SEC. Ill 



EXTERIOR PARTS OF BIRDS 



195 



fringes or processes exhibited by many non-lobate or non-palmate 

 birds. Thus, if the foot of some of the gallinules be examined in a 

 fresh state, the toes will be seen to have a narrow membranous 

 margin running the whole length. The same thing is evident in 



Fig. 51.— Incised pal- 

 mation of Hydrochelidon 

 larHbrmis; nat. size. 



Fig. 62.— Totipalmate foot of a peli- 

 can ; reduced. 



a great many waders, and on the free borders of the inner and 

 outer toes of web-footed birds. In the grouse family (Tetraonidce) 

 marginal fringes are very conspicuous ; there being a great develop- 

 ment of hard horny substance, fringed into a series of sharp teeth 

 01 pectinations (Fig. 35). These formations appear to be deciduous, 



Tio. 63.— Lobate foot of a coot ; reduced. 



Fig. 53 ftis. — Lobate foot of phalarope, 

 Ldbvpes hyperboreus ; nat. size. 



that is, to fall off periodically, like parts of the claws of some 

 quadrupeds (lemmings). 



Claws and Spurs. — With rare anomalous exceptions, as in the 

 case of an imperfect hind toe, every digit terminates in a complete 

 claw. The general shape is remarkably constant in the class ; 



