erd (meaning you
and me) by their several names of woodpeckers, cuckoos, toucans, and
plantain-eaters. All the members of this great group, of which the
parrots proper are only the most advanced and developed family, possess
the same arrangement of the digits into front-toes and back-toes. But
in none is the arrangement so perfect as in the parrots, and in none is
the power of grasping an object all round so completely developed and
so pregnant in moral and intellectual consequences.

All the Scansorial Picarians, however (if the reader with his
proverbial courtesy will kindly pardon me the inevitable use of such
very bad words), are essentially tree-haunters; and the tree-haunting
and climbing habit, as is well beknown, seems particularly favourable
to the growth of intelligence. Thus schoolboys climb trees--but I
forgot: this is a scientific article, and such levity is inconsistent
with the dignity of science. Let us be serious! Well, at any rate,
monkeys, squirrels, opossums, wild cats, are all of them climbers, and
all of them, in the act of clinging, jumping, and balancing themselves
on boughs, gain such an accurate idea of geometrical figure,
perspective, distance, and the true nature of space-relations, as could
hardly be acquired in any other manner. In one word, they thoroughly
understand space of three dimensions, and the tactual realities that
answer to and underlie each visible appearance. This is the very
substratum of all intelligence; and the monkeys, possessing it more
profoundly than any other animals, have accordingly taken the top of
the form in the competitive examination perpetually conducted by
survival of the fittest.

So, too, among birds, the parrots and their allies climb trees and
rocks with exceptional ease and agility. Even in their own department
they are the great feathered acrobats. Anybody who watches a
woodpecker, for example, grasping the bark of a tree with its crooked
and powerful toes, while it steadies itself behind by digging its stiff
tail-feathers into the crannies of the outer rind, will readily
understand how clear a notion the bird must gain into the practical
action of the laws of gravity. But the true parrots go a step further
in the same direction than the woodpeckers or the toucans; for, in
addition to prehensile feet, they have also a highly-developed
prehensile bill, and within it a tongue which acts in reality as an
organ of touch. They use their crooked beaks to hel