446 CETACEA. 



compartments. Between tlie 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 resem- 

 blance to the dense substance forming the wall of a large artery, but the con- 

 stituents 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 u.nlike 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 cavities of stomach. — This passage is of vari- 

 able 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 1*50 inch long by 1*25 broad. It 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. It 

 opens into the third cavity close to its ventral wall, and nearly on the same level 

 as its upper border. 



Third gastric cavity. — 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 Tlatanista, 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 abund- 

 ance of large and simple tubular peptic glands, about 0*10 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 cavity is re- 

 presented (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. 



