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Darwin Correspondence Project

To Fritz Müller   2 November 1867

Down. | Bromley. | Kent. S.E.

Nov 2. 1867

My dear Sir

I recd yr letter of July 17 two months ago, but did not answer it sooner, partly because you said you were starting for the interior & cd not attend to science,1 & partly because I have been working so very hard at my book.2

At last it will be finished & published towards the end of this month.3 It consists of 2 vols 8vo. which shall of course be sent to you by post direct to Itajahy St Caterina Brazil.4 In your last letter you give me various interesting details on dimorphic plants,5—on the orchid with lateral fertile anthers6 & on sexual differences in crustacea7—for all of which I heartily thank you. The Borrerias are growing well8 & Cocopizum (or some such name) has just germinated.9 These with the Plumbago will give me a rich harvest next summer.10 The Gesnerias are now in flower; there is much difference according to the age of the flower, & the individual, in the length of the pistil; but now two plants have appeared with pistils so extraordinarily long that I begin to think the species must be dimorphic.11 Escholtzia Californica has proved with me self-fertile; therefore your experiment wd be worth trying again.12 From what you will see in my book about Passiflora, it wd be interesting to observe whether any not annual endemic species is self-sterile like your orchids.13 You might like to hear about Adenanthera; I wrote to India on the subject.14

I hear from Mr J. Scott that Parrots are eager for the seeds; & wonderful as the fact is, can split them open with their beaks; They first collect a large number in their beaks & then settle themselves to split them, & in doing this drop many;15 thus I have no doubt they are disseminated, on the same principle that the acorns of our oaks are most widely disseminated. I hope you will prosper in yr wild home, & hereafter find much of interest to observe.

Believe me | my dear Sir | yours very sincerely | Ch. Darwin

P.S. A new part of Hooker & Bentham’s Botany has come out & I hope has been sent to you, but I will before long make enquiries.16


Müller had moved from Destêrro (now Florianópolis) on Santa Catarina Island to a homestead on the Itajahy (now Itajaí) river near Blumenau, Brazil (see letter from Fritz Müller, 17 July 1867 and n. 5). The information on Müller’s proposed move and interruption of his scientific work was presumably in the missing section of the letter from Fritz Müller, 17 July 1867.
Murray advertised Variation as forthcoming in the Athenaeum, 19 October 1867, p. 487. It was published in January 1868 (Freeman 1977).
On Müller’s address, see the letter from Fritz Müller, 17 July 1867 and n. 5.
Müller had identified various species of the family Rubiaceae as dimorphic (see letter from Fritz Müller, 17 July 1867 and n. 3).
The reference is to an unnamed species of Epidendrum. See letter from Fritz Müller, 17 July 1867 and n. 19.
On sexual differences in the amphipod Brachyscelus diversicolor, see the letter from Fritz Müller, 17 July 1867 and n. 16. See also letter from Fritz Müller, 1 April 1867.
In his letter of 2 June 1867, Müller noted that the rubiaceous plant that he had sent to CD under the name Diodia was in fact a plant of the closely related dimorphic genus Borreria. See also letter from Fritz Müller, 4 March 1867. In his letter to Müller of 15 August [1867], CD reported that his Borreria seeds had germinated.
The reference is to Coccocypselum, a dimorphic rubiaceous genus (see letter from Fritz Müller, 2 June 1867).
Müller had informed CD of dimorphism in Plumbago and sent him seeds (Correspondence vol. 14, letter from Fritz Müller, [2 November 1866], and this volume, letter to J. D. Hooker, 24 [March 1867]). CD later reported that he had raised three plants (letter to Fritz Müller, 26 May [1867]).
CD reported the germination of hundreds of seeds of Gesneria, supplied by Müller, in his letter to Müller of 26 May [1867]. On CD’s earlier doubt about dimorphism in the genus and later publication of his observations, see Correspondence vol. 14, letter to Fritz Müller, [late December 1866 and] 1 January 1867 and n. 8.
Müller had found Eschscholzia californica to be self-sterile (Correspondence vol. 14, letters from Fritz Müller, 2 August 1866 and [2 November 1866]).
CD refers to Variation 2: 137–8, where he recorded that various species of Passiflora were self-sterile, although P. gracilis, an annual species, was self-fertile. CD had also considered conditions that might lead to reduced fertility (Variation 2: 163–71); endemic plants would be less prone to influence by such conditions. Müller had found many Brazilian orchids to be self-sterile (see letters from Fritz Müller, 1 January 1867 and 2 June 1867).
CD had written to John Scott in India, enquiring about the dissemination of seeds of Adenanthera (see letter from John Scott, 24 September 1867). On CD’s receipt of seed from Müller, and its identification as A. pavonina, see Correspondence vol. 14, especially the letter to J. D. Hooker, 10 December [1866] and nn. 2 and 3.
CD refers to the third part of the first volume of Joseph Dalton Hooker and George Bentham’s Genera plantarum, published on 12 October 1867 (Bentham and Hooker 1862–83; see also Stearn 1956, p. 131). CD had previously sent Müller the first two parts of the work (see Correspondence vol. 14, letter to Fritz Müller, [late December 1866 and ] 1 January 1867 and n. 13, and this volume, letter from Fritz Müller, 4 March 1867).


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

Freeman, Richard Broke. 1977. The works of Charles Darwin: an annotated bibliographical handlist. 2d edition. Folkestone, Kent: William Dawson & Sons. Hamden, Conn.: Archon Books, Shoe String Press.

Stearn, William T. 1956. Bentham and Hooker’s Genera plantarum: its history and dates of publication. Journal of the Society for the Bibliography of Natural History 3 (1953–60): 127–32.

Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.


Variation to be published at end of month.

Dimorphism and self-sterility.

Seed dissemination in Adenanthera.

Letter details

Letter no.
Charles Robert Darwin
Johann Friedrich Theodor (Fritz) Müller
Sent from
Source of text
The British Library (Loan MS 10 no 19)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 5666,” accessed on 6 December 2021,

Also published in The Correspondence of Charles Darwin, vol. 15