﻿132 ON THE CLASSIFICATION OF BIRDS. 



seems not unlike that of the swifts : hut the position 

 of the toes are very different ; the three anterior are 

 very nearly of equal length, and sufficiently united at 

 their base to keep them always close to each other, 

 so that the sole becomes much broader than if the 

 divisions were distinctly cleft : the claws, as if to com- 

 pensate for the brevity of the toes, are remarkably long, 

 being two thirds the length of the toes themselves. 

 The TrochilidcB thus present a most curious analogy 

 to the larks and wagtails, for although they never, by 

 any chance, alight upon the ground, where the two 

 latter genera alone reside, yet both may be character- 

 ised as having the claws pre-eminently developed. One 

 could hardly have imagined that nature would have 

 established so beautiful an analogy between two groups 

 so diametrically opposite in all other respects, except that 

 of having the longest and the most slender bills of their 

 respective circles. The claws, however, of the Trochi- 

 lidcB are very much curved, broad, and remarkably 

 acute, a conformation which is always found in birds 

 which from living only upon trees, have additional 

 powers given them of clinging to the branches ; such, 

 in fact, are the habits of these beautiful little creatures ; 

 they never are seen, like other birds, hopping from 

 twig to twig : they are either upon the wing or seden- 

 tary ; and, as their well curved claws enable them to 

 take a firm hold on the convex surface of slender twigs, 

 we have applied the epithet of clinging to the peculiar 

 foot they possess. 



(120.) A prehensile foot is possessed by those birds, 

 which, like the TrochilidcB, rarely, if ever, touch the 

 ground ; yet they are continually wandering among 

 branches in search of their food : hence they require 

 great strength of limb, without the necessity of a 

 lengthened tarsus. This structure we accordingly find 

 in the short legged-thrushes, (BrachypodincB) the 

 orioles (Oriolince), the caterpillar catchers (CeblepyrincB), 

 the fruit eaters (AmpelidcB), and several other groups. 

 The foot of these birds very much resembles that of the 



