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Darwin Correspondence Project

To J. J. Weir   29 February [1868]1

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

Feb 29.

My dear Sir

I have hardly ever received a note which has interested me more than yr last;2 & this is no exaggeration.

I had a few cases of birds perceiving slight changes in the dress of their owners, but yr facts are of ten-fold value. I shall certainly make use of them, & need not say how much obliged I should be for any others about which you feel confident.

Do you know of any birds besides some of the gallinacæ which are polygamous?

Do you know of any birds besides pigeons, & as it is said, the raven which pair for their whole lives.

Many years ago I visited your brother who shewed me his pigeons & gave me some valuable information.3 Could you persuade him (but I fear he wd think it high treason) to stain a male pigeon of some brilliant colour & observe whether it excited in the other pigeons especially the females admiration or contempt?

For the chance of yr liking to have a copy & being able to find some parts which wd interest you, I have directed Mr Murray to send you my recent book on Variation under Domestication.4

With cordial thanks believe me | yours sincerely | Ch. Darwin

P.S. I have somewhere safe references to cases of magpies, of which one of a pair has been repeatedly (I think seven times) killed, & yet another mate was always immediately found— A gamekeeper told me yesterday of analogous case.5 This perplexes me much. Are there many unmarried birds? I can hardly believe it.— Or will one of a pair, of which the nest has been robbed, or which are barren, always desert his or her mate, for a strange mate with the attraction of a nest, & in one instance with young birds in the nest? The gamekeeper said during breeding season he had never observed a single or unpaired Partridge. How can the sexes be so equally matched?

P.S. 2d.— I fear you will find me a great bore, but I will be as reasonable as can be expected in plundering one so rich as you.—

P.S. 3d | I have just received a letter from Dr. Wallace of Colchester about proportional numbers of the 2 sexes in Bombyxii & in this note, apropos to an incidental remark of mine, he stoutly maintains that female Lepidoptera never notice the colours or appearance of the male, but always receive the first male which comes, & this appears very probable— Says he has often seen fine females receive old battered & pale-tinted males.—6 I shall have to admit this very great objection to sexual selection in insects.—

His observations no doubt apply to English Lepidoptera in most of which, the sexes are alike. The Brimstone or Oran-tip7 wd. be good to observe in this respect; but it is hopelessly difficult.—

I think I have often seen several males following one female—& what decides which male shall succeed? How is this about several males; is it not so?


The year is established by the relationship between this letter and the letter from J. J. Weir, [after 27 February] 1868.
CD had visited Harrision William Weir in 1856 (see Correspondence vol. 6, letter to W. B. Tegetmeier, 15 March [1856]). He is acknowledged for providing information on pigeons in Variation 1: 132 n. 2.
Weir’s name appears on CD’s presentation list for the second printing of Variation (see Correspondence vol. 16, Appendix IV). CD refers to his publisher, John Murray.
CD received information on magpies and partridges from William Reeves, a gamekeeper employed by John Lubbock. The note containing this information is in DAR 84.2: 202. See also letter to W. D. Fox, 25 February [1868] and n. 2.
The brimstone is Gonepteryx rhamni; the orange tip is Anthocharis cardamines. CD had asked about these butterflies in his letter to H. T. Stainton, 28 February [1868].


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.

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


JJW’s note on birds was one of the most interesting CD has ever received. Asks several questions. CD is puzzled by cases of magpies whose mates were killed but who always immediately found others.

Alexander Wallace denies any effect of colour in sexual selection among Lepidoptera.

Letter details

Letter no.
Charles Robert Darwin
John Jenner Weir
Sent from
Source of text
Field Museum of Natural History, Chicago
Physical description
LS(A) 6pp

Please cite as

Darwin Correspondence Project, “Letter no. 5958,” accessed on 26 September 2022,

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