My dear M^r Farrer

I must send you a line to say how extremely good your article appears to me to be.² It is even better than I thought, & I remember thinking it very good.³ I am particularly glad of the excellent summary of evidence about the common pea, as it will do for me hereafter to quote.⁴

Nocturnal insects will not do.⁵ I suspect that the aboriginal parent had bluish flowers. I have seen several times Bees visiting common & Sweet peas, & yet vars., purposely grown close together, hardly ever intercross. This is a point which for years has half driven me mad, & I have discussed it in my Var. of Animals & Plants under Dom:.—⁶ I now suspect (& I wish I had strength to experimentise next Spring) that from changed climate both species are prematurely fertilised & therefore hardly ever cross. When artificially crossed by removal of own pollen in bud, the offspring are very vigorous.

Farewell,— I wish I could compel you to go on working at fertilisation instead of so insignificant a subject as the commerce of the country!⁷ You pay me a very pretty compliment at the beginning of your paper.⁸ | Yours very sincerely | Ch. Darwin.

Have you read the very curious article on Instinct in the same Nature?⁹ That on parthenogenesis is also very good.—¹⁰ It is a wonderful number.—