Tir] THE DIGESTIVE ORGANS 51 



probably to store water required for intestinal digestion Jind for 

 the general wants of the bod}-, but the digestion of cellulose is 

 undoubtedly one of its functions. This substance undergoes 

 churning, maceration and decomposition and is thereby reduced 

 to a condition in which it can be absorbed. Ellenberger has 

 shown that in the horse the entire 'feed' reaches the coecum at 



(. 



Fig. SO. Coecum of horse (from Smith, Messrs Bailliere, Tindall and Cos). 

 1 Beginning of colon, 2 End of ileum. 



some time between twelve and twenty -four hours after entering 

 the stomach, that it may remain m the coecum for twenty-four 

 hours, during which time twenty per cent, of the cellulose may 

 disappear. There can be no doubt that absorption occurs in the 

 coecum to some extent. Poisonous products are removed from 

 it and carried by the blood to the liver. 



In the ox and sheep, in which cellulose digestion is known to 

 take place in the rumen, the coecum is much smaller than in the 

 horse. In the pig it is still smaller relatively to the size of the 

 animal. 



The colon in the Camivora is of small importance, acting 

 chiefly as a reservoir for the excrement %\ hich becomes somewhat 

 drier as it passes along it. In the herbivora, and particularly in 

 the horse, it is the main absorbing part of the gut. Its glands 

 liberate mucus, but do not produce ferments. It also has an 

 excretory function for metallic salts leave the body by this 

 channel. 



