken. This maintenance of the tubular form is
the function of the tonic action of the walls and is automatic. It is com-
pensatory to the action of gravity on the contents. In the recumbent position
this action is not called into play to counteract gravity and to a large extent
disappears. It is a very sensitive action and is evidently controlled centrally.
Mental disturbances such as fear and other emotions are at once shown by
a relaxation of the tone of the muscle and a consequent drop in the level of
the lowest part of the outline. Most of us know the sinking sensation in the
abdomen of the waiting period before an examination or a race. This is nothing
more than loss of tonic action from emotional causes and is seen very fre-
quently in an X-ray department at the first examination but often disappears
at subsequent examinations when the patient is no longer nervous about the
procedure.
Naturally the upper portion of the stomach moves with respiration but
the lower part does not move appreciably unless with very forced respiration.
In an athlete in good.condition even forced respiration will hardly move the
lower border. Movement of the lower border of the stomach with respiration
is one of the early signs of atony. In short, the tonic action is automatic and.
not only counteracts gravity but also compensates for diaphragmatic move-
ment, maintaining a concertina type of construction in response to the
diaphragmatic movement in order to keep the lower part of the stomach in
a definite and more or less fixed position.
The normal stomach depends for its shape very largely on the tonic action,
and a healthy well-toned stomach shows far less alteration in shape from
changes in posture than one in which tone is defective. In the models of
the stomach in the Right and Left recumbent postures I have represented
the changes one finds in an average healthy stomach—it is probable that in
a healthy athletic youth the changes would not be quite so marked, but in
a slightly atonic stomach they are far more pronounced than in the models.
(8) The normal full stomach. (Patient lying on the back.)
The cardiac end of the stomach, being the lowest part, contains the
greater part of the food. Usually there is none remaining in the pyloric half,
which is collapsed and lies across the vertebral column. The air in the stomach
lies below the abdominal wall and does not necessarily indicate more than
a small extent of the stomach—it is only when there is a considerable quantity
present that it fills the portion that crosses the middle line, chiefly because
of the weight of the abdominal wall, etc. which presses it out of this portion
into the part where there is more room and less resistance from behind.
The pyloric end however is easily filled by making the patient lie on the
—
Models of Human Stomach under Various Conditions 265
_ right side, applying slight pressure over the umbilical region while he turns
again on to his back. In this way the pyloric end and the duodenum are very
_ satisfactorily filled and can be studied for diagnostic purposes.
(4) The full normal stomach. (Patient lying on the left side.)
The whole stomach falls by the action of gravity into the left side of the
abdomen, against the abdominal wall. The pylorus is drawn over the vertebral
_ column as far as its attachments will allow and, radiographically, one cannot
detect the outline of the pyloric portion of the lesser curvature unless there
happens to be a fair quantity of air present. Sometimes one can just detect
the pyloric end but, usually, its position can only be located from the shadow
Fz remaining in the first part of the duodenum.
zz
Zs
4
Fig. 3. Anterior or ventral surface of normal full stomach, patient supine; pyloric end is flattened
out and contains no food.
Fig..4. Anterior or ventral surface of normal full stomach, patient lying on left side.
Fig. 5. Anterior or ventral surface of normal full stomach, patient lying on right side.
(5) The normal stomach. (Patient lying on the right side.)
In this case the action of gravity draws the stomach right into or even
across the middle line. The weight of the food drags on the stomach and
pulls on the greater curvature, dragging it out of the dome of the diaphragm.
The pyloric end widens to accommodate the food and fully a half of the
organ is across the middle line; This results in the pyloric end being to the
right of the first part of the duodenum and thé pylorus is directed backwards
and to the left. -
Whether the weight of ordinary food would produce such a marked result
as that obtained by examination after the heavy barium meals, is a question
which I cannot answer, but my impression is strong that, if the comparison
could be made, the difference in resulting shape would be comparatively
small,
17—3
266 A. HK. Barclay
(6) Atonic stomach. (“ Full” of food and patient standing.)
The condition indicated by the model is one of marked atony. The lower
border of the stomach would be about 4 inches below the umbilicus and would
give a broad crescentic outline.
The middle portion of the stomach is completely collapsed and the food
hangs in the lower part as in a toneless bag. There is no effort on the part of
the stomach to hold its contents up in tubular form, in fact a part of the weight
of the contents may even be taken by the contents of the pelvis. There is
generally a considerable quantity of ordinary food, which does not show,
lying above the opaque food, but the general outline can be gathered by
palpation and splashing of the opaque food up along the walls and by watching
SA.
Figs. 3.4, 4.4, 5.4. Profile views of the models shown in full view in Figs. 3, 4 and 5. (Fig. 34
does not show the flattened and empty condition of the pyloric end as the organ is curved
forwards round the vertebrae, etc.)
and palpating as new food enters. The pylorus remains in the normal position,
high above the lowest part of the stomach. Hence there is mechanical difficulty
in emptying.
The weight of the food (and in this case one knows that it is the weight
of the ordinary food, since the addition of the opaque meal makes little or
no difference) drags on the stomach and stretches the greater curvature. The
middle portion of the stomach is collapsed and the anterior and posterior
walls, being in contact, offer some slight resistance to the downward passage
of opaque food which collects in a funnel shape, and, having canalised the _
collapsed walls, breaks off in big “‘blobs” which drop down through the
retained food to mix with the heavier opaque food that lies at the bottom of
the stomach.
The drag from the weight of the food in the lower part of the stoniaete
makes the shape of the air space characteristic; it is always pyriform, with
just a narrow fluid line at the lowest edge.
In many cases one cannot tell whether this type of stomach is a resid of
obstruction or the cause of delay in emptying. It may be that at some period
Poin, TO Le ee ee ea eS
pid 5 5
mete
ata Fn Bale AS
_ Models of Human Stomach under Various Conditions 267
there has been difficulty in emptying, of a transitory nature, perhaps due
to defective gastric movements and this has led to retention of food. Tonic
action in holding the food up in tabular form is calied on too long and the
stomach drops, as tone relaxes. This in turn gives rise to difficulty in emptying
the stomach, with the result that a temporary loss of tone may give place to
a chronic condition, with marked delay in emptying and giving all the X-ray
appearances of a typical pyloric obstruction. It is however atony that is the
cause of the delayed emptying. Exactly the same result and appearance is
> produced by a pyloric obstruction, giving rise to retention of food and an
ultimate defeat of the tonic action of the stomach, é.e. in this case the atony
_is the effect of the obstruction.
RRR Re
Wo
ee
GA 7A
Fig. 6. Full atonic stomach, patient standing.
Fig. 7. Gastroptosis; patient standing, stomach full.
Fig. 6 4. Profile view of Fig. 6.
Fig. 7 4. Profile view of Fig. 7.
(7) Gastroptosis. (Stomach full, patient standing.)
The essential difference between this condition and the atonie stomach is
that tonic action is not lost: it is not a defect in muscular action. Hence the
- food is held up in tubular form in spite of the fact that the lower border may
extend to 5 inches below the umbilicus, i.e. almost to the symphysis. It is
_ along stomach and usually the pylorus is dropped to a considerable extent,
together with the kidneys and other organs, i.e. it is a part of visceroptosis,
Glenard’s disease, in which the diaphragm also is below the normal level. But
the condition of ptosis may be limited to the stomach, the pylorus retaining
its normal position, with the result that there is considerable drag on it and
symptoms result. Generally there is no delay in emptying and I have seen
a number of patients in whom the condition has given no symptoms. More
often however there are symptoms referred to the duodenum. (There is also
very frequently some evidence of old appendicular trouble.)
268 A. E. Barclay
The air space is, as in the normal stomach, the are of a circle. It must
not be overlooked that the two conditions, atony and gastroptosis may, and
often do, co-exist, and it is often very difficult to determine how much of the
appearances are due to one or other factor.
NOTE ON THE ALTERATIONS IN THE POSITION OF DIAPHRAGM AND HEART
FROM ALTERATIONS OF POSTURE
In making the series of studies necessary for building the models of the
stomach in the various bodily positions, I took a large number of radiographs.
In each case I had plates of the patient (1) standing straight forward,
(2) standing sideways, (3) lying on the back, (4) lying on the left side, (5) lying
on the right side.
When engaged in this work I came across the fact, which I had not
appreciated myself and which very few of those to whom I spoke seemed to
suspect, that the diaphragm and thoracic viscera were capable of considerable
movement from alterations of posture. When the patient lay on one side or
other, one found that the diaphragm and also the heart and mediastinal
contents moved over in accordance with the action of gravity to an extent
that was far greater than one would have conceived possible, particularly in
patients with relaxed tone.
While publishing an account of the stomach models and while the line of
thought is fresh in the reader’s mind, I am writing this short note and giving
a few of the superimposed diagrams that I obtained during this work. The
number of cases examined was not sufficiently large for a detailed study and,
when I had done a certain number of cases, I found that there was a fallacy
which could. not be excluded, i.e. that even if a special cage was made in which
the patient could lie fixed and in which he could be moved into the various
positions, it would be quite impossible to prevent movement of the spine.
The slight difference in pose from lying flat on one side or other, on a specially
padded board, or the slight rotation of the patient, brought in factors that I
could not deal with. Because of the inherent mechanical difficulties the work
was abandoned.
The diagrams were produced direct from the X-ray plates taken specially
for the purpose. They were outlined with ink on the plates and then panto-
graph tracings were made, reduced to one in five. These are reproduced
without comment as the actual facts recorded, but with the definite statement
that although they depict the facts of the movements, there are very con-
siderable faults in technique which render the diagrams of comparatively
little value. I do not see how it would be possible to eliminate the skeletal
alterations due to pose, even with a cage arrangement. Moreover the yielding
of the body within the cage would not only allow alterations of the spine
but would also bring in pressure factors that would have an effect that would
be far from negligible.
Models of Human Stomach under Various Conditions 269
_ SUMMARY
The stomach has no fixed shape. The normal pps So approximates to
_ the letter J.
The chief factors that alter the shape are, wena, in tonic action and
- accumulations of air in intestines, ete. :
___ Alterations of posture, particularly in the recumbent position, bring about
_ very marked alterations in both the shape and position of the organ.
_ The shapes as made out with opaque meals are the same as those with
normal food—the weight of the food makes little or no appreciable difference
in the normal stomach. If however there is defective tonic action, the in-
3 creased weight exaggerates this defect.
_ The diaphragm does not retain its horizontal position when the patient
lies on his side—with the abdominal organs and the thoracic contents it
moves considerably with the action of gravity upwards on the side on which
the patient lies. The movements of abdominal and thoracic contents are
parently greatest when the general tone of the patient is Jowest, while in
thy athletic persons they are comparatively slight.
The Editorial Committee beg to acknowledge the financial aid given by
the Medical Research Council in the publication of the following papers
which have appeared in this and in the previous numbers of the Journal:
“The Maturation of the Human Ovum,” by Prof. Arthur Thomson.
Vol. ut, p. 172. 1919.
“The Development of the Uro-genital System in the Marsupialia,” by
Dr E. Fraser. Vol. Li, p. 97. 1919.
“The Variations in the Distribution of Cutaneous Nerves,” by
Dr J. S. B. Stopford. Vol. tin, p. 14. 1918.
“Studies on the Anatomical Changes which accompany certain Growth-
disorders of the Human Body,” by Prof. Arthur Keith. Vol. tiv,
p. 101. 1920.
“Voluntary Muscular Movements in Cases of Nerve Lesions,” by
Prof. Wood Jones. Vol. Liv, p. 41. 1919.
The Committee also take this opportunity of acknowledging the aid
given by the Finance Committee of the Royal Society in publishing the
following papers:
“The Development of the Uro-genital System in the Marsupialia with
Special Reference to Trichosurus Vulpecula,” by Drs E. Fraser
and G, Buchanan. Vol. Li, p. 35. 1918.
‘On the Development of Pericardiaco-Peritoneal Canals in Selachians,”
by Prof. E. S. Goodrich. Vol. Li, p. 1. 1918.
“A Preliminary Note on the Morphology of the Corpus Striatum and
the Origin of the Neopallium,” by Prof. Elliot Smith, Vol. Liz
p- 271. 1919.
MOTOR POINTS IN RELATION TO THE SURFACE
OF THE BODY
By R. W. REID, M.D., F.R.C.S.
Professor of Anatomy, University of Aberdeen.
Fottowrxe upon a visit with the late Professor Paterson, University of
Liverpool, to the Orthopoedic Hospital at Shepherd’s Bush, London, and
upon subsequent visits to the Orthopoedic Department of the First Scottish
General Hospital in Aberdeen, I was much impressed with the value of electri-
cal methods employed in the diagnosis and treatment of the results of cases
of peripheral nerve lesions, and as an anatomist I thought I might do some-
_ thing to help in the matter.
Accordingly I decided to make a special dissection of a subject in order
x to show the relation of the points of entrance of the nerves into muscles with °
___ regard to the surface of the body and then to make the results of this investiga-
tion available in a graphic form for those practising these methods.
With this end in view I considered that the best plan was first to make
a cast of a subject in its entire state and thereafter to have the subject dissected
with the sole purpose of showing the various points where the several nerves
entered the muscles and then to relate these points to the surface of the cast.
Accordingly a cast was made in the Anatomy Department of this University
of one half of a muscular male subject. The body was subsequently dissected
in order to expose its muscles with the nerves entering them and then by
_ comparison and measurement the points of entry of nerves into the several
muscles were marked on the surface of the cast.
_ As this cast had unfortunately undergone a certain amount of distortion
_ owing to the flattening of the soft parts by the weight of plaster, I deemed it
advisable to make another cast of a living muscular male and to transfer by
proportional measurement the marks indicated on the first cast to the surface
of the second one. Photographs of the second cast were then made from different
points of view as shown in the accompanying Plates XXVI-XXXIV.
Subjoined is a table showing the number of the principal nerve branches
entering each muscle together with the approximate places of entry into each
muscle. The segments of the spinal cord from which the nerve supplies are
derived are also indicated in the table and this information has been obtained
from Gray’s Anatomy, Descriptive and Applied, 19th edition.
It may be mentioned that the markings refer to the special dissection
of a single cadaver but by comparison with cadavera which were being
dissected in the course of ordinary practical anatomy work, I find that they
are not subject to more variation than might be considered normal.
Anatomy LIv . 18
a Oe ee ae
R. W. Reid
272
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Journal of Anatomy, Vol. LIV, Part 4 Plate XX VI
{
2 7¢
M. temporal M. atollens aurem
N. inferior maxillary LN. facial
of 5 cranial ‘ —
M. attrahens aurem
a==-""N. facial
M. masseter | :
_oN. inferior maxillary of 5% cranial
M.orbicularis palpebrarum
-“ M. retrahens aurem
Metacial 29-5 --- Sl
M. zygomaticus major 5 LN. facial
rece ~~-----~_. . 7 ae ,
z : ‘ = ; ‘ M. buccinator
M. orbicularis oris _-N. facial
eee -"" _ M. digastric
_ M.platysma-myoides 7/ _---- N. facial
Dae ee a M. stylo-hyoid
M. digastric ~-..__ ae ..----~ N. facial
N. maxillary inferior”~-----..% = M. sterno-mastoid :
: ee N. spinal accessory (12345,C.) & cervical (2,3.)
INORG M. levator anguli scapulae
N, cervical (1,2.) a N. cervical (3,4,5.)
- M. sterno-hyoid ee a= M. omohyoid
N. cervical 1923) socal Se nae seo-> N. cervical (1,2,3.)
~~_~>~, M. sterno-thyroid
S\N. cervical (12,3)
‘..M. deltoid
N. circumflex (5.6.C)
M. subclavius
N. cervical (5,6.)-..
~
“-
~
bei, |
-
M. coraco-brachialis_ —~ ~~ —-
N. musculo-cutaneous (7.C)
M. pectoralis major
N. ant.thoracic external &-~~
internal (5,6,7,8 C, 1 T.)
___ M. teres major
= N. subscapular lower (5.6C)
___-M. latissimus dorsi
eh N. subscapular long. (5.67 C.)
M. pectoralis minor .__-
N. ied obo
internal (8C, IT.) - ae
et) Ee M. serratus magnus
N. thoracic long. (5,6,7 C.)
View of cast of trunk of living male from left side showing motor points.
(Prepared in the Anatomy Department of University of Aberdeen.)
Journal of Anatomy, Vol. LIV, Part 4 Plate XX VII
2]¢ ms
M. M. orbicularis oris
oe Mt. POs major
/ IN. facial
5 Ae M. orbicularis palpebrarum M. biceps fae cubiti
fs : facial “N.musculo-cutaneous (5.6,C.)
ie tol as aurem / M.brachialis anticus
‘1 Mi temporal 7 _/N.musculo - cutaneous(5,6,C.)
”N. inf. maxillary of 5 cranial 7 ,¢ Msupinator longus
Me ous pag eats 7 N-musculo- spiral ( 5,6,C)
er i Nine ae of 5‘ cranial See Pg M. extensor carpi radialis ag
f).------------------ #- M. buccinator / ¢ /N.musculo- spiral (6,7, C
ea acia ick Fp ae M. pal |
ny 6 oa M. digastric poe > ey, palmaris longus
7, pie ta N. maxillary inferior Wen het ia I N.median (6.C)
gg en stylo-hyoid / / , ¢ / Msupinator brevis
. sterno- mastoid
J 2% / ,? /“N.posterior interosseus (6,C,)
nde BRN Ee - M.flexor carpi radialis
- cervical th 12) Lf re eG “ N.median (6,C)
Hone it M deltoid ce L os Kg “ _M.extensor carpi radialis brevior
“NN circumflex (5,60) _,” Ch hae eee “N. posterior interosseus (6, 7,C.)
et Ss, eee vv ¢_,Mélexor lon gus pollicis
Bre eee 7’ N. median (8€.1,T)
M.latissimus dorsi
~~"N. subscapular long. (5,6,7,C.)
for muscles of hand
M. coraco-brachialis eet ei M. see plate 3.
-----y i i a oe ‘\ pronator quadrat
N musculo cutaneous (7,C) Me ee ~Nimedian (8.1) IT), us
age eeagee cane exor sublim
___M serratus magnus ‘ ‘sos ON. median (78 ay digitorum
4 | N.thoracic long. (567C) ‘. \. SM. flexor profundus
ae Me pectoralis minor Ne median(8.¢, apeatTs IT)
N. ant. thoracic internal (8,C. 1,T) “s. “\M_ flexor carpi ulnaris
~~. pectoralis major a N. ulnar (8,C, 1,7.)
N.ant.thoracic ext. & int.(5,6,7,8,C. 1T) \
M. subclavius \M. pronator radii teres
~"N. cervical (5.6) N. median (6,C))
M. sterno -thyroid
~"N. cervical (1.2.3)
.....M-sterno-hyoid
FAN cervical (7.23)
M. platysma myoides
ok cn :
View of cast of left side of trunk and upper extremity from front showing motor points.
(Prepared in the Anatomy Department of University of Aberdeen.)
Journal of Anatomy, Vol. LIV, Part 4 Plate XX VIII
J
2.) 4
M.supinator brevis
~-~ N.posterior interosseous (6C)
_ M.flexor carpi radialis
~-N.median (6 C)
-._M.extensor carpi radialis brevior
~N. posterior interosseous (6,7C)
M. Flexor carpi ulnaris
meaner (60.11). te
M.Flexor profundus digitorum i
N.median (8C,!1T) ulnar (8C,!T)
M.Flexor longus pollicis
~—N.median (8C,1T)
M.flexor sublimis digitorum
N.median (78C,iT) ae
M. pronator quadratus
~--N. median (8 C,IT)
M.opponens minimi diagiti
YN. ‘las (8 C) J
GeO ei yo M. llici
M. abductor minimi digiti _ N.median (67C)
N.ulnar (8 C) =. /
M.flexor brevis pollicis
_--7 N.median (6,7C) ulnar (8 C)
M.Flexor brevis minimi digit __ 7 M.abductor pollicis
mune (sc) ».. i= “ie ' --N.median (6,7C)
----. M.adductor obliquus pollicis
N.ulnar (8C) 4 Se:
-.M. adductor transversus pollicis
N.ulnar (8 C)
M.interossei ___ \_.--ses
N.ulnar (8C) q
M. lumbricales : oi
N.ulnar (8C), median (6,7C\
View of cast of left fore-arm and hand from front showing motor points.
(Prepared in the Anatomy Department of University of Aberdeen.)
Gratis
eee
a3
3 Journal of Anatomy, Vol. LIV, Part 4 Plate X XIX
oS ¥
274
M. Sobaidens minor
N. cervical (5,C.) ~~.
e M. retrahens aurem EON Go
s N. facial 5 eee Ns
a M. levator anguli scapulae ~~,
i N. cervical (3,45) ~---.. SS
M. sterno-mastoid 1
N. spinal- accessory (12.345C) \ \
and cervical (2,3) > HN fe
ie M. supraspinatus sree ‘
'N: musculo-spira! (78.0) ave N. Suprascapular (5,6,C.)._ rae
“M. ext® secundi internodii pollicis M. infraspinatus on ae
N. posterior interosseous (7.C )\ a MA fava ascapular (5,6,C)._ ie: he
ext’ primi internodii Hicis’, - teres minor De i Se
oc Rathi inberosseous 7.) * a te ~ pire coe ce si BratoNs .
