To J. D. Dana   8 October 1849

Down Farnborough Kent

Oct 8th— 1849

Dear Sir

I am sincerely obliged to you for your very kind letter, & the information sent. I am sure from what you say, that had it been in your power you wd. have assisted me with specimens.—1 I was not aware that you had attended to the Cirripedia,2 otherwise I shd. have had greater scruple in applying to you.— Your’s was indeed a grand voyage, & your range of research a wide one: I have always felt much interested in regard to your classification &c of the corals; I dissected enough to see what a famous field there was open. Indeed I had intended working on this subject, but my miserable health for the last ten years, (which has lost me much more than half my time) has interrupted all my former hopes & designs.—

You cannot imagine how much gratified I have been, that you have, to a certain extent agreed with my coral-island-notions.—3

To return to the cirripedia: I am allowed to work only 2 hours daily (after 5 months doing nothing) so that it will be long before I publish: the cirripedia are moreover very troublesome, from their great variability, & the necessity of examining whole animal & inside & outside of shell.— Possibly you may publish your specimens before my monograph; in that case wd it be possible for me to see any duplicates; or in no case must be sent out of the country?—4

Your Sporillus5 sounds very curious; I shd. really like to know whether it is absolutely loose & unattached amongst the sea-weed.—

I am particularly obliged to you for pointing out to me your notice on the metamorphosis of the cirripedia in Silliman’s Journal,6 for I shd. have overlooked it.— You have to a certain extent forestalled me, though we do not take quite the same view on the homologies of the parts.—7 I have, I think, worked out the anatomy of the larva in considerable detail & I hope correctly.—

I have seen Dr. Leidy’s eyes in several genera;8 indeed I had seen & noted them as “like eyes” before reading his paper; but I do not suppose I shd. have followed out what I had seen, had it not been for Dr. Leidy; for these organs are very minute & rudimentary.—

I quite agree with you that the cirripedia are Crustacea— I have lately got a Suctorial form, which bears about same relation to common cirripedia, as Lernæa does to common Crustacea.—9

Once again allow me to thank you for the kindness & frankness of your letter, & believe me, dear Sir, with every good wish & much sympathy | Yours sincerely | C. Darwin

P.S | I wrote to Dr. Baird10 & have just received an answer, begging me to thank you very sincerely for your most kind offer & say how very glad he should be to have the tracings.— His address is “Dr. Baird British Museum London”.— Dr. B. tells me in his letter that Mr Westwood is going to publish a work on the British Edriophthalmic Crustacea, in continuation of Mr Bell’s work,11 & that he was at the British Museum, when my note arrived & that he expressed a strong wish to know whether you have described new genera in this division.— If you chose to forward any thing to him; you cd. do so under cover to Dr Baird: no doubt you are aware how good & sound an Entomologist Westwood is.—

1
CD had asked to borrow cirripede specimens collected by the United States Exploring Expedition, 1838–42, in letter to J. D. Dana, 12 August [1849]. It appears that Dana was unable to provide these, presumably because they were the property of the United States government.
2
Dana had published observations on cirripede metamorphosis (see n. 6, below) and was at this time at work describing the Crustacea from the United States Exploring Expedition (see n. 4, below).
3
Evidently a topic mentioned in Dana’s letter which is now missing. Dana had discussed CD’s theory of coral reefs unfavourably in Dana 1843. See also letter to Charles Lyell, 4 December [1849].
4
Dana, naturalist to the United States Exploring Expedition, was preparing a report on the Crustacea (Dana 1852–3) from the Wilkes expedition. According to Bartlett 1940, p. 657: When he [Dana] heard that Darwin was at work on barnacles, he did little more with this particular subdivision of the Crustacea than to turn over the adult shelled forms to his conchological colleague Gould, and to publish himself certain observations that he had made during the cruise which convinced him that the Cirripedia were not Mollusca. Augustus Addison Gould prepared the Mollusca and shells (Gould 1852–6) of the expedition after the resignation of Joseph Pitty Couthouy (Bartlett 1940, pp. 650–2).
5
Acasta sporillus (a synonym of Euacasta sporillus) (Living Cirripedia (1854): 319–21).
6
Dana described how he examined the metamorphosis of several species of pedunculated cirripedes in Dana 1846, p. 225 n.
7
In Dana 1846, p. 225 n., Dana stated that the pedicel (peduncle) of the Lepadidae (which he called Anatifæ) corresponded to a pair of antennae in the larval stages. CD, however, maintained that the peduncle and all the externally visible parts of Cirripedia corresponded to the three anterior segments of the head of a crustacean. CD further believed that the prehensile antennae were associated with the fronto-lateral horns of the larvae and that they developed into the means of attachment for the organism (Living Cirripedia (1851): 9–10, 28). See also letter from J. D. Dana, [before 29 December 1850], and letter to J. D. Dana, 29 December [1850].
8
Leidy 1848.
9
CD probably refers to the suctorial cirripede Proteolepas bivincta, parasitic within the sack of another barnacle. He described this unusual form in Living Cirripedia (1854): 602: I can hardly express the perplexity which I felt when I first examined Proteolepas, and when I naturally mistook the mouth for the entire head, for I saw, as I thought, the antennæ in direct connection with the second segment of the body, posteriorly to the mouth! It was quite as monstrous and incredible an inversion of the laws of nature, as those fabulous half-human monsters, with an eye seated in the middle of their stomachs. Proteolepas has since been shown to be an isopod crustacean.
10
William Baird, of the zoological department of the British Museum and author of a monograph on the British Entomostraca (a class of Crustacea) published by the Ray Society (Baird 1850).
11
Bate and Westwood 1863–8, a treatise on the sessile-eyed Crustacea, intended to supplement Bell 1853, on the stalk-eyed Crustacea.

Manuscript Alterations and Comments

6.3 what] after del ‘my’
7.2 Suctorial] interl
7.3 Crustacea] after del ‘to’

Please cite as “DCP-LETT-1259,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-1259