10 OUR HUMBLE HELPERS 



do. There takes place a kind of chewing, it is true, 

 only the food, instead of returning to the beak, where 

 teeth are lacking for its thorough mastication, con- 

 tinues its journey, and on the way comes to the tri- 

 turating machine. Birds, then, are generally pro- 

 vided with three digestive cavities. 



"The first is the crop, situated just at the base of 

 the neck. It is a bag with thin and flexible walls, its 

 size proportioned to the resistant nature of the food 

 eaten. It is very large in birds that feed on grain, 

 especially the hen, and is medium-sized, or even 

 wholly wanting, in those that live on prey, which is 

 much easier to digest than dry and hard seeds. In 

 the crop, the food swallowed in haste remains hours 

 and even days, as in a reservoir; there it softens 

 somewhat, and is then submitted to the action of the 

 other digestive pouches. The crop corresponds in 

 a certain sense to the bag in which the pelican stores 

 up his fishing ; it represents also the first stomach of 

 the ox and the other cud-chewers or ruminants. 



"Next to the crop is a second enlargement, called 

 the succenturiate ventricle, of small capacity but re- 

 markable for a liquid of a bitter taste that oozes in 

 fine drops through its walls and moistens the food 

 as it passes. This liquid is a digestive juice ; it has 

 the property of dissolving the alimentary substances 

 as soon as trituration has done the greater part of 

 the work. The food does not remain in this second 

 stomach; it merely passes through to become im- 

 pregnated with the digestive juice. 



"The third and last stomach is known as the giz- 



