ALIMENTARY CANAL OF RODENTIA. 423 



compartment is of smaller dimensions, of a globular form, and 

 separated from the preceding, both by an external constriction 

 and an internal fold of the mucous membrane. There are, more- 

 over, two additional folds nearer to the pylorus, which seem 

 to form a third compartment. The Oryctere ( Orycterus) has its 

 stomach slightly different: its position is more longitudinal, so 

 that the left compartment is anterior, and the right posterior ; 

 the pyloric portion is short, cylindrical, and directed forward. 



In Capromys Fournieri the oesophagus, after a short course in 

 the abdomen, terminates in a stomach six inches long, about 2^ 

 inches from the left end : a pouch of the same extent is con- 

 tinued from the right of the pylorus, which is situated 1J inches 

 to the right of the cardia. 



In the Coypu (Myopotamus) the stomach closely resembles 

 that of Capromys, being of an oblong figure, both extremities 

 having pretty nearly the same volume ; the cardiac extremity 

 projects three inches beyond the entrance of the narrow oeso- 

 phagus, and the pyloric sacculus, a little more than two beyond 

 the pyloric orifice. The stomach, measured in a straight line from 

 end to end, is 7| inches ; its greatest depth 4^ inches. 



In the Agouti (Dasyprocta agouti), with a stomach 5 J inches 

 long, the constriction dividing it into cardiac and pyloric por- 

 tions is deep : the latter bulges out on each side the pylorus so 

 as to make the duodenum commence from a central depres- 

 sion. The Paca ( Coelogenys) shows the same structure. In an 

 Acouchi the gastric constriction was not present or had relaxed. 

 In the Capybara the abdominal oesophagus is two inches in extent : 

 the greater curvature of the stomach is sometimes found puckered 

 into sacculi by contraction of a band of longitudinal fibres. 



In the Rabbit and Hare (Lepus, Lin.) the stomach is roundish, 

 bent in a quick curve, with the oesophagus entering nearer the 

 left or great end than the pyloric end : the left end adheres to 

 part of the abdominal oesophagus : it is usually found partially 

 constricted into two compartments, the pyloric being the thickest 

 and most muscular. The sides of this division have a well-marked 

 tendinous patch. 



The intestinal canal usually, in Rodents, begins by a well-marked 

 dilatation, and the whole duodenum is more continuously and 

 loosely suspended than in most higher Mammals. In the Dormice 

 ( Myoxus) which hy bernate like the bear, there is no caecum. In the 

 common Mouse and Rat (Mus, fig. 317) the caecum, k, I, is short, 

 wide, and bent ; the colon, p, 'reduced to the calibre of the ileum, 

 leaves the caecum, like the duodenum quitting the stomach. The 



