words natural selection, which have served to cloak it--in the views
which the old and the new writers severally took of the variations
from among which they are alike agreed that a selection or quasi-
selection is made.

It now appears that there is not one natural selection, and one
survival of the fittest only, but two natural selections, and two
survivals of the fittest, the one of which may be objected to as an
expression more fit for religious and general literature than for
science, but may still be admitted as sound in intention, while the
other, inasmuch as it supposes accident to be the main purveyor of
variations, has no correspondence with the actual course of things;
for if the variations are matters of chance or hazard unconnected
with any principle of constant application, they will not occur
steadily enough, throughout a sufficient number of successive
generations, nor to a sufficient number of individuals for many
generations together at the same time and place, to admit of the
fixing and permanency of modification at all. The one theory of
natural selection, therefore, may, and indeed will, explain the
facts that surround us, whereas the other will not. Mr. Charles
Darwin's contribution to the theory of evolution was not, as is
commonly supposed, "natural selection," but the hypothesis that
natural selection from variations that are in the main fortuitous
could accumulate and result in specific and generic differences.

In the foregoing paragraph I have given the point of difference
between Mr. Charles Darwin and his predecessors. Why, I wonder,
have neither he nor any of his exponents put this difference before
us in such plain words that we should readily apprehend it? Erasmus
Darwin and Lamarck were understood by all who wished to understand