ave arisen _because animals can
fashion themselves into accord with_ their conditions, so that, as
Lamarck is so continually insisting, the action of the conditions is
indirect only--changed use and disuse being the direct causes; while,
according to Mr. Darwin, it is natural selection itself (which, as we
have seen, is but another way of saying conditions of existence) that is
the most important means of modification.

The identity of meaning above insisted on was, on the face of it, almost
as obscure as that between "_eveque_ and bishop." Yet we know that
"_eveque_" is "episc" and "bishop" "piscop," and that "episcopus" is the
Latin for bishop; the words, therefore, are really one and the same, in
spite of the difference in their appearance. I think I can show,
moreover, that Mr. Darwin himself holds natural selection and the
conditions of existence to be one and the same thing. For he writes, "in
one sense," and it is hard to see any sense but one in what follows,
"the conditions of life may be said not only to cause variability" (so
that here Mr. Darwin appears to support Lamarck's main thesis) "either
directly or indirectly, but likewise to include natural selection; for
the conditions determine whether this or that variety shall
survive."[357] But later on we find that "the expression of conditions
of existence, so often insisted upon by the illustrious Cuvier" (and
surely also by the illustrious Lamarck, though he calls them
"_circonstances_") "is fully embraced by the principle of natural
selection."[358] So we see that the conditions of life "_include_"
natural selection, and yet the conditions of existence "_are fully
embraced by_" natural selection, which, I take it, is an enigmatic way
of saying that they are one and the same thing, for it is not until two
bodies absolutely coincide and occupy the same space that the one can be
said both to include and to be embraced by the other.

The difficulty, again, of understanding Mr. Darwin's meaning is enhanced
by his repeatedly writing of "natural selection," or the fact that the
fittest survive in the struggle for existence, as though it were the
same thing as "evolution" or the descent, through the accumulation of
small modifications in many successive generations, of one species from
another and different one. In the concluding and recapitulatory chapter
of the 'Origin of Species,' he writes:--

"Turning to geographical distribution, the difficulties encounter