266.
[168] Just as Button's superfluous lament over the unfortunate organization of the sloth has been shown, by the increase of our knowledge, to have been uncalled for and absurd, so other supposed instances of non-adaptation will, no doubt, similarly disappear.

Mr.Darwin, in his "Origin of Species," 5th edition, p.

220, speaks of a woodpecker (_Colaptes campestris_) as having an organization quite at variance with its habits, and as never climbing a tree, though possessed of the special arboreal structure of other woodpeckers.

It now appears, however, from the observations of Mr.W.H.Hudson, C.M.Z.S., that its habits are in harmony with its structure.

See Mr.Hudson's third letter to the Zoological Society, published in the Proceedings of that Society for March 24, 1870, p.