ALIMENTARY CANAL OF ARTIODACTYLA. 



471 



mammals. In the Giraffe the outer layer is more transversely 

 disposed than the opposite spirals of the inner layer. The mucous 

 membrane of the oesophagus is thick and firm ; it is lined by a 

 smooth and dense epithelium, and is connected to the muscular 

 coat by a very lax cellular membrane. The entire tube in the 

 Giraffe is remarkable for its length, and well displays in the liv- 

 ing animal the rapidity with which the bolus is shot upward to be 

 remasticated. 



The food when first gathered into the mouth is subject in all 

 Ruminants to a coarse and brief mastication,, and is swallowed 

 without interruption of the act of grazing or browsing: the coarse 

 bolus pushes open the lips of the groove, g, fig. 362, and at once 

 enters the first cavity of the stomach, ib. b ; water that may be 

 drank finds its way mainly, as in the Camel, into the cells of the 



362 



Ruminant stomach o! the Sheep, ccxxn" 



second cavity, c. The paunch is most capacious, is usually bifid, 

 and the thick epithelium is continued over its inner surface, 

 which is multiplied by close-set villiform processes. In the 

 Giraffe, though varying at some parts of the paunch, they are, in 

 the main, more regular and uniform in their size and shape than 

 in the Ox ; they are relatively narrower and longer ; their mar- 

 gins are thickened but entire, not notched, and they become ex- 

 panded and rounded at their free extremity, instead of tapering 

 to a point, as in many parts of the paunch of the Ox : they re- 

 semble more those of the Reindeer. In the Sheep the villi are 

 flattened and expanded at the end : in the Reindeer they are 

 longitudinally plicated : they are larger and coarser in the Bison 



