167 



BILLS OF THE ACCIPITRES. 



The annexed figure of the bill of the jer-falcon 

 may be regarded as the most perfect type of those 

 of diurnal preyers upon the wing. It is short, 

 compressed, and so formed on the culmen that 

 it is perhaps stronger in proportion to its size and 

 quantity of matter, than the bill ot any other bird. 



The tooth is prominent, the notch well defined, 

 and the tomia curved in the greater part of their out- 

 line. The form of the tip of the lower mandible is 

 peculiar, acting with a sort of sliding motion against 

 the hook of the upper one ; and this sliding motion 

 is in part communicated to the tooth and notch, and 

 to all the irregularities in the lines of the tomia. The 

 action of the mandibles is, in consequence of this 

 form, compounded of the direct cut of a chisel and the 

 drawn cut of a knife. We shall find the same sort 

 of action, partially at least, in some of those sea birds 

 which live much upon floating carcasses, though in 

 these it is a simple slide at the tip, without any notch 

 or tooth. 



This is not so much a killing beak, as a tearing 



