PLATANISTA. 441 



left. The third cavity and duodenum pass to the left side behind the whole 

 mass of the small intestine, where the jejunum rests at the left side on the large 

 intestine, when it again bends abruptly round to the right side. The head of 

 the large intestine abuts against the inferior wall of the second stomachic cavity 

 on the left side, and the greatly enlarged C£ecum lies below and in contact with the 

 stomach transverse to the abdominal cavity ; its apex resting against the umbilical 

 vein, and its body being buried among the coils of the small intestine. The large 

 intestine, which is quite as capacious a tube as the small gut, has a general upward 

 direction from right to left. In this foetus, which is very near its full time, there is 

 no trace of a transverse colon ; indeed, the head of the large intestine is only in 

 contact with the inferior wall of the left cavity of the stomach ; the whole of the 

 tube being as yet restricted to the left side of the body. The sigmoid flexure rests 

 against the lower half of the inner wall of the left kidney, and is nearly concealed 

 by the uterus. 



Stomach. — This organ conforms to the general type in Cetacea. It consists 

 chiefly of two large sacs, placed side by side, opening into each other by a common 

 orifice at the termination of the oesophagus. The first or left cavity is perfectly 

 simple, but the second presents a sacculation in the right wall of its fundus ; this 

 leads into a short narrow passage or channel which conducts to the third cavity, 

 this latter being about one-eighth the capacity of the others. 



First cavity. — This (PI. XXV, fig. 1, I) must be regarded as simply a dilatation 

 of the oesophagus. It is slightly elongated, and more bulging on its left than on its 

 right margin, with its anterior wall convex from before backwards. The oesophageal 

 orifice is marked in some conditions by a series of strong folds which radiate down- 

 wards and outwards along the inner aspect of the walls of the sac, and assist in 

 closing the orifice when it is contracted. The w^alls are very strong and muscular, 

 and thicker than those of the second stomach, from which they also differ in struc- 

 ture. They have the palish-yellow tint of the oesophagus, while those of the right 

 cavity are pinkish-grey. Besides the folds already described, the walls in some 

 instances are covered, at tolerably regular intervals, by an extensive series of trans- 

 verse grooves, which, separating the foregoing folds, divide the inner aspect of this 

 cavity into numerous rounded oblong areas, and produce an appearance resembling 

 the convolutions of a mammalian brain, an effect which is heightened by the 

 circumstance that many of the transverse grooves are not continuous throughout 

 their length. The latter only appear about two inches below the oesophageal open- 

 ing, so that there is a broad area around it, marked only by longitudinal folds. In 

 one adult stomach examined, a perfect cast of the inner surface of this cavity 

 was noticed in the process of being thrown off as a layer of mucous membrane, about 

 0-02 inch thick, and rough to the touch. In this state it had a pale-yellowish colour, 

 and the folds were divided crosswise, so that the membrane had a tessellated charac- 

 ter, consisting of little raised oblongs, about half an inch broad and an inch long. 



From the relative position of the two cavities already noticed, the common 

 opening between them looks obliquely from left to right, the right margin of the 



h3 



