294 ZOOLOGY. 



less hard, covers the osseous bill externally, converting it into 

 a sort of cutting and te:iriiu; instrument ; but the bird never 

 has any true teeth : hence there is no mastication, properly so 

 called. In birds which live on flesh and tear their prey 

 the falcons (Fig. 237), the eagles (Fig. 23,) and the 

 vultures (Fig. 239) the upper mandible is short, strong, 

 hooked, and terminated by a sharp point; it is occa- 

 sionally serrated, and the more or less sanguinary charac- 

 ter of the bird may be judged of by these structures. Thus 



Fig. 236 The Kite. Fig. 237. The Falcon. 



the falcon (Fig. 237), which has all these characters of the bill 

 in the highest perfection, is the boldest of all birds of prey ; 

 whilst the kite and vulture, in which the bill is softer, less 

 hooked, and not serrated, are cowardly ; the vulture chiefly 

 living on dead or dying animals. Sea birds which live on 

 fish have the bill long and hooked 

 (Fig. 238), but much longer and softer 

 than in the true birds of prey already 

 spoken of. In others, which search 

 for small fishes and reptiles which 

 may be easily swallowed, the bill be- 

 comes still more elongated, resembling 

 a pair of pincers. Such we find in the 

 kingfishers (Fig. 244) and the cigogne 

 a sac (adjutant), (Fig. 240). Birds 

 which live on insects (insectivorous), 

 -rf- 9 oQ worms, grains, and fruits, have nothing 



of the kind. In the first, the bill is 

 very slender, and but slightly curved, or even straight, and 

 much elongated (Fig. 241); but if they take small in- 

 sects on the wing, then their bill is short and broad and 

 widely cleft, as in swallows, goat-suckers (Fig. 242), &c. The 



