ORDER PASSERES. 431 



gradually changing its shape until it assumes the form proper 

 to the adult bird. Hence species have been erroneously mul- 

 tiplied, when the differences, taken as specific, were merely 

 those of non-age. 



A general uniformity in the structure of the feet of these 

 birds, however, prevails, notwithstanding their aberrations 

 from any given type as to the bill. These, in all the species, 

 are covered with large scales ; the three toes which are 

 directed forward, are nearly equal in length, and are nearly 

 united together at the base, so as almost to form a sole ; the 

 hind toe is large and flat, and gives a powerful support to the 

 bird, which, nevertheless, does not in general move by walk- 

 ing, but by leaping, with the feet together. They, however, 

 seldom descend to the earth, and are generally seen perched 

 on the largest trees, especially those that are dead, into the 

 holes of which they retire for concealment, and, at the proper 

 season, for nidification. 



All the hornbills have, moreover, a few bristles, like eye- 

 lashes, above the eyes. The tongue, which is very small, is 

 cartilaginous, and is attached to the bottom of the throat. 

 They live gregariously, in large bands, and feed principally 

 on insects, lizards, and frogs. They also pursue small mam- 

 malia, which they swallow whole, after having killed and 

 comminuted them in the bill, and they will even attack and 

 feed on carrion. They do not, at least in a natural state, as it 

 is said, ever take fruit, though, when domesticated, they soon 

 become accustomed to it, and to bread and vegetables. 



The bony part of the bill of all birds, which is in fact an 

 elongation of the jaws, is covered with a horny case, which is 

 easily removed entire ; but in this genus, the case appears to 

 be more adherent than in others — so much so, that it can only 

 be removed piecemeal. The protuberance on the upper man- 

 dible of some species of the hornbills is, however, entire; 

 it has no bony core, and is consequently very light, and 

 necessarily so, or the weight would be too much for the bird 



