particular schemes of derivation has not established the opposite
proposition. The futility of each hypothesis thus far proposed to account
for derivation may be made apparent, or unanswerable objections may be
urged against it; and each victory of the kind may render derivation more
improbable, and therefore specific creation more probable, without settling
the question either way. New facts, or new arguments and a new mode of
viewing the question, may some day change the whole aspect of the case. It
is with the latter that Mr. Darwin now reopens the discussion.

Having conceived the idea that varieties are incipient species, he is led
to study variation in the field where it shows itself most strikingly, and
affords the greatest facilities to investigation. Thoughtful naturalists
have had increasing grounds to suspect that a reexamination of the question
of species in zoology and botany, commencing with those races which man
knows most about, viz., the domesticated and cultivated races, would be
likely somewhat to modify the received idea of the entire fixity of
species. This field, rich with various but unsystematized stores of
knowledge accumulated by cultivators and breeders, has been generally
neglected by naturalists, because these races are not in a state of nature;
whereas they deserve particular attention on this very account, as
experiments, or the materials for experiments, ready to our hand. In
domestication we vary some of the natural conditions of a species, and thus
learn experimentally what changes are within the reach of varying conditions
in Nature. We separate and protect a favorite race against its foes or its
competitors, and thus learn what it might become if Nature ever afforded it
equal opportunities. Even when, to subserve human uses, we modify a
domesticated race to the detriment of its native vigor, or to the extent of
practical monstrosity, although we secure forms which would not be
originated and could not be perpetuated in free Nature, yet we attain wider
and juster views of the possible degree of variation. We perceive that some