e any communication with Mr. Geach, if you would
express for me my _sincere_ thanks for his kindness in sending me the
very valuable answers on Expression. I wrote some months ago to him in
answer to his last letter.

I would ask him to Down, but the fatigue to me of receiving a stranger
is something which to you would be utterly unintelligible.

I think I have heard of the scales on butterflies; but there are lots
of sexual characters which quite baffle all powers of even conjecture.

You are quite correct, that I felt forced to make all additions to the
"Origin" as short as possible.

I am indeed pleased to hear, and fully expected, that your Malay work
would be known throughout Europe.

Oh dear! what would I not give for a little more strength to get on with
my work.--Ever yours,

C. DARWIN.

I wish that you could have told me that your place in the new Museum was
all settled.

* * * * *

_9 St. Mark's Crescent, N.W. October 20, 1869._

Dear Darwin,--I do not know your son's (Mr. George Darwin's) address at
Cambridge. Will you be so good as to forward him the enclosed note
begging for a little information?

I was delighted to see the notice in the _Academy_ that you are really
going to bring out your book on Man. I anticipate for it an enormous
sale, and shall read it with intense interest, although I expect to find
in it more to differ from than in any of your other books. Some
reasonable and reasoning opponents are now taking the field. I have been
writing a little notice of Murphy's "Habit and Intelligence," which,
with much that is strange and unintelligible, contains some very acute
criticisms and the statement of a few real difficulties. Another article
just sent me from the _Month_ contains some good criticism. How
incipient organs can be useful is a real difficulty, so is the
independent origin of similar complex organs; but most of his other
points, though well put, are not very formidable. I am trying to begin a
little book on the Distribution of Animals, but I fear I shall not make
much of it from my idleness in collecting facts.

I shall make it a popular sketch first, and, if it succeeds, gather
materials for enlarging it at a future time. If any suggestion occurs to
you as to the kind of maps that would be best, or on any other essential
point, I should be glad of a hint. I hope your residence in Wales did
you good. I had no idea you were so near Dolgelly ti