Contributions to the theory of natural selection. A series of essays ... By Alfred Russel Wallace ...

3S8 TIIE LIJMIIS OF NATURAL SELECTION
volume of brain is one, and perhaps the most important, measure of intellect; and this being the case, we
cannot fail to be struck with the apparent anomaly,
that many of the lowest savages should have as much
brains as average Europeans. The idea is suggested
of a surplusage of power; of an instrument beyond the
needs of its possessor.
Comparison of the Brains of Man and of Anthropoid
Ap2es.-In order to discover if there is any foundation
for this notion, let us compare the brain of man with
that of animals. The adult male Orang-utan is quite as
bulky as a small sized man, while the Gorilla is considerably above the average size of man, as estimated by
bulk and weight; yet the former has a brain of only
28 cubic inches, the latter, one of 30, or, in the largest
specimen yet known, of 34-} cubic inches. We have
seen that the average cranial capacity of the lowest
savages is probably not less than five-sixths of that of
the highest civilized races, while the brain of the
anthropoid apes scarcely amounts to one-third of that
of man, in both cases taking the average; or the
proportions may be more clearly represented by the
following figures —anthropoid apes, 10; savages, 26;
civilized man, 32. But do these figures at all approximately represent the relative intellect of the three
groups? Is the savage really no further removed from
the philosopher, and so much removed from the ape,
as these figures would indicate? In considering this
question, we must not forget that the heads of savages
vary in size, almost as much as those of civilized