40 MAMMALIA. 



and intestiniform, and puckered up by a pair of strong muscular 

 bands, like the human colon. In Mycetcs, also, at least in several 

 species, the stomach is divided into two portions by a constric- 

 tion. The stomach is always simple, and mostly very rounded (as 

 in the Cats), in the Carnivora and Cheiroptera, least of all in the 

 true insectivorous Bats, and in the insectivora among the Ferae, 

 e. g. Centenes. In many of the Vampires it is elongated and coni- 

 cal, with a small cardiac coecum. In the fructivorus Cheiroptera 

 (Pteropus) the stomach is very long, and intestiniform with a very 

 considerable co3cum, and has a transverse position, while in the 

 Walrus the very much elongated stomach is without a coecal pouch, 

 and lies perpendicularly within the abdomen. Very many differen- 

 ces are exhibited by the Rodentia, among which indeed most of the 

 genera have a simple cylindrical stomach, with a tolerably large coe- 

 cum. The stomach, however, is frequently, even when it has no 

 visible, or but an insignificant constriction externally, divided within 

 into two very distinct portions, as in Meriones. In the cardiac half 

 the epithelium is continued from the oesophagus, while the pyloric is 

 thickly beset with glands, and coated over with a soft mucous mem- 

 brane ; in the Beaver it has a very dense glandular layer. Fre- 

 quently as in the Hamster, the division into two halves is very 

 striking externally. There is seldom found a long glandular proven- 

 triculus, separated, as in Birds, by a constriction from the wide 

 muscular stomach, as in the Red-dormouse (Myoxus avellanarius), 

 but not in M. glis and nitela. In the Lemming, and in most of the 

 Musk-rats (Hypudaeus. s. Arvicola), the second or pyloric division 

 itself is divided again into several (3) sacs or portions. The stom- 

 ach is simple in most Edentata (even in the Ornilhorynchus), and 

 almost without a coecum. The squamigerous Edentata (Manis) 

 have a thick glandular layer in the left portion. Among the Mar- 

 supiata the stomach is simple in the carnivorous kinds ; in the Kan- 

 garoo it divides into a left, middle, and right portion, and is very in- 

 testiniform. Also in the Pachydermata there occurs a complex 

 stomach, as in the Peccari, while in the Elephant and Rhinoceros it 

 is simple, and double in the Tapir and Hyrax. In the Horse, the 

 stomach is simple externally ; the oesophagus, however, enters the 

 middle of the lesser curvature, and the cardiac and pyloric portions 

 are differently constructed. The sloth has a twisted intestiniform, 

 subdivided stomach ; and in the Manati and Dugong the stomach has 

 even two pedunculated coecal pouches in the middle. 



Still more peculiar is the stomach of the Ruminantia, in which order 



