136 



StJBKINGDOM VERTEBKATA. 



Mg. 229. 



cycloid, which is a line of swifter descent than a perpendic- 

 ular, and also easier for alighting. 

 To give a more powerful hold on the 

 air when carrying its prey to its 

 eyrie, its wings are hollow on the 

 under side. 



Cathartidae.* The American 

 Vultures being designed in the econ- 

 omy of nature to dispose of carrion, 

 lack the powerful talons of the 

 Falcons, but possess a strong beak 

 for dismembering the dead bodies on 

 which they feed. If one soaring aloft 

 detects with its telescopic eye a car- 

 cass, the change of its flight from a 

 Haiiaetus leucocephdius. circular sweep to a right line of 

 White-headed Eagle. A . descent is pro bably noticed by many 



others too distant to be seen by the human eye, and thus a 

 large flock quickly gathers from all quarters of the heavens, f 

 The head and neck are bare of feathers, to enable them to be 

 plunged deeply into a carcass. As the naked skin, however, 

 would suffer in the cold upper 

 air, the base of the neck is 

 encircled with a ruff of soft 

 down, arising from a loose 

 fold, into which the neck and 

 most of the head can be with- 

 drawn, while the bird remains 



Fig. 230. 



* Recent researches prove the Vultures 

 of the Old and New World so osteologi- 

 cally different as to require the latter to he 

 placed in a separate family, and the for- 

 mer to he degraded to the rank of a suh- 

 family of the Falconidse, the Vulturinse. 



t Both sight and smell seem to aid 

 them in the pursuit of their food. The 

 latter sense is remarkahly keen, and they 

 have heen seen to descend directly from 

 a great height in the air to putrefying food 

 that was concealed from their vision. 



Ehynogryphus aura, 

 Turkey Buzzard. , 



