﻿EXTERNAL ANATOMY. TOES. 123 



external signs that may appear of its insect food lurking 

 within. But although we thus distinguish the foot of 

 the Picidce, as pre-eminently scansorial, it must not be 

 supposed that they are of the only structure which is 

 quite adapted for climbing. Infinite and harmonious 

 variety is the great principle which pervades the crea- 

 tion, one result of which is the accomplishment of the 

 same purpose by a great diversity of means. Thus we 

 shall find, even in the Scansorial tribe, other modifi- 

 cations of the foot admirably adapted for climbing, 

 although the toes are in the same position as those of 

 ordinary birds. 



(113.) We now come to those few examples where 

 all the four toes are placed forward ; these, as we have 

 already intimated, are found 

 in the swifts (Cypselus, fig. 

 64., a), Colies (Colius, &.), 

 and corvorants (Carbo). We 

 might almost have in- 

 cluded the Caprimulgidce, or 

 night-jars, in this list, for 

 their hallux, or hinder toe 

 {fig. 65. a), although incapable of being brought on a level 

 with the others, is still placed so far forward, even as when 

 seen in a dried specimen, that it seems inserted on the 

 side of the foot, rather than behind the others. It has 

 been mentioned by some writer, that these birds never 

 perch, like others, across the branch of a tree, but 

 always parallel with it; so that in such a position the 

 hinder toe would have no power of acting like that 

 of other birds. If this 

 fact is correct, it favours 

 the supposition that, when 

 at rest, the hallux of the 

 Caprimulgidce is placed for- 

 ward, and that such is truly 

 its natural position. Some 

 of our field naturalists, who 

 may be in the way of procuring a fresh specimen of the 



