ornithologist's text-book. 163 



more or less rounded, and placed in the cere ; the 

 legs, which are either naked or feathered to the 

 toes, are of mean length, but muscular and strong, 

 and the tibial joint considerably elongated, to act 

 as a powerful lever in pouncing their prey. Their 

 front toes are partially united at the base, particu- 

 larly the outer and middle ones ; and their claws, 

 which are much incurved, are very sharp, and in 

 general partially retractile. To symmetry of form 

 they unite great strength and activity, and the 

 typical groups possess a power of flight, both as 

 to duration and swiftness, superior to most of the 

 feathered race; their vision is also wonderfully 

 acute, and they are distinguished for courage and 

 audacity. They prey almost entirely upon living 

 creatures, which they either strike upon the wing 

 (the mode adopted by the typical genera) or pounce 

 upon the ground, like the Buzzards and Kites. 

 Birds and quadrupeds are the usual food of most 

 of the species ; some, however, prey on fish, and 

 others principally subsist upon the larger coleop- 

 terous insects. They tear their prey in pieces with 

 their bill and claws, and parts of the feathers and 

 fur being swallowed with the flesh, are afterwards 

 ejected (together with the bones and other indi- 

 gestible portions) in pellets by the mouth. They 

 generally lead a wandering and solitary life, except 

 in the season of incubation, or at furthest continue 

 associated in pairs as male and female, which is 

 sometimes observed in birds of the aquiline kind. 

 The members of this family, as might be expected 

 from their typical character, are very numerous, 

 and distributed over every portion of the globe. 

 Many of the species in their progress from the 

 young to the adult state (which in some is not at- 

 tained before the third, in others the fourth or fifth 

 year), undergo great and remarkable changes. 

 This circumstance, from a want of observation, 



