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Darwin Correspondence Project

From Hermann Müller   6 December 1876


Dec. 6., 1876.

My dear Sir,

My hearty thanks for your newest work, on the effects of cross- and self-fertilisation in the Vegetable Kingdom, which, as the broad and reliable fundament of our modern theory of flowers, is of the highest value to me and must be so to any one interested in flowers!1

Presently, being charged with official business, I have not yet had time to thrust more than a hasty glance into this book, but I have been struck by the plenty of extremely patient and circumspect trials, which, besides so weighty other work, you have perfected during the last 10 years and here laid down. My Christ-mas-vacancies will be devoted to the serious study of them.

The honourable terms in which you mention my book “Die Befruchtung” and my later observations are the highest reward I am capable of imagining and will be to me the most efficacious encouragement for further work.2

It is with great pleasure that I give you intelligence of my brother Fritz lately having been nominated “Naturalista Viajante” of the Museum of Rio, with respectable salary. Now he will be enabled, released from the struggle for his and his family’s existence, to spend all his time to his Natural Science researches.3

A charming case of commensality of two caterpillars, of late observed by my brother, will, I hope, be published in one of the next numbers of Nature.4

With repeated thanks I remain, my dear Sir, very sincerely | Yours | H. Müller.


Cross and self fertilisation was published in December 1876 (DAR 210.11: 6); Müller’s name is on CD’s presentation list (see Appendix III).
In Cross and self fertilisation, CD frequently cited Die Befruchtung der Blumen durch Insekten und die gegenseitigen Anpassungen beider (The fertilisation of flowers by means of insects and the reciprocal adaptations of both; H. Müller 1873). On p. 6 n., CD praised Müller for specifying what kinds of insects visit the flowers of each species, and for showing ‘not only that flowers are adapted for their own good to the visits of certain insects; but that the insects themselves are excellently adapted for procuring nectar or pollen from certain flowers’. CD also cited several articles from Müller’s series in Nature on the fertilisation of flowers by insects (H. Müller 1873–7).
Fritz Müller had been appointed travelling naturalist at the National Museum, Rio de Janeiro, in October 1876; see letter to Fritz Müller, [9 February 1876] and n. 4.
Hermann Müller communicated Fritz Müller’s note ‘Commensalism among caterpillars’ in Nature, 18 January 1877, p. 264. Fritz had observed a small caterpillar that sat on the back of a larger one, protected by the latter’s stinging hairs. Commensalism occurs when an organism benefits from living in association with another of a different species without affecting it, for good or ill (Landau ed. 1986).


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

Müller, Hermann. 1873–7. On the fertilisation of flowers by insects and on the reciprocal adaptations of both. Nature, 3 July 1873, pp. 187–9; 10 July 1873, pp. 205–6; 25 September 1873, pp. 433–5; 20 November 1873, pp. 44–6; 1 January 1874, pp. 164–6; 18 June 1874, pp. 129–30; 12 November 1874, pp. 32–3; 10 December 1874, pp. 110–12; 31 December 1874, pp. 169–71; 20 May 1875, pp. 50–1; 8 July 1875, pp. 190–1; 13 January 1876, pp. 210–12; 10 February 1876, pp. 289–92; 22 June 1876, pp. 173–5; 8 February 1877, pp. 317–19; 29 March 1877, pp. 473–5; 11 October 1877, pp. 507–9.

Müller, Hermann. 1873. Die Befruchtung der Blumen durch Insekten und die gegenseitigen Anpassungen beider. Ein Beitrag zur Erkenntniss des ursächlichen Zusammenhanges in der organischen Natur. Leipzig: Wilhelm Engelmann.


Thanks for Cross and self-fertilisation.

Fritz Müller has been appointed "Naturalista Viajante" of the Rio de Janeiro Museum, which will help his income greatly.

Letter details

Letter no.
Heinrich Ludwig Hermann (Hermann) Müller
Charles Robert Darwin
Sent from
Source of text
DAR 171: 308
Physical description
ALS 2pp

Please cite as

Darwin Correspondence Project, “Letter no. 10702,” accessed on 4 October 2023,

Also published in The Correspondence of Charles Darwin, vol. 24