174 OMNIVOROUS BILLS. 



to dig them out of the earth, the bark of trees, or other 

 places of concealment. 



The bills, hi order to accord with that general 

 habit, do not require the firm texture and powerful 

 action of those of the accipitres. As many of them 

 have to seize their prey quickly, as they often catch 

 it while it is on the wing, though they do not fly after 

 it, rapidity of motion, both in darting at the food, 

 and in opening and shutting, with firmness and sharp- 

 ness at the tip, are the requisites of such a bill ; and 

 lightness in its general structure is essential to the 

 quick motion. Hence, these bills are, in very many 

 of the species, so thin and weak that they are not 

 able to break the coat of a vegetable seed between 

 the edges of the tomia, and their owners are called 

 soft-billed birds. If an arrangement were to be 

 attempted from the bill, as adapted to a certain species 

 of food, the insectivorous birds would have to be 

 taken from several orders, because the feet and wings 

 vary with the manner in which the birds get at their 

 food. 



The omnivorous bills, and even many of those of 

 the birds that live much upon seeds, the conirostres 

 of Cuvier, have considerably more resemblance to 

 those of birds of prey than the dentirostres. They 

 vary much, as might be supposed in birds which inha- 

 bit so many places ; but perhaps the most typical of 

 the whole, and the one which takes up the connexions 

 most closely and naturally from the vulture?, is the 

 bill of the raven, a resemblance to which may again 

 be traced through many genera. 



This structure of bill is intermediate between those 

 of the vultures which feed principally upon carrion, 

 and of the woodpeckers and analogous races which 

 obtain their food (chiefly insects and larvae) by dig- 



