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Darwin Correspondence Project

From Henry Doubleday   8 March 1868


March 8th 1868

My dear Sir,

I hope you will excuse my apparent neglect in not answering your letter sooner when I tell you when I tell you that I have been very unwell the last few days with a severe attack of rheumatic headache which has prevented me from doing many things which ought to have been attended to—1 it is always a very great pleasure to me to assist you in any way in my power—

In reply to your first question I may say that I have not noticed any marked difference in the numbers of the sexes of Lepidoptera during different years— I have paid pretty close attention to this Order for more than thirty years and my decided opinion is that the males are always more numerous than the females— if this were not the case it does not seem probable that a virgin female would attract fifty or a hundred males in a single day and this I have often witnessed with Saturnia carpini and Bombyx quercus:2

I agree with what Dr Wallace says about collecting larvæ and as those of many species of Macro-Lepidoptera differ very much in size—the females being much larger than the males—they are more conspicuous and consequently are more often collected than the smaller ones which produce males—3 I do not suppose Mr Stainton4 has ever reared whole broods of any of the Micro-Lepidoptera from the eggs—it is the only way to ascertain the numbers of each sex—

You may often see five or six males chasing a female butterfly and I certainly think the female is quite indifferent as to which of them copulates with her—and that it is mere chance on the part of the male— I have frequently seen ragged, worn males in copulation with fine fresh females of the common white butterflies—

The females of the large Bombyces such as Carpini and Quercus merely protrude the ovipositor and sit in an almost torpid state—quite motionless—and the first males that gets to them copulate with them immediately— this I have often witnessed— I really think it is all chance and that if a virgin female were deprived of all the scales on her wings and rendered colourless she would be as attractive to the males as a fine and perfect specimen— I give you my candid opinion founded upon observations made through a rather long series of years—

I do not think gaily coloured objects have any particular attraction for butterflies— the common white ones will often fly down to a small piece of white laying on the ground no doubt mistaking it for a butterfly of the same species—5

I am pleased that your opinion of Primula elatior accords with my own—6

I shall always be most happy to serve you in any way and with best wishes believe me | My dear Sir | Yours very Sincerely | Henry Doubleday

Charles Darwin Esq

CD annotations

1.1 I hope … power— 1.5] crossed pencil
2.3 my decided … single day 2.6] double scored pencil and red crayon
4.1 You may] after horizontal rule red crayon
4.1 You may … butterflies— 4.4] heavily crossed pencil
4.1 You may … male— 4.3] scored pencil
4.3 I have … butterflies— 4.4] double scored pencil
5.1 The … me 8.2] crossed pencil
Top of letter: ‘Keep | & numbers of sexes— | H. Doubleday’ pencil; ‘I must own no evidence in favour & some against me.’7 pencil, del pencil; ‘(5 or 6 male chasing one female)’ blue crayon, square brackets in original ms


Saturnia carpini, the emperor moth, is now Saturnia pavonia; Bombyx quercus, the oak eggar, is now Lasiocampa quercus. In Descent 1: 312, CD mentioned Doubleday’s observation of large numbers of males of these species being attracted to a female.
Doubleday refers to Alexander Wallace (see letter to Henry Doubleday, 1 March [1868] and n. 4). Macrolepidoptera: those families of butterflies and moths whose members are large enough to be of interest to the majority of collectors (OED).
Henry Tibbats Stainton.
In Descent 1: 400, CD mentioned Doubleday’s observation of white butterflies being attracted to a piece of white paper.
CD refers to evidence of sexual selection.


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

OED: The Oxford English dictionary. Being a corrected re-issue with an introduction, supplement and bibliography of a new English dictionary. Edited by James A. H. Murray, et al. 12 vols. and supplement. Oxford: Clarendon Press. 1970. A supplement to the Oxford English dictionary. 4 vols. Edited by R. W. Burchfield. Oxford: Clarendon Press. 1972–86. The Oxford English dictionary. 2d edition. 20 vols. Prepared by J. A. Simpson and E. S. C. Weiner. Oxford: Clarendon Press. 1989. Oxford English dictionary additional series. 3 vols. Edited by John Simpson et al. Oxford: Clarendon Press. 1993–7.


Proportion of sexes in Lepidoptera.

Sexual preference.

Role of coloration [see Descent 1: 311–12].

Letter details

Letter no.
Henry Doubleday
Charles Robert Darwin
Sent from
Source of text
DAR 85: B47–8
Physical description
3pp ††

Please cite as

Darwin Correspondence Project, “Letter no. 5997,” accessed on 21 October 2021,

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