CHYLIFICATION. 



in the chemical nature of some of these bodies, as for ex- 

 ample, in albumen. 



Certain alimentary substances, as fecula and gluten, are 

 not acted on by pepsin; and in order to be digested they 

 require to be previously submitted to other agents. The 

 saliva is one of these agents ; and thus it is that in herbivorous 

 animals there often exists, between the mouth and stomach 

 properly so-called, a first cavity, intended to lodge the food 

 whilst being mixed with the saliva. In the mammals 

 called ruminants, this pouch, or first stomach as it has been 

 called, is named the paunch (Fig. 25) ; and in birds, the 

 jabot or crop. 



Gullet. 



Intestine. 



Pylorus. St. p.d. 2nd Stomach. Paunch. 

 Fig. 25. Stomach of the Sheep. 



Fatty substances used as food resist the action of these 

 juices, and pass the stomach unaltered. It is only in the 

 intestines that they meet an agent equal to their solution. 



Whilst chymification proceeds, the muscular fibres act 

 circularly, and push the mass, at first, from right to left; 

 afterwards, from left to right, towards the pylorus, by which 

 the chyme passes on to the small intestine. This action is 

 called peristaltic. 



Chylification. 



67. Intestines. The portion of the alimentary canal 

 immediately following the stomach is called the intestine, 

 (Fig. 24.) This membranous tube, variable in its capacity, 

 D 2 



