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Darwin Correspondence Project

From Fritz Müller   15 June 1869

Itajahy, Sa Catharina, Brazil

June 15. 1869.

My dear Sir.

I have been prevented from answering sooner your kind letters of March 14th and 18th by a botanical excursion, I made last month.1

I do not know how to express my warm gratitude for all the pains, you have taken in the publication of the Translation of my little book, to which, after all, you attach far too much importance.2 The three copies have arrived here safely; many thanks for them. I have been much gratified by the appearance of the book in its English dress, as well as by the Translation, which appears to me to be very good. I have to thank you also for the reviews in the “Athenæum” and the “Scientific Opinion”, which you have kindly sent me. I am sorry to learn from these reviews, that some expressions of mine have shocked the religious feelings of one of the reviewers.3 I should indeed have suppressed or modified some passages, before offering my book to English readers.—

As to Faramea, I am quite sure, that the two forms are really the long-styled and short-styled form of a single species.4 The plant is very common in my own forest, and after examining numerous specimens, I cannot find any difference between the two forms excepting those in the sexual organs. The size of the flowers varies much, but is not characteristic of either form. Some long-styled flowers, which I had fertilized artificially with pollen from the opposite form, are yielding fruits.— A second very beautiful species of the same genus which grows near the mouth of the Itajahy, is probably also dimorphic; I have hitherto examined the flowers of only one plant; these were longstyled and the styles as long as in the longstyled form of the first species.—

Many thanks for the Eschscholtzia—seeds, which will be sown in a few weeks.— It is curious to see, on what trifling circumstances fertility sometimes depends.5 Thus I have in my garden several specimens of an endemic Irideous plant (Cypella?), which I suspected to be self-sterile.6 I fertilized repeatedly numerous flowers with pollen of the same and of distinct plants, without obtaining a single pod. The unprotected flowers were regularly visited by insects; by these also, for months, did not yield a single fruit, when unexpectedly all the flowers, about 20 in number, which had opened on a certain day, produced fine pods. The plants have continued to flower after this time for many weeks, but without producing any more pods.—

That curious grass with spirally contracting barbs, the Streptochæta, appears to be extremely rare here.7 I have looked in vain for more specimens at different localities; that part of my forest, where I had found it first, had been cut down in the meantime; a single specimen, which I had planted in my garden, seems to thrive well and will, I hope, furnish me with an opportunity of settling the points to which you allude in your letter.8

From seeds of a long-styled white Oxalis, legitimately fertilised with pollen of the longer stamens of the mid-styled form I raised some plants; 8 of these have hitherto flowered and of these 4 are long-styled, 4 mid-styled and none short-styled.9

I enclose seeds of the second plant of Begonia with monstrous flowers, of which I told you in my last letter. In this species, (probably the Begonia obliqua of the Flora fluminensis),10 the panicles generally consist of either 5 or 11 flowers, of which 3 or 7 are male ones and the rest female ones and which are arranged in the following manner


The male flowers (1) and (2) are often quite regular, or but little modified, one or two of the central stamens having the connectivum enlarged and provided with rudimentary stigmatic papillæ, whilst in those male flowers, which stand at the side of a female one, from one to three (or in the second plant even as many as 8) stamens are more or less completely transformed into pistils.

The female flowers have generally 5 divisions or petals, one of which is much smaller than the rest.

This small petal (α) and the male flower, which springs from diagram the same point with the female one, are always placed on opposite sides of the latter. Sometimes the male flower is wanting and in this almost always a sixth petal (β) is present in the female flower. diagram

May we not venture to admit, that the abortion of the sixth petal in those female flowers, which are accompanied by a male one, is due to the pressure exerted on the young buds by the male flowers? And not the reappearance of the sixth petal in most of the cases, in which this pressure does not exist, be compared to the reappearance of a regular structure (pelorism) in central or terminal flowers?—11 In irregular flowers it is almost always, as far as I know, the posterior stamen, which first aborts, and this abortion might be explained by a pressure caused by the axis, from the side of which the flower springs. Now, if a flower-bud be placed at the very end of the axis, no such pressure could possibly be exerted; all the segments of the flower would have exactly the same position in relation to the axis; there would be no reason for one of them differing from the rest and thus the flower would become regular even without the law of reversion coming into play.

With sincere gratitude and respect, believe me, dear Sir, | very truly yours | Fritz Müller

CD annotations

1.1 I have … readers.— 2.10] crossed pencil
3.1 As … species.— 3.10] ‘faramea (Rubiaceæ)’ added ink
4.1 Many … pods.— 4.9] crossed blue crayon
4.6 by these … pods.— 4.9] double scored pencil
5.1 That … short-styled. 6.3] crossed pencil
Top of letter: ‘Eschotzia | Dimorphic Plant in [growth] | Begonia Hooker’ pencil del ink; ‘Faramea’ blue crayon; ‘(Claparède)’ ink del ink; ‘(Peridromia)’12 blue crayon


