360 



AVES 



and allow the gastric juice to act. Fowls can pulverize glass and 

 some metals by grinding them in the gizzard. 



The small intestine consists of the duodenum and the ileum. 



Esophagus (upper portion) 

 Crop 



Esophagus C/oiver portion) 



Liver Co small portion) 



Bile ductus 

 ■Fttncreos 

 Proventricu/us 



Gizzard 



Spleen 



Ceca 

 ■Duodenal loop 





Recturf) 



Anus 



Fig. 202. Digestive tract of common fowl. (Drawn by W. J. Moore.) 



The duodenum has a U-shaped loop. This varies in different birds 

 but is ordinarily quite long and equal to twice the length of the body, 

 except in the fish eaters, where it may be but one-eighth the length 



