, the well-known physiologist, and C.F. Varley,
the well-known electrician, who have all investigated the subject for
years, agree with me both as to the facts and as to the main inferences
to be drawn from them, I am in hopes that you will suspend your judgment
for a time till we exhibit some corroborative symptoms of insanity.

In the meantime I can console you by the assurance that I _don't_ agree
with the _Q.J. of Science_ about bamboo, and that I see no cause to
modify any of my opinions expressed in my article on the "Reign of
Law."--Believe me yours very faithfully,

ALFRED R. WALLACE.

* * * * *

_9 St. Mark's Crescent, N.W. June 23, 1869._

Dear Darwin,--Thank you very much for the copy of your fifth edition of
the "Origin." I have not yet read all the additions, but those I have
looked at seem very interesting, though somewhat brief, but I suppose
you are afraid of its great and rapid growth.

A difficult sexual character seems to me the plumules or battledore
scales on the wings of certain families and genera of butterflies,
almost invariably changing in form with the species and genera in
proportion to other changes, and always constant in each species yet
confined to the males, and so small and mixed up with the other scales
as to produce no effect on the colour or marking of the wings. How could
sexual selection produce them?

Your correspondent Mr. Geach is now in England, and if you would like to
see him I am sure he would be glad to meet you. He is staying with his
brother (address Guildford), but often comes to town.

Hoping that you have quite recovered from your accident and that the
_great work_ is progressing, believe me, dear Darwin, yours very
faithfully,

ALFRED R. WALLACE.

P.S.--You will perhaps be pleased to hear that German, French, and
Danish translations of my "Malay Archipelago" are in progress.--A.R.W.

* * * * *

_Caerleon, Barmouth, N. Wales. June 25, 1869._

My dear Wallace,--We have been here a fortnight, and shall remain here
till the beginning of August. I can say nothing good about my health,
and I am so weak that I can hardly crawl half a mile from the house; but
I hope I may improve, and anyhow the magnificent view of Cader is
enjoyable.

I do not know that I have anything to ask Mr. Geach, nor do I suppose I
shall be in London till late in the autumn, but I should be particularly
obliged, if you hav