Dear Madam,

I am very much obliged for your kind letter;¹ & should esteem it a great favour if during warm weather next summer you will observe two points for me in Drosera Filiformis.² Namely to place some flies within quarter of an inch of the apex of the leaf & observe whether it bends at all after an interval of a day or two. Secondly to rub with a clean needle a few of the glands with some little force, and to touch each gland half a dozen times; & then observe whether in the course of an hour or two the hairs or filaments bearing these glands become incurved. I am glad to hear that D. filiformis catches only small insects, as I suspected this. I have observed with care several other species of Drosera.³ Does the Dionæa⁴ grow in your neighbourhood? If so I much wish to learn what sort of insects it commonly catches, more especially whether large or small kinds. I have sometimes suspected that its structure & movements favour the escape of small insects.

D^r. Gray has given a rather free translation of what I said to him about nerves; and this related only to Drosera.⁵ I have found that by pricking a particular point in the leaf I can paralyse half of it; but I must make many more trials next summer before coming to any final conclusion.

With my best thanks | I remain Dear Madam | Yours very faithfully | Charles Darwin

P.S. I subscribe to the American Naturalist, so I am glad to say that I shall see your article—⁶