My dear Sir

M^r Lubbock² told me yesterday of a fact, observed, I believe, by a friend of yours, which interests me particularly; & I sh^d. be extremely much obliged if you could get me a little more information on the subject, namely the act of cross impregnation in some Balanus.—³

The points on which I so much wish for more information, are.— Which was the species; if not known could I see a specimen of the kind. Was the probosciformed penis inserted into more than one individual? For about how long time was it inserted? Was it inserted deeply & at which end of valves? Especially did the recipient individual continue during the time exserting its cirri? Did it keep its opercular valves widely open for the reception of the organ? I am anxious to know whether the recipient was a willing agent or adulterer, or whether it was a case of rape by act.— If the recipient was in full vigour, I think it w^d be impossible to insert anything without its consent. Were the specimens under water at time?⁴ Who was the observer that I might quote his authority.

I hope you will kindly forgive all this trouble, for I am really very anxious on this point— Perhaps the simplest plan w_d. be to forward this note to your friend & back up my request.

I have been very glad to notice what famous progress you are making in your Researches.—⁵

Yours sincerely | C. Darwin