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Darwin Correspondence Project

To Fritz Müller   28 November 1868

Down Bromley | Kent

Nov 28 | 1868

My dear Sir

You end yr letter of Sep. 9 by saying that it is a very dull one; indeed you make a very great mistake, for it abounds with interesting facts & thoughts.1 Your account of the tameness of the birds which apparently have wandered from the interior, is very curious.

But I must begin on another subject: there has been a great & very vexatious, but unavoidable delay in the publication of your book. Prof. Huxley agrees with me that Mr Dallas is by far the best translator, but he is much overworked & had not quite finished the translation about a fortnight ago.2 He has charge of the Museum at York & is now trying to get the situation of Assistant Sec. at the Geolog. Soc; & all the canvassing &c, & his removal, if he gets the place, will I fear cause more than a month’s delay in the completion of the translation; & this I very much regret.3

I am particularly glad to hear that you intend to repeat my experiments on illegitimate offspring, for no one’s observations can be trusted until repeated.4 You will find the work very troublesome, owing to the death of plants & accidents of all kinds. Some dimorphic plants will probably prove too sterile for you to raise offspring; & others too fertile for much sterility to be expected in their offspring. Primula is bad on account of the difficulty of deciding which seeds may be considered as good. I have earnestly wished that some one would repeat these experiments, but I feared that years wd elapse before any one wd take the trouble. I received yr paper on Bignonia in Bot. Zeit. & it interested me much.5 I am convinced that if you can prove that a plant growing in a distant place under different conditions is more effective in fertilization than one growing close by, you will make a great step in the essence of sexual reproduction.6

Prof. Asa Gray & Dr Hooker have been staying here & oddly enough, they knew nothing of yr paper on Martha; tho’ the former was aware of the curious movements of the stamens, but so little understood the structure of the plant that he thought it was probably a dimorphic species. Accordingly I shewed them your drawings & gave them a little lecture & they were perfectly charmed with your account.7 Hildebrand has repeated his exp. on potatoes & so have I, but this summer with no result.8 I am particularly obliged to you for yr observations on the stridulation of the 2 sexes of Lamellicorns: I begin to fear that I am completely in error, owing to that common cause viz mistaking at first individual variability for sexual difference.9

I go on working at sexual selection, & tho’ never idle I am able to do so little work each day that I make very slow progress.

I will sow the seed of the Chinese Cabbage & look out for the very curious montrosity.10 I knew from Azara about the young of the tapir being striped, & about young deer being spotted; I have often reflected on this subject, & know not what to conclude about the loss of the stripes & spots.11

From the Geograph. Distribution of the striped & unstriped species of Equus there seems to be something very mysterious about the loss of stripes; & I cannot persuade myself that the common ass has lost its stripes owing to being rendered more conspicuous from having stripes & thus exposed to danger.

Believe me my dear Sir | yours very sincerely | Charles Darwin


The final portion of Müller’s letter of 9 September 1868 has not been found.
CD refers to Thomas Henry Huxley, William Sweetland Dallas, and Dallas’s translation of Müller’s book Für Darwin (F. Müller 1864; W. S. Dallas trans. 1869). See letter from W. S. Dallas, 27 November 1868.
In his letter of 27 November 1868, Dallas informed CD he had been elected to the post of assistant secretary of the Geological Society of London. Dallas had been curator of the museum of the Yorkshire Philosophical Society.
CD refers to F. Müller 1868b, which appeared in the 25 September 1868 issue of Botanische Zeitung.
Müller reported that he was surprised at the lessened fertility when he pollinated plants using pollen from other plants growing close by. He speculated that these plants might have grown from seeds of the same ‘mother plant’ and that this close relationship had lessened the fertility of the offspring (F. Müller 1868b, p. 629). In Cross and self fertilisation, p. 306, CD cited Müller’s results and agreed with his conclusions about the lessened fertility of closely related plants.
Gray and Joseph Dalton Hooker visited CD between 24 and 30 October 1868 (Emma Darwin’s diary (DAR 242)). CD refers to F. Müller 1866, where Müller described the mechanism by which Martha fragrans prevented self-pollination. The paper included diagrams of the flowers and the ‘catapult mechanism’ of the stamens (F. Müller 1866, facing p. 129). CD discussed the plant in Cross and self fertilisation, p. 5, refering to it as Posoqueria fragrans. Martha fragrans and Posoqueria fragrans are synonyms of Posoqueria densiflora.
Müller had evidently sent CD some seeds of a Brassica, but not all of his discussion of the plant has been found (see letter from Fritz Müller, 9 September 1868 and n. 12).
CD refers to Félix Azara and Azara 1809, 1: 247. CD scored the relevant passage in his copy, which is now in the Darwin Library–CUL, and noted on a separate sheet pasted into the back ‘young Tapirs striped’ (Marginalia 1: 26–8). See letter from Fritz Müller, 9 September 1868 and n. 15.


Delay in translating Für Darwin.

Comments on plan to repeat CD’s experiments on illegitimate offspring.

FM’s observations on stridulation.

Letter details

Letter no.
Charles Robert Darwin
Johann Friedrich Theodor (Fritz) Müller
Sent from
Source of text
British Library (Loan 10:26)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 6483,” accessed on 24 July 2017,

Also published in The Correspondence of Charles Darwin, vol. 16