them--in
season and out of season, as many will think--as being absolutely
essential to a comprehension of organic evolution. The third I did not
realise till I read Weismann, I have never seen the sufficiency of
normal variability for the modification of species more strongly or
better put than in your letters to Bates. Darwin himself never realised
it, and consequently played into the hands of the "discontinuous
variation" and "mutation" men, by so continually saying "_if_ they
vary"--"without variation Natural Selection can do nothing," etc.

Your argument that variations are not caused by change of environment is
equally forcible and convincing. Has anybody answered de Vries yet?

F. Darwin lent me Prof. Hubrecht's review from the _Popular Science
Monthly_, in which he claims that de Vries has proved that new species
have always been produced from "mutations," never through normal
variability, and that Darwin latterly agreed with him! This is to me
amazing! The Americans too accept de Vries as a second Darwin!--Yours
very sincerely,

ALFRED E. WALLACE.

* * * * *

SIR J. HOOKER TO A.R. WALLACE

_The Camp, Sunningdale. November 12, 1905._

My dear Wallace,--My return from a short holiday at Sidmouth last
Thursday was greeted by your kind and welcome letter and copy of your
"Life." The latter was, I assure you, never expected, knowing as I do
the demand for free copies that such a work inflicts on the writer. In
fact I had put it down as one of the annual Christmas gifts of books
that I receive from my own family. Coming, as it thus did, quite
unexpectedly, it is doubly welcome, and I do heartily thank you for this
proof of your greatly valued friendship. It will prove to be one of four
works of greatest interest to me of any published since Darwin's
"Origin," the others being Waddell's "Lhasa," Scott's "Antarctic
Voyage," and Mill's "Siege of the South Pole."

I have not seen Clodd's edition of Bates's "Amazon," which I have put
down as to be got, and I had no idea that I should have appeared in it.
Your citation of my letters and their contents are like dreams to me;
but to tell you the truth, I am getting dull of memory as well as of
hearing, and what is worse, in reading: what goes in at one eye goes out
at the other. So I am getting to realise Darwin's consolation of old
age, that it absolves me from being expected to know, remember, or
reason upon new facts and discove