The present work treats the problem of the Origin of Species on the same
general lines as were adopted by Darwin; but from the standpoint reached
after nearly thirty years of discussion, with an abundance of new facts
and the advocacy of many new or old theories.

While not attempting to deal, even in outline, with the vast subject of
evolution in general, an endeavour has been made to give such an account
of the theory of Natural Selection as may enable any intelligent reader
to obtain a clear conception of Darwin's work, and to understand
something of the power and range of his great principle.

Darwin wrote for a generation which had not accepted evolution, and
which poured contempt on those who upheld the derivation of species from
species by any natural law of descent. He did his work so well that
"descent with modification" is now universally accepted as the order of
nature in the organic world; and the rising generation of naturalists
can hardly realise the novelty of this idea, or that their fathers
considered it a scientific heresy to be condemned rather than seriously
discussed.

The objections now made to Darwin's theory apply, solely, to the
particular means by which the change of species has been brought about,
not to the fact of that change. The objectors seek to minimise the
agency of natural selection and to subordinate it to laws of variation,
of use and disuse, of intelligence, and of heredity. These views and
objections are urged with much force and more confidence, and for the
most part by the modern school of laboratory naturalists, to whom the
peculiarities and distinctions of species, as such, their distribution