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Darwin Correspondence Project

From Fritz Müller   29 March 1870

Itajahay, Sa Catharina, Brazil

March 29. 1870.

My dear Sir

I have been detained from answering sooner your letter of Decbr. 1st, by an excursion into our primeval forests and afterwards by a severe illness of one of my daughters.1 And now, I must first express my cordial thanks for a copy of No 1 of “the Academy” and for the German translation of Wallace’s exceedingly interesting work on the Malay Archipelago.2 One of the points, which have interested me most in this work, is the dimorphism and mimicry of several butterflies.3 My attention having thus been called to our endemic butterflies, I have met also with several cases of close ressemblance of species belonging to distinct genera, which must probably be attributed to mimicry. There is, for instance a very common Pieris (1), and three or four other rather rare species, when seen from above, are more or less closely imitating the colours of this Pieris.—

I am much obliged for your account on Eschscholtzia;4 the influence of external conditions on the self-fertility of this 〈foot of page, probably containing diagram, excised〉 species is very curious; it is shown in a striking manner by a plant, which I had raised 1868 from your seeds and which only flowered 1869.—5 The other plants from the same seeds, which flowered the first year (1868) had retained self-fertility in a small degree; but this plant, which flowered only the second year, and had thus been exposed for a far longer time to our climate, proved perfectly self-sterile; it has been left uncovered, but growing at some distance from the other plants, which flowered at the same time, it produced by itself only a few very poor pods containing not even a single seed. Two flowers fertilised by pollen of a distinct plant yielded large pods, one of which contained 115 seeds.—

I have been much pleased by hearing from Alex. Agassiz, that he is now inclining to your views.6 I think very high of him as one of the most skilful and conscientious observers. His “Embryology of the Starfish” is a master-piece.—7

I gave you, in my last letter, some cases of plants, the first flowers of which had a larger number of petals or stamens than the later ones.8 I have since found, in a tree of C〈assia〉 multijuja, that the first flowers of 〈foot of page excised

CD annotations

1.1 I have … Pieris.— 1.11] crossed blue crayon
2.7 it has … seeds.— 2.11] double scored red crayon
3.1 I have … master-piece.— 3.3] crossed blue crayon
4.1 I gave … flowers of 4.3] crossed ink


Müller refers to the letter to Fritz Müller, 1 December [1869] (Correspondence vol. 17). Müller had six surviving daughters (see West 2003).
The first issue of the Academy, dated 9 October 1869, contained a review of the English translation of Müller’s Für Darwin (Dallas trans. 1869; Academy 1 (1869–70): 14–15). Müller also refers to Wallace 1869c (see Correspondence vol. 17, letter to Fritz Müller, 1 December [1869]).
See Wallace 1869a, 1: 199–207.
See Correspondence vol. 17, second enclosure to letter to Fritz Müller, 1 December [1869].
See Correspondence vol. 16, letters from Fritz Müller, 22 April 1868, 9 September 1868, and 31 October 1868, and Correspondence vol. 17, letters from Fritz Müller, 12 January 1869 and 18 October 1869.
Müller refers to Alexander Agassiz (see also Correspondence vol. 17, letter to Fritz Müller, 1 December [1869]).
A. Agassiz 1864.


His observations on mimicry in butterflies

and self-sterility in plants.

Letter details

Letter no.
Johann Friedrich Theodor (Fritz) Müller
Charles Robert Darwin
Sent from
Santa Catharina, Brazil
Source of text
DAR 76: B36
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 7150,” accessed on 20 October 2017,

Also published in The Correspondence of Charles Darwin, vol. 18