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Darwin Correspondence Project

To A. R. Wallace   16 September [1868]1

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

Sept 16th

My dear Wallace

The Beetles have arrived & cordial thanks: I never saw such wonderful creatures in my life. I was thinking of something quite different. I shall wait till my son Frank returns, before soaking & examining them.—2

I long to steal the Box, but return it by this Post, like a too honest man.—

I am so much pleased about the male musk Callichroma; for by odd chance I told Frank a week ago that next spring he must collect at Cambridge lots of Cerambyx moschatus for as sure as life he wd find the odour sexual!3

You will be pleased to hear that I am undergoing severe distress about the protection & sexual selection: this morning I oscillated with joy towards you: this evening I have swung back to old position, out of which I fear I shall never get.—4

I did most thoroughily enjoy my talk with you three gentlemen & especially with you, & to my great surprise it has not knocked me up.— Pray give my kindest remembrances to Mrs Wallace, & if my wife were at home she would cordially join in this.—5

Yours very sincerely | Ch. Darwin

I have had this morning capital letter from Walsh of Illinois; but details too long to give.—6


The year is established by the reference to the recent visit of Wallace and others to Down House (see n. 5, below).
See the letter from A. R. Wallace, [14 September 1868]. CD evidently discussed beetles with Wallace during his visit the preceding weekend (see n. 5, below). Notes dated 7 and 14 September 1868 indicate that CD and his son Francis Darwin had been examining the stridulating organs of beetles found near Down House; see DAR 81: 27–8. See also Descent 1: 382. Further notes indicate that Francis and CD continued the examinations of stridulating organs, including those of Wallace’s Euchirus longimanus, on 12 October 1868 (see DAR 81: 32); for CD’s conclusions regarding E. longimanus, see Descent 1: 381–2.
For Wallace’s musk beetle ‘Callichroma’, see the letter from A. R. Wallace, [14 September 1868] and n. 5. Musk beetles, including the European Cerambyx moschatus (now Aromia moschata), release a strong odour as a sexual attractant. CD and Francis Darwin examined the beetle’s stridulating organ on 21 September 1868 (see DAR 81: 29).
During Wallace’s recent visit to Down House (see n. 5, below), CD and Wallace evidently continued their discussion regarding the relative roles of protection and sexual selection in the development of secondary sexual characters, especially colour, in insects and birds. They had intermittently engaged in this discussion in correspondence since the end of 1866, with Wallace promoting protection as a more significant factor and CD arguing for the importance of sexual selection (see Correspondence vols. 14, 15, and in this volume see especially letter from A. R. Wallace, 1 May [1868], and letters to A. R. Wallace, 5 May [1868] and 19 August [1868]). CD’s notes on the subject, dated 4 September 1868, are in DAR 84.2: 215, 216. For more on CD’s and Wallace’s differing views of sexual selection, see Kottler 1980 and Fichman 2004, pp. 262–8.
Wallace, his wife Annie Wallace, John Jenner Weir, and Edward Blyth had visited Down House over the weekend of 12 and 13 September 1868 (see Emma Darwin’s diary (DAR 242), and letter to J. D. Hooker, [8–10 September 1868]).


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.

Fichman, Martin. 2004. An elusive Victorian: the evolution of Alfred Russel Wallace. Chicago: University of Chicago Press.

Kottler, Malcolm Jay. 1980. Darwin, Wallace, and the origin of sexual dimorphism. Proceedings of the American Philosophical Society 124: 203–26.


CD’s oscillating views relating to protection and sexual selection.

Letter details

Letter no.
Charles Robert Darwin
Alfred Russel Wallace
Sent from
Source of text
The British Library (Add MS 46434: 149–50)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 6368,” accessed on 27 October 2021,

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