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 runnins; the whole length. The same thins: is evident in 



Fig. 51. — Incised pal- 

 mation of Hydrochelidoii 

 larifonnis ; nat. size. 



Fig. 52. — 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 

 ov pectinations (Eii^. 35). These formations appear to be deciduous, 



Fio. 53. — Lobate foot of a coot ; reduced. 



Fig. 53 his. — Lobate foot of jilialaroiie, 

 Lobipes 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 

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



