THE HORNBILLS. 181 



SO many variations in the same species, that it can 

 hardly be depended on as a character. From the 

 figure it will be seen that the true bill of these birds 

 has not the robust thrusting form of the bill of the 

 raven, but more resembles that of the chough ; and 

 notwithstanding its formidable outline it is feebler 

 than even that. 



The basal enlargement is cellular, and all parts of 

 the bill are comparatively weak. The mandibles are 

 also more or less notched or serrated along the whole 

 of their cutting edges. This bill, if we except the horny 

 enlargement, the use of which in the economy of 

 the bird is not known, approaches to those of the 

 toucans and other enlarged billed climbing birds of 

 the tropical forests, only in these the upper mandible 

 is much more enlarged, instead of having the en- 

 largement in an appendage. Leaving the appendage 

 out of consideration, the bills which those of these birds 

 resemble most nearly are those of the aracari, only it 

 will be seen on referring to the figure at page 269, that 

 the aracari has the better formed bill of the two. 

 Still, however, there is so much resemblance between 

 them as to lead to a presumed correspondence in the 

 habits of the birds, though their feet indicate a dif- 

 ferent haunt. Both genera eat carrion, eggs, insects, 

 and occasionally vegetable substances ; and both are 

 rather indolent and lurking birds in their general 

 habit. The toes of the aracari are yoked, so that 

 it is a branch bird, inhabiting living trees, among 

 which it jerks about something in the manner of the 

 jay. The hornbills have the toes free, like the rest 

 of the omnivorous birds ; and though most of them 

 can perch readily and firmly, they prefer perching on 

 dead branches to those which are covered with 



