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). 



a Tongue 



upper bill removed 



b Esophagus 



c Crop 



d IZsophagus 



& True stomach 



f Gizzard 



y Duodenum 



h Small int&stine 



i Caeca, 



ft Rectum 



m Cloaca, 



o Lirer 



p Spleen 



r Ga22 bladder 



<s P&ncreas 



After Wheeler. 



FIG. 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 



