1896.] INTESTINAL TRACT OF BIRDS. 151 
examined, 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 vestige of the yolk-duct 
Fig. 15. 
Numenius arquata ; intestinal tract. 2, short-circuiting vessel divided. 
occurs about the middle of its length. As in the Rails 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 ceca lie alongside the posterior part of the circular coil, 
which gives a short-cireuiting vein to the duodenal vessel. The 
rectum is straight. Glareola resembles Numenius, but is even 
simpler. In other Limicole the general tendency is to an asymme- 
trical extension of the circular loop and to a reduction of the 
ceca. The Woodcock (fig. 16) may be taken as an extreme case of 
this kind of divergence. The general arrangement of the loops 
Fig. 16. 
Scolopax rusticola ; intestinal tract. 2, short-circuiting vessel divided. 
