To Henry Doubleday 1 March 1
Down. | Bromley. | Kent. S.E.
My dear Sir
Mr Stainton has sent me a copy of your letter to him on the numerical proportions of the sexes of Insects,2 which has interested me greatly, & I venture to ask a few more questions, for the chance,—& I know it is an improbable chance—that you who have observed so acutely can throw any light on certain points.
Have you ever observed any marked difference in the numbers of the sexes during different years,—the males one season being in excess & the females during another, or conversely.—
Mr Stainton is very positive that he breeds many more females than males;3 but Dr Wallace of Colchester thinks this may arise from the larger & finer caterpillars striking the eye & being naturally chosen, & these would be the most likely to produce females.—4 What do you think of this?
Can you throw any light on the courtship of Butterflies: I think I have seen several males pursuing one female; now does the female favour one, or does the strongest male drive away the others; or is it, as Dr Wallace maintains, simple chance.—5 I fear no one can say.— I imagine that the beauty of the male in the case of species which are gaily coloured, & perhaps especially with those in which the sexes differ in colour, might determine the choice of female. Have you ever noticed anything leading you to suppose that Butterflies notice bright colours? I shd be most grateful for any hints or remarks, & I hope that you will excuse me for troubling you.
Perhaps you will remember having kindly sent me living specimens of Primula elatior; at last I have found time to draw up for Linn. Soc. an account of some observations on their powers of reproduction. It is as good a species as any in the world.— I will send you a copy of my paper whenever it is published.—6
Pray believe me | My Dear Sir | Yours very faithfully | Charles Darwin
My address for next 10 days will be 6. Queen Anne St. | Cavendish Sqr | London W.7
Has been interested in copy of HD’s letter to H. T. Stainton on numerical proportions of the sexes of insects. Do they vary during different years?
Does he have opinions about the courtships of butterflies?
Will send a copy of his paper on Primula when it is published. [See 5997.]
Please cite as
Darwin Correspondence Project, “Letter no. 5966A,” accessed on 23 April 2017, http://www.darwinproject.ac.uk/DCP-LETT-5966A