_ extensor indicis Ep = ‘. a ie Sinn :
posterior interosseous (7C) a N. circumflex (5,.6,C)s_
: ‘ - \. M.triceps. ext *cubiti ™ -
Gea ee ug musculo-: spiral (78.0 )\
:
’
'
M. triceps exte + Cubiti
Ba N. musculo-spiral 7
extensor ossis metacarpt pollicis <0”, "78 cy $5 oe
. posterior interosseous (7.C)~ 7" | : J ve
| extensor minimi digiti ______ ie. M. teres major’ /
. posterior interosseous cECy. mre N. erty lower /
extensor carpi ulnaris _------~ y 5, 6,C.) -
posterior interosseous(7.C) M: lotissimas Hae
|. extensor communis digitorum,” N. Rares long. _--*
i. posterior interosseous (7C) (S676) ae
<
§ M. trapezius |-
s N. spinal - “accessory
(1.2,.345C)
and cervical (3.4.)
M. chomboideus major
N. cervical (5 C.) --77
View of cast of left side of trunk and upper extremity from behind showing motor points.
(Prepared in the Anatomy Department of University of Aberdeen.)
nee
yo
Journal of Anatomy, Vol. LIV, Part 4 PlateXXX .-
| 7k
M. rectus femoris
-"N. crural anterior (2,34.L.)
Ba tensor fascize femoris
M. pectine
N. gluteeal superior (4,5 L, 1,S.)
N. crural eri? 34 fh)
M. adductor brevis
N. obturator (3,4.L)---
M. vastus externus
‘N. crural anterior (2,3,4,L)
M. crureu
M. adductor longus
="=""N. crural mien (2,34,L)
N. cas (3.4,L}-----
> grac
Rater (3,4,L.-----
M.sartorius .
=-====\i crural anterior (2,34,L)
M. vastus internus
N.crural anterior (234,L)---
_ M. extensor longus digitorum
““"N. tibial anterior (45,L, 1,5.)
M. tibialis anticus
. tibial anterior (4,5,L,1,S.)" 77"
roneus longu
Ni. emrscide: Eien eous (4,5 L: lS.)
M. extensor proprius hallucis
N. tibial anterior (4.5,L,1,S.)"~ 777
M. peroneus tertius
we Ribial anterior (4,5L,1.S.)
M., extensor brevis digitorum
“"N. tibial anterior (451, 1.5)
View of cast of left lower extremity from front showing motor points.
(Prepared in the Anatomy Department of the University of Aberdeen.)
ee
Journal of Anatomy, Vol. LIV, Part 4 Plate XX XI :
27
. pyriformis
---~"N. sacral plexus (1,2,S.)
- sone . gemellus superior
ey a” ---N. Sacral plexus (1,2,3,S)
gluteeus minimus : - Be A . obturator internus
‘
2S 235 4235 25 235 25 ZS
~
gluteeal superior (4,5L,1S.) ~~~
\
‘
‘
- sacral plexus (1,2,3,S.)
- gemellus inferior
. sacral plexus (5,L.1,S)
. obturator externus
. obturator ( 3,4,L.)
- quadratus femoris
- sacral plexus (5,L,1,S)
. adductor magnus
- obturator (3,4,L.)
Pe ONS aaa Te Ty pe te
M.
N,
M. glutzeus medius
N. gluteal superior (4,5L, 1S.)-~
- glutzeus maximus
- luteal inferior (5,L.1,2,8)-"~
M. semitendinosus
it Gicens Flexor cruris ay i £ $=-_—_—_ N. sciatic great (4,5,L, 1.2.3.8.)
E N. sciatic great (4,51,1.23S)""""Btss==-f Ga M. adductor magnus
: : z --~" _N. sciatic great (4,5,L.)
4 _______M. semimembranosus
q ~"N. sciatic great (4,5,L,1,2,3,S.)
M. plantaris |
N. popliteal internal (4,5 1,1,S)°-~
. * M. gastrocnemius
t papliteur ‘¥---------- N. popliteal internal (1,2 S.)
M
N. popliteal internal (4,5 L, |,S.)---4--—- M. soleus
ne ae N. popliteal internal (1.2 S)
M. soleus
le — - ---- N. tibial posterior (1.2 S.)
M. tibialis posticus
N. tibial posterior (5,L, 1S) ----
M. flexor longus digitorum
-------N. tibial posterior (5.L,1,S.)
peroneus brevis M. flexar longus hallucis
musculo-cutaneous (4,5.L,|S.)°" "| ae TTT TN. tibial posterior (5,L,!,2,S)
View of cast of left lower extremity from back showing motor points.
(Prepared in the Anatomy Department of University of Aberdeen.)
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:
Journal of Anatomy, Vol. LIV, Part 4 Plate XX X1I-
27f
M.glutaeus minimus
N. Sluteeal superior (4,5L,1S)--
M. pyriformis
M.glutaeus medius Le. Sacral plexus (1,2 S)
N. gluteal superior (4,5L,1S)- -** M.gemellus superior
/“N. Sacral plexus (i,2,3,S)
“ M. obturator internus
LoN. sacral plexus (|,2,35)
+ .._ M. gemeliis inferior
'N. Sacral plexus (5L,IS)
~=-=.M.obturator externus
N. obturator (3,4 L)
a * .
iY *s~__M.quadratus femoris
N.gac
s
M.tensor fasciz femoris
N. gluteal superior (4,5L,!S)
M. vastus externus
N.crural anterior (2,3,4L) ~~ ral plexus (5,L,1S)
~~. M.gluteeus maximus
N.Gluteeal inferior (SL,12S)
“sM.crureus
N.crural anterior (2,3,4L)
“
s+-~.. M. biceps Flexor cruris
N. sciatic great (4,5L,1,2,3 S)
M. plantaris -
N. popliteal internal (4,5L,! ah.
~
M.extensor longus digitorum
N. tibial anterior (4,5 L,1S)7~ 77
M. gastrocnemius
---N: popliteal internal (1,2 S)
.---M.popliteus -
if N.popliteal internal (4,5L,!S)
~™M. soleus
N. popliteal internal (1,2 S)
qf----M.soleus :
N.tibial posterior (1,2 S)
~~--M. tibialis posticus
N. tibial posterior (5L,!S)
M.extensor proprius hallucis_
N. tibial anterior (4,5L,!S) :
M.tibialis anticus
N.tibial anterior (4,5L,1S) ---
M. peroneus longus ;
Bee i5 cota (4,5L,1S)--— ff ----_-. M. Flexor longus hallucis
: N, tibial posterior (5L,1,2 S)
Mperoneus brevis = _- -------
N. musculo-cutaneous (4,5L,! S)
M.peroneus tertius
N.tibial anterior (4,5L, 1S)
M. extensor brevis digitorum
N. tibial anterior (4,5L,!S)
s
View of cast of left lower extremity from outside showing motor points.
(Prepared in the Anatomy Department of University of Aberdeen.)
7
Journal of Anatomy, Vol. LIV, Part 4 Plate XX XIII
c.
27 ¢
M.adductor brevis
_--N. obturator (3,4 L)
_-M. adductor longus
_-7” N.obturator (3,4 L)
-
M. adductor magnus _
N. obturator (3;4 L)
Pee ; M.sartorius _
N. obturator (3,4 L) ee “""-"N.crural anterior (2,3,4 L)
M.Semitendinosus = ___---- .---M. adductor magnus
N.sciatic great (4,5 L)
F : nosu ~.___M. vastus internus
y M. semimembra ° es N. crural anterior (2,3,4 L)
a N. sciatic great (4,5L,1,2,3S)
z
M. soleus &
N. tibial posterior (1,2 S) ~
M. tibialis posticus -=
N. tibial posterior (5L,! S)
_M. flexor longus digitorum
--~"N. tibial posterior (5 L,1S)
M.Flexor longus hallucis
N.tibial posterior (5L,1,2Sj ~~)
View of cast of left lower extremity from inside showing motor points.
(Prepared in the Anatomy Department of University of Aberdeen.)
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Seer eee ae
Journal of Anatomy, Vol. LIV, Part 4
Plate XXXIV
q
r7¥
M. lumbricales
N. plantar internal (5 L,! S)
--” N. plantar external (1,2 S)
M.adductor transversus hallucis__
N.plantar external (1,2 S)
j ___M. interossei
M.flexor brevis hallucis N. plantar external (I,2 S)
N. plantar internal (5L,1S) ~"7-"
M.adductor obliquus hallucis | ; Sse ne ee
N. plantar (1,2 S} ----- M. Flexor brevis minimi digiti
E ~ N. plantar external (I,2S)
M.flexor brevis digitorum .---~~
N. plantar internal (5L,) S)
.~...M.abductor hallucis
M.Flexor accessorius N. plantar internal (5 L,1S)
N.plantar external (1,2 S) -----
“ss. M. abductor minimi digiti
N. plantar external (1, 2S)
View of cast of sole of left foot showing motor points.
(Prepared in the Anatomy Department of University of Aberdeen.)
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"Motor Points in Relation to the Surface of the Body 275
In making this investigation I wish to acknowledge the assistance given
by Mr William Banbury, of the School of Art, Aberdeen, in making the cast
which is figured in the Plates and I particularly desire to make mention
of the great interest and help rendered by Mr G. O. Thornton, B.A., LL.B.,
tudent of Medicine in this University, especially in the making of the special
dissection and in transferring the motor points to the surface of the casts.
I wish, also, to thank Mr George Milne, artist, of the firm of Messrs George
Robb, Lithographers, Adelphi, Aberdeen, for the great care he bestowed in
connection with the photographing and lettering of the casts.
In the plates the black dots indicate motor points and the black lines
icate groups of motor points.
__ Copies of the casts marked and lettered in black and red (£13. 13s. per set)
may be had on een to Messrs Robb, Lithographers, Adelphi,
Aberdeen, N.B.
‘
f
;
A CASE OF PARTIAL TRANSPOSITION OF THE
MESOGASTRIC VISCERA
By J. C. BRASH,
Assistant Professor of Anatomy, University of Birmingham,
AND M. J. STEWART,
Professor of Pathology, University of Leeds.
(From the Departments of Anatomy and Pathology, University of Leeds.)
INTRODUCTION
"Tue case here recorded is an example of a very rare type of partial heterotaxy,
viz., one in which the stomach, duodenum, spleen and pancreas only are
involved.
CLINICAL HISTORY
The patient was a boy of 13 who died of acute septico-pyaemia resulting
from osteomyelitis of the second left metatarsal bone. Clinically the liver
was found to be distinctly enlarged, but the heterotaxy was entirely unsus-
pected during life.
POST-MORTEM EXAMINATION
The principal lesion present was pyaemic infarction of the lungs. Both
organs contained numerous haemorrhagic infarcts of various sizes, the larger
especially showing central suppurative softening.
The condition of partial heterotaxy was at once evident on inspection,
in situ, of the abdominal viscera. The liver was obviously much enlarged, the
left lobe being quite as prominent as the right. The stomach was completely o
transposed, but was otherwise morphologically normal. The fundus lay to the
right of the middle line, immediately under the right lobe of the liver, and in — %
relation to it was a bunch of spleens of various sizes. The duodenum passed
from the pylorus upwards and to the left, turned acutely downwards, and S
then to the right. Thereafter it passed upwards, and once more to the left.
The pancreas, which appeared greatly shortened, arose from the duodenum
at the junction of the first and second parts as above described. It passed a
almost directly upwards and terminated in the region of the cardiac orifice
of the stomach, to which it was firmly adherent, Its total length was slightly a
under three inches.
None of the other viscera, either thoracic or abdominal, were transposed. 4 &
The relatively large size of the left lobe of the liver (it was almost as big as the
Partial Transposition of the Mesogastric Viscera 277
right) was not found to be associated with any evidence of heterotaxy of that
organ.
__ The stomach, duodenum, spleen and pancreas were removed en masse and
__ preserved for subsequent dissection.
DETAILED DESCRIPTION OF THE SPECIMEN
_ Stomach. The stomach, although lying entirely beneath the liver, exhibits
_ a striking resemblance in shape to the ordinary, moderately contracted, post-
mortem stomach, save that it is reversed, the lesser curvature being to the
left, the greater curvature to the right. The fundus is well developed. There
is a well marked incisura angularis in the lesser curvature rather more than
two-thirds of the distance between the cardiac orifice and the pylorus, and
there is a more or less definite pyloric antrum on the greater curvature. The
pyloric portion exhibits the usual contraction for a distance of 3 cm. from the
pylorus.
+ Duodenum. A statement of the course of the disdel cies has been made in
the account of the post-mortem examination, and from this it appears that
it took the form of a double loop. The concavity of the first loop, very narrow
owing to the close apposition of the two limbs in the recent condition, was
directed downwards and tothe right, and, being in association with the pancreas,
represents the ordinary concavity of the first and second portions reversed.
The second loop, the concavity of which was directed upwards and to the left,
was produced by the third portion of the duodenum passing in more or less
norma! fashion upwards and to the left to the duodeno-jejunal junction. The
first and second portions of the duodenum are in fact reversed, and the transi-
tion to the normal arrangement takes place at the junction of the second and
third portions. The compressed double loop form of the duodenum is the
result. _
_ The body level of the pylorus and the exact position of the duodeno-
jejunal junction relative to the posterior abdominal wall were not ascertained.
_ Asa result of this arrangement there is an apparent shortening of the first
portion of the duodenum, which extends to the left of the pylorus for about
38cm. only, just sufficient to allow of the downward bend to the second
_ portion without kinking. The second portion measures about 8 to 9 em. in
length, and the total length of the duodenum is about 24 em. An examination
_ Of the interior of the duodenum lends support to the view that the first portion
_ isshortened. Valvulae conniventes are present to within 1-3 em. of the pylorus,
and the bile papilla (papilla major) is situated at a distance of 5 cm. from the
pylorus. The distance of the papilla major from the pylorus varies, according
to a number of authors, from 8 to 12 cm. in the adult, and valvulae conniventes
_ do not, as a rule, appear in the normal first portion of the duodenum, i.e., for
_ a distance of about 5 cm. from the pylorus in the adult. The present specimen,
_ however, is from a subject aged 13, and moreover has been preserved by the
278 J. C. Brash and M. J. Stewart
Kaiserling process since 1911, so that no doubt some contraction has taken
place. On the other hand, as discounting these factors to a considerable extent,
the position of the papilla minor relative to the papilla major is of importance.
It is situated 2-2 em. on the pyloric side of the papilla major, the normal
variation, according to the same authors, being from 2 to 4 cm. in the adult.
Both the papillae are situated on the posterior wall of the second portion o.
the duodenum, and their position relative to the circumference of the gut is
the reverse of that normally found, the papilla minor being situated 1-2 em.
to the right of the papilla major. The papilla major has well marked “hood”
and “‘frenulum” valvulae conniventes; the papilla minor, much less prominent,
has a frenulum but no hood.
In two other subjects of the same age (13) the various distances were found
to be as follows: pylorus to papilla major, 5-6 em. and 6-5 cm.; papilla major
to papilla minor, 1-5cem. to 2:5em.; pylorus to first vulvula connivens,
25cm. As the duodena from which these measurements were taken had been
similarly preserved in formalin, there remains a considerable probability that
_ there is an actual shortening of the first part of the duodenum in the specimen
under discussion.
Pancreas. The pancreas is not divisible into head, neck and body, the whole
organ being compressed into one mass measuring 7:1 cm. greatest length, by
3-7 cm. greatest breadth. The length of the pancreas is stated in the notes of
the post-mortem examination to have been slightly under 3 inches. We have
here, therefore, an indication that no serious amount of contraction has since
taken place. The long axis lies almost at right angles to the first part of the
duodenum, and the blunt extremity is adherent to a number of lymphatic
glands matted together on the posterior aspect of the region of the cardiac
orifice of the stomach. The lower end of the organ lies behind the first loop
formed by the duodenum, and extends more to the right than to the left of
its descending portion. It is also closely adherent to the short first portion of
the duodenum, and, for a little way, to the lesser curvature of the stomach,
coming here into intimate relationship with the bile duct, hepatic artery and
portal vein. The pancreas is separated from the nearest spleen by a distance
of 2-5 em. :
Ducts of the Pancreas. The main duct (Wirsung), commencing at the upper,
blunt extremity, runs downwards nearer to the right than the left border of
the organ, bends. slightly to the left at the level of the upper border of the
first part of the duodenum, and continues downwards in a slightly curved
course with the concavity forwards and to the right. Increasing gradually in
size it joins the common bile duct as it enters the wall of the duodenum, the
junction being effected on the posterior aspect and slightly on the right side .
of the bile duct. From the point at which the main duct bends to the left the
accessory duct (Santorini), continuing the direction of the upper part of the
main duct, passes vertically through the right side of the portion of the pan-
creas adhering to the pyloric region, and opens into the duodenum at the papilla —
ar este ey en ee
ee ee
ak, oh he
Ce coe A A ae
a ee Re ee A hs me
Spleen in greater sac. Splenic Vein.
Hepatic Artery.
| Common Bile Duct
| Portal Vein.
Spleen in lesser sac.
') Sup. Mes.
j Vessels.
¥ Papilla
~~“Minor
Fig 1. Ventral aspect of specimen.
Splenic Vessels.
Spleen in lesser sac.
!
ce ae.
Pancreatic Duct..4@
(Wirsung) 7 Sie
WV
0 er
Paricreatic Duct
(Santorini)
280 J. O. Brash and M. J. Stewart
minor. Though varying slightly in size and distinctly narrower as it approaches
the gut than at its origin from the main duct, the accessory duct is quite
pervious, and readily allows a stylet to be passed through it. Dissected from
behind it appears to be the direct continuation of the duct coming from the
extremity of the organ, while the actual continuation of the duct of Wirsung
apparently springs at an angle from its anterior aspect.
The tributary of the accessory duct, usually described as passing from the
lower part of the head of the pancreas upwards in front of the duct of Wirsung,
does not appear to be present. Two small tributaries are seen from behind
entering the left side of the accessory duct, but neither of these could be traced
beyond the line of the main duct.
It would appear therefore that the pancreas shares the incomplete trans-
position of the duodenum so far as final position is concerned, though develop-
mentally the transposition may be considered to be complete in the sense that
the ventral pancreas has rotated with the bile duct to the left instead of to
the right. The picture of finally complete transposition. could easily be pro-
duced in the specimen before us by turning the duodenum more over to the
left, and rotating the pancreas to the right behind the body of the stomach.
The ducts of the pancreas would then assume their normal positions reversed,
and the relative positions of the papillae would similarly become the exact
reverse of normal, the minor taking a position ventral to but on the right of
the major. It seems probable that this has been prevented by the third portion
of the duodenum assuming what is practically its normal position, and so
hindering the complete turning over to the left of the second portion.
Spleen. The spleen is divided into thirteen separate portions, two large
and-eleven small, which lay in the right hypochondrium below the right lobe —
of the liver. The two larger spleens, measuring respectively 9-2 em. by 5-6 em.
and 6-1 cm. by 4°1 cm., are closely applied to the greater curvature of the
stomach and attached to it by folds of gastro-splenic omentum. The smaller
of the two with concave gastric and convex parietal surfaces, lies above and
to the right of the larger, and presents the usual relation to the peritoneum,
its peritoneal covered surface being visible beyond the greater curvature of
the stomach, i.e., in the greater sac. The larger of the two has its peritoneal —
relations reversed, the peritoneal covered surface being in relation to the
ee en Pee ae
ie Pe i Mee re
posterior surface of the stomach, i.e., in the lesser sac and shut off from the f o
greater sac by the continuation downwards, as the great omentum, of the
gastro-splenic omentum attached to the other.
The peritoneal connection of this spleen is more directly with the posterior —
wall of the lesser sac than with the greater curvature of the stomach, i.e., it
is attached to the dorsal mesogastrium dorsal to the smaller spleen, which —
lay in the greater sac. Its shape is of considerable interest as throwing light
upon the factors that probably mould the normally situated organ. The vessels —
enter the dorsal aspect at a distinct hilum, and the whole dorsal surface,
applied to the posterior wall of the lesser sac and in relation, no doubt, to —
Partial Transposition of the Mesogastric Viscera 281
the right kidney, is markedly concave. The gastric surface on the other hand,
though directly applied to the greater curvature and posterior aspect of the
stomach, does not appear to be much impressed thereby. It is distinctly
convex in all directions, with a slight concavity in the middle. It would appear
therefore that the natural growth of the spleen around its entering vessels
is to some extent responsible for its final shape. This conclusion is strengthened
_ by an examination of the smaller spleens, which exhibit various stages of the
formation of a concave surface on the side of the entering vessels and a convex
surface on the other side. This deduction from the appearance of the spleens
seems to be justified in spite of the fact that the organs were not hardened
in situ, and it is reasonable to suppose that the moulding action of the stomach
on a normally situated spleen is greatly helped by the natural ptsiad eb of a
concavity on the side of the hilum.