The first part of this letter, down to paragraph six, ‘hitherto’, was published in Correspondence vol. 17. The last two pages were later found at the Royal Botanic Gardens, Kew; CD evidently sent them to Joseph Dalton Hooker. The footnotes to the first part of the letter have been altered. See Correspondence vol. 17, letters to Fritz Müller, 14 March 1869 and 18 March 1869. In a letter of 12 June 1869, Müller told his brother, Hermann Müller, that he had travelled to the furthest part of his land to get supplies of garlic vine (Pseudocalymma alliaceum) to use as rope for his garden fences (Möller ed. 1915–21, 2: 158).
Müller refers to the translation of his book Für Darwin (F. Müller 1864) into English as Facts and arguments for Darwin (Dallas trans. 1869; see Correspondence vol. 17, letter to Fritz Müller, 14 March 1869).
The review in the 21 April 1869 issue of Scientific Opinion (Anon. 1869) was positive, but the one in the 27 March 1869 issue of the Athenæum was critical, and the author remarked, ‘It is to be feared that Dr. Müller’s moral code is rather Crustacean than Christian’ ([Leifchild] 1869). The reviewer, John Roby Leifchild, had written a review of Origin for the Athenæum that CD found unfair ‘under a theological point of view’ (see Correspondence vol. 7, letter to C. S. Wedgwood, [after 21 November 1859]). In his letter to his brother Hermann, Müller confided that he thought the remark about his moral code a rather good joke (Möller ed. 1915–21, 2: 158).
See Correspondence vol. 17, letter to Fritz Müller, 14 March 1869 and n. 9. In Forms of flowers, p. 129, CD included an illustration by Müller of the different forms of flowers and pollen-grains in Faramea. What Müller described as possibly a species of Faramea was subsequently identified as Rudgea jasminoides from specimens Müller sent to the Royal Botanic Gardens, Kew (see Baker 1956, pp. 27–9).
CD had sent seeds of Eschscholzia californica (California poppy); see Correspondence vol. 17, letter to Fritz Müller, 14 March 1869. In Cross and self fertilisation, pp. 331–3, CD discussed the effects of climate on self-fertility in E. californica, noting differences between plants grown in Brazil and England.
Cypella is a South American genus of the family Iridaceae. Müller later published observations on two species of Cypella in ‘Biologische Beobachtungen an Blumen Südbrasiliens’ (Fritz Müller 1883).
See Correspondence vol. 17, letter from Fritz Müller, 12 January 1869 and nn. 3–5, and letter to Fritz Müller, 14 March 1869 and n. 13. Müller had described the unusual floral structure of Streptochaeta, which, he hypothesised, might be a connecting link between common grasses and other monocotyledons.
In his letter of 14 March 1869 (Correspondence vol. 17), CD had suggested that Müller should try to determine whether the bracts of the grass were sensitive and how soon they became apical in the bud.
The Oxalis (wood sorrel) species was identified at the Royal Botanic Gardens, Kew, as Oxalis martiana (a synonym of O. latifolia subsp. latifolia, Cuban purple wood-sorrel; see Correspondence vol. 17, letter from Fritz Müller, 18 October 1869). CD later described it as Oxalis regnelli (a synonym of O. triangularis subsp. papilionacea, false shamrock) in Forms of flowers, p. 173.
See Correspondence vol. 17, letter from Fritz Müller, 14 March 1869. CD had sent seeds of the first Begonia to George Bentham for the collection at the Royal Botanic Gardens, Kew (ibid., letter to George Bentham, 10 May [1869]; Royal Botanic Gardens, Kew, Inwards book). An illustration of Begonia obliqua appears in Flora fluminensis 10: tab. 48; the name was used illegitimately, however, and the plant figured is Begonia fischeri (see Jacques and Mamede 2005, p. 580). An annotation at the end of the letter in an unknown hand reads, ‘Obliqua is an erect plant 2 feet high with only 2 sepals to male flowers’.
Peloric flowers are aberrant forms in which a usually irregular floral structure appears regular or symmetrical. In Variation 2: 345–7, CD had discussed the tendency of terminal or central flowers to be peloric.
CD’s notes are for his reply to Müller of 8 September [1869] (Correspondence vol. 17); he refers to Joseph Dalton Hooker and Edouard Claparède. Peridromia is a synonym of Hamadryas (the genus of cracker butterflies).


Baker, Herbert G. 1956. Pollen dimorphism in the Rubiaceae. Evolution 10: 23–31.

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 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.

Flora fluminensis. By José Mariano da Conceição Velloso. 11 vols. Paris: A. Senefelder, 1827.

Forms of flowers: The different forms of flowers on plants of the same species. By Charles Darwin. London: John Murray. 1877.

[Leifchild, John R.] 1869. [Review of Facts and arguments for Darwin by Fritz Müller, translated by W. S. Dallas.] Athenæum, 27 March 1869, p. 431.

Müller, Fritz. 1864a. Für Darwin. Leipzig: Wilhelm Engelmann.

Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.

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


FM much gratified by the appearance of Für Darwin translation.

Discusses dimorphism in Rubiaceae.

Letter details

Letter no.
Johann Friedrich Theodor (Fritz) Müller
Charles Robert Darwin
Sent from
Santa Catharina, Brazil
Source of text
DAR 110: B115; Royal Botanic Gardens, Kew (Directors’ Correspondence 215/175)
Physical description
ALS 4pp ††

Please cite as

Darwin Correspondence Project, “Letter no. 6783,” accessed on 1 October 2023,

Also published in The Correspondence of Charles Darwin, vol. 17 and 24 (Supplement)