370 The Bird 
We have seen that in perching birds the arrangement 
is three toes in front and one behind; and now turning 
to the woodpeckers we are struck with the excellent 
toe arrangement of these climbing birds,—their claws 
spreading so that they point almost to the four points 
of the compass, thus forming an admirable grapple or 
vise, which makes a vertical position as safe for a wood- 
pecker as a horizontal one for a percher. 
Woodpeckers, the world over, have feet and toes 
which are remarkably alike; but in Canada and the most 
northern parts of our own country, and in certain por- 
tions of the Old World, there are several woodpeckers 
which are unique among the birds of this Order in pos- 
sessing but three toes. For some unknown reason their 
first, or great, toe, which in all other woodpeckers points 
backward, has disappeared, leaving but a vestigial trace 
beneath the skin, while the outer toe is reversed to take 
its place. We may see one of these hardy three-toed fel- 
lows sliding and hitching up a pine-tree, pounding and 
hammering vigorously, the loss of an entire toe evidently not 
handicapping him in the least. In such fashion does Nature 
occasionally upset our hard-worked-out theories, leaving 
us confused and baffled before her inexplicable surprises. 
Is it not rather disconcerting to find that this same 
arrangement of two toes in front and two behind also 
holds good for the other Orders of birds mentioned above, 
the parrots, cuckoos, and owls,—their toes all arranged 
in pairs, fore-and-aft? This is an excellent example of 
what is called parallelism, or the independent develop- 
ment of similar structures. 
