There are many strange and wonderful forms among the feathered tribes; but there are, perhaps, none which more astonish the beholder who sees them for the first time than the group of birds known by the name of hornbills. They are all distinguished by a very large beak, to which is added a singular helmet-like appendage, equaling in size the beak itself in some species, while in others it is so small as to attract but little notice. On account of the enormous size of the beak and helmet, the bird appears to be overweighted by the mass of horny substance which it has to carry, but on closer investigation the whole structure is found to be singularly light and yet very strong, the whole interior being composed of numerous honeycombed cells with very thin walls and wide spaces, the walls being so arranged as to give very great strength when the bill is used for biting, and with a very slight expenditure of material.

The greatest development of beak and helmet is found in the rhinoceros hornbill, although there are many others which have these appendages of great size. The beak varies greatly in proportion to the age of the individual, the helmet being almost imperceptible when it is first hatched, and the bill not very striking in dimensions. The beak gains in size as the bird gains in strength. In the adult the helmet and beak attain their full proportions. It is said that a wrinkle is added every year to the number of the furrows found on the bill. The object of the helmet is obscure, but the probability is that it may aid the bird in producing the loud roaring cry for which it is so celebrated. The hornbill is lively and active, leaping from bough to bough with great lightness, and appearing not to be in the least incommoded by its huge beak. Its flight is laborious, and when in the air the bird has a habit of clattering its great mandibles together, which together with the noise of the wings produces a weird sound. The food of the hornbill seems to consist of both animal and vegetable matters. We take our illustration from Wood's "Natural History."