dated horn they are arranged more or less in transverse series of oblique folds, and are
much more marked than in the greatly dilated left horn, and it is somewhat remarkable
that the spongy texture becomes more pronounced, coarser and thicker as it
approaches the right pole of this unfecundated horn, a feature also characteristic of
the uterus of Tlatanista and to a more limited degree of the Tapir. These are the
general facts connected with the appearance of the surface of the gravid uterine
mucosa of Orcella. The whole inner surface of the uterus, left and right horns, from
the os uteri internum to both EaJlopian orifices was clothed by the chorion as in the
case of diffuse placenta generally, but as its intimate relation to the uterine surface
had been disturbed before I had an opportunity to remove the foetus, I did not
observe the chorionic villi in situ among the cryptose tissue of the uterine mucosa
There can be no doubt but that the smooth spots which stud its surface correspond
generally and even particularly in a large number of cases, to the bare spots on the
uterine mucosa.
Microscopic structure of the fcetal and the gravid uterus.—The recent interest
taken in the histology of the unimpregnated and pregnant uterus and of the foetal
membranes generally, but especially in the case of the Cetacean group through
the labours of Eschricht,1 Meigs,2 Bolleston,3 and more particularly the able
memoirs of Prof. Turner,4 has induced me to record my observations on these
structures in such rare forms as Orcella and Tlatamsta.
Injections of parts were only made in a limited number of instances, but as
the specimens had been preserved in alcohol, the injections did not reach the cryptose
structure of the uterine mucosa, and only partially so into the chorion ; however,
the general characters of the tissues were elucidated.
In the parietes of the uterus of the almost mature foetus as displayed under a
low and a higher magnifying power (Plate XXXVIII, figs. 5 and 6), the free mucous
membrane superficially is comparatively smooth, there are few rugæ or manifestations
of mucous crypts, the membrane is wavy in outline, and any depressions
that exist are shallow. The epithelial layer is thin, and the cells are apparently
cylindrical. The subjacent or true uterine membrane, on the other hand, is relatively
of considerable thickness, and, as usual, is composed of closely woven delicate
connective tissue, everywhere studded with corpuscular bodies, similar to those
described by Turner in the gravid uterus of Orca. These corpuscles, together with
their nuclei, give it almost a granular appearance. The corpuscles are irrégular in
shape, subcircular, ovoid or elliptical. The involuntary muscular fibres with much
fibro-areolar tissue intermixed, even in this very early condition, form a well
marked layer, varying in thickness from a third to a fourth the depth of the preceding.
A fibro-serous coat of about equal thickness to the last is in some places
partially separated from it by largish blood-vessels which here often run between
J “ Delphini Phocænæ gravidi.”
* Journ Acad. Nat. Sc. Philadelphia, 1848, vol. i. p. 267.
3 Trans. Zool. Soc. vol. v, p. 307.
* Trans. Boy, Soc. Edinb, voL xxvi. and Lectures on the Comp. Anat. of Placenta, etc.
these coats horizontally. Elsewhere the blood-vessels pass directly through with
a moderate or relatively good-sized calibre, but as soon as they enter the proper
tissue of the uterine wall they break up into numbers of small capillaries. These
last as they proceed inwards and approach the interior mucous lining still further
split up, and, in divaricating ramifications, form quite a rich but minute net-work,
or kind of capillary plexus, analogous to what Turner has observed in the gravid
uterus of Orca.
The most interesting fact appertaining to this uterus is that I could nowhere
detect the slightest traces of utricular glands; and in my search for these I passed
in review a very considerable series of microscopic sections taken from different parts
of the organ. Even where rudiments of uterine glands might be supposed likely to
be found, as in the neighbourhood of mucous crypts and depressions, tEeir absence
was conspicuous, as is seen in Plate XXXVIII, fig- 7, representing a vertical section
of the left wall of the cavity of-the uterus under consideration.
As might be anticipated, in the case of the gravid uterus, a very different state
of things obtained. The walls had vastly increased in thickness, the constituents
of the muscular, the serous and the mucous layers in relative proportions, and there
was a corresponding development of blood-vessels. The internal surface of the uterus
was no longer smooth, but presented instead a highly spongiose character due to the
existence of numerous minute recesses with occasional larger tubular orifices. The
former appear as dots all over the surface of figure 4 of Plate XXXV, and in figure 5
they are seen to be divided and sub-divided into small secondary cryptlets. The
minute recesses or crypts are produced by a highly reticulated anastomosing network
of the fibres of the mucosa, generally outwardly radiating from a bare glistening
spot as in the pig, tapir,1 camel, and Monodon, and as occurs also in JPlatanista.
The strands'of membrane so radiating ultimately blend with the outlying portions
of other and neighbouring areas of radiation. The cryptlets contained in these
1 in a gravid nteros of a Tapir, in which a foetus had attained a len g th o f 4 inches, th e surface of
th e chorion w as quite destitute of villi, b u t w hen i t w as removed i t w as found to be covered b y irregular
finft Wavy folds. The uterine mucosa was perfectly free from a truly cryptose structure, b u t it s surface
was irregularly, bu t p rofusely and minutely, covered over w ith exceedingly wavy ridges and b y smooth
g listening spots which h ad a smoother surface than th e rest of th e mucosa. T hese spots when examined
w ith a hn.Wi lens presented a central orifice. Th ey also manifested a d istinct tendency to an arrangement
in lon g p arallel lines in the long axis of each horn. In th e u terus near the completion o f p regnancy,
the surface of th e chorion, which wholly invested the inner surface of the uterus, was villous throughout,
th e v illi consisting, o f two kinds, v iz., very small v illi with larger v illi intermixed. The v illi were
separated from each other b y m inute round bare spots and b y longitudinal and transverse lin e s corresponding
to those o f th e uterus. There w as a very extensive, perfectly nude, sh in in g area a long th e course
of th e vessels , from th e cord, extending from th e pole o f the r igh t (unfecundated) to th a t o f th e le ft
(fecundated) horn, and h avin g a b readth of 3 inches in some places. This area w as o f th e same nature
as th a t w hich occurs in Orcella, Platamsta, and Mams. N o bare area occurred a t either of the poles, nor
could I detect any on the surface opposed to the os u te ri imtemum.
T he uterine surface was ve ry minutely, bu t profusely c ryp to se ; th e arrangement o f the strands of
membrane, however, producing th e crypts was different from w h a t I have observed in any other uterus.
Coarse strands o f membrane ran for considerable lengths side b y side w ith a marked parallelism
giv in g off branches anastomosing w ith each other, and from these finer b ranches defined innumerable
minute crypts on either side o f th e coarser strands which were a t a higher lev e l than th e intervening