skip to content

Darwin Correspondence Project

From Raphael Meldola   4 April 1879

Offices, | 50, Old Broad Street, | E.C. | Atlas Works, | Hackney Wick, | London, E.

April 4th. 1879

My dear Mr. Darwin,

I enclose a specimen just received from Fritz Müller which you may perhaps like to see—a branchiated Trichopteron! You will see from his letter the special interest which attaches to the insect. The branchiæ can be seen projecting from between the segments. I must beg you to return the specimen as I will exhibit it at the next meeting of the Entom. Soc.1

Weismann’s book is getting on—2 The 1st. essay (Seasonal dimorphism) is nearly ready for publication & about 12 the 2nd. essay roughly translated.

I sent an abstract of the article in Kosmos on Epicalia Acontius to Nature a long time ago but suppose it has been ‘crowded out’ as it has not yet appeared.3 It would have been very appropriate in this week’s Nature as a check upon Wallace’s restrictions upon sexual selection in his review of Grant Allen’s “Colour in Nature”.4 In this review Wallace states “We may also remark that the sexual allurement of a peculiar odour given out by special patches of scales on butterflies’ wings has been discovered by Fritz Müller in the genera Mechanitis, Dircenna, & Thecla, all very brilliantly coloured groups, a clear indication that colour is not a sexual allurement or we should find it most developed, not in conjunction with, but in the absence of, the attraction of odour.”5 The words which I have italicised are open to criticism— in fact I venture to think the argument totally fallacious. It does not follow that because colour has been acquired through Sexual Selec. the same agency should not have added other attractions in the same species. Do you concur in this?

Yours very faithfully, | R. Meldola.

Ch. Darwin Esqre. LLD. F.R.S. &c.


Trichoptera is the order of caddisflies. In a paper read to the Entomological Society of London on 7 May 1879, Müller stated that he had not observed branchiae in any Brazilian species of Trichoptera (F. Müller 1879b, p. 132). At the same meeting, an insect from the family Leptoceridae (order Trichoptera) with tracheobranchiae, discovered in Brazil by Müller, was exhibited. Müller’s description of the insect was published in the proceedings of the society; it was probably taken from his letter to Meldola, which has not been found (Transactions of the Entomological Society of London (Proceedings) 58 (1879): xiii–xiv). Tracheobranchiae are the gill-like breathing organs in certain insect larvae (OED).
Meldola was translating August Weismann’s book Studien zur Descendenz-Theorie (Studies in the theory of descent; Weismann 1875–6). CD’s annotated copy of Weismann 1875–6 is in the Darwin Library–CUL. Meldola’s translation appeared in three parts; the first part, on the seasonal dimorphism of butterflies, was published in 1880 (Weismann 1880–2).
Meldola’s note ‘Butterflies with dissimilar sexes’, published in Nature, 24 April 1879, pp. 586–8, was based on Müller’s article on sexual dimorphism in Epicalia acontius (a synonym of Catonephele acontius, the Acontius firewing), published in Kosmos in January 1879 (F. Müller 1879a).
Alfred Russel Wallace’s review of Grant Allen’s book on colour in nature (G. Allen 1879a) was published in Nature, 3 April 1879, pp. 501–5. Wallace had long been a critic of sexual selection (see, for example, Correspondence vol. 24, letter to A. R. Wallace, 17 June 1876 and n. 18).
Nature, 3 April 1879, p. 504.


Allen, Grant. 1879a. The colour-sense: its origin and development. An essay in comparative psychology. London: Trübner & Co.

Müller, Fritz. 1879a. Epicalia Acontius. Ein ungleiches Ehepaar. Kosmos 4 (1878–9): 285–92.

Müller, Fritz. 1879b. Notes on the cases of some south Brazilian Trichoptera. Transactions of the Entomological Society of London (1879): 131–44.

Weismann, August. 1875–6. Studien zur Descendenz-Theorie. 2 vols. I. Ueber den Saison-Dimorphismus der Schmetterlinge; II. Ueber die letzten Ursachen der Transmutationen. 1. Die Entstehung der Zeichnung bei den Schmetterlings-Raupen, 2. Ueber den phyletischen Parallelismus bei metamorphischen Arten, 3. Ueber die Umwandlung des mexikanischen Axolotl in ein Amblystoma, 4. Ueber die mechanische Auffassung der Natur. Leipzig: Wilhelm Engelmann.

Weismann, August. 1880–2. Studies in the theory of descent. Translated by Raphael Meldola. 3 parts. Part I (1880): On the seasonal dimorphism of butterflies. Part II (1881): The origin of the markings of caterpillars. On phyletic parallelism in metamorphic species. Part III (1882): The transformation of the Mexican axolotl into amblystoma. On the mechanical conception of nature. London: Sampson Low, Marston, Searle, & Rivington.


Sends specimens from F. Müller.

Criticises A. R. Wallace’s review of Grant Allen’s The colour-sense [Nature 19 (1879): 501–5].

Letter details

Letter no.
Raphael Meldola
Charles Robert Darwin
Sent from
Atlas Works, Hackney
Source of text
DAR 171: 135
Physical description
ALS 3pp

Please cite as

Darwin Correspondence Project, “Letter no. 11975,” accessed on 22 April 2024,