Page:Natural History, Birds.djvu/22

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Like the carnivorous quadrupeds, these birds are fitted, by their structure, for a life of rapine. For the most part they feed on living flesh, derived from quadrupeds, birds, reptiles, or fishes, which they pursue and capture by their own strength and prowess. Their natural weapons are not less effective than those with which their mammalian representatives are armed. The beak is strong, crooked, with the point acute and curving downward, and the edges trenchant and knife-like; their feet also are very muscular, and the four toes are armed with powerful talons, long, curved, and pointed, of which those of the hind and innermost toes are the strongest. In the family of the Vultures, however, which feed on the flesh of animals already dead, these characters are much less developed, particularly those which belong to the talons, the true weapons of the more raptorial kinds, the beak being used in both mainly as an instrument of dissecting the food, not of slaying it.

The base of the beak is enveloped in a naked skin, called the cere, in which the nostrils are pierced: the stomach is simple, consisting of a membranous sac without a muscular gizzard. The breast-bone is broad, and in most cases completely ossified, without openings, so as to afford a greater