Ill] 



THE DIGESTIVE ORGANS 



35 



It is noteworthy that the stomach of the pig is intermediate 

 in character between that of the carnivorous dog and the herbi- 

 vorous sheep, for the pig is not p^irely herbivorous, but, hke 

 man, can subsist on a very varied diet. 



In the horse nearly one-half (the cardiac portion) of the 

 internal lining of the stomach (that is, the mucous membrane) 

 is merely of the nature cf a continuation of the lining of the 



Duct 



Chief cells 



I Parietal cells 

 V Gland 



Duct 



J Gland 



.SCALE 100^ 



Fundus gland Pyloric gland 



Fig. 22. Gastric glands (after Heidenhain from Smith, Messrs Bailliere, Tindall 

 and Cox). [The parietal cells are the acid-secreting ones. 



oesophagus. This part which is sometimes called the pro- 

 ventriculus comes to an abrujit end and is succeeded by the 

 secretory part or fundus. Here the tubular glands which secrete 

 the gastric juice are separated by finger-shaped villous processes 

 protruding into the cavity. The villous part is followed by a 

 smooth pyloric portion which opens into the duodenum or first 



3—2 



