THE ANATOMY OF A BIRD 9 



but they really are not, nor are those of the scaly manis, which are 

 more comparable to closely matted tufts of hair. The scales of a 

 fish are totally different, since they are not formed by the true skin, 

 the epidermis, at all, but by the underlying dermis. In no bird, 

 however, are there scales upon any part of the body except the 

 legs. But one bird makes a near approach to having scales else- 

 where. This is the Penguin, the feathers of whose wings are 

 flattened and very scale-like. But the characteristic fringing of 

 the feather can be detected on a careful examination. The penguin 

 uses its wings as paddles to fly under water. A branching and 

 delicate feather would be worse than useless under such circum- 

 stances ; hence the superfluous fringing of the stem of the feather 

 has been got rid of, and the feather itself has become flattened and 

 lies close to the skin. 



Beak. 



The beak is simply a horny tract of skin which has become 

 hardened for its special uses. It is not even distinctive of the bird ; 

 for turtles, particularly the snapping turtles, have beaks which are 

 not only precisely like those of birds, but are equally effectual when 

 turned to aggressive ends. It is a commonplace of knowledge that 

 the bill or beak presents an almost endless variety of form, which is 

 associated with an equally diversified use. The remarkable shovel- 

 shaped bill of the duck is suitable for dabbling in soft mud, just as 

 is the hooked beak of the hawk or owl for tearing living prey. The 

 most prevalent form of bill is that possessed by most passerine birds, 

 a conical longer or shorter bill. The relatively enormous beak of 

 the toucan is serrated along the free edge, which enables its possessor 

 to obtain a firmer grasp of the fruits upon which it feeds. The 

 ridges upon the inner surface of the beak in the ducks serve an 

 analogous purpose ; the same structure is seen in the bill of the 

 Flamingo, though the outline of the bill is unlike that of the duck, 

 and gave rise to the idea, or at any rate had something to do with 

 the former impression, that the flamingo was a long-legged duck. 

 But, as a matter of fact, there is a stork in which there is precisely 

 the same ridging of the beak, and it is more usual now to place the 

 flamingo among the storks, or near to them. The Spoonbill, as 

 its name denotes, has a beak which is at the extreme of the series 

 of beaks which are useful for sifting the mud at the bottom of 

 pools and rivers ; the extremity is widened and flattened out. 



