BIRD. 



425 



The bills of all these birds are thick and strong, 

 enlarged at the base, sharp at the tip, and the man- 

 dibles are often fortified by a margin, which, acting 

 upon the tough rinds of seeds, bursts them, and 

 extracts the farinaceous part, which is much more 

 readily and effectually done by the flat grinding 

 margins of the bill than it would be by sharp edges. 

 The different effect of these two kinds of form in 

 effecting this purpose may be perceived by any one 

 who tries to crack a nut with a pair of scissors, and 

 another with a pair of nut-crackers of the same lever- 

 power. 



The birds which have those bills do not feed ex- 

 clusively, or at all times, upon seeds. Indeed, it will 

 readily be understood, that at those very times when 

 these birds stand most in need of food, that is. while 

 they are preparing their nests and rearing their broods, 

 the supply of seeds for them is very limited compared 

 with what it is in winter. The groundsels, and 

 various other wild plants, keep flowering and pro- 

 ducing seeds with little interruption all the year 

 round ; but the supply from these, even where farming 

 is conducted in the most slovenly manner, would not 

 support the tenth of those flocks which feed on the 

 fields in winter. Accordingly, though there are a 

 few tribes which eat the seeds of those plants, these 

 form but a small portion of the whole, and there are 

 very few genera which are not, to some extent or 

 other, animal in their feeding during the nesting time. 

 It is worthy of observation, too, that at that season 

 they disperse over the breadth of the country, so 

 that more than the pair, or the family, when these 

 grow up, arc seldom seen together, or in anywise 

 associated, even though the same species should 

 collect in thousands during winter. This is a wise 

 provision in nature ; tor the birds crowd to the fields 

 at the very time when their presence there is most 

 useful ; and again, when their individual labours are 

 more immediately required in reducing the numbers 

 of insects and worms, they are distributed over the 

 country. 



The bills of those birds are familiarly exemplified 

 in that of the common house sparrow, which may be 

 considered as about the average. As is the case in 

 the birds of prey, the smallest bills in this order or 

 division aie often the most efficient. The tits are 

 perhaps those which, among our native birds, connect 

 the conirostres most immediately with the feeders on 

 tree insects, or rather, perhaps, with the omnivorous 

 tribes, and they are equally remarkable for the small- 

 ness and the efficiency of their bills. The bottle tit 

 (Pants longicaudatus) has the bill so very short, that 

 it barely appears beyond the produced feathers at 

 the base ; yet this minute bill is one of the most 

 active, hardy, and efficient little instruments in the 

 whole animal economy. It can bite sharply and 

 hold firmly, and there are few birds which construct 

 more elaborately beautiful nests. Though on a very 

 small scale, the bill of this interesting little bird is a 

 perfect model, the maximum of usefulness with the 

 minimum of matter. The bills of the other species 

 of the genus are all finely formed, though none of 

 them are quite equal to this one. 



The bills of this genus partake a little of the cha- 

 racters of those of some of Cuvier's tenuirostres, though 

 they are capable of performing more severe labour 

 than most of these. They do not break the hard 

 crusts of seeds by squeezing them between the man- 

 dibles, but rather hew them asunder by strokes of 



the bill, and in the same way they dig into the folds 

 of buds and the crevices of bark for the larvse and 

 the eggs of insects; nor have they any aversion to 

 carrion when it comes in their way. 



The bearded reed bird, which has generally been 

 described as one of the genus P. anis, has the bill in- 

 termediate between those of that genus and the 

 finches and linnets. It is stout in proportion to its 

 size, but it is slightly curved in the upper mandible, 

 and thus it is a bruising bill rather than a thrusting 

 one. The habits of the bird correspond. It lives in 

 reeds over the marshes, the seeds of which are not 

 so hard in the coats as the seeds of plants on dry 

 ground. 



The larks may be regarded as more directly con- 

 necting the conical-billed birds with the insectivorous 

 ones ; and they have so many points of resemblance 

 to the pipits, which are insectivorous, that these used 

 to be included in the same genus. The buntings 

 stand in nearly the same relation to the larks that 

 the bearded reed bird does to the tits, one of them at 

 least is a reed bird, and they are all more vegetable 

 in their feeding than the larks. 



The finches and linnets have the bill the most per- 

 fectly conical ; and they are thus the most typical 

 birds of the order. They are vegetable, or nearly so, 

 in their feeding, at all seasons. Extending over a 

 great range in latitude, and inhabiting places very 

 different in their vegetation, from the- dense forest to 

 the bushless waste, they feed very indiscriminately on 

 the seeds of trees and herbaceous plants, and often 

 the thick tunics of wintering buds. Their bills are 

 simply bruising bills, though they vary in form, size, 

 and strength, according to the food of the birds. In 

 general, however, the mandibles are of equal length, 

 and very sharp at the tips. The following U the 

 general type. 



Finch. 



The crossbills form a very curious exception to 

 the bills of this order of birds, as will be seen in the 

 following figure of the common crossbill (Loxia cur- 

 virostra), which is of the natural size, and taken from 

 a dissection by Mr. Yarrel, to whom we are indebted 

 for the original and the best account of this curious 

 organ, and the mode of its action. 



Figure l,is a profile of the bill, with the skull and 

 the principal muscles. The one marked a, and situated 



