﻿152 



ON THE CLASSIFICATION OF BIRDS. 



dinary direction is in front, although not equally so, for 

 the external toe (c) has a more sidelong direction than the 

 inner, just as we see in the owls, the 

 structure of whose foot we have already 

 described: so far from this toe being 

 sub- versatile, it cannot be brought 

 even a quarter way round (d) without 

 an unnatural effort, so that its ordin- 

 ary position (e) would be about dou- 

 ble that distance from the middle toe, 

 which is between the middle and the 

 inner one. In support of this opinion 

 we find that this outer toe is actually 

 connected to the middle one by a 

 distinct membrane, as if to prevent it 

 from having that versatile power which is seen in the 

 cuckows (fig. 82.), where this membrane is completely 

 wanting. Other writers, unacquainted, apparently, with 

 the true structure of the Musophagidce, have imagined 

 that these birds connected the order Rasores with that of 

 Insessores ; but we see nothing to justify this opinion, 

 and very many facts and considerations against it. The 

 feet are evidently a union of the perching and the aber- 

 rant scansorial characters, without any of the rasorial. 



(131.) Having now attempted to define, with that 

 precision which the present state of science demands, 

 the numerous modifications in the form and functions 

 of the feet in those groups belonging to the Insessorial 

 order, we shall but slightly touch upon such as are 

 peculiar to the others : we have done this briefly ; first, 

 because the variations are much fewer, and secondly, 

 because the student will not have the same facilities of 

 comparison, except in such species as are indigenous. 

 Very many of the Rasorial, Grallatorial, and Natatorial 

 genera are composed of very large birds, whose size 

 excludes them from private collections, and which can 

 only be seen through the glazed cases, — often placed 

 in bad lights, and unfavourable situations, — of public 

 museums. Where, as \n> this case, the greatest accuracy 



