CoMMraTive anatomy. 129 



at once, where the grass is long, which is the case with 

 the ox in particular ; or biting close, where it is short, 

 which the horse and the sheep are able to do, in a degree 

 that one could hardly expect. The retired under jaw of a 

 swine ivorhs in the ground, after the protruding snout, like 

 a prong or ploughshare, has made its way to the roots upon 

 which it feeds. A conformation, so happy, was not the 

 gift of chance. 



In birds this organ assumes a new character ; new both 

 in substance and in form, but, in both, wonderfully adapted 

 to the wants and uses of a distinct mode of existence. We 

 have, no longer, the fleshy lips, the teeth of enamelled bone ; 

 but we have, in the place of these two parts, and to perform 

 the office of both, a hard substance (of the same nature 

 with that which composes the nails, claws and hoofs of 

 quadrupeds) cut out into proper shapes, and mechanically 

 suited to the actions which are wanted. The sharp edge 

 and tempered point of the sparrow^ shWX, picks almost every 

 kind of seed from its concealment in the plant ; and not 

 only so, but hulls the grain, breaks and shatters the coats 

 of the seed, in order to get at the kernel. The hooked 

 beak of the hawk tribe, separates the flesh from the bones 

 of the animals which it feeds upon, almost with the cleanness 

 and precision of a dissector's knife. The butcher bird, 

 transfixes its prey upon the spike of a thorn, whilst it picks 

 its bones. In some birds of this class, we have the cross 

 bill, i. e. both the upper and lower bill hooked, and their 

 tips crossing. The spoon bill, enables the goose to graze, 

 to collect its food from the bottom of pools, or to seek it 

 amidst the soft or liquid substances with which it is mixed. 

 The long tapering bill of the snipe and woodcock, pene- 

 trates still deeper into moist earth, which is the bed in which 

 the food of that species is lodged. This is exactly the in- 

 strument which the animal wanted. It did not want 

 strength in its bill, which was inconsistent with the slender 

 form of the animal's neck, as well as unnecessary for the 

 kind of aliment upon which it subsists ; but it wanted 

 length to reach its object. 



But the species of bill which belongs to birds that live 

 by suction, deserves to be described in its particular rela- 

 tion to that office. They are what naturalists call serrated 

 or dentated bills ; the inside of them, towards the edge, 

 being thickly set with parallel or concentric rows of short, 

 strong, sharp-pointed prickles. These, though they should 

 M 2 



