from specifying,
for the sufficient reason that he did not know. Nevertheless much of
the process of Evolution, especially that by which organs have become
degenerate and rudimentary, was certainly attributed by Darwin to
such inheritance, though since belief in the inheritance of acquired
characters fell into disrepute, the fact has been a good deal
overlooked. The "Origin" without "use and disuse" would be a materially
different book. A certain vacillation is discernible in Darwin's
utterances on this question, and the fact gave to the astute Butler
an opportunity for his most telling attack. The discussion which best
illustrates the genetic views of the period arose in regard to the
production of the rudimentary condition of the wings of many beetles
in the Madeira group of islands, and by comparing passages from the
"Origin" (6th edition pages 109 and 401. See Butler, "Essays on Life,
Art, and Science", page 265, reprinted 1908, and "Evolution, Old and
New", chapter XXII. (2nd edition), 1882.) Butler convicts Darwin
of saying first that this condition was in the main the result of
Selection, with disuse aiding, and in another place that the main cause
of degeneration was disuse, but that Selection had aided. To Darwin
however I think the point would have seemed one of dialectics merely. To
him the one paramount purpose was to show that somehow an Evolution
by means of Variation and Heredity might have brought about the facts
observed, and whether they had come to pass in the one way or the other
was a matter of subordinate concern.

To us moderns the question at issue has a diminished significance. For
over all such debates a change has been brought by Weismann's challenge
for evidence that use and disuse have any transmitted effects at all.
Hitherto the transmission of many acquired characteristics had seemed
to most naturalists so obvious as not to call for demonstration. (W.
Lawrence was one of the few who consistently maintained the contrary
opinion. Prichard, who previously had expressed himself in the same
sense, does not, I believe repeat these views in his later writings, and
there are signs that he came to believe in the transmission of acquired
habits. See Lawrence, "Lect. Physiol." 1823, pages 436-437, 447
Prichard, Edin. Inaug. Disp. 1808 (not seen by me), quoted ibid. and
"Nat. Hist. Man", 1843, pages 34 f.) Weismann's demand for facts in
support of the main proposition revealed at once that none havi