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Darwin Correspondence Project

To B. D. Walsh   14 February 1868

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

Feb. 14. 1868

My dear Sir,

I want you to ransack your memory or notebook for some scraps of information, and I know you will excuse me troubling you. I am working on Sexual selection and all sorts of facts would be most useful to me.

I will specify some points. In the N. American Homoptera and Orthoptera do the males and females ever differ conspicuously in colour?

Can you give me any proofs of the females being attracted by the music of the males?1

I want to hear anything about the battles of male insects, Any facts about the attachment or love of the male to the female or reciprocally.—2

Have you any idea of the use of the strange horns in the male Lamellicorns?3

I especially want to hear of insects in which the males and females are very unequal in numbers; especially of the apparently rarer cases of the females being in excess. I want to see what bearing the relative inequality of number has on Sexual Selection. You who so thoroughly understand my views will easily understand the class of facts I want; I shall be grateful if you will ransack your memory. Do your Libellulæ differ much in colour sexually?4

I wrote a little time ago to you saying that my new book had been despatched to New York— It has had a very large sale here.5

I hope the world progresses favourably in all ways with you.—

Believe me | Yours very sincerely | Charles Darwin


This is a great hobby of mine, can you aid me?6


CD discussed the stridulation of male insects in Descent 1: 339, 350–60, 366, 378–85.
Battles between male insects for females are discussed in Descent 1: 375–8; CD noted that some lamellicorn beetles lived in pairs and showed ‘mutual affection’ (ibid., p. 377).
CD described the horns of male lamellicorn beetles in Descent 1: 369–74.
CD discussed coloration in Libellulidae (dragonflies) in Descent 1: 361–4. Dragonflies now constitute a suborder (Anisoptera) of the order Odonata (dragonflies and damselflies).
See letter to B. J. Walsh, 27 January [1868]. Walsh’s name is on CD’s presentation list for Variation (see Correspondence vol. 16, Appendix IV). On the sales of Variation, see the letter from John Murray, 6 February [1868].
CD’s remark is written on a printed questionnaire on expression enclosed with this letter. For a transcription of a copy of the printed questionnaire, see Correspondence vol.16, Appendix V.


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

Descent: The descent of man, and selection in relation to sex. By Charles Darwin. 2 vols. London: John Murray. 1871.

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


Requests entomological data on sexual selection, especially proportions of sexes.

Sends Queries about expression with note: "a great hobby of mine".

Letter details

Letter no.
Charles Robert Darwin
Benjamin Dann Walsh
Sent from
Source of text
Field Museum of Natural History, Chicago (Walsh 12)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 5876,” accessed on 3 August 2020,

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