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Darwin Correspondence Project

To Nature   13 November [1869]1

Will you permit me to add a few words to Mr. Bennett’s letter, published at p. 58 of your last number?2 I did not cover up the Lamium with a bell-glass, but with what is called by ladies, “net.” During the last twenty years I have followed this plan, and have fertilised thousands of flowers thus covered up, but have never perceived that their fertility was in the least injured.3 I make this statement in case anyone should be induced to use a bell-glass, which I believe to be injurious from the moisture of the contained air.4 Nevertheless, I have occasionally placed flowers, which grew high up, within small wide-mouthed bottles, and have obtained good seed from them. With respect to the Vinca, I suppose that Mr. Bennett intended to express that pollen had actually fallen, without the aid of insects, on the stigmatic surface, and had emitted tubes. As far as the mere opening of the anthers in the bud is concerned, I feel convinced from repeated observations that this is a most fallacious indication of self-fertilisation.5 As Mr. Bennett asks about the fertilisation of Grasses, I may add that Signor Delpino, of Florence, will soon publish some novel and very curious observations on this subject, of which he has given me an account in a letter, and which I am glad to say are far from being opposed to the very general law that distinct individual plants must be occasionally crossed.6

Down, Beckenham, Kent, Nov. 13


The year is established by the publication date of the letter in Nature.
See letter from A. W. Bennett to Nature, 8 November 1869; Alfred William Bennett’s letter was published in the 11 November 1869 issue of Nature.
For an example of one of CD’s many notes on the use of netting, see Correspondence vol. 10, letter to John Scott, 19 December [1862]. For a description of the netting that CD used, see Cross and self fertilisation, pp. 10–11.
Bennett mentioned the bell-glass in his letter to Nature, 8 November 1869.
In both Bennett 1869, and the letter from A. W. Bennett to Nature, 8 November 1869, Bennett only mentioned the pollen discharging from the anthers of Vinca major. In Cross and self fertilisation, p. 362, CD maintained that V. major was generally sterile when insects were not present.
In his letter of 1 November 1869, Federico Delpino discussed his work on grasses, and mentioned his intended publication (Delpino 1871).


Bennett, Alfred William. 1869. On the fertilisation of winter-flowering plants. Nature 1: 11–13.

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.

Cross and self fertilisation: The effects of cross and self fertilisation in the vegetable kingdom. By Charles Darwin. London: John Murray. 1876.


Comments on A. W. Bennett’s letter [Nature 1 (1869): 58] on fertilisation of winter-flowering plants. CD used net, not a bell-glass to cover Lamium.

Refers to F. Delpino’s observations on fertilisation of grasses; CD is glad to say these observations are compatible with "the very general law that distinct individual plants must be occasionally crossed".

Letter details

Letter no.
Charles Robert Darwin
Sent from
Source of text
Nature 1 (1869): 85

Please cite as

Darwin Correspondence Project, “Letter no. 6987,” accessed on 1 December 2021,

Also published in The Correspondence of Charles Darwin, vol. 17