ions when he published the first
edition of _The Origin of Species_. Wells, whose "Essay on Dew" is
still remembered, read in 1813 before the Royal Society a short paper
entitled "An Account of a White Female, part of whose skin resembles
that of a Negro" (published in 1818). In this communication, as Darwin
said, "he observes, firstly, that all animals tend to vary in some
degree, and, secondly, that agriculturists improve their domesticated
animals by selection; and then, he adds, but what is done in this
latter case 'by art, seems to be done with equal efficacy, though more
slowly, by nature, in the formation of varieties of mankind, fitted
for the country which they inhabit.'"[29] Thus Wells had the clear
idea of survival dependent upon a favourable variation, but he makes
no more use of the idea and applies it only to man. There is not in
the paper the least hint that the author ever thought of generalising
the remarkable sentence quoted above.

Of Mr. Patrick Matthew, who buried his treasure in an appendix to a
work on _Naval Timber and Arboriculture_, Darwin said that "he clearly
saw the full force of the principle of natural selection." In 1860
Darwin wrote--very characteristically--about this to Lyell: "Mr.
Patrick Matthew publishes a long extract from his work on _Naval
Timber and Arboriculture_, published in 1831, in which he briefly but
completely anticipates the theory of Natural Selection. I have ordered
the book, as some passages are rather obscure, but it is certainly, I
think, a complete but not developed anticipation. Erasmus always said
that surely this would be shown to be the case some day. Anyhow, one
may be excused in not having discovered the fact in a work on Naval
Timber."[30]

De Quatrefages and De Varigny have maintained that the botanist Naudin
stated the theory of evolution by natural selection in 1852. He
explains very clearly the process of artificial selection, and says
that in the garden we are following Nature's method. "We do not think
that Nature has made her species in a different fashion from that in
which we proceed ourselves in order to make our variations." But, as
Darwin said, "he does not show how selection acts under nature."
Similarly it must be noted in regard to several pre-Darwinian pictures
of the struggle for existence (such as Herder's, who wrote in 1790
"All is in struggle ... each one for himself" and so on), that a
recognition of this is only the first step in Dar