It is further.interesting to note that there is a slight notching of the right
border of the large spleen in the lesser sac: were the stomach and the dorsal
mesogastrium reversed so as to occupy their normal position this border would
become the ventral border of a normally situated spleen. None of the other
spleens show any sign of notching.
The eleven small spleens, varying in greatest diameter from 4-5 mm. to
19 mm., lie grouped around the larger ones, seven in the greater sac and four
in the lesser.
Liver. The general position and appearance of the liver have been de-
scribed in the account of the post-mortem examination. Its most striking
feature is the large size of the left lobe, which apparently extended well into
_ the left hypochondrium, though not so far as to occupy the position of the
normally situated spleen. The right lobe, extending into the right hypochon-
drium, is considerably reduced in vertical depth, being flattened from above
downwards by the presence of the subjacent, well developed stomach. The
visceral surface presents the usual arrangement of fissures as in a normal right
sided organ. The gall bladder lies in a shallow fossa to the right of the umbilical
fissure, which is converted by a thick pons hepatis into a tunnel giving passage
to the ligamentum teres.
The bile passages are normally arranged, and the common bile duct lies
in front of and to the right of the hepatic artery in the transverse fissure. As
it passes downwards it comes to lie in what has been the free edge of the
lesser omentum, and taking up a position to the left of the hepatic artery, it
passes behind the short first portion of the duodenum. Thereafter, partially
surrounded by processes of the main part of the pancreas, it reaches the
posterior wall of the second portion, where it is joined by the main duct of
the pancreas before finally piercing the wall of the gut.
_ Peritoneal Relations. Owing to the presence of adhesions the exact position
and relations of the foramen of Winslow were not observed, but there is
- evidence of a well formed lesser sac, there being only one small adhesion
between the posterior surface of the stomach near the cardiac end of the lesser
282 J.C. Brash and M. J. Stewart
curvature and the largest of the spleens. The relation of the spleens to the
lesser sac has already been described, and the continuity of the gastro-splenic
omentum with a well formed great omentum mentioned.
The whole of the duodenum was bound down to the posterior abdominal
wall, the first and second portions by their connections with the pancreas,
and the third, in the ordinary way, being crossed by the superior mesenteric
vessels in their course to the mesentery.
Blood Vessels. The coeliac axis artery divides into the coronary and splenic
only. The coronary, running upwards behind the pancreas, supplies a few
branches to its upper part. Reaching the lesser curvature at the cardiac
orifice, it runs along it in the usual way, dividing into two parallel vessels of
which the anterior and larger anastomoses with a pyloric branch of the hepatic
artery.
The splenic artery runs to the right behind the pancreas for a short distance,
and then behind the peritoneum of the posterior wall of the lesser sac to break
up into a number of branches for the various spleens. A few branches reach
the greater curvature of the stomach, constituting in the usual way vasa brevia
and the gastro-epiploic artery. The main splenic artery is only slightly tortuous
as it passes behind the first large spleen, and none of the branches to the
individual spleens show any tortuosity at all.
The hepatic artery is derived, not from the coeliac axis, but from the
superior mesenteric through an enlarged pancreatico-duodenal arch passing
over the back of the lower end of the pancreas. There is no obvious anasto-
motic branch between the hepatic.artery thus formed and the coelide axis
or its branches. As it reaches the first part of the duodenum, where it lies
to the right of the common bile duct, the hepatic artery gives off a small
pyloric branch, while a branch to the greater curvature of the stomach (to
complete the gastro-epiploic anastomosis) springs from the vessel as it lies
on the back of the pancreas.
The superior mesenteric artery takes a normal course across the front
of the third part of the duodenum, but does not lie behind the pancreas, which
is entirely to its right. It gives off the hepatic artery as already described.
The portal vein is formed on the left side of the lower part of the pancreas —
by the junction of the superior mesenteric vein coming from below and the
left, and the splenic vein from above and the right. The termination of the
inferior mesenteric vein has not been preserved, but in all probability it joined
the superior mesenteric. The splenic vein runs in front of and partly embedded
in the pancreas, receiving in its course pancreatic tributaries and the coronary
vein. The portal vein so formed turns forward in the left side of the pancreas
to reach the back of the first part of the duodenum. Here it lies on the left
and partly in front of both the common bile duct and the hepatic artery, but
at the portal fissure it is found occupying its usual position behind these
structures. In this situation it describes a curve to the right before dividing
into its two terminal branches, but otherwise it is quite normal in its distribu-
4 + 5 at ° i N s)
Pe ee ae, ee Ree Te ee, > a
PE Seen See ee Se
Partial Transposition of the Mesogastric Viscera 283
tion. The right and left portal branches are of nearly equal size, and the liga-
mentum teres and ligamentum venosum show the usual relation to the left
branch.
DISCUSSION
We have before us, therefore, a case of incomplete heterotaxy of the meso-
gastric organs, and the question of the causation of this rare condition presents
itself for discussion(2). It should first be noted that incomplete heterotaxy, apart
from abnormalities of the great thoracic vessels only, is much rarer than the
complete variety. More than 300 cases of the latter have actually been re-
_ eorded, and Arneill(1) has demonstrated that many are observed clinically
and escape record. He has further shown that the proportion of clinical to
post-mortem cases has completely altered. Gruber(5) had collected seventy-
‘nine cases recorded up to 1865, only five or six of which had been observed in
life, and Arneill himself, in 1902, had records of forty-four cases, thirty-eight
of which were clinical. Of Gruber’s seventy-nine cases seventy-one were
complete, and the remaining eight were abdominal only and all incomplete.
So far as we can ascertain, no case has yet been recorded of transposition of
all the abdominal viscera unaccompanied by transposition of the thoracic
viscera also. We have been unable to trace all the examples of incomplete
abdominal heterotaxy of which mention has been noted during a search through
the literature of the subject, but three illustrative cases may be quoted.
_ In 1894 Launay (7) recorded the discovery in a woman, who died of cancer
of the pancreas, of partial transposition very similar to that here described,
but with the liver also transposed. He referred to another and similar case
recorded by Debouie(4) in 1857, making special note of the fact that in the
latter the three parts of the duodenum were found to be “normal.” Debouie
himself describes the duodenum as having its three portions situated in the
_ exact reverse of the normal position, the concavity of the curve formed by them
being directed to the right. As the liver in this case was not transposed, the
_ relative positions of the organs were almost exactly the same as in the present
example. The spleen was represented by a reddish spherical tubercle about the
_ size of a cherry stone, and attached to the fundus of the stomach in the right
hypochondrium. This case was discovered in a child born a little before term.
The spleen in Launay’s case consisted of two portions, together about the
volume of one normal spleen, situated in the right hypochondrium and attached
to the tail of the pancreas and the stomach. :
In 1854 Allen Thomson (9) wrote an account of a much more curious and
interesting condition where all the organs, thoracic and abdominal, with the
exception of stomach, duodenum, pancreas and spleen were transposed, the
exact opposite of the case here described. The stomach, normally situated,
lay beneath the left lobe of the transposed liver, and the duodenum had a
doubly looped course almost the reverse of that here described, passing finally
to the right to its junction with the transposed jejunum. The pancreas occupied
284 J. C. Brash and M. J. Stewart
a position departing only slightly from that of the natural organ in consequence
of the deviation of the duodenum, and the spleen, though situated lower than
usual, was otherwise normal.
It appears that a definite distinction must be made as regards probable
causation between complete and incomplete heterotaxy. The former must be
dated back at least to the segmentation of the ovum(3), whereas the latter
is more probably conditioned by subsequent anomalies in the development
either of a median organ which later becomes asymmetrical, or of Originally
symmetrical, paired bilateral structures one of which constantly disappears
or has a different developmental history from the other. Examples are seen
in the cases of partial transposition involving the heart and great vessels.
Paired organs which normally have no connection with each other develop-
mentally, e.g. reproductive glands, kidneys, suprarenals, cannot conceivably
be transposed except as part of a general transposition of all the organs. In
this connection it is interesting to quote the following paragraphs from Allen
Thomson:
It is right to state that in attributing the origin of certain malformations to some original
peculiar constitution of the germ, and of others to changes and injuries which are ascertained to
occur in the progress of development, to the latter of which divisions the malformation of trans-
position appears most probably to belong, it is by no means intended to be denied that there may
in these cases also be a nisus or predisposition belonging to the germ originally and derived by it
possibly like other qualities from hereditary transmission.
In offering such explanation of the origin of malformations I do not profess entirely to discover
their cause, but rather attempt to point out that part of the process of development with which
they are most intimately and constantly connected.
In each case of partial transposition, therefore, a dynamic is to be sought
to account for the more obvious changes, though of necessity the true explana-
tion will only thus be thrown further back.
[t is now generally believed that “‘the individual anlagen of an organism
mutually influence one another during development so as.to cause the forma-
tion of a normal organism” (Keibel (6)), and it seems reasonable to seek the
determining condition of partial transposition in the growth of any structure
which normally is not associated with the middle line in its development,
particularly if there is reason to believe that bilateral rudiments of such a
structure exist. The only structure that fulfills these conditions in connection
with the mesogastrium is the ventral pancreas: the stomach itself, the duo-
denum, the liver and the dorsal pancreas are all median structures.
. The bilateral origin of the ventral pancreas has been denied, on the ground
that in the majority of human embryos studied at the period of its first ap-
pearance, an unpaired ventral pancreas is found, situated as a rule in the
middle line, in the caudal angle between the hepatic diverticulum and the
duodenum. On the other hand there are a number of embryological investi-
gations on record which suggest the occasional presence of bilateral rudiments,
Now in complete heterotaxy the ventral pancreas will be transposed, and
if the normally developing ventral pancreas be the right rudiment, then for
EN) MEAS Ne
SP ae ee
ii
ee ce a ea cae Teh Cr eh) Nagy oe i in pene RE Oe IGE Dean eee See AS ee ee eae cae ome ee
~ Partial Transposition of the Mesogastric Viscera 285
the transposed organ the left rudiment will develop, this as a result and as a
part of the general mirror-image formation of the body. In a case of partial
heterotaxy, on the other hand, involving the pancreas, though the left rudi-
ment of the ventral pancreas will again develop, it will now be part of a local
____ process only. It is suggested that the dynamic of such a partial case as the
____ present, involving the organs of the mesogastrium, may be found in the sur-
vival of the left rudiment of the ventral pancreas instead of the right, as is
believed usually to be the case.
4 The observed facts of the relative times at which the developmental
happenings concerned occur are, at any rate, not opposed to the possibility
__ which is suggested. The hepatic diverticulum appears in the middle line before
the sagittal enlargement of the stomach is indicated, and the rudiment of the
ventral pancreas associated with the hepatic diverticulum is already present
in the earliest embryo in which the rotation of the stomach has been observed.
It is suggested as a possibility that the side of the hepatic diverticulum on _
which the ventral pancreas develops is the side to which it will move, and that
_ this in turn will affect the twisting of the stomach, and of course the dorsal
_ mesogastrium and subsequently developed spleen. It does not follow that the
. liver will be affected, since it has already proceeded on its developmental path
before the bending over of the bile duct takes place, and similarly the small
intestine need not be affected beyond the local displacement due to the trans-
_ position of the duodenum. There is no reason why the twisting of the intes-
tinal loop should be affected, as this is a separate phenomenon of later date.
If the effect does not extend beyond the duodenum then it is likely that the
duodenum itself will be shortened; where it is completely transposed as in
Launay’s case by doing away with the third portion, where the effect does
_ not extend to the whole duodenum by shortening the first part, as in the present
F- case.
__ If this hypothesis be correct then the case described by Allen Thomson
appears as a remarkable instance of an anomaly within an anomaly. It must
be explained as a partial transposition superimposed on a complete transposi-
tion, the result being the apparently normal situation of the mesogastric
organs.
It should be pointed out that the relative position of the two papillae in
the second portion of the duodenum furnishes evidence that the pancreas in
the present case is, in fact, transposed ; and it is also worth noting that according
to Lewis (8) the rotation of the stomach is from the first greater at the pyloric
than at the cardiac end.
_ Multiplicity of spleens has been noted as a common condition in trans-
position. So far as actual numbers go, the highest number on record (Otto,
quoted by Testut) is twenty-three, and the next highest seven (recorded twice
by Baillie and Cruveilhier). There were thirteen in the present instance.
286 J.C. Brash and M. J. = :
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
sash dag voy Hose
Conkuin. “The Cause of Inverse Symunotry.” Anat. Anzeiger, 1903, 23, a7.
Dersovig. Bull. de la Soc. anat. de Paris, 1857, 2me Sér., 2, 59.
GruBER. Quoted by Arneill.
Manual of Embryology, 1912, vol. 31, Be 20, p. 980. a
Launay. “Un Cas d’inversion isolée des organes du mésogastre antérieur et
Bull. de la Soc. anat. de Paris, 1894, 5me Sér., 8, 320. :
Lewis. “The Development of the Intestinal Tract, and Respiratory Gacsanl
Mall’s Manual e nhl eat Ys 1912, vol. u, chap. 17, pp. 330, 403, and 429.
THE PRONEPHROS AND EARLY DEVELOPMENT
: OF THE MESONEPHROS IN THE CAT .
By ELIZABETH A. FRASER, D.Sc.,
‘ heewsh Assistant, Embryological Laboratory, University of London,
University College.
Cowparartvety few observations have been made on the early development
of the excretory system in the Mammalia. The existence of a pronephros was
first recorded in the rabbit and rat by Renson (88), and later Janosik (’85)
described pronephric canals in the rabbit. A more detailed investigation of
the anterior end of the excretory organ (called by this author mesonephros)
in the same animal has been given by Martin (’88), and a few observations
were made by Rabl (’96) in 1896. The most complete accounts of the mamma-
lian pronephros are those of Kerens (07) in both the rabbit and the mole, and
of Felix (712), who has described in some detail both pro- and mesonephros
in the human embryo. Embryos of the marmot have been studied by Janosik
(04), and van der Stricht (713) has recorded the existence of a pronephros
_ in an embryo of the bat, Rhinolophus hipposideros.
The anterior end of the organ which gives rise to the Wolffian duct shows
_ varying stages of degeneration in different genera; the course of development
is much abbreviated, and events follow each other with great rapidity. The
correct interpretation of what takes place is therefore not easy, and whilst
_ more knowledge of the conditions in other mammals is greatly needed, the
exact significance of these rudimentary structures can only be appreciated
after careful comparison with the corresponding parts of the orgen in lower
vertebrates.
Owing to the rapidity at which development takes place in early stages,
a very complete and well preserved series of embryos is an essential factor
for accurate observations. The series of cat embryos in the possession of
Professor J. P. Hill, from which my investigations are taken, is an excellent
one, and the embryos are mostly in a good state of preservation. I should like
to express my gratitude to Professor Hill and to thank him for his kind criti-
cism.
In stages possessing 17 to 35 somites and older, the sequence is a very close
E one, and moreover consists of many individuals of the same age. It is thus
% quite adequate for a study of the excretory system during this period. The
_. number of embryos with 9 to 16 somites, during which time the Wolffian duct
first makes its appearance, is smaller, and, though fairly complete, does not
justify a definite and final conclusion as to the exact mode of origin of the duct
at this early stage. The observations of these early stages were made from one
_ Anatomy LIv 19
-
288 Blinabeth A. Fraser
embryo of each of the stages with 8, 9, 10, and 12 somites, two embryos with
14, and two with 16 somites.
These investigations were begun in 1918 during my tenure of a research
assistantship under the Department of Scientific and Industrial Research.
I am much indebted to Mr F. Pittock of University College for the beautiful
microphotographs on plates XXXVI, XX XVII, and XXXVIII.
DESCRIPTION OF STAGES
8 to 10 somites. The primordium of the excretory organ in the cat first
appears in embryos with 8 to 10 somites. At this stage a central cavity is
beginning to appear in the somites, and each one is united with the lateral
plate by a narrow somitic stalk or intermediate cell mass. In the more cranial
portion, that is opposite the first six somites, the somitie stalk appears to
consist of two single layers of cells, separated by a lighter portion extending
inwards from the coelom, with indications here and there of a definite lumen.
More posteriorly the stalk increases in thickness and more definite cavities
can be seen within it, although these never extend into the cavity of the somite
itself.
At the anterior end of the 7th somite, almost simultaneously with the
formation of the intermediate cell mass, the somatic wall of the latter, about
midway between the somite and the lateral plate, becomes slightly thickened, —
and consists of two or three layers of cells which extend up dorsally towards
the ectoderm. The thickening becomes very distinct between the 7th and 8th
somites, and forms a marked swelling on the somatic side of the stalk; behind
this levelit gradually increases in size, becoming more prominent. Plate XX XV,
fig. 1, shows the swelling in the region of the 8th somite. Although, perhaps
most developed at the cranial end of the 9th somite (plate XXXYV, fig. 2),
the whole somatic wall of the stalk is much thickened throughout this somite,
and at the end of the latter and opposite somite 10 (plate XXXVI, fig. 3) it
extends out towards the ectoderm as a definite dorsal outgrowth, which is still
well marked posterior to the segmented region of the embryo. Although at the 4
cranial end, opposite somites 7 and 8, the swellings may be slightly more
marked at some points than at others, no definite metamerism can be dis- ;
tinguished, the thickenings posteriorly forming a continuous ridge.
At the beginning of the 8th somite for a few sections, and again opposite :
the 9th, the intermediate cell mass becomes isolated from the somite, and is
at the same time marked off from the lateral plate by a constriction; in a
cross section through one of these points the mid-region of the stalk appears
as a somewhat tubular structure, being composed of cells surrounding a latent
lumen (plate XX XV, fig. 1 a).
Between the somites and again opposite the middle of each, from the level
of the sixth somite backwards, a small portion of the coelom becomes partially
cut off from the general body cavity just laterally to the somitic stalk. From
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-Pronephros and Early Development of Mesonephros in Cats 289
between the 8th and 9th somites backwards to the hinder end of the embryo
this portion closes in to form a small vesicular chamber, lying immediately
to one side of the thickened region of the intermediate cell mass (plate XX XV,
fig. 2, c.ch.); in front of the 8th somite cranially this structure is less well
developed, and opposite the 6th somite can hardly be distinguished. The
_ eavity of the chamber may occasionally extend inwards into the intermediate
cell mass.
12 somites. The central cavity of the somite is more distinct, and the
hinder end of each is united with the lateral plate by the intermediate cell
mass, whilst the mid-region of the somite is again connected with the latter
by a few cells. Opposite the 6th somite a few cells extend up dorsally from the
somatic layer of the stalk, but these disappear, and no thickening is present
in the region of the 7th somite. Opposite the 8th and 9th, the middle portion
of the stalk remains attached to the lateral plate in the form of a circular mass
as in the last stage, its component cells surrounding a lightly staining area in
which a central cavity may be distinctly visible (plate XX XV, fig. 4). From
the 8th somite posteriorly, this mass increases in size, its somatic wall thickens.
and extends out towards the ectoderm. This thickening becomes gradually
more conspicuous, continuing throughout somite 10 (plate XXXV, fig. 5), and
forming opposite the 11th (plate XXXVI, fig. 6 a, 6b) and beginning of the
_ 12th somites a prominent solid outgrowth, which lies closely adjacent to the
_ ectoderm pressing the latter slightly outwards. For some distance behind the
_ segmented region of the embryo, a well marked swelling is to be seen on the
somatic side of the intermediate cell mass which is thick in this region. Except
opposite the anterior part of the 9th somite, where the swelling appeared to
be less marked, no segmentation could be distinguished.
The vesicular chambers, described in the last stage, are now much better
_ developed. They are present opposite somites 10 (plate XXXV, fig. 5),
11 (plate XXXVI, fig. 6 a, 6 6), and 12, and continue behind the segmented
region of the embryo as far back as the shortened primitive streak region or
_ tail bud, forming a series of coelomic chambers, which are becoming separated
off from the general body at intervals one behind the other. Some are larger
than others, as for example opposite somite 10 (plate XXXV, fig. 5, c.ch.)
_ where we find a well marked chamber with a wide central cavity lying ventro-
__ laterally to the thickened portion of the somitic stalk. Fig. 7 a and b shows the
_ condition near the hinder end of the embryo. I put forward the suggestion,
__ which seems to me a probable one, that these structures represent vestigial
pronephric chambers, each one communicating with the general coelom by a
peritoneal funnel. In some places, as opposite somite 10, a distinct lumen can
__ be seen passing in from the coelom all along the intermediate cell mass as far
as the wall of the somite.
14 somites. The sections of this embryo are unfortunately rather oblique,
thus making a correct interpretation of the swellings of the intermediate cell
mass more difficult in the region of the 8th-to the 10th somites on that side,
19—2
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290 Hlizabeth A. Fraser
The pronephric ridge extends from the 8th somite posteriorly. The anterior
portion, from the 8th to the mid-region of the 9th somite, is separated from
the remainder by a gap of -04 mm.; behind this gap the ridge extends con-
tinuously backwards, gradually increasing in thickness to the end of the 14th
somite, marking the Jimit of the segmented region. Here and there a central
cavity may be observed within it. Plate XXXVI, fig. 8, p.7. shows the ridge
at the level of the 13th somite.
