150 GENERAL ORNITHOLOGY part ii 



oppositely falcate, as in the crossbill, constituting metagnathism. 

 A bill mucb flattened and widened at the end (rare) is spaiulak 

 (Lat. spatula., a spoon) ; examples : spoonbill, shoveller duck. One 

 is called lamellate, when it has a series of plates or processes just 

 inside the edges of the mandibles ; as in all the duck order, and in 

 a few petrels ; the design is to furnish a sifter or strainer of water, 

 just what is effected in the whale, by the baleen in its mouth. 

 Finally, the far end of the bill, of whatever shape, is called the tip 

 or apex (Fig. 26, n) ; the near end, joined to the rest of the skull, 

 the base ; the rest is the continuity. Some other features of the hill 

 as a whole are best treated under the separate head of 



The Covering of the Bill. — (a.) In the great majority of bu-ds, 

 including nearly all perchers, many walkers, and some waders and 

 swimmers, the sheathing of the mandibles is wholly hard, horny, or 

 corneous (Lat. cornu, a horn) ; it is integument modified much as in 

 the case of the nails or claws of beasts. In nearly all waders, and 

 most swimmers, the sheath becomes, wholly or partly, softer, and 

 is of a dense, leathery texture. But some swimmers, as among the 

 auks, furnish bills as hard-covered as any, while some perchers have 

 it partly quite soft, so that no unexceptional rule can be laid down ; 

 and, moreover, the gradations from one extreme to the other are 

 insensible. Probably the softest bill is found among the snipes, 

 where it is skinny throughout, and in typical snipes and woodcocks 

 vascular and nervous at the tip, becoming a true organ of touch, 

 used to feel for worms out of sight in the mud. In all the duck 

 order the bill is likewise soft ; but there it is always terminated by 

 a hard, horny imguis or " nail," more or less distinct ; and such a 

 horny claw also occurs in other water birds with softish bills, as the 

 pelican. An interesting modification occurs in all, or nearly all, of 

 the pigeon order ; these birds have the bill hard or hardish at tip 

 and through most of continuity, but towards and at the base of the 

 upper mandible the sheath changes to a soft, tumid, skinny texture, 

 overarching the nostrils ; it is much the same with most plovers. 

 But the most important feature in this connection is afforded by 

 the parrots and all the birds of prey : one so remarkable that it 

 has received a distinct name : Cere. The cere (Lat. cera, wax ; 

 because it looks waxy) is a dense membrane saddled on the upper 

 mandible at base, so different from the rest of the bill, that it might 

 be questioned whether it does not more properly belong to the head 

 than to the bill, were it not for the fact that the nostrils open in it. 

 Moreover, the cere is often densely feathered, as in the Carolina 

 paroquet, in the bill proper of which no nostrils are seen, these 

 being hidden in the feathered cere, which, therefore, might easily 

 be mistaken at first sight for the bird's forehead. A sort of false 

 cere occurs in some water birds, as the jaegers, or skua-gulls (genus 



