EXTERNAL ANATOJiy. SCANSOBIAL FEET. 
die scansorial tribe, we pass to tbat tribe itself. e 
have already described the various constructions of foot 
in four of the families (111.), the toucans, parrots, wootl- 
peckers, and cuckows, all of which have the feet dis- 
posed in pau^. The Ccvihiudctj or creepers, which 
form the fifth or Rasorial family of this circle, have 
proportionably larger feet * than any of the others, and 
the toes are differently disposed. It w’ould scarcely be 
imagined that much further variation could be found, 
where all had three toes forward and one backward, 
and yet there are greater diversities in this group than 
in all the other families of the ScansoTCS put together. 
We shall commence with the wrens, as the most aber- 
rant of all the creepers, in which we consequently find 
the faintest indication of the typical characters. So little, 
indeed, do the majority of these birds climb, in the true 
sense of the word, that it is only by tracing their close and 
unquestionable relation to others, in which both the 
scansorial structure and the faculty of exercising it is 
more apparent, that we arrive at the positive certainty 
of their belonging to this family. The length and form 
of the bill, and the brown cast of the plumage of our 
common species accords with the rest of the family, but 
it is the peculiar length of 
the hind claw (Jig. 71-) 
which shows that this genus 
occupies a station in the 
same circle with Lochmia, 
Tichodroma, Platgurus, and 
Thryofhurus, each of which 
have additional scansorial 
characters. The hind claw in Troglodytes (6) is hardly 
as long as that in the middle, and the tarsus exceeds 
both ; but in the nuthatch (Sitta, Jig. 72.), the length 
of all the toes is greatly increased, yet the hinder and 
the middle are of the same length, and both of them 
* Thus preserving their analogy to the Cracuf^. Rast^es, naUid^, Me- 
gapodia, &c., all of which they represent in the circle of the - 
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