compartments. Between the outer and inner coats of the walls, and at the bases
where the inner lining is inbent, there further obtains a triangular space, three in all.
So far as I could observe and make out, the wall of the body was made
up of a series of layers closely adherent to each other, and composed of a brittle
granular, or indistinctly cellular material. The transverse sections bore a resemblance
to the dense substance forming the wall of a large artery, but the constituents
were not truly fibrous, but possibly, as I have already said, of a chitinous
nature.
The exceeding regularity in the shape and composition of these cup-shaped
bodies renders it very difficult to conceive what their true nature and function may
be. They can hardly be glands or secretory organs. They are totally unlike any
pathological product I know of, and have been observed always in the same position
in many stomachs of this animal. Neither do they answer to inorganic, crystalline
or any other deposit that I am aware of.
Passage between second and third canities o f stomach.—This passage is of variable
length, depending on the condition of the stomach. In contracted stomachs it
hardly merits the name of a channel, being little more than an orifice; but in soft
flaccid stomachs it is T50 inch long by T25 broad. I t bends slightly to the left side
in leaving the second cavity, and then turns abruptly to the right to reach the third
cavity. Its surface is quite smooth and does not present any glandular tracts. I t
opens into the third cavity close to its ventral wall, and nearly on the same level
as its upper border.
Third gastric canity.—The third and smallest cavity (PI. XXVI, fig. 1, III)
is either globulose or oval, according to its conditions, and the mucous membrane
may present either a perfectly smooth or slightly rugose surface depending on its
physiological condition at the time being. When contracted it presents a few
longitudinal folds, radiating from the pyloric septum, and its surface is covered over
with minute funnel-like orifices; but, in its distended and flaccid state, the folds
disappear and the orifices are surrounded with pale areas of a different texture
from the general mucous surface, which is grey. The orifices have the appearance
as if the flaccid condition of the organ had permitted them to become expanded
into colourless areas consisting almost entirely of their distended and everted tubes.
This third chamber of the compound stomach of Platanista, notwithstanding
its small size as compared with the preceding first and second compartments, may
nevertheless, from analogy and otherwise, be regarded as the true digestive sac.
While its walls, to some extent, agree with the appearance of cavity number two,
it nevertheless is more ruddy and vascular. Its mucous membrane contains abundance
of large and simple tubular peptic glands, about OTO inch in length; These
glands are parallel and clearly resemble in appearance and structure the simple
glands of the pyloric end of the stomach of the pig.
In Plate XXVI, fig. 1,' as in Plate XXVII, fig. 1, a fourth tcavity is represented
(IV), but this is not a true gastric chamber, but an enlargement of the
upper part of the duodenum, of which more presently, in speaking of the intestines.
Intestines.—The small intestine varies from 24 feet 1 inch to 22 feet 2 inches
in specimens measuring from 6 to feet. Behind the pylorus, there is a well-
defined sac (Pl. XXVI, fig. 1, IV), about l -75 of an inch in length, formed by a
thickened and constricted ring in the intestinal wall. The inside of this sae is
marked by strong longitudinal folds with no trace of transverse ones. Another
short sac (fig. 5, i), slightly smaller, succeeds, and has its inner wall thrown into a
few longitudinal rugæ.
The ductus communis choledochus is situated at the termination of an oblong
eminence on the upper wall of this sac. Near its orifice (Eig. 5, o) the duct preserves
the character of the intestiiie, and is thrown into transverse folds, like the valvulæ
conniventes (which latter are so strongly developed, in this Cetacean), but, beyond
this, the mucous lining has a beautiful spongy texture (Eigs. 6 and 7), like the
mucosa of a gravid uterus.
The pancreatic duct opens into the ductus communis choledochus about the
middle of its course on its anterior wall, and the spongy texture passes into it
as well. I shall return to the consideration of it when we come to describe the
pancreas.
The valvulæ conniventes (Pl. XXVI, fig. 4) begin to show themselves immediately
after the ductus communis choledochus is passed, and they prevail so strongly
and in such quantity that it is sometimes difficult to lay the canal open. These folds
as in Syperoodon obtain throughout the small gut, except on its last 4 or 5 feet, where
occur short patches of longitudinal folds, about 2 inches long, alternating with long
tracts of transverse folds ; but in some conditions the last portion of the small
intestine, about two or three feet, has been found perfectly smooth, so that valvulæ
conniventes appear to be alone persistent.. They commence as a few short feeble
transverse folds, becoming more and more pronounced as they are traced backwards.
They are placed somewhat obliquely across the tube, in transverse section ; the
extremities of alternate folds seeming mutually to overlap ,each other, so that the
tract passed by the food is spiral. Some folds are much shorter than others, while
a few are connecting folds passing obliquely from one alternate series to another.
The folds are so deep that when the canal is cut across transversely the free margins
of alternate folds are seen to overlap, thus dividing off the canal into a multitude
of little chambers.
The small intestine (Eig. 11, i) is considerably contracted as it approaches the
great intestine, and the two communicate by a very small orifice sufficient only ta
admit the passage of a crowquill in an individual five feet long. At the point where,
the two join, there is a short diverticulum (Eig. 11, cce), from the large intestine pro-*
longed upwards as a cæcum, 2 to 3’50 inches long, and having the same calibre as
the great gut ; and in this respect Platanista differs from all the toothed whales.1
The large intestine of the adult, is two feet long, and it describes an abrupt
turn to the right on a line with the lower third of the kidney, indicating the com-.
1 Cuvier : Leçons d’Ânat. Comparée, 2me. edit., t. iv, 2me. Pt., p. 268. Flower : Medical Times and Gazette,
1872, vol. ii, p. 428.