INTESTINAL TEACT OF B1EDS. 



235 



It is plain that in the Limicolse there is displayed a ground-form very close to what I 

 described as the Gruiform metacentre, but rather more archecentric than that. Prom 

 this condition the Charadriidso exhibit a striking set of progressively more apocentric 

 modifications, reaching a climax in the conformation of the gut in Scolopax. The other 



Fig. 55. 



Intestinal Tract of Stercorarius crepidatus. Lettering as before. 



families, the Chionidae, Glareolidse, Thinocoridae, (Edicnemidae, and Parridtc, all display 

 types closely allied to that of Numenius, but still simpler. In other words, a form of 

 gut like that in Numenius is a metacentre common to the Gruiformes and the Limicolse : 

 from this the Gruiformes have diverged in one direction, the specialized Charadriidte in 

 another, while the other families cluster about the metacentre. 



