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Darwin Correspondence Project

To T. H. Huxley   1 July [1856]1

Down Bromley Kent

July 1st

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 shd. 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. 2d.— | 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, shd 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. 3d | You have some slides with cement-glands of sessile cirripedes in London, please do not destroy them; as I shd. like sometime to have them back.—10

I have antennæ preserved, shd. you ever wish to see them.


The year is indicated by CD’s use of information in this letter in chapter 11 of his species book (see n. 4, below), which was completed late in the summer of 1856 (Natural selection, p. 531).
CD had asked Huxley to give him examples of organisms that were truly hermaphrodite, that is, in which cross-fertilisation seemed anatomically impossible. (The joke apparently arose through Huxley entering this request in his diary in the form CD quoted.) Such examples would disprove CD’s belief that all hermaphrodites could, and occasionally did, cross. The issue is discussed at length in Natural selection, pp. 44–6. CD refers to Huxley’s observations on ascidians which, though hermaphrodite, were thought by Huxley to release their spermatozoa and ova at different times, thereby being functionally unisexual (Natural selection, p. 45). He also mentions having asked Huxley whether he knew of ‘any animals whose structure was such that an occasional cross was physically impossible’ (Natural selection, p. 46). See also letters to T. H. Huxley, 8 July [1856], and to J. D. Hooker, 13 July [1856].
Huxley endeavoured to compile a catalogue of the ascidians in the collection of the British Museum (see T. H. Huxley 1852). The catalogue, however, was never completed by Huxley.
Huxley’s reply has not been found, but CD cited it in Natural selection, p. 556: ‘In the Ascideae, the genus Boltenia has allied species in the arctic & antarctic seas, & Prof. Huxley thinks that the genus is not Tropical; but here again from our ignorance much caution is requisite.’ See also letter to T. H. Huxley, 8 July [1856].
CD refers to Huxley’s lectures on general natural history, delivered at the School of Mines, that were published serially in the Medical Times & Gazette beginning with the issue of 3 June 1856 (T. H. Huxley 1856–7).
In Huxley’s fifth lecture, published on 21 June 1856 and covering the Actinia, Huxley founded his discussion of the coral-forming actinians on CD’s Coral reefs, warmly praising the work ‘as a striking example of the manner in which Geology and Natural History may be made to elucidate one another.’ (T. H. Huxley 1856–7, 12: 623).
See letters to T. H. Huxley, 27 May [1856], and to J. W. Lubbock, 27 May [1856]. Huxley was appointed examiner in comparative anatomy and physiology at the University of London. The appointment was announced in the Medical Times & Gazette 13 (1856): 103.
CD refers to the antennae of sessile cirripedes. Huxley discussed this group of Crustacea in his twelfth lecture on general natural history. For earlier correspondence between CD and Huxley concerning cirripede anatomy, see Correspondence vol. 5.
Huxley had visited Tenby in the summers of 1854 and 1855 to carry out researches on marine invertebrates. He returned there again in September and October 1856 (L. Huxley ed. 1900, 1: 143).
A set of slide specimens of cirripede parts prepared by CD is in the Cambridge Zoology Museum.


Coral reefs: The structure and distribution of coral reefs. Being the first part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy RN, during the years 1832 to 1836. By Charles Darwin. London: Smith, Elder & Co. 1842.

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.

Huxley, Thomas Henry. 1852. Researches into the structure of the Ascidians. Report of the 22d meeting of the British Association for the Advancement of Science held at Belfast, Transactions of the sections, pp. 76–7. Reprinted in Foster and Lankester, eds. 1898–1903, 1: 194–6.

Huxley, Thomas Henry. 1856–7. Lectures on general natural history. Medical Times & Gazette n.s. 12: 429–32, 481–4, 507–11, 563–7, 618–23; 13: 27–30, 131–4, 157–60, 278–81, 383–6, 462–3, 537–8, 586–8, 635–9; 14: 133–5, 181–3, 255-7, 353–5, 505–8, 638–40; 15: 159–62, 186–9, 238–41, 467-71.

Natural selection: Charles Darwin’s Natural selection: being the second part of his big species book written from 1856 to 1858. Edited by R. C. Stauffer. Cambridge: Cambridge University Press. 1975.


Asks for information on geographical distribution of ascidians; are any closely allied species or genera found in north and south temperate zones that do not have representatives in the tropics?

Answers some questions on [cirripede] antennae.

If THH ever sees a tree washed ashore, will he observe whether any earth is embedded between roots?

Letter details

Letter no.
Charles Robert Darwin
Thomas Henry Huxley
Sent from
Source of text
Imperial College of Science, Technology, and Medicine Archives (Huxley 5: 175, 37–9)
Physical description
ALS 8pp

Please cite as

Darwin Correspondence Project, “Letter no. 1914,” accessed on 30 January 2023,

Also published in The Correspondence of Charles Darwin, vol. 6