To J. J. S. Steenstrup 20 May 
Down Farnborough Kent
My dear Sir
I thank you very sincerely for your last letter which answered all my long list of questions quite fully & satisfactorily.1 Mr. 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
Describes progress in illustration of fossil cirripede specimens. Thanks for answers to questions. Comments on hermaphroditism. Describes his discovery of parasitic male cirripedes.
- Letter no.
- Charles Robert Darwin
- Johannes Japetus Smith (Japetus) Steenstrup
- Sent from
- Source of text
- Det Kongelige Bibliotek, Copenhagen (NKS 3460 4to)
- Physical description