The early
evolutionists maintained that all existing forms of animal and
vegetable life, including man, were derived in course of descent
with modification from forms resembling the lowest now known.
Mr. Darwin went as far as this, and farther no one can go. The
point at issue between him and his predecessors involves neither the
main fact of evolution, nor yet the geometrical ratio of increase,
and the struggle for existence consequent thereon. Messrs. Darwin
and Wallace have each thrown invaluable light upon these last two
points, but Buffon, as early as 1756, had made them the keystone of
his system. "The movement of nature," he then wrote, "turns on two
immovable pivots: one, the illimitable fecundity which she has
given to all species: the other, the innumerable difficulties which
reduce the results of that fecundity." Erasmus Darwin and Lamarck
followed in the same sense. They thus admit the survival of the
fittest as fully as Mr. Darwin himself, though they do not make use
of this particular expression. The dispute turns not upon natural
selection, which is common to all writers on evolution, but upon the
nature and causes of the variations that are supposed to be selected
from and thus accumulated. Are these mainly attributable to the
inherited effects of use and disuse, supplemented by occasional
sports and happy accidents? Or are they mainly due to sports and
happy accidents, supplemented by occasional inherited effects of use
and disuse?
The Lamarckian system has all along been maintained by Mr.
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