My dear Sir

I must have the pleasure of thanking you for your long & interesting letter.¹ The cause & means of the transition from an hermaphrodite to a unisexual condition seems to me a very perplexing problem, & I shall be extremely glad to read your remarks on Smilax, whenever I receive the essay which you kindly say that you will send me.² There is much justice in your criticisms on my use of the terms object, end, purpose; but those who believe that organs have been gradually modified by natural selection for a special purpose, may I think use the above terms correctly though no conscious being has intervened.³ I have found much difficulty in my occasional attempts to avoid these terms; but I might perhaps have always spok[en] of a beneficial or serviceable effect. My son Francis will be interested by hearing about Smilax. He has dispatched to you a copy of his paper on the glands of Dipsacus, & I hope that you will find time to read it, for the case seems to me a new & highly remarkable one.⁴

We are now hard at work on an attempt to make out the function or use of the bloom or waxy secretion on the leaves & fruit of many plants; but I doubt greatly whether our experiments will tell us much.⁵ If you have any decided opinion whether plants with conspicuously glaucous leaves are more frequent in hot than in temperate or cold,—in dry than in damp countries, I should be grateful if you would add to your many kindnesses by informing me. Pray give my kind remembrances to your son, & tell him that my son has been trying on a large scale the effects of feeding Drosera with meat, & the results are most striking & far more favourable than I anticipated.⁶

With the highest respect, | I remain, my dear Sir | Yours sincerely | Charles Darwin