The coelomic chambers, so well developed in the last stage, cannot be —
recognised anteriorly, but from behind the 10th somite posteriorly there is
present what appears as a thickened region of the somitice stalk, somewhat
circular in cross section, lying immediately ventro-laterally to the pronephric
ridge (plate XXXVI, fig. 8, th.). It has a solid connection with the coelomic
epithelium, and within it at intervalssmall central cavities, often very indistinct,
may be observed. Opposite this connection a slight groove in the coelomic wall
may sometimes be seen. After running for some distance behind the last somite
the thickened portion of the stalk disappears, and from this region backwards
‘to near the hinder end of the embryo, we find a series of small coelomic cham-
bers, similar to those of the last stage, in process of separating off from the
general body cavity. If we compare fig. 8 with fig. 6 a and b of the preceding
stage, there seems great probability that this thickened region of the stalk
represents the united coelomic chambers of the earlier embryo, which have
become closed off from the coelom.
The first indication of the formation of the excretory duct occurs at this.
stage. On the right side opposite somite 10, the solid dorsal margin of the
pronephric ridge is continued backwards for -03 mm. as a free cellular cord ©
lying close to the ectoderm, the tip of which, only a few cells in thickness, —
unites once more with the ridge near the end of the somite. Small portions
are again separated off from the dorsal margin of the ridge for -01 or -02 mm.
opposite somites 11 and 12, and at this level they appear to be simply split —
off at intervals from the ridge, remaining connected with the latter at the
intervening points. Whether the condition opposite somite 10, where the —
distal end of the free portion is distinctly tapering, represents a definite
segmental outgrowth, is a question which must be left undetermined until
more embryos of exactly this stage are available. In the next stage, an embryo
of 16 somites, the dorsal margin of the ridge from near the anterior end of the —
13th somite continues posteriorly quite free from the intermediate cell mass
as far as the hinder region of the 15th somite. In one embryo of this age,
however, its free tip terminates at the level of the anterior end of the 14th
somite on the left side. The free portion forms a thin strip of cells, often —
distinctly tubular, and elongated in a dorso-lateral direction above the somitic _
stalk.
17 somites. The hinder end of each somite is united with the intermediate _
cell mass, except in the case of the first somite, which is smaller and quite
isolated, Opposite the posterior end of the 7th somite there is a slight out-
Pronephros and Early Development of Mesonephros in Cats 291
growth from the dorsal side of the somitic stalk, but this is quite divided off
from the ridge behind.
As in the embryo with 14 somites the odebuaie chambers have completely
disappeared in front of the 11th somite, but
from the hinder end of the latter backwards
_ there is present a thickened region of the stalk
as described in the last stage. The small central
_ cavities within it have now become more distinct,
so that the region from the 11th to the end
of the 15th somite takes the form of definite
_ vesicles, attached end to end by solid cellular
- connections (text-fig. 1, ves.). There are two or
_ three vesicles opposite each somite, though they -
are less developed opposite somite 11; each has
a well marked central cavity and is attached to
the coelomic epithelium by a solid mass of
cells, opposite which a narrow slit-like peri-
_toneal funnel may be present (plate XX XVII,
figs. 12 and 13). Behind the level of the 15th
_ somite, the vesicles run back into a solid swollen
region of the somitie stalk, and only at about
the level at which the 21st somite will later
develop do we find small coelomic chambers
still being cut off from the general coelom.
The pronephric ridge, from the 8th as far
as the anterior portion of the 11th somite, is
seen as in preceding stages in the form of a
thickening of the intermediate cell mass, but.
from this level to the end of the 13th somite,’
where the coelomic chambers have completely
closed in, and have become transformed into
a longitudinal cord of vesicles, as above de-
-seribed, the ridge passes on to this cord, and
_ appears as a thickening on its dorsal wall, and
where vesicles are developed, on the dorsal wall
of the latter. This condition is well seen in
plate XXXVII, fig. 14, which represents a
section through the region of the 12th somite
_in an older embryo of 19 somites.
_ The separation of the excretory duct now is
more pronounced. At the anterior end of the
_ 8th somite a few cells pass off from the dorsal
wall of the thickened side of the stalk and
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Text- Fic. 1. Embryowith 17 somites.
Diagram of the pronephric ridge
(p.r.) and primordium of the ex-
cretory duct (ex.d.), which has split
off at intervals from the dorsal side
of the ridge. f.ex.d. = free distal end
of duct. S 9, 10, ... =level of somite
9, 10, .... ves.=vesicles in the
thickened region of the somitic
stalk.
disappear without again uniting with the latter, but posterior to this level
* :
292 | Elizabeth A. Fraser
once opposite the end of the 9th somite, twice opposite the 10th (plate XX XVII,
fig. 9, ew.d.), and three times opposite the 11th and 12th, alternating with
the vesicles, the dorsal margin of the ridge becomes split off, anteriorly as a
small, posteriorly as a larger mass of cells, elongated in the direction of
the long axis of the somitic stalk, and wedged in between the ridge. and the
ectoderm (text-fig. 1, ew.d.). The cells are for the most part radially
arranged surrounding either a definite or a latent lumen. Proceeding in
the caudal direction, the duct is divided off for longer intervals, so that
opposite the 12th somite it is free throughout the greater part of the somite,
union only occurring in odd sections. It is, however, very difficult to deter-
mine exactly when the duct is completely free, as a dividing line is often not
easy to see, The duct is last connected with the ridge at the posterior end of the
13th somite where it terminates on the left, but on the right side it continues
back near to the end of the 14th somite as a few cells almost embedded in the
ectoderm, the latter at this point being very thin. An excretory tubule later
arises opposite each vesicle where the connection with the duct is retained.
19 somites. The cranial end of the excretory primordium is now under-
going degeneration. A small solid outgrowth arises from the intermediate
cell mass opposite the anterior portion of the 9th somite, but this is quite
disconnected from the rest of the organ, the cranial end of which lies on a
level with the hinder end of the 9th somite (plate XX XVIII, fig. 20, p.r.). The
excretory duct is free behind the end of the 14th somite on the right, and behind
the mid-region of this somite on the left side (plate XX XVIII, fig. 16), and
running posteriorly, diminishes to a few cells which disappear behind the level
of the 18th somite. It is noteworthy that posterior to the mid-region of the
14th somite on the left side a definite outgrowth was observed, extending out
from the vesicle towards the duct, but failing to reach the latter. The region,
therefore, which gives rise to the Wolffian duct, certainly does not extend
posteriorly beyond the mid-region of the 14th somite, and very possibly not
beyond the 13th somite.
The coelomic vesicles are well marked, three being present opposite the 11th,
12th, and 13th somites (plate XX XVII, fig. 14, plate XX XVIII, fig. 15, ves.),
and two opposite each succeeding one up to the 16th, where they become less .
distinct, continuing back into a thickened area of the somitic stalk, which soon
becomes solid, and which can be followed to the hinder end as a slightly swollen
region of the mesoderm lying immediately adjacent to the coelom. Each vesicle
is connected with the coelomic epithelium (plate X XXVIII, fig. 16, con.)
by a solid mass of cells, opposite which a groove may be present.
In embryos with 20 somites, the vesicles opposite the 16th and 17th somites
are already united with the Wolffian duct, the latter extending a short distance
behind the 20th somite. Plate XX XVIII, fig. 17 shows the duct (ez.d.) near its
posterior end in an embryo of 21 somites, lying in an indentation in the
ectoderm. In some eases, as was observed in embryos of 22 to 23 somites, solid
sprouts appear to grow out from the ventro-lateral wall of the duct towards
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Pronephros and Early Development of Mesonephros in Cats 293
the vesicle, although more usually, the union between the two is effected by
outgrowths from the dorso-lateral wall of the vesicle towards the duct.
Later stages. In succeeding stages the pronephric ridge disappears opposite
the 8th somite, whilst in the region of the 9th, 10th, and cranial part of the
11th somites small tubular remnants are found, sometimes connected with the
coelomic epithelium by a few cells. Behind this level definite mesonephric
tubules are developed, although they are only small and vestigial opposite the
11th somite. In embryos of 27 somites for example, three or four are developing
_ opposite the 11th somite, three opposite the 12th and 13th (plate XX XVIII,
_ fig. 18), two or three opposite the 14th, and two opposite each succeeding
somite; each is connected with the coelomic epithelium by a short solid band.
of cells, these bands being more distinct at some places than at others.
Text-Fic. 2. Embryo with 45 somites. Transverse section (composite) through the external
glomerulus (ezt.gl.) and first excretory tubule (¢) in the region of the 9th somite and 6th
spinal ganglion. Left side. a=aorta. cd.=degenerate cord of cells connecting the tubule
with the glomerulus. pe. =posterior cardinal vein. W.D.=Wolffian duct.
(SL 5-5-4 to 7)
From the 18th somite backwards the vesicles are no longer united with
_ the excretory duct; they gradually run into each other and their central cavities
become reduced. The duct reaches the wall of the cloaca about this stage,
and actually opens into the latter in embryos with 36 to 37 somites.
or The mesonephriec tubules are formed in the typical manner. The vesicle
becomes flattened and invaginated, and develops into the Malpighian body,
whilst the connection between the latter and the Wolffian duct becomes
elongated and coiled to form the tubule. Definite glomeruli first appear in
embryos with 35 to 36 somites, from the region of the 12th somite posteriorly ;
small and very rudimentary glomeruli may develop, opposite the end of the
11th somite, but these always remain vestigial. Plate XX XVIII, fig. 19, shows
_ a well marked glomerulus developing in the region of the 12th somite in the
embryo with 35 to 36 somites. At this stage the first somite is very small but
apparently has not yet disappeared.
294 . Elizabeth A. Fraser
The primordium of the ureter first appears in an embryo of 38 to 39 somites
as a slight dilatation on the dorsal side of the excretory duct, some distance
behind the last tubule. At this stage, excluding about five tubular remnants
at the anterior end, there are altogether 43 tubules on the left side, the last
four not yet united with the duct. In an embryo with 50 to 51 somites, where
the distal end of the ureter is expanding into the thick walled pelvis, surrounded
by a dense layer of mesenchyme, about 50 tubules were counted; of these,
one or two at the cranial end possessed only rudimentary glomeruli, whilst
two or three glomeruli at the posterior end were very small and poorly de-
veloped. At one stage with 45 somites a very small but definite external
glomerulus was present on a level with the first degenerate tubule of the left
side, in the region of the 9th somite and the 6th spinal ganglion. A solid
degenerate cord of cells connected the distal end of the tubule with the
glomerulus (text-fig. 2, eat.gl.). In no other embryo was an external glomerulus
observed.
In the oldest stage examined (about 55 somites) the Malpighian capsules
were still connected with the coelomic epithelium either by strands of cells,
or, more rarely, by a diffuse cellular mass.
SUMMARY AND DISCUSSION
The cranial end of the excretory system in the cat is first developed in
the form of a continuous ridge, the pronephric ridge, which arises as a thicken-
ing of the somatic layer of the intermediate cell mass or somitic stalk uniting
the somite with the. lateral plate. This thickening, which first appears in
embryos with 8 to 9 somites, begins in the region of the 7th somite and
increases gradually in thickness from before backwards to the level of the
18th or 14th somite. During the same time as the formation of the ridge, in
~ embryos with 9 to 17 somites, a series of coelomic chambers becomes cut off
from the general body cavity. They are very poorly developed anteriorly,
but from the 9th somite backwards to the region of the shortened primitive
streak, they form a well marked series one behind the other, being most con-
spicuous in the embryo of 12 somites. I have suggested that these structures
represent vestigial pronephric chambers. When best developed (plate XXXV,
fig. 5),each forms a well defined chamber lying immediately ventro-laterally to
the pronephric ridge and communicating with the general body cavity by a
narrow passage, the peritoneal funnel. In older embryos the coelomic chambers
disappear completely in front of the 10th somite, probably becoming once
more a part of the general coelom, but from this level down to the posterior
end, they appear to become closed off from the coelom, and come to form a
longitudinal cord of tissue, roughly circular in cross section, the entire cord
being connected throughout its length with the coelomic epithelium by a short
solid band of cells, representing the united and now closed peritoneal funnels.
The cavities of the chambers become very much reduced in the anterior
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Pronephros and Early Development of Mesonephros in Cats 295
portion from the 11th to the 14th somites but apparently never quite disap-
pear, but behind this level they become completely obliterated. Very soon,
however, cavities again appear, and the whole structure becomes divided up
into a series of vesicles, three opposite each of the somites from the 11th to
the 14th inclusive and two opposite each succeeding somite as far as the
latter are developed, each vesicle being united with the coelomic epithelium
by a solid column of cells, opposite which vestiges of a funnel may be present
as a groove running inwards from the coelom.
In the region in front of the 11th somite the pronephric ridge has the form
of a thickening of the dorsal wall of the somitice stalk, but from the hinder
part of the 11th to the 13th or 14th somite, it appears as a thickening on the
dorsal side of the longitudinal cord of tissue formed by the closed coelomic
chambers, and therefore, at the points where vesicles ety: as a swelling
on the wall of each vesicle.
From the pronephric ridge the excretory duct takes its origin. The ridge
may be represented by a very slight swelling of the somatic wall of the stalk,
consisting of a few cells, opposite the 6th somite, whilst opposite the 7th, it
is very small and never contributes towards the formation of the excretory
duct, nor are any tubules developed in this region. The rudiment opposite the
8th somite is more definite and may possibly take a small part in the composi-
tion of the duct. From this level posteriorly, a small portion becomes split off
from the dorsal margin of the ridge at regular intervals, the amount separated
off increasing in size from before backwards. The points at which connection
is retained later become luminated and constitute the excretory tubules; from
the region of the 11th to the 13th somites the tubules develop at the level of
the vesicles, the splitting off occurring between the vesicles. Thus the region
from the 8th or 9th to the 13th somites gives rise to the Wolffian duct, its
main seat of origin being opposite the 11th, 12th, and 13th somites, Behind
_ the 13th somite the duct grows back independently, and its union with the
vesicles is a secondary one, occurring either as a solid outgrowth from the
dorso-lateral wall of the vesicle towards the duct, or apparently sometimes as
an outgrowth of the ventro-lateral wall of the duct towards the vesicle. It
must be noted, however, that opposite the 14th somite a vesicle may be found
_ to be united with the duct before the latter has begun to grow freely backwards,
as in one embryo of 19 somites, so that the region from which the duct arises
may extend as far as the 14th somite, and possibly varies in different embryos.
In any case, at this level and also opposite somite 15, the union of the vesicles
with the duct occurs very early; moreover, as will be seen from the subsequent
discussion, the exact point from which the duct begins its independent growth
is probably not of great morphological importance.
Unfortunately, the exact mode of origin of the anterior portion of the
duct was not determined with certainty. In one embryo, that of 14 somites, a
definite but very short outgrowth from the ridge is present at the level of the
10th somite; this extends dorsally and posteriorly, its hinder tapering end,
296 Elizabeth A. Fraser
which consists of only two cells, uniting once more with the ridge. Posterior
to this level, however, the duct appears simply to become split off from the
ridge between the points at which tubules arise, and all signs of metamerism
are absent from the first. Whether the condition opposite somite 10 is the
normal one, and whether it represents a segmental outgrowth, it was not
possible to decide without more embryos of this age. Definite segmental
outgrowths, which unite to form the pronephric duct, have been described in
the rabbit and mole by Kerens (’07) and at the cranial end in man by Felix (’12).
They may possibly occur in the cat opposite the 8th and 9th somites as well
as the 10th, but in this mammal the anterior end of the organ is very degenerate,
and if a stage of definite segmental outgrowths is present, it is passed through
with great rapidity, and could only be observed by the careful examination
of many embryos of the same age.
The excretory duct when first formed is solid or possesses a latent lumen,
and appears as a mass of cells lying dorsally to the pronephric ridge and just
above the vesicles posteriorly to the ridge. Its posterior free tip consists of a
fine cellular strand almost embedded in the ectoderm and sometimes almost
indistinguishable from it. There is, however, no definite evidence that the
ectoderm takes a part in the formation of the duct. Soon a distinet cavity
appears within it, and it reaches the ventro-lateral wall of the cloaca in embryos
with 27 to 29 somites, actually opening into the latter in stages with 36 to
37 somites.
The anterior end of the excretory organ in the cat is obviously undergoing
atrophy. Opposite the 6th and 7th somites degeneration is almost complete,
and neither in this region nor opposite somite 8 are any tubules developed.
Isolated tubular remnants are present opposite the 9th somite, and posterior
to this level they gradually become larger and more definite. They are still
rudimentary and few in number opposite the 10th and beginning of the 11th
somite, but towards the hinder region of the latter they increase in size and
the first internal glomeruli are apparent, although here the latter are always
very small and quite vestigial, the anterior end of the functional mesonephros
lying in the region of the 12th somite.
The pronephric region in both reptiles and mammals is usually regarded
as that region from which the excretory or Wolffian duct arises. That this
distinction has no value is shown by Brauer in the Gymnophionan Hypogeophis.
Here the pronephros is probably as well developed as in any other vertebrate,
except perhaps the Myxinoids, and stretches from the 4th to the 15th segments ;
twelve pronephric canals are laid down but only the first three of these form
the pronephric duct. The level at which the excretory duct becomes inde-
pendent does not therefore necessarily mark the hinder limit of the pro-
nephros. According to Kerens (’07), the duct takes its origin in the mole from
three tubules arising opposite the 8th, 9th, and 10th somites, whilst in the
rabbit an extra one is developed opposite the 7th somite. These tubules, which
are thus strictly segmental, are all small and atrophy early. Posteriorly to the
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Pronephros and Early Development of Mesonephros in, Cats 297
10th somite the last tubule passes back into a cellular cord which becomes
entirely separated from the lateral! plate.
In the marmot as described by Janosik (’04), the dorsal portions of the
“middle plate,’’ connecting the somite with the lateral plate, from the distal
end of the 6th to the 12th somites, give rise to a cell mass which eventually
forms a cell strand, the latter growing distally as the Wolffian duct. The strand
remains conneeted with the coelomic epithelium at intervals by rudimentary
canals, six or seven being present. From the level of the 13th somite to the
15th or 16th, the duct is split off as a whole from the dorsal side of the middle
plate, and posterior to this region it grows back independently. The cranial
portion, as far as the level of the 12th somite, is regarded as homologous with
the pronephros, and that between the 12th and 15th or 16th somite is con-
sidered as a region of transition between pro- and mesonephros. Here, and
posteriorly to the hinder end of the mesonephros, the middle part separates
off both from the somite and the coelomic epithelium, forming a cellular cord,
which later divides into a species of dysmetameric vesicles. This process
strikingly recalls the conditions in the cat. It is worthy of note that the pri-
mordium of the mesonephric canals, both in the marmot and the cat, is
regarded as a portion cut off from the coelomic epithelium.
In an embryo of the bat, Rhinolophus hipposideros, van der Stricht (713)
has described two pronephric vestiges between the 7th and 8th somites, and
one between the 9th and 10th on the left side, whilst on the right one is found
opposite the 7th somite and two opposite the 8th and 9th.
The pronephros in man, as observed by Felix (712), extends from the 7th to
the 14th segments. Only the three anterior primordia are completely separated
- from each other and show some metamerism, whilst the hinder tubules are
not segmental, altogether six being present opposite the 10th, 11th, and 12th
segments. Whether this dysmetamerism is primary or not was not determined
owing to want of sufficient material.
In Echidna (Keibel (’03)) vestiges of eight primordia have been observed
in the region of the 4th, 5th, and 6th spinal ganglia, behind which typical
mesonephric tubules begin, the first glomeruli appearing between the 7th and
8th spinal ganglia, that is presumably between the 10th and 11th somites,
_ __ at a level only slightly in front of the anterior glomeruli in the cat.
In the marsupial Trichosurus vulpecula (Buchanan and Fraser (’18)) there
are a large number (about 14 to 16) of degenerating excretory tubules, be-
ginning opposite the 4th spinal ganglion and extending as far as the 8th, where
rudimentary internal glomeruli are developed. As the necessary early stages
were missing it was not possible to ascertain how many of these take part in
the formation of the excretory duct. In an embryo of Perameles, however,
with 15 to 16 somites, the excretory tubules appear to be primarily connected
with the duct as far back as the 13th somite, and it is quite possible that this
condition also exists in Trichosurus, for it is evident, from our observations
on the cat, that the presence of internal glomeruli does not mark the boundary
298 Elizabeth A. Fraser
between so-called pro- and mesonephric tubules, as was supposed in the earlier
paper on Trichosurus (718). In Trichosurus, as in the cat, there was absolutely
no evidence of the two kinds of tubules occurring in the same segment.
The mode of origin of the mesonephric tubules in the cat follows that
described in other forms. The dorsal wall of each vesicle becomes flattened
and then invaginated to form the Malpighian capsule, on the dorsal side of
which the glomerulus arises. The solid connection between the vesicle and the
Wolffian duct soon becomes tubular and coiled, and eventually develops into
the secretory and excretory parts of the organ. The vesicles extending from
the level of the hinder end of the 11th to the 13th somites, from which the _
duct takes its origin, give rise to tubules which are serially homologous with
those behind this region; all are typical mesonephric tubules. That being so,
the distinction in the cat between pronephric and mesonephrie regions is
purely arbitrary, for no definite line can be drawn between the two areas.
