STOMACHS OF MAMMALIA. 



141 



munications between these several ^stomachs of the cetacea 

 are probably intended to ensure the thorough solution of their 

 contents, by preventing the exit of all such portions as have 

 not perfectly undergone that process. 



Supernumerary cavities of this kind, belonging to the 

 stomach, are more especially provided in those animals 

 which swallow food either in larger quantity than is imme- 

 diately wanted, or of a nature which requires much prepa- 

 ration previous to digestion. The latter is more particularly 

 the case with the horned ruminant tribes that feed on the 

 leaves or stalks of vegetables, a kind of food, which, in pro- 

 portion to its bulk, affords but little nutriment, and requires, 

 therefore, a long chemical process, and a complicated diges- 

 tive apparatus, in order to extract from it the scanty nutri- 

 tious matter it contains, and prepare it for being applied t^ 

 the uses pf the system. This apparatus is usually considered 

 as consisting of four stomachs; and, in order to convey a 

 distinct idea of this kind of structure, I have selected for re- 

 presentation, in Fig. 312, that of the Sheep, of which the 



four stomachs are marked by the numbers 1, 2, 3, 4, re- 

 spectively, in the order in which they occur, when traced 

 from the oesophagus (c) to the intestine (p.) 



