﻿120 ON THE CLASSIFICATION OF BIRDS. 



short, yet perfectly formed. Now it deserves especial 

 attention that all groups which represent the Struthi- 

 onidcB in other circles, either have the fewest number 

 of toes, or their disposition is variable ; as if this was 

 the point in the circle where these members changed 

 their character, and number, even in the genera. Hence 

 it is that the whole of the typical Grallatorial birds have 

 the hind toe so short, that it may be termed obsolete. 

 By the same law we find nearly all the Charadriadce, 

 or the plovers (the most aberrant of the Grallatores) , 

 with only three toes, like most of the ostriches, which 

 in every thing else they symbolically represent. Thus, 

 also, we account for the disappearance of the hinder toe 

 in the sub-genus Apt emus, or the three- toed wood- 

 peckers, — the variation of the structure of the foot, 

 among the Halcyonidce, or kingfishers, — and in the Mu- 

 sophagidce, or plantain-eaters, one genus of which 

 (Colius) has all the four toes placed forward. Each 

 and all of these groups represent the Struthionidce in 

 their respective circles, in which they are the most 

 aberrant. We may now proceed to the variations of 

 the toes in regard to situation. 



(110.) The toes vary in their position no less than 

 in their number, even in such birds as have only three. 

 The direction of these members, in cursorial or three- 

 toed birds, is forward, and their divisions are mostly 

 cleft to the base ; but in the three-toed woodpeckers, 

 where the hallux is wanting, one of those which are 

 versatile, and which is generally 

 called the exterior hind toe, is di- 

 rected more backwards than usual ; 

 so that there are two before, and 

 one behind. The usual structure 

 of the kingfishers is to have three 

 anterior, and one posterior toe (fig. 

 63. a) ; but in such as have only 

 three it is the inner anterior toe 

 which disappears, so that the hallux, 

 which is wanting in Apternus^ re- 

 mains in the sub-genus Ceyx. (6. 6.) 



