To Alphonse de Candolle   11 October 1869

My dear Sir

I am very much obliged for y^r extremely interesting letter. Your experiment strikes me as a very valuable & simple one,—so simple that now that it has been once suggested, I am surprized that no one ever thought of trying it before.¹ Nägeli, indeed, in one of his recent essays complains that no one has made this experiment with Alpine & lowland forms of the same species.² I forwarded your letter to D^r Hooker, who seems very glad to have the opportunity of making the trial.³ As I shall have many experiments in progress next spring, which cannot be deferred, & as I have little strength to spare, I believe it would be the wisest plan to send all the seeds to Kew.⁴ But I will open some of the packets & see how many seeds there are, so that if numerous I will try a few myself— I will not however sow them till the spring, for I have lately had some experience in raising during the winter hardy annuals in my greenhouses, & I find that they become much drawn up—

With my best thanks for your kindness & the most sincere respect, I remain | My dear Sir | yours very faithfully | Charles Darwin