My Dear Sir!

I thank you very much for your kind letter, and for the seeds of Lychnis githago, which I propose myself to sow next spring.¹ I have finished my experiments on tendrils for this year, and hope to continue them next summer. In the course of this winter I hope to be able to send you a copy of my paper on tendrils.²

In respect to the movements of Oscillaria, I am very sorry to say that I never studied them so exactly as to have an opinion on their mechanism, which seems to be very difficult to recognise.³

You ask me whether I feel sure, that cellwalls have not a power of contraction. I am quite sure that they often have this power, but only in cells that are extended by their turgescence. Such cells will contract by losing water. I suppose that the cells in the tentacles of Drosera are turgescent, and that those of the outerside draw water from those of the innerside; thereby the first ones will extend themselves, the last ones will contract. For this is the case with tendrils. I am not able to say whether the cause of the movements of the tentacles of Drosera is the same as it is with tendrils, and my plants of Drosera are now too old to make an experiment.⁴

I should be much obliged to you, if you would thank your son Francis for the kind words he added to your letter.⁵

With much respect I remain | Dear Sir | Yours very truly. | Hugo de Vries.