structurally and functionally, a very different and very inferior organ
to that of man, since it is not applied to similar purposes, nor is it
capable of being so applied.

When we look at the feet of monkeys we find a still greater difference,
for these have much larger and more opposable thumbs, and are therefore
more like our hands; and this is the case with all monkeys, so that even
those which have no thumbs on their hands, or have them small and weak
and parallel to the fingers, have always large and well-formed thumbs on
their feet. It was on account of this peculiarity that the great French
naturalist Cuvier named the whole group of monkeys Quadrumana, or
four-handed animals, because, besides the two hands on their fore-limbs,
they have also two hands in place of feet on their hind-limbs. Modern
naturalists have given up the use of this term, because they say that
the hind extremities of all monkeys are really feet, only these feet
are shaped like hands; but this is a point of anatomy, or rather of
nomenclature, which we need not here discuss.

Let us, however, before going further, inquire into the purpose and
use of this peculiarity, and we shall then see that it is simply an
adaptation to the mode of life of the animals which possess it. Monkeys,
as a rule, live in trees, and are especially abundant in the great
tropical forests. They feed chiefly upon fruits, and occasionally eat
insects and birds'-eggs, as well as young birds, all of which they find
in the trees; and, as they have no occasion to come down to the ground,
they travel from tree to tree by jumping or swinging, and thus pass the
greater part of their lives entirely among the leafy branches of lofty
trees. For such a mode of existence, they require to be able to move
with perfect ease upon large or small branches, and to climb up rapidly
from one bough to another. As they use their hands for gathering fruit