Sir C. Lyell, while agreeing with my main argument on Man, thinks I am
wrong in wanting to put him back into Miocene times, and thinks I do not
appreciate the immense interval even to the later Pliocene. But I still
maintain my view, which in fact is a logical result of my theory, for if
man originated in later Pliocene times, when almost all mammalia were of
closely allied species to those now living, and many even identical,
then man has _not_ been stationary in bodily structure while animals
have been varying, and my theory will be proved to be all wrong.

In Murchison's address to the Geographical Society just delivered he
points out Africa, as being the _oldest_ existing land. He says there is
_no_ evidence of its having been ever submerged during the tertiary
epoch. Here, then, is evidently the place to find _early man_. I hope
something good may be found in Borneo, and that then means may be found
to explore the still more promising regions of tropical Africa, for we
can expect nothing of man _very_ early in Europe.

It has given me great pleasure to find that there are symptoms of
improvement in your health. I hope you will not exert yourself too soon
or write more than is quite agreeable to you. I think I made out every
word of your letter though it was not always easy.--Believe me, my dear
Darwin, yours very sincerely,

ALFRED R. WALLACE.

* * * * *

_Down, Bromley, Kent, S.E. June 15, 1864._

Dear Wallace,--You must not suppose from my delay that I have not been
much interested by your long letter. I write now merely to thank you,
and just to say that probably you are right on all the points you touch
on except, as I think, about sexual selection, which I will not give up.

My belief in it, however, is contingent on my general beliefs in sexual
selection. It is an awful stretcher to believe that a peacock's tail was
thus formed; but believing it, I believe in the same principle somewhat
modified applied to man.

I doubt whether my notes would be of any use to you, and as far as I
remember they are chiefly on sexual selection.

I am very glad to hear that you are on your Travels. I believe you will
find it a very convenient vehicle for miscellaneous discussion. With
your admirable powers of writing, I cannot doubt that you will make an
excellent book.--Believe me, dear Wallace, yours sincerely,

CH. DARWIN.

P.S.--A great gun, Flourens, has written a little dull book