Sir,

In reply to your question¹ respecting the impregnation of Peas & Beans when in blossom by insects, winds &c.

Undoubtedly some varieties of Peas & Beans will naturally become impregnated with others when growing near & if each is in a similar stage of growth— Peas accidentally so impregnated have been selected from the rest & thus a new race is obtained— the dwarf blue Knights marrow was obtained in this way.—²

I have never known a whole crop to be deteriated in this manner—but individuals frequently may be seen & if not removed—in a few years by their increase would spoil the stock—

Not so in Cabbage Broccoli Sprouts—Turnips—for here impregnation is easier effected the flowers being open & the pollen abundant— it passes in Clouds & in one Season spoils so large a number as to render the Stock of no value— I have known a single plant of Red Cabbage in bloom—spoil Savoys & Cabbages & Broccolis in neighboring Gardens—and which was not found out till the year after—when mongrels of all sorts shewed themselves to the disappointment of those who sowed—& where the Exchanges of seed took place amongst the neighbors it was very unfortunate—for “all were tarred with the same brush”

I am Sir | Your obedent Servant | William Masters Charles Darwin Esqr