DIGESTIVE APPARATUS OF BIRDS. 185 
siderable modification of form, resulting from the fact that, as 
these animals do not masticate their food, they require some 
(sophagus 
Ventriculus 
Succenturiatus 
Gi ; Liver 
Gall-bladder 
Bile ducts 
Fig. 111.—Dicestive Apparatus or FowL. 
other means of reducing it. This means is provided for them 
in their stomach. In the tribes whose food is of such a 
nature as to require being moistened before it is rubbed down, 
and especially in those which feed upon grains, the cesopha- 
gus has a pouch-like dilatation, termed the crop or craw 
(fig. 111); mm this it is retained, and exposed to the action 
