GASTETC OLAXDS OF THE MAKSUPIALTA. 11 



important difference in the disposition of the gland regions of 

 the stomach as compared with Myoxus, that the cardiac glands of 

 the latter, that is the glands composed of parietal and central cells, 

 are restricted to the bulbus ventriculi, and the rest of the stomach 

 contains only pyloric glands ; while in the three first mentioned 

 forms the whole stomach is glandular, and cardiac glands, although 

 predominantly crowded together in the gastric-gland thickening, 

 are not wholly restricted to it as they are to the bulbus of 

 Myoxus, but are found to a certain extent over the region of the 

 fundus. The area on the stomach of the Beaver occupied by 

 cardiac glands is thei-efore to be regarded (on Toepfer's view) 

 as homologous with the "Yormagen" of Myoxus. The extent to 

 wliich these glands extend over the lateral wails and region of 

 greater curvature of the stomach has not been investigated, nor 

 have the precise limits of the pyloric glands been determined, 

 either for Castor or for the Marsupials referred to. 



In Manis^ although the gastric gland on the greater curvature 

 of the stomach cannot be regarded as homologous with those in 

 other mammals, it is more comparable to the bulbus ventriculi 

 of Myoxus than to any of the others, for here there is a definite 

 restriction of the cardiac glands to a portion of the stomach- 

 wall, where they are arranged as a complex glandular organ, 

 the rei«t of the stomach being non-glandular, with the excep- 

 tion of certain patches which contain glands probably homologous 

 with the pyloric glands of the other mammalia. Here, too, it 

 seems that a direct correlation with the nature of the food and 

 the other parts of the alimentary canal and disposition of tlie 

 mucous membrane of the stomach exists ; a proposition that can 

 hardly be made with regard to the gastric glands of either the 

 Marsiipialia or the Kodentia. Tliere are simple stomachs un- 

 provided with any complex glandular apparatus in the Phalangers, 

 as in the Myoxiclce other than M. avellanarius. 



The formation of the " gastric gland" as we find it in the 

 Marsupials seems to be explicable in one of two ways. First, as 

 the result of a tendency to localization of the gland regions, — a 

 tendency which finds its expression alike in the structures I have 

 described, in the glandular cardiac appendage of Manaius, and 

 more completely in the " gastric gland " of Manis and the bulbus 

 ventriculi of Myoxus. But we may also with Oppel (8. pp. 402-3) 

 in the case of the Beaver and the Marsupials, regard it as 

 due to the necessity for increase in the area of the gastric 



