TO PROF. MELDOLA

_Parkstane, Dorset. January 6, 1897._

My dear Meldola,--The passage to which you refer in the "Origin" (top of
p. 6) shows Darwin's firm belief in the "heredity of acquired
variations," and also in the importance of definite variations, that is,
"sports," though elsewhere he almost gives these up in favour of
indefinite variations; and this last is now the view of all Darwinians,
and even of many Lamarckians. I therefore always now assume this as
admitted. Weismann's view as to "possible variations" and "impossible
variations" on p. 1 of "Germinal Selection" is misleading, because it
can only refer to "sports" or to "cumulative results," not to
"individual variations" such as are the material Natural Selection acts
on. Variation, as I understand it, can only be a slight modification in
the offspring of that which exists in the parent. The question whether
pigs could possibly develop wings is absurd, and altogether beside the
question, which is, solely, so far as direct evidence goes, as to the
means by which the change from one species to another closely allied
species has been brought about. Those who want to begin by discussing
the causes of change from a dog to a seal, or from a cow to a whale, are
not worth arguing with, as they evidently do not comprehend the A, B, C
of the theory.

Darwin's ineradicable acceptance of the theory of heredity of the
effects of climate, use and disuse, food, etc., on the individual led to
much obscurity and fallacy in his arguments, here and there.--Yours very
sincerely,

ALFRED R. WALLACE.

* * * * *

TO PROF. POULTON _Parkstone, Dorset. February 14, 1897._

My dear Poulton,--Thanks for copy of your British Association
Address,[28] which I did not read in _Nature_, being very busy just
then. I have now read it with much pleasure, and think it a very useful
and excellent discussion that was much needed. There is, however, one
important error, I think, which vitiates a vital part of the argument,
and which renders it possible so to reduce the time indicated by geology
as to render the accordance of Geology and Physics more easy to effect.
The error I allude to was made by Sir A. Geikie in his Presidential
Address[29] which you quote. Immediately it appeared I wrote to him
pointing it out, but he merely acknowledged my letter, saying he would
consider it. To me it seems a most palpable and extraordinary blunder.
The erro