Down, January 31, 1880.
My Dear Sir,
I hope that you will permit me to have the satisfaction of thanking you cordially for the lively pleasure which I have derived from reading your book. Never have the wonderful habits of insects been more vividly described, and it is almost as good to read about them as to see them. I feel sure that you would not be unjust to even an insect, much less to a man. Now, you have been misled by some translator, for my grandfather, Erasmus Darwin, states ('Zoonomia', vol. 1, p. 183, 1794) that it was a wasp (guêpe) which he saw cutting off the wings of a large fly. I have no doubt that you are right in saying that the wings are generally cut off instinctively ; but in the case described by my grandfather, the wasp, after cutting off the two ends of the body, rose in the air, and was turned round by the wind ; he then alighted and cut off the wings. I must believe, with Pierre Huber, that insects have "une petite dose de raison". In the next edition of your book, I hope that you will alter part of what you say about my grandfather.
I am sorry that you are so strongly opposed to the Descent theory ; I have found the searching for the history of each structure or instinct an excellent aid to observation ; and wonderful observer as you are, it would suggest new points to you. If I were to write on the evolution of instincts, I could make good use of some of the facts which you give. Permit me to add, that when I read the last sentence in your book, I sympathized deeply with you.
With the most sincere respect,
I remain, dear Sir, yours faithfully,
P.S. Allow me to make a suggestion in relation
to your wonderful account of insects finding their way home. I formerly wished
to try it with pigeons : namely, to carry the insects in their paper "cornets", about a hundred paces in the opposite direction to
that which you ultimately intended to carry them ; but before turning round to
return, to put the insect in a circular box, with an axle which could be made to
revolve very rapidly, first in one direction, and then in another, so as to
destroy for a time all sense of direction in the insects. I have sometimes
imagined that animals may feel in which direction they were at the first
start carried. If this plan failed, I had intended placing the pigeons within an
induction coil, so as to disturb any magnetic or dia-magnetic sensibility, which
it seems just possible that they may possess.