To J. J. Weir   22 March [1868]¹

My dear Sir

I hope that you will not think me ungrateful that I have not sooner answered your note of the 16^th.—; but in fact I have been overwhelmed both with calls & letters; & alas one visit to the B. Museum of an hour or hour & a half does for me for the whole day.²

I was particularly glad to hear your & your Brothers statement about the “gay” deceiver-pigeons.³ I did not at all know that certain birds could win the affections of the females, more than other males, except indeed in the case of the Peacock.⁴ Conversely M^r Hewitt, I remember, states that in making hybrids the cock-pheasant would prefer certain hen-fowls & strongly dislike others. I will write to M^r. H. in a few days & ask him whether he has observed anything of this kind with pure unions of fowls, ducks &c.—⁵ I had utterly forgotten the case of the Ruff; but now I remember having heard that it was polygamous;⁶ but polygamy with Birds, at least, does not seem common enough to have played an important part. So little is known of habits of foreign Birds: Wallace does not even know whether Birds of Paradise are polygamous.—⁷

Have you been a large collector of caterpillars,—I believe so. I inferred from a letter from D^r Wallace of Colchester that he w^d. account for M^r. Stainton & others rearing more ♀ than ♂. by their having collected the larger & finer caterpillars. But I misunderstood him, & he maintains that collectors take all caterpillars, large & small, for that they collect the caterpillars alone of the rarer moths or butterflies.—⁸ What think you?

I hear from Prof. Canestrini in Italy that females are born in considerable excess with Bombyx mori, & in greater excess of late years than formerly!⁹ Quatrefages writes to me that he believes they are equal in France.—¹⁰ So that the further I go, the deeper I sink into the mire.—

With cordial thanks for your most valuable letters | Yours very sincerely | Ch. Darwin

We remain here till April 1^st— & then hurrah for home & quiet work.—¹¹