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Darwin Correspondence Project

To J. D. Dana   24 February [1850]

Down Farnborough Kent

Feb. 24th.

My dear Sir

I have been truly sorry to have delayed so long in sending the pamphlets,1 but it has not been my fault, or indeed anyones, as Prof. Bell has been delayed unavoidably in getting them together. I shall now send next Wednesday, through Delf all that I have collected from Bell, A. White & Baird: Mr Westwood had intended sending some, but the death of his Father has interrupted him. Dr. Baird will also send a copy of his volume on British Entomostraca2 through Delf.—

I thank you most sincerely for the full answers to all my queries, & I feel somewhat ashamed at the length of them. I am particularly obliged to you & Dr Gould for the Coronula denticulata & even more for Scalpellum, which genus has revealed to me a wonderful story,3 but it is too long here to tell you.— I have written to Dr. Mantell4 about these specimens.— Thank you also for telling me about your notice on my Geology in American Journal,5 which I did not know of.— I always wait for several years, & then read up each Journal in mass— I have read all the early volumes of this excellent periodical.—

Will you be so kind as to give my sincere & respectful thanks to Dr. Pickering;6 I am particularly interested on Geograph. Distrib in Pacific & shall hereafter have occasion to use the list, which shall be shown to my excellent friend Dr. Hooker when he returns from his Botanical tour in India.—

I wished to know about boring crustacea in relation to boring cirripedia.—7 With respect to the oviducts, it is almost too long a story:8 they do not debouch near the antennæ, but a duct does which I believe is homologous with the oviduct of other Crustacea. This duct is the grand characteristic of Cirripedia, a sticky substance or tissue (for I hardly know which to call it) comes out of this duct from a gland & fixes first the anterior part of head of the larva & subsequently of the mature cirripede to whatever substance it becomes attached.— I have not published this yet, except in a very brief notice in Athenæum of a short speech which I made at the British Association Meeting at Birmingham;9 —I have, however, worked out my observations in considerable detail.—

What you tell me of the minute crust in the Creusia, makes me think you wd like to have & describe some specimens which I will send with the Books. Goodsir (poor fellow I fear he must be called the late Goodsir being with Sir J. Franklin)10 described in Eding. New Phil. Journal July 1843) a parasite, which he considered the male Balanus:11 this is quite an error; his male Balanus is a female, of which I send specimens gorged with ova containing larvæ: his parasite is, I believe, the male of this female, as the character of the little larvæ show, & comes near to Ionus (NB it is pretty this paratism, considering that cirripedia are crustacea).12 My specimens I find have been rather injured by mould, but I think you will be able to clean them. I found them attached & parasitic within the so-called sack of a Balanus (from South Wales) with a membranous basis which is the commonest British species on tidal rocks— British authors often call it (I believe incorrectly) Balanus punctatus— one of its varieties is Lepas elongatus of old authors.— Though Mr Goodsir was wrong about this case, I may remark as an odd fact, that I have 3 species in two genera of bisexual cirripedia, with the males parasitic on the females; in one of these cases there are always 2 males to one female, the males being lodged in little pockets in the shell of the female!13 The compound animal is a real case of Diandria monogynia14 in Animals!!

Yours most sincerely obliged | C. Darwin

P.S 1 | I have lately been working at fossil Secondary Pedunculate Cirripedia— Have you ever heard of any having been found in America?

P.S. 2. You will see in next number of Geolog. Journal, that Sir C. Lyell has read your volcanic Chapters & he was very much interested by them.15


CD refers to the complemental males in some species of Scalpellum. See Living Cirripedia (1851): 215–81.
The notice of South America appeared in American Journal of Science and Arts 2d ser. 3 (1847): 146, of which Dana was an editor.
Published in the Athenæum, no. 1143, 22 September 1849 (Collected papers 1: 250–1).
Henry D. S. (Harry) Goodsir, physician with the Franklin expedition of 1845. By this date, none of the many search expeditions had yet discovered the fate of the expedition.
See Living Cirripedia (1851): 55 n., where CD made the same point. This parasitic crustacean he there described as related to Bopyrus, in which, as in the Lernaea, the males are much smaller than, and different in appearance from, the females. This parasite is now known as Hemioniscus balani. Ione was a genus of parasitic isopods.
Scalpellum ornatum, Ibla cumingii, and S. rutilum (Living Cirripedia (1851): 183, 248, and 253).
Plants with two stamens and one pistil. CD repeated this point in Fossil Cirripedia (1851): 15, and in Living Cirripedia (1851): 248.
Lyell had added a discussion of Dana’s views to C. Lyell 1850a, as CD recommended in letter to Charles Lyell, [7? December 1849].


Baird, William. 1850. The natural history of the British Entomostraca. London.

Collected papers: The collected papers of Charles Darwin. Edited by Paul H. Barrett. 2 vols. Chicago and London: University of Chicago Press. 1977.

Fossil Cirripedia (1851): A monograph on the fossil Lepadidæ, or, pedunculated cirripedes of Great Britain. By Charles Darwin. London: Palaeontographical Society. 1851.

Goodsir, Henry D. S. 1843. On the sexes, organs of reproduction, and mode of development, of the cirripeds. Account of the Maidre of the fishermen, and descriptions of some new species of crustaceans. Edinburgh New Philosophical Journal 35: 88–104.

Living Cirripedia (1851): A monograph of the sub-class Cirripedia, with figures of all the species. The Lepadidæ; or, pedunculated cirripedes. By Charles Darwin. London: Ray Society. 1851.

South America: Geological observations on South America. Being the third 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. 1846.


Regrets delay in sending pamphlets for JDD.

Thanks him for information concerning cirripedes.

Sends thanks to Charles Pickering for information about plant distribution.

Discusses boring species of cirripedes.

Believes Harry D. S. Goodsir mistaken about parasites on Balanus ["Observations on organs of generation in Crustacea", Edinburgh New Philos. J. 36 (1843–4): 183–6]. In fact parasites are the males of the species.

Letter details

Letter no.
Charles Robert Darwin
James Dwight Dana
Sent from
Source of text
Yale University Library: Manuscripts and Archives (Dana Family Papers (MS 164) Series 1, Box 2, folder 43)
Physical description
ALS 4pp

Please cite as

Darwin Correspondence Project, “Letter no. 1305,” accessed on 9 February 2023,

Also published in The Correspondence of Charles Darwin, vol. 4