INTESTINAL TRACT OP BIRDS. 



231 



base, and the supni-duodenal loop is better separated. la Beouri:/ rostra acocelta a still 

 more a})ocentric modification in the same direction is reached. Tlie axial loop lias 

 grown outwards to more than twice the length attained in Truiga, and is folded irregu- 

 larly as a flat ribbon, partly rolled on itself and partly spirally twisted. The c;T)ca 

 remain long, and the other parts of the gut arc as in Trim/a. A still greater apocentrit; 

 divergence of precisely the same kind occurs in Scolopax rusticolu (Plate 22). I have 

 already figured the very remarkable conformation assumed by its gut (26. tig. 16). The 



Fig. 50. 



Intestinal Tract of Chionis alha. Lettering as in fig. 41. 



change is simply that the axial loop has grown still longer than in llecurcirostra, and 

 the rolling-up and spiral twist is still better marked. The caeca have degenerated, and 

 have left isolated a small supra-duodenal loop with a bridging vein. 



QinoyiiD.v..— Chionis alba (fig. ,jO) shows a comparatively slight modification of the 

 Xumeniiis type, and is plainly much more archecentric than most of the Charadriida}. 

 Meckel's tract is relatively longer; the axial fold with its large Meckel's diverticulum is 



35* 



