THE GANNET'8 OSTEOLOGY 515 



and Classification of Birds," p. 4) ; but whether the 

 palmate foot or the grasping foot be the more primitive, 

 there is hardly enough evidence to show. Mr. Pycraft, 

 whose studies of the Archoeopteryx have led him to regard 

 birds as descended from an arboreal stock, thinks it was 

 the latter. The second toe has three phalanges, the third 

 four, and the fourth five. This union of the toes in one 

 web, which is visible in the embryo long before it is 

 hatched, is a character which the three species of Gannets, 

 and their close aUies the Boobies, have in common with 

 the Pelicans, Cormorants, Darters, and Tropic-birds, but 

 only partially with the Frigate-bird, which has a smaller 

 web. It cannot be said that these genera have very much 

 in common. With the exception of the Pelicans and 

 Gannets, they perch upon trees and even breed upon them, 

 for which their webbed feet seem to be but ill adapted. 

 The reason for a junction, therefore, of the four toes 

 remains unexplained, unless we adopt the hypothesis that 

 it is an obsolete character, inherited in the remote past ; 

 but even then its function remains unsolved. 



The Claws. — Gannets' claws are stout sheaths, curved 

 and obtusely pointed. The third claw inclines outwards 

 and is probably a little prehensile. Its inside rim is 

 pectinated, but not always to the extremity, the pecti- 

 nations generally dividing it into eight teeth ; in Gannets 



K K "4 



