Dear Sir

My old friend Prof. Henslow has told me that I might use his name in introducing myself to you, and in venturing to ask from you a little information with respect to the Anacharis if you have the leisure and the inclination to give it.² Of course I do not by any means expect full answers or information, but any at all on any of the following points, would greatly oblige me.

(1) Is it true that since the Anacharis spread so largely over the waters of your country, that it has become reduced in frequency.³ If this be so can you give me any dates of maximum increase and subsequent decrease.

(2). Do water-molluscs or other animals feed on it? or can you in any way account for its decrease, if it be true that it has decreased.

(3) Do you know in the places where it now or formerly most abounded, whether it took the place of, and reduced the numbers of, or locally extirpated any other kinds of plants; and what plants?

(4) In those cases in which the Anacharis has travelled up non-navigable brooks, have you any idea how it has been transported up the stream?

If you give me any information, will you permit me to publish it at some future time, with due caution, on your authority.⁴ Hoping that you will excuse the liberty which I have taken, I remain, Dear Sir | Yours faithfully | C. Darwin