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Darwin Correspondence Project

To C. S. Bate   1 April [1853]

Down Farnborough Kent

April 1st

My dear Sir

I am very much obliged to you for the specimens on the Slate & Old Red Sandstone: they certainly show no boring, as I anticipated wd be the case:1 as you have examined many specimens I will venture to quote you.2 I shd. be still very glad to get some on limestone, especially on impure limestone. I fully believe verruca burrows to the very slight degree it ever does, by some solvent; & it has ducts opening on its under side which might emit some solvent or carbonic acid gas as you suggest. In the only 3 other known, & much more effective, burrowing cirripedes;3 I think the evidence is quite sufficient to show that it is mechanical. Perhaps you may think it worth while to read what I have said under Lithotrya:4 the points being worn, (& then periodically renewed) shows to demonstration that there is friction.

If you go on, (as I do not doubt) with your microscopic investigations, I wish I cd. persuade you to reinvestigate, what I have described on the Complemental Males of Scalpellum vulgare, so common on your coasts:—5 You must, however, dissect a good deal under the simple microscope: in all probability you would find out something new, & the subject in my (perhaps prejudiced) eyes seems very curious.— In your researches do you use boiling strong caustic potash for 14 of an hour? it is really beautiful the way it dissolves every thing, except the external integument (leaving them like glass) of the articulata.6

With very many thanks | Believe me Your’s truly | C. Darwin


See letter to C. S. Bate, 10 January [1853], in which CD asked Bate to collect specimens of Verruca strömia attached to rocks of different kinds. CD wished to verify his hypothesis that Verruca burrowed by means of a solvent that acted only on calcareous surfaces.
‘Mr. Bate, to whom I am indebted for some of these specimens, also informs me that he could discover no impressions on the slate-rocks, whence specimens of the Verruca had been removed.’ (Living Cirripedia (1854): 514).
Alcippe, Lithotrya, and Cryptophialus.
CD discussed the burrowing power of Lithotrya in Living Cirripedia (1851): 336–48.
CD thought he was justified in considering the ‘parasites’ living on the shell of Scalpellum vulgare as complemental males, although he added in a footnote that he hoped that ‘some naturalist, with more skill than I possess, will examine these parasites on Scalpellum vulgare, which unfortunately is the only species of the genus that can be easily obtained.’ (Living Cirripedia (1851): 243 n.).
CD had earlier advised Bate in the technique of dissecting and preserving cirripede specimens (see letter to C. S. Bate, 18 August [1851]).


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.

Living Cirripedia (1854): A monograph of the sub-class Cirripedia, with figures of all the species. The Balanidæ (or sessile cirripedes); the Verrucidæ, etc. By Charles Darwin. London: Ray Society. 1854.


Thanks for specimens of cirripedes attached to rocks, which show no boring. CD hopes to see some on limestone.

Encourages CSB to do research on the complemental males of Scalpellum vulgare.

Letter details

Letter no.
Charles Robert Darwin
Charles Spence Bate
Sent from
Source of text
American Philosophical Society (Mss.B.D25.)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 1511,” accessed on 4 August 2021,

Also published in The Correspondence of Charles Darwin, vol. 5