My Dear Sir

I am very much obliged to you for your Work on Domesticated Animals & propose to myself the great pleasure of thoroughly digesting it.—²

I am afraid that in my last I did not clearly shew that I understood your point on “Sexual Selection” in Lepidoptera, but I take it to be, do the females give a preference for certain males?³

It unfortunately happens that we find a most battered male in copⁿ with a newly emerged female, and this is commonly the case with Butterflies, indeed it would appear that the female is ready to receive the male at once, but the male requires excercise particularly of the wings before it is fit for the procreative act, & this is the case even with Bombyx mori.—⁴

Some Butterflies when settled never open their wings, for instance Gonepteryx rhamni and the species of the genus Edusa, the underside of the former is very like a leaf and of the latter somewhat so being greenish & yellowish combined.—⁵

The common species of the genus Pieris and Hipparchia Ægeria very commonly fight but their colors are not bright.—⁶

On the other hand the bright colored Vanessæ I never saw in copⁿ.—⁷

Nearly the whole of the Noctuæ⁸ are dull colored insects & fly by night, but the Genus Triphæna (Yellow Underwings) fly by day, the ♂ & ♀ are alike & the bright yellow underwing is in my opinion an advantage in the struggle for existence, thus, I placed a vigorous specimen of Tri^a pronuba⁹ in my aviary, it was at once attacked by a robin, in endeavouring to escape it shewed the yellow color, this caught the bird’s attention, and of course when seized a little piece was bitten out & the insect escaped, this was repeated about 50 times before the capture was made & the insect swallowed. I feel confident that if the struggle had taken place in nature the moth would certainly have escaped.—

Again I allowed Triphæna fimbria to escape just in front of a swallow, the bird at once dashed in pursuit but from its inability to seize the insect, it effected its escape and flew off unscathed, at a great height¹⁰

I may mention here a curious fact that has been known to me nearly a quarter of a century.—

The late Edward Doubleday of the British Museum once shewed me a Lepidopteran ♂ without wings, I at once exclaimed it ought to have come from Kirguelens Land, & curiously enough it did¹¹

I presume that on that island no insectivorous bird exists & it is also probably a very windy place, so that wings being not only useless, but injurious have become obsolete.

I have never heard of the insect since his death but should suppose it is probably in the British Museum.—

I have this day secured a very dull colored Bullfinch, nearly black, for experiment & propose the highten the color of a chaffinch by staining the breast with roseine,¹² leaving my other chaffinch ♂ the ordinary dull color of a caged bird of the species.—

Bates & Moore are coming to dine with me today   I will have some conversation with them & write further in a few days¹³

I am | My Dear Sir | Yours very faithfully | J Jenner Weir

C Darwin Esq^r.—