way, while the two latter constituted broad folds, which were persistent in the enlarged
vagina of the pregnant female. Besides these there are some other, hut much smaller,
folds around the opening. At the middle of the canal there is a strongly marked
cross fold (PI. XXXII, fig. 1, cf) on the ventral aspect, with some short oblique
creases at its sides, and a short transverse fold before it. The first-mentioned limits
anteriorly the longitudinal folds that arise at the opening of the vagina, and it can
he detected in the vagina of the gravid female. The dorsal surface of the canal
has only a few feeble longitudinal folds, and the area immediately before the
transverse furrow of the ventral surface is perfectly smooth, but anteriorly to this
occur the three or four great permanent folds, the os tinea, characteristic of Cetacean
vaginae. The first two of these folds are quite smooth, but the third has generally
its mucous membrane thrown into twenty to twenty-two thin secondary leaf-like
folds, and in this respect it closely resembles the os uteri externum, which is covered
with similar la.mpllfft more perfectly developed, and which are more or less continuous
with others which occur on the os uteri internum itself. At the free margins
of this the third fold and of the os uteri externum these lamellae are bent upon
themselves, and in the gravid uterus they are converted into very thin overlapping
leaves. The appearance of the vaginal folds and the character and distribution
of the lamellae in the virgin are shown in fig. 1, PI. XXXII, while at fig. 2,
PI. XXXII, is a representation of the inner orifice of the os uteri internum in the
gravid female. The long axis of the entrance to the womb is directed obliquely
forwards slightly to the left, but the uterine orifice is to the right of the middle line.
The body of the uterus, which is 0*65 inch in length, is curved firstJxi the left and
then to the right side, so that the orifice of the left horn is brought into the same line
with the os uteri internum, while the opening to the right horn lies external to it.
Owing to the oblique position of the vagina, and consequently of the uterus,
the left horn also lies at a lower level than the right. These relations of the parts
in such cases would seem to be conducive to the fertilization of the left horn in
preference to that of the right, which is placed at a higher level and eccentric to the
os uteri.
In the unimpregnated uterus (fig. 3), the horns bend backwards towards the
organ, until they are on a level with the ovaries. The walls of the common cavity
of the uterus (fig. 1, u) become thickened as they approach the horns, and the
lamellae of the mucous surface become swollen into rugae. The mouths of the
horns are large enough to admit a crowquill, and they are separated from each
other at their commencement, for about O’65 inch, by the common septum, the free
margin of which constitutes their inner lip. Their inner surfaces ( f ) are covered
with from six to seven prominent longitudinal folds, usually terminating at their
mouths in free ends, although they sometimes there unite. At the angle where each
horn bends backwards on itself the mucous fold which passes over its induplication
forms an angular projection inwards, and the rugae or folds converge to the opening
of the Eallopian tube, where they terminate. The right horn is 1*75 inch long, and
the left 1*65 in length with a diameter of 0’36 inch.
In the vagina of the virgin Platanista the mucous membrane has the general
character of that structure in the sow.
Fallopian tubes.—These describe five distinct curves from the horns to the pavilion
(PI. XXXI, fig. 1), two of which are much greater than the others. The first of
these occurs at the uterine end of the tube, and lies close to the attachment of the
ovary, where its wall is quarter of an inch thick in the virgin. In the impregnated
dolphin, it forms a well-defined prominence lying below the ovary on the left side,
where its outer surface is finely corrugated (fig. 1 ,/ ) ; below the right side there is no
such projection, although the corrugations are found marked over the area of the
carve. In the virgin, this bend of the Eallopian tube, which is the narrowest part also
in the mother, is visible externally as a small swelling (PI. XXXII, fig. 3). The next
curve is the better developed of the two. I t lies a short way behind, where the tube
begins to widen to the ostium abdominale, and is best seen in the virgin and on the
right side of the mother. I t is worthy of note that the right Eallopian tube of the
impregnated dolphin has retained the characters of the convolutions of the virgin,
while the left Eallopian tube has considerably departed from them; therefore, may
we not surmise that the virgin character 6f the right Eallopian tube would indicate
that if this dolphin had ever before been a mother, she must have conceived as now
in the left horn ? In the virgin the Eallopian tubes of both sides are of equal extent,
2-50 inches, while in the impregnated dolphin the right Eallopian canal is longer than
the left, the latter being only 6-50, while the former measures 7'50 inches in length.
In the virgin, the tube has such a capacity that it can be slit open with moderate
facility by a pair of ordinary dissecting scissors, and, of course, it is much wider
in the impregnated female on both sides of the body. Erom its ostium uterinum the
tube contracts as it passes through the first curve which has been described, and
widens as it approaches the second, more rapidly dilating as it approaches the ostium
abdominale,immediately before which it is somewhat again reduced in diameter. I t is
lined with fine permanent lamellar folds of different depths, which have an origin at
the commencement of the tube, either distinct from the folds of the horn, or, as in
the specimen before me, two of the folds of the left tube result from the division of
•one of the folds of the horn (PI. XXXI, fig. 3) and immediately become so divergent as
to embrace within them four other folds which have an independent origin of their
own, only two or three other folds of separate origin being external to the embracing
laminae. The folds become slightly larger as they approach the ostium abdominale
and much more numerous, and are connected together by oblique finer folds, which,
in their turn, have cross fibres running between them, so that the appearance of a
fibrous mesh'work is produced around the ostium abdominale. The laminae are
prolonged outwards on to the pavilion in a radiate manner. In the impregnated
female, the folds preserve the same characters as in the virgin, until they reach the
dilated portions of the tube, and more especially around the ostium abdominale,
where they form thin leaf-like overlapping folds like those which occur round the
mouth of the uterus itself, and are prolonged on to the pavilion as thin radiating
folds, some of which are an inch and a half in breadth. In the virgin the orifice of
N 3