404 THE FEEDING OF ANIMALS 



progresses rapidly when food is retained long in the crop 

 from injury or by overloading with coarse material. 



The divided crop of pigeons secretes, with both sexes 

 for several days after the young are hatched, a thick 

 milky fluid which serves to feed the young birds. With 

 other domestic birds the crop serves for little more than 

 a temporary retaining reservoir. 



The stomach, which is a single organ in some birds, 

 is represented by two reservoirs in domestic fowls. The 

 first, through which the food passes after leaving the 

 crop, is the glandular stomach, the succentric ventricle 

 or proventriculus, and the second, closely connected, is 

 the gizzard or muscular stomach. The first, from its 

 structure, has been considered the true stomach, but it is 

 now believed that gastric juice is secreted in the gizzard. 

 The food does not accumulate in the first stomach but 

 in passing through carries along such juices as are 

 there secreted. 



The gizzard is a powerful grinding apparatus. There 

 is a strong lining which is capable of resisting great 

 pressure and the action of the sharp sand and pebbles. 

 In this organ the grains and seeds, with other materials, 

 are more finely ground than by the mastication of many 

 other animals. 



The intestines are long in domestic fowls. While 

 serving the same purpose as in mammals and having 

 a general resemblance to the mammalian form, they do 

 not clearly show the same divisions. The diameter is 

 about the same throughout. The caeca, each of which is 

 closed at one end and opens into the intestines at the 

 other, seem to be important and essential modifications 

 of that canal. Each caecum is from 6 to 7 inches long 

 in mature fowls. Not far from the openings of the caeca 



