Thanks AH for specimens of Alcippe.
Discusses capacity of Lithotrya to bore its own hole. Believes Arthrobalanus also makes cavities this way.
Asks to see paper on cirripedes by Sven Lovén.
Comments on paper by AH [see 1253].
Down Farnborough Kent
I am truly obliged to you for your very kind letter & offer of specimens of Alcippe.— You cannot imagine how much I shall enjoy seeing in your Paper & in actual specimens a new form of cirripede; for I am wearied out with examining scores & scores of closely allied common cirripedes.—
I venture to predict that if you take the outer tissue of Alcippe & clear the corium from it & place it under the compound microscope, you will find the rasping minute points, & I believe you state that it inhabits shells abounding with cavities of Cliona &c &c.—
I am most particularly obliged to you for informing me of Lovens cirripede, of which I had not heard.— I
I presume you have a superabundance of materials, but if at any time you
Once again allow me to thank you cordially for the very kind manner in which you have
taken my request & believe me, dear Sir | Your's sincerely
obliged | C. Darwin
To | A. Hancock Esq
I see in the Athenæum they have omitted to express how valuable I thought
your discovery & how interesting your whole paper.— I am very curious to see what you say about the palpi, I c
- f1 1256.f1See letter to Albany Hancock, [c. 21 September 1849]. In Living Cirripedia (1854): 527, CD thanked Hancock, ‘to whose very great kindness I am indebted for permission to dissect and examine his entire stock of this truly remarkable Cirripede.’
- f2 1256.f2Alcippe lampas was the new species of burrowing cirripede described in A. Hancock 1849b.
- f3 1256.f3In his lecture presented at the Birmingham meeting of the British Association in 1849, Hancock stated that Alcippe was the only cirripede known to burrow into a chamber of its own making. He mentioned that Lithotrya, the other genus believed to burrow, rather appeared to inhabit pre-existing cavities in calcareous bodies. CD disagreed with this opinion. In his comments on Hancock's presentation, he stated: ‘had Mr. Hancock examined specimens, instead of drawings, of the Lithotria in rock, he would almost certainly have acknowledged its power of excavating cavities.—’ (Collected papers 1: 251).
- f4 1256.f4In Living Cirripedia (1851): 344–8, CD discussed the secretion of the ‘cups’ in which the barnacle sat in its burrow, and how they were only indirectly related to the excavating activities of Lithotrya. Hancock appended a note to the discussion of Lithotrya in his paper on Alcippe (A. Hancock 1849b, p. 313 n.):
Whilst this was passing through the press I have been assured by Mr. C. Darwin, and his opinion on this subject is of the greatest value, that the dorsal cup of Lithotrya is undoubtedly formed by the animal, and that it has the power of enlarging the cavities in which the larva takes up its abode.He remained, however, unconvinced (see especially letter to Albany Hancock, 25 December ).
- f5 1256.f5Living Cirripedia (1854): 568, 570.
- f6 1256.f6CD's original description of Arthrobalanus is in DAR 31.2: 305–8. His drawings are in DAR 29.3: 72, and are reproduced in Correspondence vol. 3, facing p. 320.
- f7 1256.f7Alepas squalicola, named and described by Sven Lovén in Lovén 1844. CD concluded that it formed a new genus and renamed it Anelasma squalicola. See Living Cirripedia (1851): 169–80.
- f8 1256.f8Joshua Alder, with whom Hancock published Alder and Hancock 1845–55, a study of the nudibranchiate Mollusca.
- f9 1256.f9CD refers to Xenobalanus, a genus of sessile cirripedes. In Living Cirripedia (1854): 439, CD related his dismay when, believing the group to be among pedunculated barnacles, he found that it did not accord well with the defining characteristics of this family. But upon dissection he discovered a rudimentary shell, ‘of which a mere fragment would equally well have declared the true position and relationship of the whole animal [among the sessile cirripedes].’ The general resemblance of Alepas (renamed Anelasma) and Xenobalanus prompted CD to consider whether the former genus did not also belong among the Balanidae, but he finally decided the two genera were only analogically similar (Living Cirripedia (1854): 445–6). See also letter to J. J. S. Steenstrup, 30 December , n. 2.
- f10 1256.f10CD had retained most of his specimens of marine invertebrates, although some apparently went to the Royal College of Surgeons (see letter to J. T. Quekett, 7 September ). For CD's collection of nudibranchs, see letter to Albany Hancock, [26 January – March 1850], n. 3.
- f11 1256.f11See n. 3, above.
- f12 1256.f12See letter to Albany Hancock, [c. 21 September 1849], n. 8.