CHAPTER XI 

 DIGESTION IN LOWER ANIMALS 



148. Digestion in dogs. All four-footed animals have 

 essentially the same digestive organs, secreting the 

 same juices as man. Their food, also, is absorbed and 

 assimilated in the same way, but there are slight modifica- 

 tions according to the kind of food eaten. A dog's stom- 

 ach and intestine have thicker walls, and their juices have 

 far more digestive power ; so dogs can digest even bones, 

 which form one of their regular articles of diet. 



149. Digestive organs in cattle. A horse lives upon 

 hay, which man cannot digest at all. Cattle have an 

 arrangement which enables them to gather a large amount 

 of food at once, and then to chew it at leisure. As grass 

 is eaten, it is swallowed almost whole. It goes first 

 to a small intermediate stomach, and then to a large 

 pouch called the paunch or rtimen, which in an ox holds 

 about two bushels. When this is full, the animal lies 

 down and proceeds to chew the food. It forces the food 

 back into the mouth in small masses, called the cud, which 

 it chews and swallows again. But this time the food is 

 guided on to a third stomach, whence it soon passes into 

 the fourth. The fourth stomach corresponds in size and 

 shape to man's, and is the true digestive stomach, while 

 the others are only storehouses and passageways for the 

 food. 



104 



