296 



ANATOMY AND PHYSIOLOGY OF THE FOWL 



The Digestive Organs. The digestive system is one of the 

 most complex combinations of organs in the bird's body (Fig. 142). 



b 



a Tonoue 



upper bill removed 



c, Crop 



d Esophagus 



& True stomach 



f Gizzard 



y Duodenum 



h Small int&stine 



i Caeca. 



k Rectum 



m Cloaca 



o Liver 



& Spleen 



Gall bladder 



After Wheeler. 



Fio. 142. The digestive tract. 



Teeth, though found in prehistoric birds, are wanting in birds of 

 the present time. The digestive organs of domestic fowls are as 



