INTESTINAL TEACT OF BIEDS. 



217 



TuRNiCES. — In the Tumices (I have-not seen Pedionomus) the duodenum {Turnix 

 JDussumieri, fig. 37) is a long, narrow loop ; Meckel's tract is suspended at the periphery 

 of a nearly circular mesenteric expansion and bears no trace oi the diverticulum. 

 There is no specially formed supra-duodenal loop, but the very large caeca (which are 

 dilated towards their extremities) are drained partly by a bridging vein from the 

 duodenal vein. The rectum is relatively long and very slightly expanded into folds. 



Fig. 3' 



f 



Intestinal Tract of Tnrnix Dussumieri. 

 )•., recurrent factor of middle mesenteric vein. Other lettering as before. 



This intestinal tract is markedly archecentric. The simple character and the arrange- 

 ment of the blood-vessels are closely similar to the condition of Palamedea. The chi&f 

 modifications are absence of the Meckel's diverticulum, the increased length of the caeca, 

 and the relatively shorter rectvim. So far as the character of the gut indicjites systematic 

 position, there is no reason either to retain Turnix among the Galliformes or to remove 

 it from that assemblage. It is simply an archecentric form. 



