DOMESTIC ANIMALS 



105 



parently not eating anything. If you have formed the habit 

 of observing carefully, you must have seen that from time 

 to time they swallow a mouthful, and that this food passes 

 down through the gullet into the stomach. A few moments 

 later, you will notice something passing up through the 

 gullet and into the animal's mouth with a peculiar belching 

 sound. Evidently the animal is far from being sick or un- 

 comfortable, for it at once begins to chew, this ball with ap- 

 parent satisfaction. The ball which you saw passing up is 

 called the cud. It came 

 out of the honeycomb bag. 

 After the cud is thor- 

 oughly masticated, it is 

 swallowed a second time ; 

 but now passes into the 

 third stomach, which is 

 provided with many folds 

 of delicate membrane re- 

 sembling the leaves of a 

 book; from this it is car- 

 ried into the fourth stom- 

 ach, where most of it is 

 digested, and the remain- 

 der passed on into the small intestine. (The teacher ought 

 to observe these parts in a freshly killed sheep.) The whole 

 stomach then, as we learned, consists of four parts: the 

 large paunch, the honeycomb bag, the many-plies or third 

 stomach, and the fourth stomach. 



How the stomach of the cud-chewers is adapted to their food, 

 size, and mode of life. I suppose you know that sheep and 

 goats, as well as cattle, chew the cud. All wild cattle, sheep, 

 goats, antelopes, and deer are cud-chewers, and they also 

 have teeth like sheep and cattle. As you see now, many 

 very large and heavy animals are Ruminants (cud-chewers). 



FIG. 24. STOMACH OF A SHEEP. 



a, gullet ; b, paunch ; c, honeycomb hag ; 

 d, many-plies; e, fourth stomach; 

 /, small intestine. 



