Ɛpsilon

To Alphonse de Candolle   3 August 1877

Down, | Beckenham, Kent. | Railway Station | Orpington. S.E.R.

Aug 3. 1877

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

LS

2
In his letter of 31 July 1877, Candolle had informed CD that he would send a copy of the first part of the forthcoming work, Monographiae phanerogamarum (A. de Candolle and Candolle eds. 1878–96), which included a section on the Smilaceae (a synonym of Smilacaceae, the greenbrier family), written by him. CD’s copies of the first three volumes of the work, published between 1878 and 1881, are in the Darwin Library–Down. For Candolle’s discussion of different methods of fertilisation in genera of Smilaceae, see A. de Candolle and Candolle eds. 1878–96, 1: 26–8 (see also letter from Alphonse de Candolle, 31 July 1877 and n. 3).
4
Francis Darwin sent Candolle a copy of his paper ‘On the protrusion of protoplasmic filaments from the glandular hairs on the leaves of the common teasel (Dipsacus sylvestris)’ (F. Darwin 1877b). For more on Francis’s research, see the letter to J. D. Hooker, 25 January [1877] and n. 6.
5
For CD’s earlier research on bloom, see the letter to Fritz Müller, 14 May 1877 and n. 2.
6
Casimir de Candolle had studied the effects of feeding insects to Dionaea muscipula (Venus fly trap; C. de Candolle 1876). Francis began his experiments with Drosera rotundifolia (common or round-leaved sundew) on 11 June 1877 (see F. Darwin 1878a, p. 21). In his published results, Francis briefly discussed Candolle’s paper (F. Darwin 1878a, p. 19) and reviewed much of the literature on the subject that questioned both the necessity of animal food to plants and the ability of leaves of plants to digest animal matter.

Please cite as “DCP-LETT-11092,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-11092