1896.] 



INTESTINAL TRACT OF BIHDS. 



151 



exaraiued, Numenius (fig. 15) certainly is nearest the common type. 

 The duodenum is a simple loop supplied with the usual vein ; the 

 circular loop is nearly symmetrical, and the restige of the yolk-duct 



Fig. 15. 



Numenitis arquaia ; intestinal tract, a, short-circmting Tegael divided. 



occurs about the middle of its length. As in the Eails this is 

 remarkably large even in adult life, and frequently is bent on itself 

 and tied down by remains of the primitive ventral mesentery. 

 The long caeca lie alongside the posterior part of the circular coil, 

 which gives a short-circuiting vein to the duodenal vessel. The 

 rectum is straight. Olareola resembles Numenius, but is even 

 simpler. In other Limicolao the general tendency is to an asymme- 

 trical extension of the circular loop and to a reduction of the 

 caeca. The Woodcock (fig. 16) may be taken as an extreme case of 

 this kind of divergence. The general arrangement of the loops 



Pig. 16. 



Scolopax rusticola ; intestinal tract, ir, short-circuiting vessel divided. 



