My dear Sir

I thank you very sincerely for your last letter which answered all my long list of questions quite fully & satisfactorily.¹ M^r. J. Sowerby (the author of Min: Conch:)² is now drawing your specimens; but from having his hands very full of work he is, I am sorry to say, much delayed: for my own sake I do all I can to urge on his progress. I wait with eargerness to receive your northern Cirripedes & remarks: I am now at work on the Genus Balanus & very difficult I find it, as many species are quite undistinguishable by any one external character. I thank you much for the drawing of Lithotrya: I think I may have the same species from Timor: but the manner of boring here indicated is quite new to me.³

I have heard of your work on Hermaphroditism,⁴ but have not seen it, though I have long wished to do so; for on merely hypothetical grounds I have always thought Hermaphroditism improbable.⁵ Alas I cannot read Danish at all, & German with extreme difficulty. How much shame does your perfect English cause me!— You will perhaps be interested by hearing that I once found a Balanus which had had its probosciform organ cut off & healed absolutely imperforate, & yet the ova had been impregnated & contained larvæ; some of the neighbouring individuals in the cluster having certainly impregnated these ova.⁶ I have two cases of bisexual cirripedes, the male differing considerably from the female & being parasitic within the sack of the female.⁷

Pray believe me With feelings of much respect & gratitude, | Your’s sincerely | C. Darwin