To Henry Walter Bates 11 February 1
Down. | Bromley. | Kent. S.E.
My dear Bates
I have just found that I much require information on the proportion of males & females throughout, as far as possible, the animal kingdom. Unfortunately I did not see this, or rather I saw it only obsurely, & have kept only a few references.—2 I am nearly sure you give facts in Amazonia.—3 Trimen gives some cases in Mauritius of males in great excess.4 I know I have got one reference of Wallace of female Butterflies in excess.5 This, I imagine, is much rarer; will you try & remember any cases whatever of female insects of any order (except in parthenogenetic cases) in excess.— I know the Brimstone6 & some other English Male Butterflies are in excess.— How is it with Lamellicorns; but perhaps the horned males wd. be most collected. Should you dislike asking for information at Ent. Soc. publickly; of which I was pleased to see you are President?7 How about male Dragon-flies? I know you will aid me if you can.—
Perhaps I will have my next Book, which is chiefly on Sexual Selection, illustrated by wood-cuts; in which case I shall have to supplicate for hints for good species to engrave. For instance is any insect better than common Stag-Beetle to show enormous development of mandibles in male; I rather think there is a splendid Beetle from Chiloe, which I collected.—8 As beggars say the smallest trifle will be gratefully accepted.—
I hope you have got my Book, but do not, I beg, write merely to thank for form sake9
My dear Bates | Yours very sincerely | & very troublesomely | C. Darwin
Asks about proportions of male to female insects.