ALIMENTARY CANAL 



29 



' short-circuiting ' connection, as Mitchell terms it, 

 between the duodenal and the main mesenteric stem. 



Fig. 13. — Saliaetus dlbicilla ; IntSetinal Teaot. 

 X as in flg. 12. (After Chalmers Mitchell.) 



Pia. 14. — Ara ararauna ; Intestinal Tkaot. 

 .r, as in flg. 12. (After Chalmebb Mitchell.) 



In other groups of birds this simple state of affairs is further 

 evolved, but in some there are remains of the primitive 



