illustration of Mr. Darwin's great conscientiousness in acknowledging
suggestions received by him from the most humble sources." (Letter from
Mr. Fraser to F. Darwin, March 21, 1888.)

Down, April 14th [1871].

I am very much obliged for your letter and the interesting facts which it
contains, and which are new to me. But I am at present so much engaged
with other subjects that I cannot fully consider them; and, even if I had
time, I do not suppose that I should have anything to say worth printing in
a scientific journal. It would obviously be absurd in me to allow a mere
note of thanks from me to be printed. Whenever I have to bring out a
corrected edition of my book I will well consider your remarks (which I
hope that you will send to "Nature"), but the difficulty will be that my
friends tell me that I have already introduced too many facts, and that I
ought to prune rather than to introduce more.


LETTER 460. TO E.S. MORSE.
Down, December 3rd, 1871.

I am much obliged to you for having sent me your two interesting papers,
and for the kind writing on the cover. I am very glad to have my error
corrected about the protective colouring of shells. (460/1. "On Adaptive
Coloration of the Mollusca," "Boston Society of Natural History Proc."
Volume XIV., April 5th, 1871. Mr. Morse quotes from the "Descent of Man,"
I., page 316, a passage to the effect that the colours of the mollusca do
not in general appear to be protective. Mr. Morse goes on to give
instances of protective coloration.) It is no excuse for my broad
statement, but I had in my mind the species which are brightly or