From George Henslow   18 May 1866

Dear M^r. Darwin

I have at last written my article on Hybridism for the Popular Science Review,¹ & have much to thank you for so kindly lending me yr books &c. on the subject.² I will forward them to the address given to me within a few days.

I have wanted to ask you whether you would mind running over the proof sheet (about 8 pp.) so that you might give me a hint or two as to any passage you might think objectionable, or any statement too positively asserted &c, as being a subject I knew nothing about previously, I might have been led into making some wrong or hazardous statement. If however, ill health, time &c. should prevent you, pray do not hesitate a moment in saying so & obliging³

Yours faithfully | Geo. Henslow.