are likewise of some importance for its success, and these depend in
part on the nature and amount of the food which can be obtained. In
Europe the men of the Bronze period were supplanted by a race more
powerful, and, judging from their sword-handles, with larger hands (3.
Morlot, Soc. Vaud. Sc. Nat. 1860, p. 294.); but their success was
probably still more due to their superiority in the arts.
All that we know about savages, or may infer from their traditions and
from old monuments, the history of which is quite forgotten by the
present inhabitants, shew that from the remotest times successful
tribes have supplanted other tribes. Relics of extinct or forgotten
tribes have been discovered throughout the civilised regions of the
earth, on the wild plains of America, and on the isolated islands in
the Pacific Ocean. At the present day civilised nations are everywhere
supplanting barbarous nations, excepting where the climate opposes a
deadly barrier; and they succeed mainly, though not exclusively,
through their arts, which are the products of the intellect. It is,
therefore, highly probable that with mankind the intellectual faculties
have been mainly and gradually perfected through natural selection; and
this conclusion is sufficient for our purpose. Undoubtedly it would be
interesting to trace the development of each separate faculty from the
state in which it exists in the lower animals to that in which it
exists in man; but neither my ability nor knowledge permits the
attempt.
It deserves notice that, as soon as the progenitors of man became
social (and this probably occurred at a very early period), the
principle of imitation, and reason, and experience would have
increased, and much modified the intellectual powers in a way, of which
we see only traces in the lower animals. Apes are much given to
imitation, as are the lowest savages; and the simple fact previously
referred to, that after a time no animal can be caught in the same
place by the same sort of trap, shews that animals learn by experience,
and imitate the caution of others. Now, if some one man in a tribe,
more sagacious than the others, invented a new snare or weapon, or
other means of attack or defence, the plainest self-interest, without
the assistance of much reasoning power, would prompt the other members
to imitate him; and all would thus profit. The habitual practice of
each new art must likewise in some slight degree strengthen the
intellect. If the new invention were an important one, the tribe would
144