The whole excretory organ must be looked upon as one continuous organ,
the anterior portion of which shows progressive deterioration from behind
forwards.
‘The view that pro- and mesonephros are different parts of the same organ
was first put forward by Balfour and Sedgwick (’79), was later supported by
Renson (’83) and Weldon (83), and has since been upheld by several recent
investigators [Wiedersheim (’90) in reptiles, Field (91) in Amphibia, Price
(97 and ’04) in Myxinoids, Brauer (’02) in the Gymnophiona, Kerens (707) in
Reptilia, Aves and Mammalia, Burland (718) in Chelonia, and Borcea (’05)
in Elasmobranchii|. More recently Graham Kerr (719) has supported the same
theory in his text book on the embryology of Fishes and Sauropsida, Many ~
observers | Riickert (’88), van Wijhe (’89) and Rabl (’96) in Selachu, Semon
(792) in Ichthyophis, Hoffmann (’89) in Lacerta, Felix (91) in the chick, Maas
(97) in Myxine, Wheeler (’99) and Hatta (’00) in Petromyzon, Gregory (09)
in the Turtle] regard the pronephros as having once extended all down the
body, but as having later undergone atrophy, being replaced, except in the
cranial region, by another series of tubules forming the mesonephros. These
authors contend that both pro- and mesonephric canals may develop in the
same segments, the mesonephric primordia arising from a more dorsal part
of the somitic stalk than the pronephric. It must be said, however, that the
figures given to illustrate so-called mesonephric primordia in the pronephric — Pe
region are quite unconvincing.
It seems very probable, as Brauer (’02) suggests, that the canal-like
connection between the somite and the nephrotome, seen in the last stage __
of separation between the two, has in some instances, been mistaken for a —
mesonephriec canal. In the cat, the portion of the somitic stalk connecting the
hinder end of the somite with the pronephric ridge often contains a distinct _
central cavity, forming, in cross section, a vesicular region of the stalk. This —
is especially well marked in embryos with 19 somites (plate XX XVIII, fig. 20,
$.q.), but later completely disappears. In the cat, however, such structures have _
OP a akong er earns ial een Se Sa Pe
On ee
Pronephros and Early Development of Mesonephros in Cats 299
no. connection whatever with the mesonephric vesicles, which arise laterally
to the pronephric ridge.
Borcea (05), in his studies on Elasmobranchii, also considers that the
mesonephric canals arise from a more dorsal part of the nephrotome than the
pronephric, but that the limits between the two cannot be definitely deter-
mined, and he holds at the same time that pro- and mesonephros are parts
of one organ, at first similar, but later undergoing physiological differentiation
in two directions. This difference in function has led to a difference in de-
velopment (Borcea, p. 340).
That the external glomeruli of the pronephros are homodynamous with
the internal glomeruli of the mesonephros, the one gradually passing into the
other, has been pointed out by Sedgwick (’81), also by Renson (’83) and
Mihalkovies (’85), although the latter worker did not consider the homology
between the two excretory organs a complete one. Many of the later workers
also look upon the Malpighian capsules simply as pronephric chambers or
nephrotomes, which have become completely closed off from the body cavity,
the external glomerulus thus becoming internal. This view is upheld by
_ Wiedersheim (90) and Burland (713) in Reptilia, Field (91) in Amphibia,
_ Price (97) in Myxinoidei, Brauer (’02) in Hypogeophis, and Borcea (’05) in
Elasmobranchii. The similarity of the two structures is illustrated in Lepi-
dosteus (Balfour and Parker (’82) and Beard (’94)) where the glomerulus of
the pronephros lies in a chamber which is cut off from the body cavity, and
which is identical with a Malpighian capsule. According to Price, who has
investigated Bdellostoma, the homology between the two is a very complete
one. In the Mammalia this homology has not been demonstrated, the rudi-
mentary state of the anterior end of the excretory organ and the absence of
external glomeruli, except in a very degenerate condition, making a comparison
between the latter and the internal glomeruli of the mesonephros almost
impossible. In early embryos of the cat there is a series of coelomiic chambers
extending from the 6th somite to the hinder end of the body. Such structures
do not appear to have been previously described in a mammal; they are,
however, quite definite in the cat, and it has been suggested that they are
equivalent to vestigial pronephric chambers. They are especially well developed
in the embryo with 12 somites, but they very soon undergo a change, and from
the region of the 11th somite backwards, close off from the coelom and come
to form an almost solid cord (corresponding with a nephrogenic cord), attached
throughout its length to the coelomic epithelium. This cord later divides up
into a series of vesicles, the central cavity in each of which, behind the level
of the 13th somite, arises secondarily. Each vesicle remains united with the
coelomic epithelium by a solid mass of cells. Though it is difficult to demon-
strate conclusively that the longitudinal cord of tissue, in which the vesicles
arise, is actually derived from the pronephrié chambers, this interpretation
- seems to be the correct one. If so, then the pronephric chambers are homo-
logous with the Malpighian capsules.
300 EKlizabeth A. Fraser
The connections of the vesicles with the coelomic epithelium, representing
the closed peritoneal funnels, persist for a considerable period. When the
Malpighian body is developed, its ventral wall is seen to be connected with
the coelomic epithelium either by a more or less definite cord of eclls, or by a
diffuse mass of mesenchyme, similar to that described in the marsupial
Perameles (Fraser, ’19). In the cat, these atrophied funnels are still present
in an embryo with about-55 somites, but as I have not yet studied older stages,
it is not possible to say whether or not they are transformed directly into the
rete tubules as in the case of Perameles. The development of the vasa efferentia
has, however, been studied by Sainmont (’06). This author states that the
rete first appears in embryos of 24 days, when it arisés as outgrowths from
the walls of the Malpighian capsules. It is not unusual for the peritoneal con-
nection of the mesonephric tubules to be lost and regained, a secondary union
arising as an outgrowth from Bowman’s capsule towards the coelomic epithe-
lium, and developing finally into a definite open peritoneal funnel. This |
condition is found, for example, in Hypogeophis (Brauer, ’02) and also in
Amphibia (Fiirbringer ’78). That great variation exists is evident from the
divergence of opinion expressed by so many observers, not only in different
vertebrates but in one and the same species, some attributing the origin of the
rete to outgrowths of the Malpighian bodies, others to evaginations of the
peritoneal epithelium, and yet others to a condensation of mesenchyme lying
between the peritoneum and Bowman’s capsules. Many workers, again,
experience great difficulty in distinguishing the exact origin of the cells from
which the rete is derived.
In conclusion, it may be said that the anterior region of the excretory
system in the cat is as well developed as in other mammals, with the probable
exception of the Marsupialia and the Monotremata. The number of rudi-
mentary tubules, although slightly in excess of man, is apparently less than
in marsupials. The cranial end is undergoing atrophy as in all mammals,
and whilst the incompletely formed tubules in front of the 11th somite may
possibly have a segmental origin, behind this level all signs of metamerism
have disappeared. Vestigial external glomeruli may develop in later stages
(e.g. 45 somites) but only rarely; such structures have been described in man,
and in the marsupial Trichosurus, but in the rabbit, mole, and marmot they
appear to be completely absent. The whole excretory system is composed of
one continuous series of tubules, the structure of which increases in complexity
in an antero-posterior direction, there being no clear distinction between the
anterior tubules ordinarily regarded as forming the pronephros, and the pos-
terior tubules of the mesonephros.
CONCLUSIONS
The embryonic excretory system in the cat is one continuous organ, the
degenerate anterior end passing posteriorly into the fully developed meso-
nephros, .
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—
Pronephros and Early Development of Mesonephros in Cats 301
In early stages an intermediate cell mass or somitic stalk connects the
____mesoblastic somite with the lateral plate.
= A pronephric ridge is developed as a thickening of the somatic wall of the
intermediate cell mass. This ridge extends from the level of the 6th to the
13th or 14th somite increasing in thickness from before backwards. The
hinder portion, from the region of the 9th somite posteriorly giv es origin to
the excretory or Wolffian duct.
During the formation of the pronephric ridge and immediately laterally
to it, a series of coelomic chambers become cut off from the general body cavity
communicating with the latter by a narrow passage. These extend from about
the level of the 6th somite almost to the posterior end of the embryo. It is
suggested that they represent vestigial proochias chambers, each with a
peritoneal funnel.
The chambers in front of the 11th somite soon disappear, but behind this
region it appears as if they become completely closed off from the body cavity
so as to form an almost solid longitudinal cord of tissue, attached throughout
its length to the coelomic epithelium by a solid band of cells, representing the
‘closed peritoneal funnels.
Later this cord becomes divided into a series of vesicles each united to the
coelomic epithelium by a cord of cells. In the region from about the 11th to
the end of the 13th somite the cavities of the coelomic chambers become reduced
but nevertheless persist, but posteriorly the vesicles arise secondarily within
the cord. There are three vesicles opposite the 11th to the 14th somites, and
two opposite each somite posteriorly.
; The greater part of the Wolffian duct arises in the region of the 11th to the
13th somites. It becomes split off from the dorsal margin of the ridge between
the vesicles, connection being retained opposite the latter where tubules later
arise. In front of the 11th somite definite segmental outgrowths may possibly
occur from the ridge, the distal ends of which unite to form the anterior end
of the excretory duct.
Behind the level of the 13th or 14th somite the duct grows back indepen-
dently, its free tip lying in an indentation of the ectoderm. There is no
direct evidence that the ectoderm takes a part in its formation.
The Wolffian duct reaches the wall of the cloaca in embryos with 29 somites
and opens into the latter in embryos with 36 to 37 somites.
From the 11th to the 13th somites the connection of the vesicles with the
Wolffian duct is thus primary, behind this level the union is a secondary one.
Each vesicle develops into the Malpighian body of a mesonephric tubule and
the connection between the vesicle and the duct becomes the excretory tubule.
Definite mesonephric tubules are present from the level of the hinder end of
_ the 11th somite posteriorly, though the glomeruli at the extreme anterior end are
quite rudimentary. In front of this level only vestigial tubules are developed.
An external glomerulus was observed in only one embryo with 45 somites
in the region of the 9th somite and the 6th spinal ganglion.
(702)
("18)
(13)
(91)
(12)
(91)
(19)
(°78)
(709)
(700)
(89)
(85)
(704)
(03)
(07)
(19)
(97)
(88)
(85)
(97)
(04)
(96)
Klizabeth A. Fraser
LIST OF REFERENCES
Barour, F. M. “On the Origin and History of the Urinogenital Organs of Vertebrates.”
Journ. Anat. and Phys. vol. X. 1875.
A Treatise on Comparative Embryology. London, 1885.
Baxrour, F. M. and Sepewrcx, A. “On the Existence of a Head-Kidney in the Embryo
Chick and on certain points in the Development of the Miillerian Duct. ” Quart. Journ.
Mier. Sc..vol, xx. 1879.
Batrour, F. M. and Parxer, W. N. “On the Structure and Development of Lepidosteus.”’
Phil. Trans. Roy. Soc. 1882.
Brarp, J. “The Pronephros of Lepidosteus osseus.”” Anat. Anz. No. 6, 1894.
Borora, I. Recherches sur le Systeme Uro-génital des Elasmobranches. Paris, 1905 and
Arch. de Zool. Hxper. et Gén. T. tv. 1905-06.
Braver, A. “Beitriage zur Kenntnis der Entwicklung und Anatomie der Gymnophionen.
III. Die Entwicklung der Excretionsorgane.”’ Zool. Jahrb. Bd xvu. 1902.
Bucuanan, G. and Frasger, E. A. “The Development of the Urogenital System in the
Marsupialia, with special reference to T'richosurus vulpecula.” Part I, Journ. of Anat,
vol. Lit. 1918.
Buruanp, T. H. “The Pronephros of Chrysemys marginata.” Zool. Jahrb. Bd. xxxvi. 1913.
Fertrx, W. “Die erste Anlage des Excretions-systems des Hiihnchens.” Festschr. Ndgeli u.
Kolliker, Zurich, 1891.
—— “The Development of the Urogenital Organs.” Manual of Human Embryology,
Keibel and Mall, vol. m. 1912. '
Frey, H. H. “The Development of the Pronephros and Segmental Duct in Amphibia.”
Bull. Mus. Comp. Zool. vol. xx1. 1891.
Fraser, E. A. “The Development of the Urogenital System in the Marsupialia, with
special reference to T'richosurus vulpecula.” Part Il, Journ of Anat. vol. tut. 1919.
Firprincer, M. “Zur vergleichenden Anatomie und Entwickelungsgeschichte der Ex-
kretionsorgane der Vertebraten.”” Morph. Jahrb. Bd. 1v. 1878.
Gregory, E. R. “Observations on the Development of the Excretory System in Turt
Morph. Jahrb. Bd x1. 1909.
Harra, 8. “Contributions to the Morphology of Cyclostomata. IT. The Development of
Pronephros and Segmental Duct in Petromyzon.” Journ. Coll. Sc. Tokyo, vol. x1.
1900-01. :
Horrmann, C. R. “Zur Entwicklungsgeschichte der Urogenitalorgane bei den Reptilien.”
Zeitschr. f. wiss. Zool. Bd xivi. 1889.
Janosik, J. ‘“Histologisch-embryologische Untersuchungen tiber das Urogenitalsystem.”
Sitzber. Akad. Wien. 3 Abth. Bd xct. 1885.
“Uber die Entwickelung der Vorniere und des Vornieren-ganges bei Siugern.” Eztr,
Bull. Ac. Soc. Prague, 1904. Arch. f. mikr. Anat. Bd Lxtv. 1904.
Keren, F. “Zur Entwickelungsgeschichte des Urogenitalapparates von Echidna aculeata
var. typica.” Semon. Zool. Forsch. in Australien wu. den malayischen Archipel. Lief. xxm.
1903.
Kerens, B. “Recherches sur les premiéres phases du développement de I’ Appareil exeréteur
des Amniotes.” Arch. de Biol. T. xxi. 1906-07.
Kerr, J. Granam. Textbook of Embryology, vol. 1. Vertebrata. 1919.
‘Maas, O. “Ueber Entwicklungsstadien der Vorniere und Urniere bei Myxine.” Zaol Jahrb.
Bd x. 1897.
Martin, E. “Ueber die Anlage der Urniere beim Kaninchen.” Arch. f. Anat. u. Phys. 1888.
Mimarkoyics, G. von. “Untersuchungen iiber die Entwickelung des Harn und Geschlechts-
apparates der Amnioten.” Internat. Journ. of Anat. and Hist. vol. 1. 1885.
Prior, G. C. “Development of the Excretory Organs of a Myxinoid, Bdellostoma stouti
Lockington.” Zool. Jahrb. Bd x. 1897.
—— “Further study of the Development of the Excretory System in Bdellostoma stouti.”
Amer. Journ. of Anat. vol. Iv. 1904.
Rast, C. “Uber die Entwicklung des Urogenitalsystems der Selachier.” Morph. Jahrb. —
Bd. xxtv. 1896. Ke
’
_Pronephros and Early Development of Mesonephros in Cats 303
(83) Reson, G. “Recherches sur le rein cephalique et le corps de Wolff chez les Oiseaux et
les Mammiféres” (Extrait). Arch. f. mikro. Anat. Bd xxu. 1883. !
(’88) Rtcxert, J. “Ueber die Entstehung der Excretionsorgane bei Selachiern.” Arch. f. Anat.
u. Phys. 1888.
(91) —— “Entwickelung der Excretionsorgane.” Anat. Hefle. Abth. 2, Bd 1. 1891.
(706) Sarnmont, G. “Recherches relative a l’organogenése du testicule et de l’ovaire chez le
chat.” Arch. de Biol. T. xx. 1906-07.
(81) Sepewror, A. “On the early development of the anterior part of the Wolffian Duct and
Body in the Chick, together with some remarks on the Excretory System of the Verte-
brata.”” Quart. Journ. Micr. Sc. vol. xxt. 1881.
; (92) Semon, R. “Studien iiber den Bauplan des Urogenitalsystems der Wirbeltiere.” Jen.
Zeitschr. f. Naturwiss. Bd. xxv1. 1892.
: (13) Srricut, O. van pER. “Le Mésonephros chez la Chauve-souris.” Compt. Rend. de I’ Assoc.
: des Anat. 1913.
So (99) Swaen, A. et Bracuet, A. “Etude sur les premiéres phases du développement des organes
; dérivés du mésoblaste chez le poissons téléostéens.” Arch. de Biol. T.-xv1. 1899.
“ (83). We pon, W. F. R. “Note on the Early Development of Lacerta muralis.” Quart Journ.
; Mier. Sc. vol. xxut. 1883.
(99) Wueerer, W. M. “Development of the Urinogenital Organs of the Lamprey.”’ Zool.
Jahrb. Bd xu. 1899.
(790) Wiepmnsuem, R . “Uber die Entwicklung des Urogenitalapparates bei Krocodilen und
Le Schildkréten.” Anat. Anz. Bd v. 1890.
(39) Wuue, J. W. van. “Ueber die Mesoderm-segmente des Rumpfes und die Entwicklung
des Excretionssystems bei Selachiern.” Arch. f. =e Anat. Bd xxxm1. 1889.
REFERENCE LETTERS
_ a@=dorsal aorta; b.c. = body cavity; c.ch. =coelomic chamber; ect. ectoderm; ent. =entoderm;
_ ex.d. =excretory duct; m.p.=medullary plate; n.=notochord; .t.=neural tube; p.f. = peritoneal
funnel; p.r.=pronephric ridge; S1, 2, ... somite 1, 2, ... ; smpl.=somatopleure; spl. =splanchno-
pleure; ves. =coelomic vesicle. .
DESCRIPTION OF PLATES
The figures are reproduced at a magnification of 200 diam.
‘Fig. la. Embryo with 9 to 10 somites. Transverse section at the level of the 8th somite, showing
the somitic stalk or intermediate cell mass at the point where it is isolated from the somite.
Left side. (Sl. 2-6-14.)
Fig. 16. Embryo with 9 to 10 somites. -01 mm. behind 2, showing the thickening of the dorsal
wall (p.r.) of the somitic stalk. (Sl. 2-6-15.)
_ Fig. 2. Embryo with 9 to 10 somites. Transverse section at the level of the 9th somite on the
left side, showing the coelomic chamber (c.ch.) and thickening of the somitic stalk. The latter
_____ in this section is not united with the somite. (Sl. 2-7-8.)
_ Fig. 3. Embryo with 9 to 10 somites. Transverse section at the level of the 10th somite, showing
_ the thickening of the somitic stalk (p.r.). (Sl. 2-7-16.)
Fig. 4. Embryo with 12 somites. Transverse section through the hinder end of the 8th somite,
showing the mid-region of the somitic stalk, which is attached to the lateral plate and dis-
connected from the somite. Left side. (Sl. 2-1—14.)
_ Fig. 5. Embryo with 12 somites. Transverse section at the level of the 10th somite, showing the
_ well developed coelomic chamber (c.ch.) and the pronephric ridge (p.r.). The peritoneal
___ funnel does not appear in this section. Left side. (Sl 2-3-11.)
‘Fig. 6 a and b. Embryo with 12 somites. Two consecutive transverse sections at the level of the
1lth somite, showing the pronephric ridge (p.r.) and the coelomic chamber (c.ch.) with its
peritoneal funnel (p.f.). Left side. (SI. 24-10 and 11.) ©
Anatomy Liv 20
304. Elizabeth A. Fraser
Fig. 7aand b. Embryo with 12 somites. Two consecutive transverse sections in the region of the
shortened primitive streak, showing a coelomic chamber (c.ch.) with its peritoneal funnel
(p-f.). Left side. (Sl. 3-3-10 and 11.) ,
Fig. 8. Embryo with 14 somites. Transverse section at the level of the 13th somite, showing the
pronephric ridge (p.r.) and the thickened region of the somitic stalk (th.) derived in all pro-
bability from a closed coelomic chamber. Right side. (SI. 3-4-7.)
.Fig. 9. Embryo with 17 somites. Transverse section at the level of the 10th somite, showing the
separation of the excretory duct (ex.d.) from the dorsal margin of the pronephric ridge (p.r. Me
Left side. (Sl. 4-3-8.)
Fig. 10. Embryo with 17 somites. Transverse section showing the pronephric ridge (p.r.) at the
level of the 10th somite. Right side. (Si. 4-3-9.)
Fig. 11. Embryo with 17 somites. Transverse section showing the pronephric ridge at the level
of the 11th somite. Right side. (Sl. 4-5-7.)
Fig. 12. Embryo with 17 somites. Transverse section at the level of the anterior end of the 13th
‘somite, through the anterior wall of a vesicle (ves.), and showing the last vestige of the peri
toneal funnel (p.f.). The excretory duct (ex.d.) lies free above the vesicle. Right side.
(SI. 5-2-3.)
Fig. 13. Embryo with 17 somites. Transverse section, ‘03 mm. posterior to fig. 12, showing the
central cavity within the vesicle, and the free excretory duct (ex.d.) above the latter. (SL. 5—
2-6.)
