398 MISCELLANEA. [1880. 



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 sympathised deeply with you.* 



With the most sincere respect, 



I remain, dear Sir, yours faithfully, 

 Charles Darwin. 



P.S. — Allow me to make a suggestion in relation to your 

 wonderful account of insects finding their way home. I for- 

 merly 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 



* The book is intended as a memorial of the early death of M. Fabre's 

 son, who had been his father's assistant in his observations on insect 

 life. 



\ This idea was a favourite one with him, and he has described in 

 ' Nature' (vol. vii. 1873, p. 360) the behaviour of his cob Tommy, in whom 

 he fancied he detected a sense of direction. The horse had been taken by 

 rail from Kent to the Isle of Wight ; when there he exhibited a marked 

 desire to go eastward, even when his stable lay in the opposite direction. 

 In the same volume of ' Nature,' p. 417, is a letter on the ' Origin of 

 Certain Instincts,' which contains a short discussion on the sense of di- 

 rection. 



