10 



VERTEBRATA. 



Amonirst their distinctive features the most important are those furnished by the bill and 

 feet The fonner of these organs is always rather short and strong, with the upper mandible 

 longer than the lower one, strongly hooked at tlie tip, or curved throughout its wliole length, 

 very sliarj) at the point, and sometimes armed with teeth on the margins. The base of the bill 

 is coveretl by a cere, in which the nostrils are pierced. The feet are usually short and powerful, 

 composed of four toes, armed with long, curved, and acute claws. With the latter these birds 

 seize their prey in a deadly grasp, and with them they hold the victim whilst the powerful 

 bill is cncfaixed in tearinc: off portions of its liesh. At the same time, the wintrs are always of 

 large size, and often of extraordinary length, giving the birds an astonishing rapidity of flight. 

 The tail is long and broad, usually composed of twelve feathers ; it is sometimes rounded and 

 sometimes forked at the end. 



The tarsi are rarely furnished with scutella as in the Passerine birds, but, like the toes, they 

 are generally covered with a reticulated skin, although in some cases a few scutella are found 

 upon the front of the tarsi and the upper part of the toes. The latter arc arranged three in front 

 and one behind, and the anterior toes are usually united at the base by a short membrane, except 

 in the owls, in which the outer toe is capable of being turned backward and the inner one alone 

 is united to the middle toe by a membrane. In some instances the feet are feathered down to the 

 toes. The raptorial birds are very generally distributed over the globe. They vary greath^ in 

 size, but the majority feed upon the flesh of animals which they capture for themselves; some of 

 the smaller species, however, condescend to prey upon insects. They are divided into three ex- 

 tensive families, the Falcons, the Vultures, and the Owls. 



THE FALCON"rD^. 



In this family, which not only includes Falcons proper, but Haivks and Eagles, the destruct- 

 ive power is most perfectly developed; and we 

 find in the birds composing it natural instruments 

 for striking, trussing, and dissecting their prey, 

 combined with a power of flight and strength of 

 limbs equivalent to the necessities of the case, 

 whether the prey be aerial — that is, in the act of 

 flight — or on the ground. These natural weapons 

 are rendered still more formidable by the organiza- 

 tion of the whole animal, which is calculated to 

 give them the greatest possible effect. The nails, 

 or claws, to be available, must be sharp ; and, in 

 order that they may be kept in this state and fit 

 for duty, there is a provision to enable the bird to 

 prevent them from coming in contact with the 

 ground or other foreign hard bodies ; for the claws 

 are retractile, not indeed in the same manner as 

 those of the cats, which have the power of with- 

 drawing or sheathing theirs within the inteofu- 

 ments, but by a conformation which gives the bird 

 of prey the power of elevating its claws at pleas- 

 ure. The claws of falcons when sitting on stones 

 or large branches of trees have often a cramped 

 appearance ; but this arises in most instances from 

 the care of the bird so to arrange its talons that 

 their points may not be blunted against the perch. 

 HEAD AND FOOT OF PEREGEiNE FALCON. jt Is ouc of thc remarkable chara^cteristics of this 



family, in common with other Raptores, that the females are considerably larger than the males. 

 All the Falconidse have wings of large size, and are remarkably powerful fliers. Tliey pursue 