Fig. 14. Embryo with 19 somites. Transverse section in the region of the 12th somite, showing the
pronephric ridge (p.r.) forming a thickening of the dorsal wall of the vesicle (ves.). (SI. 1-7—15.)
Fig. 15. Embryo with 19 somites. Transverse section at the level of the 13th somite, showing the
free excretory duct lying immediately dorsally to a vesicle, and a short distance behind its
last connection with the pronephric ridge. Left side. (Sl. 4-5-10.)
Fig. 16. Embryo with 19 somites. Transverse section between the 14th and 15th somites, showing
the solid connection (con.) of a vesicle with the coelomic epithelium. The .now luminated
excretory duct is seen lying dorsally to the vesicle. Left side. (Sl. 1-9-6.)
Fig. 17. Embryo with 21 somites. Transverse section showing the excretory duct (ev.d.) near its
hinder end lying in an indentation of the ectoderm. s.mes.=somitic mesoderm, (Sl. 7-4—5.).
Fig. 18. Embryo with 27 somites. Transverse section through a developing mesonephric tubule
at the level of the 13th somite. Right side. M.c.=future Malpighian capsule. (Sl. 2—1-17.)
Fig. 19. Embryo with 35 to 36 somites. Transverse section at the level of the 12th somite and
9th spinal ganglion, showing an excretory tubule (ex.t.) with its developing glomerulus (gl.).
Left side. (Sl. 3-4-5.)
Fig. 20. Embryo with 19 somites. Transverse section between the 9th and 10th somites, showing
the vesicular region (S. 9) of the somitic stalk connecting the hinder end of the 9th somite
* with the pronephric ridge (p.r.). Right side. (Sl. 1-5-9.)
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ON CERTAIN ABSOLUTE AND RELATIVE MEASURE-
. MENTS OF HUMAN VERTEBRAE
By EDGAR F. CYRIAX, M.D. (Edin.),
London. -
Some years ago Anderson! and Dwight? made a series of measurements of
certain diameters of human vertebrae, namely the anterior vertical, posterior
vertical, transverse and antero-posterior of the body and the transverse of
the whole bone. Their results agreed very closely in most cases. Neither of
these authors however appear to have measured the antero-posterior diameter
of the whole vertebra nor to have attempted to ascertain whether any constant
ratios existed between the various measurements obtained. It seemed to me
that such an investigation might prove of interest, partly from the purely
anatomical and anthropological aspect, partly from the view of interpretation
of skiagrams and correct estimation of spinal deformities, and possibly also
from the medico-legal point of view,
I accordingly made a series of measurements of (as far as could be ascer-
tained) normal human vertebrae taken from 36 articulated and disarticulated
skeletons and spinal columns, 9 dry preparations of vertebral war injuries
and about 600 loose vertebrae: in all 1482 bones were thus examined. The
actual measurements taken were as follows:
(1) The mesial anterior vertical diameter of the body.
(2) The lateral diameter of the body. In the cervical region this was
measured just above its lower margin, in the dorsal and lumbar at the middle
of the body, thus obtaining its minimum lateral diameter.
(3) The maximum diameter of the whole vertebra, i.e. the spread of the
transverse processes.
(4) The maximum antero-posterior diameter of the whole vertebra.
This was measured from the centre of the lower margin of the body to the
most distant point on the spinous process.
For the sake of brevity these diameters will be referred to as: body, A.V.D.;
body, L.D.; T.D. and A-P.D.
From the measurements thus obtained, the following ratios were then
calculated:
(a) Body A.V.D. to T.D.
(b) Body A.V.D. to A-P.D.
(c) Body L.D. to T.D.
(d) Body L.D. to A-P.D.
(e) T.D. to A-P.D.
1 Journ. of Anat. and Phys. 1883, xv. 341-344.
2 Quoted Piersol, Human Anatomy, 1908, p. 122.
306 Edgar F. Cyriax
I found that although individual characteristics are quite constant, very
great variations occurred in both measurements and ratios, specially the latter,
60 per cent. being quite common, and 100 per cent. being reached in a few
cases. As examples I give the results. obtained from the first six specimens
examined in the following three vertebrae:
Fifth cervical. :
mm. mm mm mm mm. mm. .
(a) Body A.V.D. .. 16 ec as ae
(6) Body L.D. ... « 24-5 24 24 22 20 18-5
(c) T.D. ee ee ee ee ee ee :
(d) A-P.D. 46-5 47 51 485 45:5 41-5 2
Ratio of (a) to (c).... 25 16 Dh ge 23 26
» (a)to(d)... 32 19 25 27 ry eal
Sy (6) to(c)... 42 41 39 38 42 37
. (db) to(d)... > 68 51 47 45 44 45
oe (c) to (d)... 127 123 121 121 105 122
Siath dorsal.
mm. mm mm, mm mm. mm.
(a) Body A.V.D. jae 19 19 21 20 21
Gy Body B.D... ks 88 Ba Oe ee a
(eo). TD. ps doe. DAS. 54 63°5 68 67-5 68:5
BaP De ae 62 70 77 72:5. 75
Ratio of (a) to(c)... 35 35 30 31 30 ~—s 3
o tayo)... ee Cy ae ee Re
we NOY BO (0) ccd AR Ma Os Be
Syed) an 80 88 0 ee
» (c)to(d).. 91 87 gl a Se
Third lumbar.
mm, mm mm, mm mm. mm.
(a) Body A.V.D. ... ~—-30 24 24 27 30 28
(b) Body L.D.... ... 45 42-5 44 41 39 31-5
(oy TD. OS tee 108 83 82 98 79 76:5
(d) A-P.D. Sie V5 85 77 85 86:5 76 70:5
% % % % % %
Ratio of (a) to (c)... 28 29-29 28 38 37
a fa) told: O68 31 28 31 39 © 40
sp Ab} 40 {e) a. = ADs BN 54s 49 41
» (6)to(d)... 53 55 OB 47 51 45
. » (¢) to (d) ... 113 104 ~—:109
The summary of the measurements (calculated to the nearest whole
number) and ratios are given below. I have not made separate summaries
of male and female bones respectively because in all but a very few cases it.
was impossible to be certain that any given skeleton consisted entirely of the
bones of purely one individual; moreover I was informed that the makers of
articulated skeletons occasionally join male spinal columns to female pelves
Summary of diameters.
No. of Body A.V.D. Body ‘LD. T.D. A-P.D
imens Ave Ayer ~ Average Ave 2
152 _ _—_- — _— — — 707 63 90 4541 39 53
157 39-22 30 49 _ — — 5449 44 65 5059 43 58
42 1235 10 16 2094 14 25 5348 44 60 4492 39 &
37 12-55 7. 16: 20-30 17.26 - 6607 «47 OL 460? DO OU
38 12-16 S16 «22-08-18 26 Bide: 48-64 47-67 41 61
38 12-07 7. 16 25-28 19 29 5850 50 66 52:21 44 62
98 13-44 10.17 29-24 23 36 67-95 59 80 5875 51 70
110 1646 12. 19 340. 2 37 #471. ST 80 ‘61-24 8 71
40 7G 38. 21 31-17 20 3T 8A C‘*SS CS OO C2
37 17-22 13 22 2948 23 36 6553 54 78 6472 5&4 73
37 17-78. 15 22 27:30 22 32 63-04 62 74 65-72 - 8 6
36 18-06 12 21 27-68 22 30 6335 51 69 6664 56 79
—D6__35 ___18:34 15 22 27-77 22 33 63-58 54 69 6783 58 77
36 18-75 13 22 2864 23 34 6439 54 77 469-63 58 80
36 19:18 16 23 30-42 24 35 6249 52 70 69-86 60 80
36 20-28 16 25 32-12 24 38 6424 52 71 #=+71-43 +6 S84
53 21-21 16 26 3402 26 38 5849 49 67 +7056 58 = 81
95 2218 16 27 3583 27 45 53:24 44 66 47098 58 86
—Dil2__1% 23-15 17 29 #3797 30 50 47:86 38 63 73-21 61 89
38 24°38 19: 2) 30-17 = =6-28 ; 44 72-55. 58 88 —C18-58 65ST
39 25:53 20 32 41-14 +28 45 980-23 64 #93 £8194 69 92
38 26-64 21 32 42:79 #31 OS1 8905 69 108 83-54 70 . 95
37 26-78 21 32 4489 35 53 83-62 63 102 82:30 69 94
113 2781 23 34 4797 39° 58 8600 68 108 7653 61 9%6
Summary of relations of diameters.
Body A.V.D Body A.V.D Body L.D. Body L.D.
to T.D. to A-P.D. to T.D to A-P.D T.D. to A-P D
Average Ge Average Average Ave "Average
%: MmMax. % on ax. on . Max o% Min. Max.
—_ —_—- — — —_—_- — — —_ — — —_- — 172 144 195
71 58 89 79 62 95 —_— —_- — oo —_- — 107 92 129
24 18 30 29 22 37 39 32 47 47 35 «56 119 109 132
23 15 27 28 17 3 39 33 «48 47 41 56 122 102 145
21 16 27 26 19 32 40 35 49 47 37 «55 120 98 140
21 14 24 23 15 30 43 35 «(57 48 39 «61 112 95 136
20 15 25 23 18 28 43 33. «53 50 42 61 116 98 135
21 16 28 25 20 32 41 34 49 48 40 62 122 97 142
25 19 29 27 21 32 43 33 «SCO 47- 36 «56 114 100 126
26 22 «35 27 22 32 45 36 55 46 By Gis +9 | 101 87 114
28 23 «36 27 24 35 43 38 53 42 34 49 96 80 111
29 19° 37 27 20 33 44 36 «648 42 30 47 96 83 110
29 24 35 27 23. «32 45 39 50 41 35 «448 94 76 104
29 22 37 27 20 31 44 32 «52 41 30 49 93 68 106
31 25 39 27 21. 35 49 42 56 at 36 650 90 78_ 103
33 26 42 28 24 37 52 37 «61 45 37 (52 87 69 103
36 30 649 30 25 39 58 48 70 48 41 65 83 70 93
43 30 55 31 23 «43 67 53 92 50 42 60 75 57 90
49 35 «71 32 26 «41 79 56 «98 52 40 67 63 49 87
34 25 47 31 25 «442 54 45 67 49 43 58 92 79 109
32 24 45 31 24 43 51 43 59 50 41 57 98 86 116
30 22 38 32 27 40 48 34 «61 51 44 65 107 91 127
"32 24 42 33 27 40 £54 43 72 55 46 69 102 84 121
32 23 «61 36 30 46 56 43 65 63 48 77 112 84 144
308 Edgar F. Cyriax
and vice versa. All that can be said with certainty is that the greater number
of bones were from male subjects,
Endeavours on my part to work out formulae derived from one or more
measurements or ratios, from which to estimate others, were quite un-
successful, :
CONCLUSIONS
My results agreed fairly closely with those of Anderson and Dwight; in
many cases they corresponded exactly and in many others differences of only
1mm. were encountered. The only differences greater than 3mm. were:
5mm. as regards the lateral diameters of the bodies of the last two lumbar
vertebrae and 5 mm. as regards the transverse diameter of the whole bone in
the fifth lumbar vertebra. The reader is referred to the original measurements
of the authors mentioned for more detailed comparison.
PRA SES, aa ee
NOTE ON THE PERSISTENCE OF THE UMBILICAL
ARTERIES AS BLINDLY-ENDING TRUNKS OF
UNIFORM DIAMETER IN THE INDIAN
DOMESTIC GOAT
By W. N. F. WOODLAND, D.Sc., LE.S.,
Muir Central College, Allahabad, U.P., India.
My attention was first drawn to this peculiar condition of the umbilical
arteries in the Indian domestic goat when five kids (two females and three
males) were being dissected at an examination in Allahabad. In all of these
five kids the umbilical arteries, each invested in a fold of the peritoneum and
loosely attached to the wall of the urinary bladder, were as shown in the
accompanying figure (kindly drawn for me by Mr B. K. Das, M.Sc.). Each
AORTA-------
post. Mes. ART.----7 \----" OVARIAN ART
EXT. ILIAC -------
L_FALLOP. TUGE
~~ L-OVARY
UMBILICAL
‘
ARTERY ~~~ -- ---— UTERUS
on ARTERIES
: re
,
BLINO EXTREMITY
’
BLIND ExTREmity
- URINARY BLADDER
B.K. 04s
umbilical artery is given off, as in the sheep, from the base of the internal
iliac, from which point of origin the uterine artery also arises. In the sheep
and many other Mammals the umbilical artery is merely represented by its
branches to the bladder, the original main trunk at most persisting (in the
horse! and cat?, é.g.) as a “fibrous cord” extending to the fundus of the bladder
1 See The Comparative Anatomy of the Domesticated Animals, by A. Chauveau, 1891.
2 St George Mivart, The Cat, 1881; also the Anatomy of the Cat, by J. Reighard and H. 8.
Jennings, 1901.
310 W. N. F. Woodland
and navel, but in the common Indian goat each umbilical artery maintains
a uniform diameter (nearly twice the size of the artery labelled internal iliac’
for about 5 ems. and then suddenly ends blindly in the manner shown. From
three to five vesicular arteries are given off towards the end of each umbilical —
artery. This same condition of the umbilical arteries was also found to exist —
in two other kids (sex unrecorded) and in adult goats (two specimens examined
both males). I injected several of these umbilical arteries with carmine fluid
to determine if any outlet existed at the extremities but all results were
negative.
The number of individuals, without. exception, in which these peculiar
umbilical arteries were found precludes the idea that they are individual
abnormalities, and this fact may prove of some use in practice, since these
umbilical arteries, occurring in such a common animal, would, as Professor
Bayliss suggested to me, be extremely serviceable in connection with bl
pressure experiments. I have not been able to discover any other instances in
Vertebrates of arteries ending blindly in this fashion.
Be a.
“y
FISSURAL PATTERN IN FOUR ASIATIC BRAINS
By SYDNEY J. COLE, M.A., M.D. (Oxon.),
Medical Superintendent of the Wilts County Asylum, Devizes.
‘Tue specimens here delineated are from the racial series in the Museum of
the Royal College of Surgeons of England, and for the privilege of examining
them I am indebted to the kindness of Professor Keith.
They consist of a Chinese brain, a Japanese, a Goanese, and an Arabian.
The drawings have been prepared in exactly the same way as those of
three Chinese brains given in my paper in this Journal in 1911 (vol. xLvI,
p- 54). That is to say, the pictures of the mesial and basal surfaces are tracings
from photographs, modified only so far as to indicate, by a slight break in the
line of a sulcus, the presence and position of any bridging gyrus concealed
within it. The picture of the convex surface, on the other hand, besides giving
such indications of deep gyri, departs so much in another respect from photo-
graphic outline that it has become “‘a sort of Mercator’s projection” after
Kohlbrugge’s manner?. From a photograph of the lateral aspect of the hemi-
sphere, taken perpendicularly to a sagittal plane, a tracing has been made,
which has then by freehand drawing been extended upwards and at both ends
so that the resulting picture, besides showing all that appeared in full view in
the preliminary photograph, gives an equally full view of the vertex of the
hemisphere and of the frontal and occipital poles. The upper border of the
drawing accordingly represents, not the crest of the hemisphere as seen from
the side, but the flat part of the mesial surface as seen edgeways from above.
In the process of extending the drawing, the circumferential pole-to-pole
dimensions of the parts all along the crest of the hemisphere have been un-
avoidably exaggerated; but their transverse dimensions, radial in the draw-
ing, have been kept to the original scale. Except by some such device as this,
a comprehensive record of the fissural pattern could not be given without
cumbersome and costly multiplication of pictures from numerous points of
view.
The Arabic figures upon the drawings give the approximate depth of the
sulci in millimetres at the points against which they are placed. The Roman
figures are marks by which we may identify corresponding points in two views
of the same hemisphere. -
I give no formal description of the specimens, but notes on some points
which the pictures themselves do not reveal. No weights are given; they
-would be valueless, if only because the strength of the hardening fluids em-
ployed is not known, nor how long the specimens had remained first in for-
malin and then in spirit. The maximum sagittal diameter of the hardened
hemisphere, taken in conjunction with the pictures of the mesial and basal
surfaces, permits, however, a rough estimate of size. The other customary
1 J, H. F. Kohlbrugge, Die Gehirnfurchen Malayischer Volker, Amsterdam, 1909, p. 11.
312 Sydney J. Cole
measurements are dispensed with, partly because of some distortion of the
specimens, but also on general grounds, notably the want of fixed points,
from which alone such measurements, if they are to have value, can be taken.
P
;
A
:
CHINESE Brain D (figs. 1-5). Yu Ling, male, aet. 29, South China.
Left Hemisphere.—Maximum sagittal diameter, 163 mm.
XXVii
Fig. 2. D.
In the border of the orbital operculum there is one considerable notch,
having the shape of an obtuse angle.
A little behind the lower end of the sulcus centralis, the border of the |
fronto-parietal operculum shows a notch, the end of a furrow that runs out
from the superior limiting suleus of the insula.
Fissural Pattern in Four Asiatic Brains 313
The incisura parieto-occipitalis (vii) extends outwards to join the intra-
parietal sulcus, but the depth to which it cuts the superior surface of the
arcus parieto-occipitalis is only about 4 mm.
The intraparietal sulcus shows the oft-deseribed appearance of three
arches, but, as will be seen from the drawing, the middle arch is specious
merely.
vill
XVI t xix
bad Fig. 4. D.
There are pronounced interdigitations in the superior and inferior frontal
sulci; in the sulcus centralis, throughout its length; in the sulcus temporalis
“superior, especially near the origin of a posterior branch 14 mm. deep; and in
the sulcus lunatus. Interdigitations are well marked in all that part of the
-suleus cinguli anterior to Eberstaller’s Briicke 3, especially at the place where
314 Sydney J. Cole
Briicke 2 would be looked for; at this place the interdigitations are associated
with the appearance of notches in the lips of the sulcus; these notches are
indicated in fig. 2. r
The gyrus cunei is well developed.
Right Hemisphere.—-Maximum sagittal diameter, 163 mm.
In the border of the orbital operculum, about opposite the middle of the —
sulcus orbitalis transversus of Weisbach, there is a pair of small notches.
‘Far back on the border of the fronto-parietal operculum, and indicated in
the drawing just below a depth-mark 22, is a notch, the end of a sulcus that
runs out from the superior limiting sulcus of the insula.
Fig. 5 D.
The incisura parieto-occipitalis (xviii) runs out to join the intrapariecta
sulcus, and cuts the superior surface of the arcus parieto-occipitalis to a depth
nowhere less than 14 mm. There is a well-defined arcus intercuneatus turn-
ing beneath the inner end of the incisura (see inset to fig. 4).
The posterior end of the sulcus occipitalis paramesialis (xx) has a rather
deep confluence with the upper end of the sulcus lunatus, The posterior lip
of the suleus lunatus overhangs the anterior lip in opercular fashion.
Interdigitations are well marked throughout the intraparietal, postcentral,
superior temporal and superior frontal sulci; less well marked all along the
sulcus centralis.
The gyrus cunei is well developed.
VSO Te EL ae ney Co Ree
Fissural Pattern in Four Asiatic Brains 315
JAPANESE Brain (figs. 6-10). Male.
Left Hemisphere—Maximum sagittal diameter, 151 mm.
The Sylvian fissure has a small anterior horizontal limb; and nearly oppo-
Xxi
Fig. 7. Jap.
site the middle of the sulcus orbitalis transversus the border of the orbital
operculum has a small notch (indicated in fig. 10).
Behind the lower end of the sulcus centralis, the border of the fronto-
parietal operculum shows a small notch, the end of a furrow that runs straight -
316 | Sydney J. Cole
out from the superior limiting sulcus of the insula. The sulcus 20 mm. deep,
immediately behind this notch, fails to reach the superior limiting sulcus.
Heschl’s transverse gyri are well developed.
Fig. 9. Jap.
All the deep gyri indicated in fig. 6 in the intraparietal and postcentral
sulci are very well defined. Interdigitations are strongly marked in the intra- -
parietal, superior postcentral, superior precentral and superior frontal sulci,
and throughout the suleus centralis. There is an absence of deep bridging
gyri in the sulcus cinguli, but there are many slight interdigitations.
SA Pree eres Se eee) TC MS ets BPS aera tr aaron hee eee |
Pe eee RN Re ee er em SEY pet Ns pe Coals ng toe BN RoE Se A ety
ats:
ee
Ses
ine
“SA Ba as ca ie
Pe eee Pe Sy RN a er eg
o
Re ne are ER
am
4
Fissural Pattern in Four Asiatic Brains 317
On the inner aspect of the occipital pole is a well defined impression of the
superior longitudinal venous sinus. The upturned end of the calearine sulcus
lies in this impression, and so comes to appear in fig. 6, but it does not invade
the convexity proper.
The gyrus cunci is well developed.
The rhinal fissure has shallow confluence with the incisura temporalis and
with the collateral sulcus. .
Right Hemisphere—Maximum sagittal diameter, 148 mm.
There are no notches in the border of the orbita] operculum.
Fig. 10. Jap.
