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Darwin Correspondence Project

From Hermann Müller   23 October 1875


Oct. 23. 1875.

My dear Sir.

Many thanks for your kind letter of Oct. 9. Today I have written to my brother that I have received your cheque of £8–2–9.1

Your work on the comparative growth, fertility etc. of plants raised from self-fertilised and crossed seeds will be of the highest value for further searching into the mutual relations between flowers and insects.2 I am the more glad to hear that you have begun putting your notes thereabout together, as newly some Italian and American botanists have done their best work in order to obscure this matter.

Pedicino and Orazio Comes of Naples have published some observations on self-fertilisation of flowers and, taking no notice of what hitherto has been written on the frequency and relative importance of self fertilisation, have inferred from their observations that intercrossing may not be of any general importance.3

At the anniversary meeting of the American Naturalists in Detroit of Aug. 12. 1875 Thomas Meehan of German town has read a paper: “Are insects any material aid to plants in fertilisation?”4 the results of which he comprehends in the following sentences:

“1) that the great bulk of colored flowering plants are self-fertilisers

2) that only to a limited extent do insects aid fertilisation

3) that Selffertilisers are every way as healthy and vigourous, and immensely more productive than those dependent on insect aid

4) that where plants are so dependent, they are the worse fitted to engage in the struggle for life, the great underlying principle in natural selection.”

The whole paper, published in “The Philadelphia-Press, Friday, August 13, 1875” abounds with perversities and is, I think, no worth of any refutation.5 But the following passage has struck me, as I am quite ignorant as to the memoir alluded to, and I would be very much obliged to you for information whether these statements of Mr Meehan are correct and in what work or journal your sons memoir alluded to has been published. The words run thus: “Quite recently Mr. George Darwin has shown, in a remarkable paper made up of an extensive study of the old families among the English nobility where intermarriages among relatives have been a sort of social necessity for ages, that the popular idea (sc. of a sort of necessity for cross-fertilisation) is erroneous. These intermarriages have resulted as productively and as heathily, mentally and morally, as the average marriages of the rest of the world.”6

With very sincere respect I remain, | my dear Sir | yours faithfully | H. Müller

CD annotations

Verso of last page: ‘Gardener  He is one of those men who take a pleasure in denying & disputing everything  He wrote to me saying he did not wish to [‘dispute’ del] deny my conclusion & the report not accurate. I assume then that his remarks on you were a mere burlesque | Even Sexuality of Plants he denied | I have had occasion to look to Befruchtung, with even greater admiration than at first— It is excellent—’7 blue crayon


CD’s letter has not been found, but an entry in CD’s Account books–banking account (Down House MS) for 9 October 1875 recorded that he had received a cheque from his publisher, John Murray, for £8 2s. 9d., for Fritz Müller’s publication and sent it directly to Hermann Müller. The publication was the English translation of Fritz Müller’s Für Darwin (F. Müller 1864; Dallas trans. 1869).
CD noted in his ‘Journal’ that he began writing Cross and self fertilisation on 1 September 1875, but this may be an error, since he also noted that he was working on corrections to Variation 2d ed. until 3 October 1875 (see ‘Journal’ (Appendix II); see also letter to Thomas Meehan, 3 October 1875).
Nicola Antonio Pedicino and Comes had published papers on fertilisation in Rendiconto dell’Accademia delle Scienze Fisiche e Matematiche (Pedicino 1875; Comes 1875).
Meehan had sent a copy of his paper (Meehan 1875) as reprinted in the Philadelphia Press to CD (see letter to Thomas Meehan, 3 October 1875 and n. 2).
Meehan evidently told CD that the reprinted version of his paper contained inaccuracies (letter to Thomas Meehan, 3 October 1875), but the sentences quoted by Müller are identical (other than in spelling) to the version that appeared in the Proceedings of the American Association for the Advancement of Science (Meehan 1875).
Meehan referred to George Howard Darwin’s paper on marriages between first cousins (G. H. Darwin 1875a) in Meehan 1875, p. 244.
CD’s annotations are notes for his reply to Müller (see letter to Hermann Müller, 26 October 1875).


Comes, Orazio. 1875. Continuazione degli studii sulla impollinazione. Rendiconto dell’Accademia delle Scienze Fisiche e Matematiche 14: 64–71.

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

Meehan, Thomas. 1875. Are insects any material aid to plants in fertilization? Proceedings of the American Association for the Advancement of Science 24: 243–51.

Pedicino, Nicola Antonio. 1875. Della impollinazione nella Thalia dealbata, Fraso, e del modo di ricercare sperimentalmente i processi di impollinazione. Rendiconto dell’Accademia delle Scienze Fisiche e Matematiche 14: 25–7.

Variation 2d ed.: The variation of animals and plants under domestication. By Charles Darwin. 2d edition. 2 vols. London: John Murray. 1875.


Is glad CD is working on cross- and self-fertilisation; reports recent works of botanists, notably Thomas Meehan’s ["Are insects any material aid to plants in fertilisation?", Philadelphia Press 13 Aug 1875], in which the importance of cross-fertilisation is denied.

Letter details

Letter no.
Heinrich Ludwig Hermann (Hermann) Müller
Charles Robert Darwin
Sent from
Source of text
DAR 171: 305
Physical description
3pp †

Please cite as

Darwin Correspondence Project, “Letter no. 10219,” accessed on 16 May 2021,

Also published in The Correspondence of Charles Darwin, vol. 23