or with which he [I] desires to supplement it
[natural selection]"; and he thinks it "unaccountable" that I "should
make so great a fuss about so small a matter as the effect of use and
disuse of particular organs as a separate and a newly-recognised
factor in the development of varieties." I do not suppose that the Duke
of Argyll intended to cast upon me the disagreeable imputation, that I
claim as new that which all who are even slightly acquainted with the
facts know to be anything rather than new. But his words certainly do
this. How he should have thus written in spite of the extensive
knowledge of the matter which he evidently has, and how he should have
thus written in presence of the evidence contained in the articles he
criticizes, I cannot understand. Naturalists, and multitudes besides
naturalists, know that the hypothesis which I am represented as putting
forward as new, is much older than the hypothesis of natural
selection--goes back at least as far as Dr. Erasmus Darwin. My purpose
was to bring into the foreground again a factor which has, I think, been
of late years improperly ignored; to show that Mr. Darwin recognized
this factor in an increasing degree as he grew older (by showing which I
should have thought I sufficiently excluded the supposition that I
brought it forward as new); to give further evidence that this factor is
in operation; to show there are numerous phenomena which cannot be
interpreted without it; and to argue that if proved operative in any
case, it may be inferred that it is operative on all structures having
active functions.

Strangely enough, this passage, in which I am represented as implying
novelty in a doctrine which I have merely sought to emphasize and
extend, is immediately succeeded by a passage in which the Duke of
Argyll himself represents the doctrine as being familiar and well
established:--

"That organs thus enfeebled [i.e. by persistent disuse] are
transmitted by inheritance to offspring in a like condition of
functional and structural decline, is a correlated physiological
doctrine not generally disputed. The converse case--of increased
strength and development arising out of the habitual and healthy
use of special organs, and of the transmission of these to
offspring--is a case illustrated by many examples in the breeding
of domestic animals. I do not know to what else we can attribute
the long slender legs and bodi