In the border of the fronto-parietal operculum are seen two notches, the
terminations of two furrows that run out from the superior limiting sulcus.
One appears near “xxxi,”’ and the other just behind “28.”
Heschl’s transverse gyri are well developed.
Interdigitations are fairly well marked in the middle third of the suleus
centralis, and throughout the sulcus frontalis superior. They are well de-
veloped throughout the precentral, postcentral and superior temporal sulci.
There is an absence of deep gyri in the suleus cinguli.
In the parieto-occipital fossa there is no definite arcus intercuneatus.
The gyrus cunei is fairly well developed.
In each hemisphere the sulcus rhinencephali inferior of Retzius is faintly
marked,
318 Sydney J. Cole
BRAIN OF A NATIVE OF Goa, India (figs. 11-15). Male. Age unknown, “but
not old.”
Left Hemisphere-—Maximum sagittal diameter, 169 mm.
In the border of the orbital operculum there is one considerable notch,
situated in a sagittal plane about 5 mm. internal to the outer extremity of the
sulcus orbitalis transversus.
XXt xix
CX
Fig. 12. Goa.
The upper end of the suleus diagonalis has a superficial connection with
the inferior precentral sulcus, and its lower end runs into the anterior ascend-
ing Sylvian. limb.
In the internal arrangements of the parieto-occipital fossa there is some
suggestion of an arcus intercuneatus and its accompanying sulci. In fig. 11 a
Fissural Pattern in Four Asiatic Brains 319
notch is shown which establishes a superficial connection between the parieto-
occipital fissure and an ascending branch of the intraparietal sulcus lying
close in front of it. This branch is partly shown also in the inset to fig. 12,
Fig. 14. Goa.
where the above-mentioned notch may be seen descending from it a short
distance into the parieto-occipital fossa (shaded area).
The gyrus cunei is very well developed.
Interdigitations are strongly marked in the intraparietal, postcentral and
Anatomy Liv 21
320 Sydney J. Cole
inferior precentral sulci; well marked in the suleus temporalis superior and
all along the sulcus centralis; less well marked in the sulcus frontalis superior.
The rhinal fissure is well developed, and joins the incisura temporalis
(fig. 12). .
Right Hemisphere.-—Maximum sagittal diameter, 166 mm.
In the border of the orbital operculum there are two slight notches, one
in a sagittal plane with each of the two anterior branches of the sulcus orbi-
talis transversus. The inner one of these notches appears in fig. 15.
' Fig. 15. Goa.
Rather far back on the border of the fronto-parietal operculum is a notch,
the termination of a furrow that runs out from the superior limiting sulcus.
Interdigitations are well marked in the intraparietal, postcentral and su-
perior temporal sulci, in the sulcus centralis, and in that part of the sulcus
cinguli that lies anterior to Briicke 2. They are not very well marked in the
sulcus frontalis superior.
The gyrus cunei is very well developed.
Brain oF A NATIVE OF ARABIA (figs. 16-20). Hamid Naggi, male, aet. 80.
“Dark, and probably half negro.’? Died in England, of tuberculosis and
peritonitis. :
Presumably to facilitate penetration by the hardening fluid, the mesial
surface of each hemisphere has been incised and the gash stuffed with wool,
Fissural Pattern in Four Asiatic Brains 321
. erushing the corpus callosum and adjacent parts. In figs. 17 and 19, the
gaping chasms are shown in solid black, across which some broken white lines
have been drawn to connect.portions of sulci properly continuous.
Left Hemisphere-—Maximum sagittal diameter, 166 mm.
Besides the large anterior ascending limb of the Sylvian fissure there is a
small anterior horizontal limb (figs. 16 and 20), There are no notches in the
border of the orbital operculum.
Fig. 17. Hamid Naggi.
In the border of the fronto-parietal operculum, a little behind the lower
end of the sulcus centralis, there is a notch, the termination of a furrow that
runs out from the superior limiting sulcus.
Interdigitations are present throughout the sulcus centralis. They are
well marked in the superior and middle frontal sulci, the postcentral and
intraparietal sulci, and the superior and middle temporal sulci.
21—-2
322 Sydney J. Cole
The gyrus cunei is well developed.
The sulcus rhinencephali inferior is fairly well defined.
Right Hemisphere.-—Maximum sagittal diameter, 163 mm.
The outer root of the sulcus olfactorius has a superficial connection with
a sulcus which runs outwards and forwards towards the middle of the sulcus
orbitalis transversus.
Fig. 19. Hamid Naggi.
There is a large anterior ascending limb of the Sylvian fissure (xi). And
there is an orbital limb, which in the basal view (fig. 20) is seen emerging from
beneath the temporal pole, behind that point in the sulcus orbitalis trans-
versus against which a depth-mark 8 is placed.
The border of the fronto-parietal operculum is notched by two small sulci,
one a little behind and the other a little in front of the lower end of the suleus
centralis, The posterior of these runs out from the superior limiting sulcus
Fissural Pattern in Four Asiatic Brains 323
The anterior, just within the Sylvian fissure, has a shallow connection with a
p suleus that joins the superior limiting sulcus.
= Interdigitations are well marked in the superior frontal and superior tem-
= poral sulci. They are present throughout the sulcus centralis. They are less
pronounced in the intraparietal sulcus.
Fig. 20. Hamid Naggi.
The posterior lip of the sulcus lunatus overhangs the anterior lip con-
siderably, in opercular fashion. On raising it,.a bold buttress is seen on the
anterior wall of the sulcus, immediately above the origin of an anterior branch
10 mm. deep.
The gyrus cunei is well developed.
The sulcus rhinencephali inferior is faintly marked.
FURTHER OBSERVATIONS ON THE GASTRO-
INTESTINAL TRACT OF THE HINDUS
By Dr N. PAN,
Professor of Anatomy, Medical College, Calcutta, India
ly my last paper published in the Journal of Anatomy (vol. Lut. Parts 2
and 3, April, 1919), I embodied the results of my observations on 65 cases.
Subsequently, I continued my observations in the same line on additional
84 cases and the conclusions derived from the first series of 65 cases have been
mostly corroborated.
The subjects in the present series are also Hindus, living on bulky Carbo-
hydrate food. The method of preservation has been the same, viz., a pre-
liminary injection of 8 oz. of Formalin after death followed after 24 hours by
an injection of a solution of Arsenic. :
STOMACH
Capacity of the Stomach. In Table A, the stomachs of both males and
females have been arranged in order of increasing capacity. It shows that the
capacity is very variable, ranging from 6 oz. to 200 0z., giving an average of
75 oz. In 54 out of these 84 cases (i.e. in 64 per cent.) the capacity is over
50 oz. Taking the two series of cases together (65 + 84 = 149 cases) the
average capacity comes to 73-5 oz. Thus in Hindus, the average capacity of
the stomach is much bigger than in Europeans and may be definitely said to
lie between 70 and 80 oz, :
In Table B, female stomachs have been arranged in order of increasing
capacity. In this series, there are 23 subjects and the capacity ranges from
8 to 154 0z., giving an average of 59 oz. In my first series of 29 female subjects, _
the average capacity was 60 oz. Taking the two series together the average
comes to 59-7 oz.
In Table C, stomachs of male subjects have been arranged in order of
increasing capacity. The capacity ranges from 6 to 200 oz., giving an average
of 81 oz. In my first series of 36 male subjects the average capacity was
803 oz. So the results of the two series tally with each other very closely. Now,
it may be definitely stated that the capacity of male stomachs is much bigger
than that of the female stomachs. In females, the average capacity is 60 02z.,
whereas, in males it is roughly 80 oz. This difference in the capacity of the
stomachs in the two sexes may be explained by observing the social custom
of the Hindus, The members of a family take their food in batches; the male
members take their meals first, and the female members in the last batch,
Observations on the Gastro-Intestinal Tract of the Hindus 325
Table A.
Stomachs of both sexes arranged in order of increasing capacity.
- Length Greatest Capaci Length Greatest Capacity
in width 77 in width in
Sex inches ininches ounces No. Sex inches in inches ounces
og 7 3 6 43 M. 12 6 a
: 7h 7 44 M. 11} 5
F. 14 ry Bg 45 M. ll 6 80
F. 7 t 9 46 F. ll 6 80
F. 7 24 10 47 M. 123 5 80
M. 5} 4 12 48 M. ul 7 82
F. 8 4 12 49 M. ll 7 85
F. 8 5 14 50 M. 12 6 88
M. 8 4 15 51 M. 12 8 93
-M. 7 3} 16 52 F. 12 7 96
F. 94 4 21 53 M. ll 7 96
M. 7h 4} 22 54 F. ll 6 96
F. 10 4} 22 55- M. 11h 6 96
M. 6 zs 24 56 F. 12 f Boe 96
M. 74 4. 2 57 M. 15 5 98
M. 10 4} 30 58 jE 5 102
F. 8 5 32 59 M. ll 7 104
M. 10 6 32 60 uM. 14 63 104
F. 93 5 33 61 M. 13 6} 104
eae 5 40 62 M. 12} 6 104
M. 8} 5 40 63 M. 13 8 104
22 F. ll 7 40 64 M. 12 8 105
23 F. 8 4} 41 65 M. 13 6 105
24 M. 10 4} 43 66 F. 12 8 105
25 M. 93 5 43 67 M. 13 6 106
26 M. 9 5 45 68 M. 14 8 106
ge 27 M. 8} eerie 69 M. 14 6 109
28 M. 10 7 48 70 M. 13 8 110
29 F. 9 5 48 71 M. 14 8 110
30 - M. ll 8 48 72 M. 15 8 112
31 M 12 5 58 73 F, 16 9 119
32 F. 9 5 58 74 M. 12 9 120
33 - F. 8 6 60 75 M. 14 5} 130
34 M. 12 5 60 76 M. 144 6} 132
35. M. 9 5 62 77 F. 144 5} 132
36 M. 12 33 62 78 M. 125 8 135
37 M. 10 54 68 79 M. 15 ll 139
38 F. 10 6 70 80 M. 17 6 144
39 M. 114 7 70 81 F. 154 8} 154
40 M. 12 6} 70 82 M. 14 8 180
41 M. 103 6 72 83 M. 15 9 180
42 M. 12 7 80 84 M. 20 7 200
Table B. ;
Female stomachs arranged in order of increasing capacity.
Length Greatest Capacity Length Greatest Capacity
in width in in width in
No. inches ininches ounces No. inches in inches ounces
1 7k 4 8 13 9 5 58
2 7 + 9 14 8 6 60
3 7 23 10 15 10 6 70
_ ‘8 + 12 16 ll 6 80
5 8 5 14 17 11 6 96
6 9} 4 21 18 12 7 96
7 10 43 22 19 12 7 96
8 8 5 32 20 12 8 105
9 94° 5 33 21 16 9 119
10 ll 7 40 22 144 5} 132
ll 8 4} 41 23 154 8} 154
12 9 5 48
326 N. Pan
Table C.
Male stomachs arranged in order of increasing capacity.
Length Greatest Capacity Length Greatest Capacity
in width in in width in
No. inches ininches ounces No. inches in inches _— ounces
1 7 3 6 32 Il 7 82
2 7h 44 73 33 11 7 85
3 53 a ba 34 12 6 88
4 8 4 15 35 12 8 93
5 7 34 16 36 11 7 96
6 74 4} 22 37 113 6 96
7 6 4 24 38 15 5 98
8 7h 4} 25 39 12 5 102
9 10 4} 30 40 ll 7 104
10 10 6 32 41 123 63 104
ll 10 5 40 42 13 64 104
12 84 5 40 43 122 6 104
13 10 42 43 44 13 8. Te
14 93 5 43 45 27 8 105
15 9 5 45 46 » 13 6 105
16 8} 4} 46 47 13 6 106
17 10 7 48 48 14 8 106
18 ll 8 48 49 14 6 109
19 12 5 58 50 13 8 110
20 12 5 60 51 14 8 110
21 9 5 62 52 15 8 112
22 12 34 62 53 12 9 120
23 10 5h 68 54 14 5} 130
24 113 7 70 55 14 64 132
25 12 64 70 56 12) 8 135
26 103 6 72 57 15 11 139
27 12 7 80 58 17 6 144
28 12 6 80 59 14 8 180
29 11} 5 80 60 15 9 181
30 11 6 80 61 20 7 200
31 12} 5 80
partake of the remains of a meal which are usually insufficient. Thus they
are often underfed, resulting in a reduction in size of their stomachs.
My observations on the stomachs of stillborn full term foetuses are yet
incomplete.
Measurements of Stomachs
Table A shows the measurements in both males and females, The length
varies considerably giving an average of 11-1 inches in both sexes taken
together. In my first series of 65 cases, the average length was 11-25 inches.
So, here also the result of my previous observation has been corroborated.
As regards the breadth, the average of this series comes to 6 inches, and this
corroborates my previous statement that the increase in the breadth of the
stomach of the Hindus is more marked than the increase in length.
DUODENUM
Observations have been made on the same 84 subjects (Tables D and E).
In both males and females taken together, the average length of the Duodenum
is found to be 9-4 inches. This also tallies with the result of my previous
observation, showing that the average length of the Duodenum in Hindus is
less,
Observations on the Gastro-Intestinal Tract of the Hindus 327
JEJUNUM AND ILEUM
The average length of the Jejunum and Ileum in both males and females
taken together (Tables D and E) is found to be 20 ft 7 inches. Adding to this
9-4 inches, the average length of the Duodenum, the average length of the
Small Intestine is found to be 21 ft 4} inches. This approaches closely the
result of my observation on the first series of 65 cases, in which the average
length came to 21 ft 93 inches. Thus it confirms my statement that the
average length of the Small Intestine of the Hindus is less than in Europeans.
Taking the average length of the Small Intestine of females only (Table D),
_the average is found to be 19 ft 94 inches. Here the results of the two series
of female cases have been conflicting. For, in my first series of 29 female
cases, the average length was found to be 22 ft 14 inches. So no definite
statement can be made regarding the length of the Small Intestine in females
here, until further observations are carried out on a larger number of cases.
Aggregated Lymph Nodules (Peyer’s Patches)
Taking the male and female subjects together (Tables D and E), the
average number is found to be 21. Thus it confirms my statement that the
average number here lies between 20 and 30.
Vermiform Process
The length of the Vermiform Process has been noted in the same 84 sub-
jects (Tables D and E). The average length in these cases is nearly 3 inches.
Taking the average of 149 cases (first and second series together) the length
Table D.
Female subjects.
of of Sei. a a Number of of f Mesocolon
enum and Ileum Appendix Peyer’s Intestine —$_—_.
No. in inches infeet in inches es in feet Mesocoecum Ascending Descending
1 8 144 3 24 4} nil nil pres.
2 7 134 24 15 2 nil nil nil
3 7 144 2 23 ri nil nil pres.
4 10 oe 23 13 24 pres. nil nil
5 *8 2 8 43 nil nil pres.
6 8 8t 2 ll 3 nil nil nil
ee 10 22 24 15 54 nil nil nil
8 10 20 24 20 7 nil nil nil
9 10 254 24 33 43 nil nil nil
10 8 18 2 17 3 nil nil pres.
1l 8 204 1 57 6} nil nil nil
12 103 23 23 20 6 nil nil nil
13 10 134 24 20 34 nil nil pres.
14 12 20 14 23 34 pres. pres. pres.
15 9 202 24 27 6} nil pres. pres.
16 113 12. 2 8 4 pres. pres. pres.
17 ll 21} 43 28 74 nil nil nil
18 7} 17 2 21 4 nil nil nil
19 10 20 4h 23 64 nil nil nil
20 1l 164 5 14 54 nil nil nil
21 12 21 4 13 6 pres. pres. pres.
22 93 22 5 15 5 nil nil nil
23 93 25 14 13 4} nil pres. pres.
328 N. Pan
Table E.
: Male subjects.
Length Length Length
Len igth of of Jej. of V. Number of of Mesocolon
Duodenum and Ileum Appendix Peyer's Intestine —— +
No. in inches infeet ininches Patches infeet Mesocoecum Ascending Descending
1 104 22 4 24 6 nil nil nil
2 7 19 2 26 nil nil nil
3 7 16} 34 19 41 nil nil nil
4 3 24 2 23 A nil nil nil
5 10 16 2 5 34 pres. pres. pres.
6 8 134 24 0 4} il . nil pres
7 5 24 3 28 54 nil nil nil
8 11} 16 3 16 32 nil nil nil
9 10 184 2 27 4} nil nil nil
10 9} 12 3 12 34 nil nil nil
ll 9 21 2 25 43 nil nil nil
12 ll 212 3 8 5 nil nil nil
13 8 24 2 22 5 nil nil nil
14 12 23 24 5 54 nil nil nil
15 10 1 4 37 3 nil nil “nil
16 9 224 43 12 4} nil nil nil
17 1l 193 3 17 74 nil nil nil
18 8 163 3 19 34 nil pres pres.
19 10 21 4 25 4 nil nil
20 10 174 2 25 5 nil nil nil
21 94 18 34 16 32 nil nil nil
22 9 21 3 28 4 nil nil nil
23 73 27 4 21 32 nil pres. nil
24 10 21 5 26 4 nil nil nil
25 9 154 23 20 4 nil nil nil
26 9 274 22 29 54 nil nil nil
27 93 20 3 10 ff nil nil nil
28 9 29 “3 21 54 nil nil nil
29 10 22 24 25 6 nil nil nil
30 6 18 2 27 3 nil nil nil
31 11 32 13 21 54 nil nil nil
32 113 19 3 25 4} pres pres pres.
33 8 214 * 43 12 5? nil nil nil
34 93 16 24 29 4} nil nil nil
35 84 193 2 38 + pres pres nil
36 6 232 2 34 43 nil nil pres.
37 9 254 4 32 4h nil nil nil
38 9 25 24 20 4} nil pres nil
39 9 173 22 18 43 pres. pres pres.
40 10 132 32 3 34 nil nil
41 12 19 2 25 5 nil nil nil
42 114 24 + 23 54 nil nil nil
43 84 214 24 32 nil nil to pe
44 8 21 4 34 4} nil nil nil
45 9 25 3} 20 64 nil nil pres.
46 11 224 4} 27 A nil nil nil
47 11 26 34 29 52 nil nil pres.
48 1l 24 ft 34 41 nil nil nil
49 83 214 4 14 5 nil pres pres.
50 12 27 23 21 7 nil nil nil
51 9 204 2 21 6} nil nil nil
52 114 25 1} 37 8 nil nil nil
53 10 174 3 16 4} pres. pres pres.
54 93 22 5 15 5 nil nil
55 10 224 3h 15 5 nil nil nil
56 ll 28 4h 23 9 nil nil pres
57 12 244 34 23 5 nil nil
58 9 25 3 27 4} nil nil nil
59 84 15 2 20 33 pres. nil nil
60 ll 214 2 - 25 4 pres. pres pres.
61 9 27 4 28 94 nil nil nil
Observations on the Gastro-Intestinal Tract of the Hindus 329
of the Vermiform Process is found to be 2-8 inches. So it confirms my state-
ment that the average length of the Vermiform Process is less in Hindus. The
largest Appendix found has been 5 inches..
As regards the position of the Vermiform Process, it has been found to
oecupy all possible positions, viz. (1) upwards and lateralwards, (2) vertically
upwards, (3) upwards and medialwardsy (4) horizontally medialwards,
(5) downwards and medialwards, (6) vertically downwards, (7) downwards
and lateralwards, (8) horizontally lateralwards. In 63 per cent. of these cases,
it has been found directed upwards. In one case, the Vermiform Process
23 inches in length, was directed upwards and medialwards and lodged in a
deep peritoneal recess. This recess was an unusual one (not the Inferior
Ileocoecal pouch), and was situated below the Ileum, one inch to the left of
the Ileocoecal junction, with its opening directed downwards and to the right.
One and a half inches of the terminal part of the appendix was inside the
pouch, and could not be drawn out as it was adherent inside the pouch, due
perhaps to previous inflammation.
COECUM
The position of the Coecum has been noted in these 84 cases. In 7 cases,
it has been found in the right Lumbar region just above the crest of the
Ilium. In 4 subjects, it has been found 2 inches above the medial margin of
the Psoas Major, at the brim of the lesser Pelvis. In one case it was hanging
into the Pelvis. In the remaining 72 cases, its position was normal in the
right Iliac Fossa.
LARGE INTESTINE rnctupine Rectum AND ANAL CANAL
The length of the Large Intestine has been noted in the same 84 cases (‘Tables
D and E). The length varies from 2 ft 4 inches to 9 ft 6 inches, giving an
average of 4 ft 10 inches. The extremes found by other observers are not below
3 ft nor above 7 ft. But here the minimum length found in a female subject
is 2 ft 4 inches, and the maximum length found in a male subject is 9 ft 6 inches.
The greatest width has been usually found in the Coecum and the average
greatest width in these cases has been 2} inches.
MESOCOECUM (Tables D and E)
Mesocoecum has been found in 11 out of these 84 cases, i.e. in 13 per cent.
of males and females taken together. This confirms the result of my observa-
tion on the first serics of 65 cases, in which it was found in 14 per cent.
