My dear Huxley

The Society for Prevention of Cruelty to animals ought to be at me, for troubling you, overworked & unwell as you are; but I do cruelly want one question answered; & you can lay aside for present the remarkable case, of “Darwin, an absolute & eternal hermaphrodite”² Have you published a Catalogue of the Ascidians in B. Mus;³ if so & you could lend it me for a few days, I daresay my question would be answered.— My question is, are there any Ascidian genera, with closely allied species in the northern & southern cold or temperate seas, but such genera not found anywhere in the Tropical seas.—⁴ I have some vague idea that there are some genera of compound Ascidians in this predicament.— But it is very likely that the subject has been so neglected that even if you knew of a genus in north & south, yet you could not form any opinion whether or no it occurred in Tropics. The best chance would be in very northern genera.— I sh^d. like to quote you as authority

Hoping for forgiveness | Yours most truly | C. Darwin

Thanks for the last lecture,⁵ which as all the others have done, has interested me much.—

You pay me a grand compliment, far more than I deserve; but this did not lessen my satisfaction.⁶

What success with Examinership?⁷

P.S. | Two closely allied genera, one in north & the other in south, with no closely allied in Tropics, is almost equally a case in point. I think it quite possible that Ascidians in spirits may be hardly recognizable, & if so my queries are unanswerable.—

P.S. 2^d.— | I see I have not answered your question about the antennæ.⁸ It is mere chance whether easy or excessively difficult to detect antennæ, depending on nature of surface & amount of cement poured out. Generally young are best. It is easy in some cases for reasons I cannot explain. The best specimens are young attached to calcareous substances which can be dissolved. But you must remember these organs very small. For months, at first, I only obscurely made them out, & could never conceive what they were! How I have puzzled over them!

As you will be a good deal of sea-side for next few years,⁹ I wish you would remember to observe, sh^d you chance ever to see a tree washed on shore, will you carefully observe whether any earth, ever so little, is embedded between roots—on account of transport of plants.—

P.S. 3^d | You have some slides with cement-glands of sessile cirripedes in London, please do not destroy them; as I sh^d. like sometime to have them back.—¹⁰

I have antennæ preserved, sh^d. you ever wish to see them.