ng him whether he has tried any more
experiments, and will keep back this letter till I receive his answer.
Mr. Riley of the United States supports Mr. Weir, and you will
find reference to him and other papers at page 426 of the new and
much-corrected edition of my "Descent of Man." As I have a duplicate
copy of Volume I. (I believe Volume II. is not yet published in german)
I send it to you by this post. Mr. Belt, in his travels in Nicaragua,
gives several striking cases of conspicuously coloured animals (but not
caterpillars) which are distasteful to birds of prey: he is an excellent
observer, and his book, "The Naturalist in Nicaragua," very interesting.

I am very much obliged for your photograph, which I am particularly glad
to possess, and I send mine in return.

I see you allude to Hilgendorf's statements, which I was sorry to
see disputed by some good German observer. Mr. Hyatt, an excellent
palaeontologist of the United States, visited the place, and likewise
assured me that Hilgendorf was quite mistaken. (268/4. See Letters
252-7.)

I am grieved to hear that your eyesight still continues bad, but anyhow
it has forced your excellent work in your last essay.

May 4th. Here is what Mr. Weir says:--

"In reply to your inquiry of Saturday, I regret that I have little
to add to my two communications to the 'Entomological Society
Transactions.'

"I repeated the experiments with gaudy caterpillars for years, and
always with the same results: not on a single occasion did I find richly
coloured, conspicuous larvae eaten by birds. It was more remarkable
to observe that the birds paid not the slightest attention to gaudy
caterpillars, not even when in motion,--the experiments so thoroughly
satisfied my mind that I have now given up making them."

LETTER 269. TO LAWSON TAIT.

(269/1. The late Mr. Lawson Tait wrote to Mr. Darwin (June 2nd, 1875):
"I am watching a lot of my mice from whom I removed the tails at birth,
and I am coming to the conclusion that the essential use of the tail
there is as a recording organ--that is, they record in their memories
the corners they turn and the height of the holes they pass through by
touching them with their tails." Mr. Darwin was interested in the idea
because "some German sneered at Natural Selection and instanced the
tails of mice.")

June 11th, 1875.

It has just occurred to me to look at the "Origin of Species" (Edition
VI., page 170), and it is certain that Bronn,