408 



THE RHINOCEKOS HORNBILL. 



while in others it is so small as to attract but little notice. On account 

 of the enormous size of the beak and the helmet, which in some species 

 recede to the crown of the head, the bird appears to be overweighted 

 by the mass of horny substance which it has to carry, but on a closer 

 investigation the whole structure is found to be singularly light, and 

 yet very strong. 



On cutting asunder the beak and helmet of a Hornbill, we shall find 

 that the outer shell of horny substance is very thin indeed — scarcely 

 thicker than the paper on which this description is printed — and that 

 the whole interior is composed of numerous honeycombed cells with 

 very thin walls and very wide spaces, the walls of the cells being so 

 arranged as to give very great strength when the bill is used for biting, 

 and with a very slight expenditure of material. 



Perhaps the greatest development of beak and helmet is found in the 

 Rhinoceros Hornbill. 



As is the case with all the Hornbills, the beak varies greatly in pro- 

 portion to the age of the 

 individual, the helmet 

 being almost impercepti- 

 ble when it is first hatch- 

 ed, and the bill not very 

 striking in its dimensions. 

 But as the bird gains in 

 strength, so does the beak 

 gain in size, and when it is 

 adult the helmet and beak 

 attain their full propor- 

 tions. 



When at liberty in its 

 native forests the Hornbill 

 is lively and active, leap- 

 ing from bough to bough 

 with great lightness, and 

 appearing to be not in the 

 least incommoded by its 

 large beak. It ascends 

 the tree by a succession 

 of easy jumps, each of 

 which brings it to a high- 

 er branch, and when it has 

 „ , . attained the very summit 



ot the tree It stops and pours forth a succession of loud roaring sounds 

 which can be heard at a considerable distance. 



The food of the Hornbill seems to consist of both animal and 



A^ 



The Rhinoceros Hornbill (Buceros Rhi 



