My dear Sir

I thank you much for your letter, which has interested me more than anything which I have read for a long time.—¹ I have gradually been coming to the opinion that in all the cases to which you refer, growth was preceded by a change in the turgescence of the cells, or by some such change; but then I had very little evidence, & my opinion was chiefly founded on general considerations, which are often deceptive.— I hope that you will publish in the course of the Winter, so that I may be able to read & refer to your evidence before the Spring.²

I may just mention, in case you wanted plants to observe, that the hypo-cotyledonous stem of Lychnis githago (var Githago segetum) contracts in a most striking manner: it is at first quite smooth, but after formation of some true leaves becomes covered with zig-zag ridges.³

Once again thanking you for your letter, I remain | My dear Sir | Yours very faithfully | Ch. Darwin

(P.S. I am writing this away from my home.)⁴