ASCENDING MESOCOLON (Tables D and E)
Ascending mesocolon has been found in 15 out of these 84 subjects, i.e. in
17-8 per cent. of both males and females taken together. This confirms the
result of my observation on the first series of 65 cases, in which Ascending
Mesocolon was found in 17 per cent.
330 | N. Pan :
DESCENDING MESOCOLON (Tables D and E)
Descending Mesocolon has been observed in 23 out of these 84 cases, i.e. in
27 per cent. of both sexes taken together. In my first series of 65 cases,
Descending Mesocolon was found in 21-5 per cent. It will be observed that a
Descending Mesocolon has been found in a large percentage (43 per cent.) of
the female cases of the present series (Table D),
Taking the average of 149 cases (first and second series), a Descending
Mesocolon is found in 24-5 per cent,
The following table shows the results of the observations on the two
series of cases separately, and the average of the two series considered —
together.
Table F.
tens Length of Ba 8
ts) of -
Stomach Jejunum No.of Mesocolon
Duo- and Peyer's Vermiform Meso- —
: : Sy SEY
Capacity Length Breadth denum fTIleum Patches Process colon Ascending Descending
(a) Average of
first series of
65 cases’ ... 71-5 0z. 11-25” — 5-8" 9-5%. 21’ 23 2-5” 14 17 21-5
(b) Average of
second series
of 84 cases... 7502. LE". 6” 9:4" - 20°68" “20-8... 204" - Ag 17-8 = 27:3
(c) Average of
both _ series
taken together 73-502. 11-2” 50" 0-4" 209" “216 =." 13-4 17-4 24-5
CONCLUSION
The average total length of the intestinal canal in Hindus is thus caleulated
to be 26 ft, and is thus much less than the length noted in persons who take
a greater proportion of meat and a smaller proportion of carbohydrate food.
In persons living on bulky carbohydrate food the intestinal canal is ex-
pected to be longer in order to accommodate a bulky refuse. Thus in herbi-
vorous animals the intestinal canal is comparatively longer, whereas in car-
nivorous animals the intestinal canal is shorter but more muscular.
The experiments of Babak (cited from Madinavetia, Physiologia Palleo-
logica de la Digestion, Madrid, 1910) have shown that in animals of the same
species even, taken quite young and growing, if some are fed exclusively upon
vegetable food and others mostly on meat a similar adaptation in length
occurs, viz. a greater length in the animals fed on vegetable diet.
In Japanese and -Chinese, who also live mostly on a bulky carbohydrate
food, a marked increase in the length of the intestinal canal has been noted.
But here taking the average of 149 cases, there is rather a decrease in the
length of the intestinal canal observed. Thus it occurred to me that greater
accommodation for the excreta may be provided by an increase in the breadth -
rather than an increase in length. So I noted the breadth as well in the second
series of 84 subjects. The average greatest breadth of the small intestine in
these cases has been found to be 1} inches and that of the large intestine
Observations on the Gastro-Intestinal Tract of the Hindus 331
24 inches, So it is probable that the intestinal contents are comparatively
rapidly ejected as they excite peristalsis mechanically by their bulk and
nature and as such these vegetarians as a rule seldom suffer from constipation
and the intestines rarely remain loaded.
In carnivorous animals a shorter vermiform process is found than in
herbivorous animals. Consistently with this a larger vermiform process is
expected to be present in vegetarians. But here it is shorter and it may be
that the nature of the diet plays no part in determining the length of the
_ vermiform process.
I thank my assistants, specially Dr Nagendra Nath Chatterjee, Assistant
_ Professor of Anatomy, for their kind co-operation in carrying out these
_ observations.
aa
REVIEW
Cunningham’s Manual of Practical Anatomy, Vols. 1, 1 and 1m.
Seventh edition. Henry Frowde and Hodder and Stoughton.
As an example of the high standard of excellence to which the art of book-production can attain,
this new edition of Cunningham’s Practical Anatomy is superb. The original two-volumed manual
is now published in three volumes, owing, we are told, to the introduction of many new illustrations
of dissections, sections, and radiographs, and to the amplification of the instructions for dissection.
The Basle nomenclature is retained throughout, while at the commencement of the first volame
is a glossary of the two terminologies.
The descriptive part of the work is very complete, and the instructions to the dissector are
clear and practical. We realise the advantages of the metric system in weights and measurements,
but surely the literal translation of 1} inches into 38 mm. gives the student an impression of
unjustifiable accuracy.
The movements of joints are described in some detail, but we observe a departure from the
*usually recognised classification of joints by terming the sacro-iliac joint a diarthrosis, and the
intercentral and intersternal as synchondrodial rather than symphysial joints. The radiographs
of bones, joints, and injected arteries are well produced. The illustrations, both coloured and un-
coloured, are extremely fine; indeed, it is doubtful whether they are not too fine. Experience
shows that students who rely on illustrations for visual memorization, learn their anatomy in
two dimensions, and possess but a feeble appreciation of depth.
And this raises the question as to whether a practical dissecting manual, by undue elaboration,
does not tend to defeat its own ends. The aim of a dissecting manual is, we take it, to show the
student how to set about displaying the various structures of the body, and, when displayed, how
to identify them. It should draw his attention to points of use and interest which he might
otherwise overlook, but it should direct his observation and not observe for him. It should aim at
giving the student a correct sense’of proportion, laying adequate stress on features of importance,
and avoiding undue emphasis on unimportant structures. In connection with this point, we note
that the description of the gleno-humeral ligaments implies that they are equally important as the
coraco-humeral and other ligaments of the shoulder-joint. Lastly, a practical anatomy book should
have due regard for the relatively limited time set apart for anatomy in the modern curriculum,
a curriculum which is becoming more and more crowded with courses of instruction in the side-
branches of medical science. We are far from agreeing with those who advocate the elimination
from anatomical teaching of all details which have not a direct and obvious application to medical
and surgical matters, but we think it must be admitted that there is a limit to the assimilative
powers of the medical student, and we believe that this limit is overstepped by the elaborate detail
and the unnecessary complexity of these volumes of practical anatomy. We remark, by way of
illustration, that no less than four superficial patellar bursae are described, a subcutaneous, a
subfascial and a subtendinous prepatellar bursa, and a subcutaneous infrapatellar bursa. Again,
the diagram of the brachial plexus as given on page 40 of vol. 1 is one which no average medical
student has the time to master during his dissections. In short, it seems to us that these books err
in containing too much descriptive detail which overtaxes the student’s powers, and too plentiful
and too excellent illustrations which tend to replace the student’s own powers of observation
altogether. We are reminded of a certain elaborate type of guide-book which requires so much
study and concentration that the sightseer has not the time to contemplate sufficiently the features
which the book purports to point out.
a
33 3,
INDEX
Aborigine, Australian, tibia of, W.
Wood, M.D., F.R.C.S. (Edin.), 232
Acanthias blainvillii, constrictor muscles of
the branchial arches in, Edward Phelps
Allis, Jr, 222
Alexander, G. F., M.B., Ch.B. (Edin.), the
ora serrata retinae, 179
_ Allis, Edward Phelps, Jr, the constrictor
muscles of the branchial arches in Acanthias
blainvillii, 222
eis. development of the hypobranchial.
and laryngeal muscles in, F. H. Edgeworth,
M.D., 125
Anomalies, cardiac and genito-urinary, in the
same subject, Alexander Blackhall-Morison,
M.D., F. RC P., and Ernest Henry Shaw,
MRC. P., 163
Arteries, umbilical, persistence of, as blindly-
ending trunks of uniform diameter in the
Indian domestic goat, W. N. F. Woodland,
D.Se., LE.S., 309
Asiatic brains, fissural pattern in four, Sydney
J. Cole, M.A., M.D. (Oxon.), 311
Australian aborigine, tibia of, W. Quarry Wood,
M.D., F.R.C.S. (Edin.), 232
gorge ge E., M.A., M.D. (Camb.), models
of human stomach showing its form
under various conditions, 258
Barclay-Smith, E. In Memoriam, Professor
‘Alexander Macalister, M.D., F.R.S., etc.,
1844-1919, Portrait, 96
Blackhall Morison, Alexander, M.D., F.R.C.P.,
persistent foramen primum, with remarks
on the nature and clinical physiology of the
condition, 90
Blackhall-Morison, Alexander, M.D., F.R.C.P.,
and Ernest Henry Shaw, M.R.C. P., cardiac:
and genito-urinary anomalies in the same
subject, 163
Body, surface of, motor points in relation to,
R. W. Reid, M.D., F.R.C.S., 271
Brain, Asiatic, fissural pattern in, Sydney
_ J. Cole, M.A., M.D. (Oxon.), 311
Branchial arches in Acanthias blainvillii, con-
strictor muscles of, Edward Phelps Allis, Jr,
222
Brash, J. C., and M. J. Stewart, a case of partial
transposition of the mesogastric viscera, 276
mammalian, the ileo-caecal region of
Callicebus personatus, with some observa-
tions on the morphology of, T. B. Johnston,
M.B., Ch.B., 66
Callicebus personatus, ileo-caecal region of,
with some observations on the morphology
of the mammalian caecum, T. B. Johnston,
M.B., Ch.B., 66
Cardiac and genito-urinary anomalies in the
Anatomy Liv
same subject, Alexander Blackhall-Morison,
M.D., F.R.C.P., and Ernest Henry Shaw,
M.R.C.P., 163
Carter, J. Thornton, the microscopical struc-
ture of the enamel of two sparassodonts,
cladosictis and pharsophorus, as evidence of
their marsupial character: together with a
note on the value of the pattern of the enamel
as a test of affinity, 189
Cat, pronephros and early development of the
mesonephros in, Elizabeth A. Fraser, D.Sc.,
287
Cladosictis, sparassodonts, and pharsophorus,
microscopical structure of the enamel of, as
evidence of their marsupial character: to-
gether with a note on the value of the pattern
of the enamel as a test of affinity, J. Thornton
Carter, 189
Cole, Sydney J., M.A., M.D. (Oxon.), fissural
pattern in four Asiatic brains, 311
Crew, F. A. E., M.B., sexual dimorphism in
Rana temporaria, as exhibited in rigor
mortis, 217
(C. Rhinocephalus), a cyclops lamb, —
J. Gladstone, M.D., F.R.C.S., and C. P
Wakeley, M.R.C.S., L.R.C.P., 196
am, D. J., Manual of Practical
Anatomy, vols. 1, 0 and 11, seventh edition,
Review, 332
Cyclops lamb (C. ee us), Reginald J.
Gladstone, M.D., F.R.C.S., and C. P. G.
Wakeley, M.R.CS., L.R.C. ‘es 196
Cyriax, Edgar F., M.D. (Edin. ), on certain
absolute and relative measurements of
human vertebrae, 305
Dimorphism, sexual, in Rana temporaria, as
exhibited in rigor mortis, F. A. E. Crew,
M.B., 217
Edgeworth, F. H., M.D., on the development
of the hypobranchial and laryngeal muscles
in amphibia, 125
—on the development of the laryngeal
muscles in sauropsida, 79
Embryo, functions of the liver in, J. Ernest
Frazer, F.R.C.S. (Eng.), 116
Enamel, microscopical structure of, of two
; onts, cladosictis and pharsophorus,
as evidence of their marsupial character:
together with a note on the value of the
pattern of the enamel as a test of affinity,
J. Thornton Carter, 189
Epithelium, ciliated, in the oesophagus of a
seventh month human foetus, F. H. Healey,
B.Sc., 180
Exostoses, multiple, the nature of the struc-
tural alterations in the disorder known as,
Arthur Keith, 101
22
334
Eye, posterior pole of, relative positions of the
optic disc and macula lutea to, James Fison,
M.A., M.D. (Cantab.), 184
Fison, James, M.A., M.D. (Cantab.), the
‘relative positions of the optic disc and macula
lutea to the posterior pole of the eye, 184
Foetus, seventh month human, note on the
occurrence of ciliated epithelium in the
oesophagus of, F. H. Healey, B.Sec., 180
Foramen primum, persistent, with remarks on
the nature and clinical physiology of the
condition, Alexander Blackhall-Morison,
M.D., F.R.C.P., 90
Fraser, Elizabeth A., D.Sc., the pronephros
and early development of the mesonephros
in the cat, 287
Frazer, J. Ernest, F.R.C.S. (Eng.), functions
of the liver in the embryo, 116
Gastro-intestinal tract of the Hindus, further
observations on, Dr N. Pan, 324 |
Genito-urinary and cardiac anomalies in the
same subject, Alexander Blackhall-Morison,
M.D., F.R.C.P., and Ernest Henry Shaw,
M.R.C. P., 163
Gladstone, ‘Reginald J., M.D., F.R.C.S., and
EE: G. Wakeley, M.R.C.S., L.R.C.P., a
cyclops lamb (C. Rhinocephalus), 196
Goat, indian domestic, persistence of the
umbilical arteries as blindly-ending trunks
of uniform diameter in, W. N. F. Woodland,
D.Sc., LE.S., 309
Goddard, T. Russell, hypertrophy of the inter-
stitial tissue of the testicle in man, 173
Graafian Follicle, ripe human, together with
some suggestions as to its mode of rupture,
Arthur Thomson, 1
Growth-disorders of the human body, studies
on the anatomical changes which accompany
certain. I. The nature of the structural
alterations in the disorder known as multiple
exostoses, Arthur Keith, 101 —
Healey, F. H., B.Sc., note on the occurrence
of ciliated epithelium in the oesophagus of
a seventh month human foetus, 180
Hindus, gastro-intestinal tract of, further
observations on, Dr N. Pan, 324
Hypertrophy of the interstitial tissue of the
testicle in man, T. Russell Goddard, 173
Hypobranchial and laryngeal muscles in
TE EES development of, F. H. Edgeworth,
M.D.,
Tleo-caecal region of Callicebus personatus, with
some observations on the morphology of
the mammalian caecum, T. B. Johnston,
M.B., Ch.B., 66
In Memoriam, Prof. Alexander Macalister,
M.D., F.R.S., etce., 1844-1919, Portrait,
E. Barclay- Smith, 96
Interstitial tissue of ‘the testicle in man, hyper-
trophy of, T. Russell Goddard, 173
Johnston, T. B., M.B., Ch.B., the anatomy of
a Symelian monster, 208
— the ileo-caecal region of Callicebus per-
Index
sonatus, with some observations on the
morphology of the mammalian caecum, 66
Jones, Prof. Frederic Wood, D.Sc., voluntary
muscular movements in cases of nerve lesions,
41
Keene, Mrs Lucas, and F. G. Parsons, sexual
differences in the skull, 58
Keith, Arthur, studies on the anatomical
changes which accompany certain growth-
disorders of the human body. I. The nature
_ of the structural aiseréileen: in the disorder
known as multiple exostoses, 101
Lamb, cyclops (C. Bese WY one ee J.
Gladstone, M.D., F.R.C.S., and C. P. G.
Wakeley, M.R.C.S., L.R.C.P., 196
Laryngeal and hypobranchial muscles in am-
phibia, ser orpeees of, F. H. Edgeworth,
M.D.,
— ciel in sauropsida, development of, F.
H. Edgeworth, M.D., 79
— nerves, recurrent, ‘note on, Prof. F. G.
Parsons, 172
Liver, functions of, in the embryo, J. Ernest
Frazer, F.R.C.S. (Eng.), 116
Macalister, Prof. Alexander, M.D., F.R.S., etc.,
1844-1919, In Memoriam, Portrait, E.
Barclay-Smith, 96
Macula lutea and optic disc, relative positions
of, to the posterior pole of we Pik: James
Fison, M.A., M.D. (Cantab.), 1
Meatus, external auditory, fe of, Prof.
F. G. Parsons, 171
Mesogastric viscera, case of partial transposi-
tion of, J. C. Brash and M. J. Stewart, 276
Mesonephros and pronephros in the cat, early
development of, Elizabeth A. Fraser, D.Sc.,
287
Models of the human stomach showing its
form under various conditions, A. E, Barclay,
M.A., M.D. (Camb.), 258
Motor points in relation to the surface of the |
body, R. W. Reid; M.D., F.R.C.S., 271
Muscle, abnormal, in popliteal space, Prof.
F. G. Parsons, 170
Muscles, constrictor, of the branchial arches
in Acanthias blainvillii, Edward Phelps Allis,
Jr, 222
— laryngeal, in Ea development of,
F. H. Edgeworth, M.D.,
Muscular movements, wae in cases of
nerve lesions, Prof. Frederic Wood Jones,
D.Se., 41
Nerve lesions, voluntary muscular movements
in cases of, Prof. Frederic Wood Jones,
D.Sc., 41
Nerves, recurrent laryngeal, note on, Prof.
F. G. Parsons, 172
Oesophagus of a seventh month human foetus,
occurrence of ciliated epithelium in, F. H.
Healey, B.Sc., 180
Optic disc and macula lutea, relative positions
of, to the posterior pole of the eye, James
Fison, M.A., M.D. (Cantab.), 184
Index
Ora serrata retinae, G. F. Alexander, M.B.,
Ch.B. (Edim:), 179
Pan, Dr N., further observations on the gastro-
intestinal tract of the Hindus, 324
Parathyreoid duct of Pepere and its relation
to the post-branchial body, Dr Madge
.Robertson, 166
Parsons, Prof. F. G., note on abnormal muscle
in popliteal space, 170
— level of external auditory meatus, 171
— note on recurrent laryngeal nerves, 172
Parsons, F. G., and Mrs Lucas Keene, sexual
differences in the skull, 58
Paterson, A. M., M.D., F.R.C.S., the anatomy
of the peripheral nerves, 100
re parathyreoid duct of, and its relation
the post-branchial body, Dr Madge
abertanes 166
Pharsophorus, sparassodonts, and cladosictis,
microscopical structure of the enamel of,
as evidence of their marsupial character:
Sncther with a note on the value of the
pattern of the enamel as a test of affinity,
J. Thornton Carter, 189
* Popliteal space, note on abnormal muscle in,
Prof. F. G. Parsors, 170
Post-branchial body, age tae duct of
Pepere and its relation Dr Madge
Robertson, 166 :
Pronephros and mesonephros in the cat, early
es rims of, Elizabeth A. Fraser, D. Sc.,
287
Rana temporaria, sexual dimo in, as
exhibited in rigor mortis, F. A. E. Crew, M.B.,
217
Reid, R. W., M.D., F.R.C.S., motor points in
relation to the surface of the body, 271
Retinae, ora serrata, G. F. mivaatee. M.B.,
Ch.B. (Edin.), 179
Review, The Peripheral Nerves, 100
Cunningham’s Manual of Practical Ana-
tomy, seventh edition, vols. 1, m and m1, 332
Rigor mortis, sexual dimorphism in Rana tem-
poraria, as exhibited in, ¥. A. E. Crew, M.B.,
ce Ay §
Robertson, Dr Madge, on the parathyreoid
duct of Pepere and its relation to the post-
branchial body, 166
Sauropsida, development of the
muscles in, F. H. Edgeworth, M.D., 79
eal
335
Sexual differences in the skull, F. G. Parsons,
and Mrs Lucas Keene, 58
Shaw, Ernest H , M.R.C.P., and Alexander
Blackhall-Morison, M.D., F.R.CP., cardiac
and genito-urinary anomalies in the same
subject, 163
Skull, sexual differences in, F. G. Parsons, and
Mrs Lucas Keene, 58
Sparassodonts, cladosictis and pharsophorus,
microscopical structure of the enamel of, as
evidence of their marsupial character: to-
gether with a note on the value of the
pattern of the enamel as a test of affinity,
J. Thornton Carter, 189
Stewart, M. J., and J. C. Brash, a case of
transposition of the mesogastric
viscera, 276
Stomach, human, models of, showing its form
under various conditions, A. E. Barclay,
M.A., M.D. (Camb.), 258
Symelian monster, anatomy of, T. B. Johnston,
M.B., Ch.B., 208
Testicle, hypertrophy of the interstitial tissue
of, T. Russell Goddard, 173
Thomson, Arthur, the ripe human Graafian
follicle, together with ea suggestions as
to its mode of rupture, 1
Tibia of the Australian aborigine, W. Quarry
Wood, M.D., F.R.C.S. (Edin.), 232
Umbilical arteries, persistence of, as blindly-
ending trunks of uniform diameter in the
Indian domestic goat, W. N. F. Woodland,
D.Se., LE.S., 309
Vertebrae, human, certain absolute and
relative measurements of, Edgar F. Cyriax,
M.D. (Edin. ), 305
Viscera, m ric, case of transposi-
tion of, J. C. Brash; and M. J. Stoware, 276
Wakeley, C. P. G., M.R.C.S., L.R.C.P., and
Reginald J. Gladstone, M.D., F.R.C.S., a
cyclops lamb (C. Rhinocephalus), 196
Whittaker, C. R., F.R.C.S. (Edin.), nerves of
the human body, 100
Wood,. W. Quarry, M.D., F.R.C.S. (Edin.),
the tibia of the Australian aborigine,
Woodland, W. N. F., D.Sc., L-E.S., note on the
persistence of the umbilical arteries as
blindly-ending trunks of uniform diameter
in the 1 Indian domestic goat, 309
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