Gratified by what RO says about his book [Living Cirripedia, vol. 1 (1851)]. The anatomical work is the only part he is really interested in; finds the "mere systematic part infinitely tedious"; but will be surprised if he is ever proved wrong on the males of Ibla and Scalpellum.
Down Farnborough Kent
I will forward by this post the correspondence to Capt. Nelson. I have told him that an abstract will certainly (as I presume) appear which I hope will in some degree satisfy him.—
I cannot tell you how much gratified I am at what you say about the Cirripedia. I really feel rewarded for more labour than you would readily believe it possible could have been bestowed on the work. I have, however, made a mess of it for I got so frightened at the thoughts of all the sessile species, that I have not illustrated & given in nearly detail enough my anatomical work, which is the only part of the work which has really interested me. I find the mere systematic part infinitely tedious. I can, however, honestly state that all that I have said on the males of Ibla & Scalpellum is the result of the most careful & repeated observations. If I am ever proved wrong in it, I shall be surprised. But my pen is running away with me,—it is your fault for I have been so much pleased with what you say.
Making out the homologies of the shell & external parts of Cirripedes, as I fully believe correctly, (and I am glad to say that Dana admits the view) gave me great satisfaction— But I must not bore you with my triumph—
I have been very seldom in London for the last year, when I was last there, I called at the College to see you, but you were just gone out.
Pray believe me in a great state of triump, pride vanity, conceit &c &c &c
Yours sincerely | Charles Darwin
- f1 1484.f1The date is based on the publication of Living Cirripedia (1851), in which CD discussed the males of Ibla and Scalpellum (see n. 4, below).
- f2 1484.f2Richard John Nelson had studied coral formations in the Bermudas as well as the geology of the islands (DNB).
- f3 1484.f3CD's description of the anatomy of Lepadidae ran to fifty-five pages in Living Cirripedia (1851): 8–63 and included few illustrations of anatomical parts. In Living Cirripedia (1854), however, there is a 120-page discussion of the anatomical characteristics of the Balanidae and illustrations of the larval stages, mouth, thorax, nervous system, and cementing apparatus.
- f4 1484.f4The existence in Ibla and Scalpellum of true males and females, and of complemental males with hermaphrodites, are discussed in Living Cirripedia (1851): 207–14, 231–44, and summarised on pp. 281–93.
- f5 1484.f5CD's discovery of males in these genera has not been challenged.
- f6 1484.f6CD based his views on the homologies of cirripedes on Henri Milne-Edwards's description of the twenty-one segments of an archetypal crustacean (Milne-Edwards 1834–40, 1: 13–14). CD identified seventeen of these twenty-one segments in cirripedes, assuming the four terminal abdominal segments were lacking. This enabled him to make out anatomical features of the Cirripedia which had hitherto been obscure. See Living Cirripedia (1851): 25–8, and Correspondence vol. 4, Appendix II.
- f7 1484.f7James Dwight Dana originally held the view that the peduncle of Lepadidae corresponded to a pair of larval antennae (Dana 1846 and Living Cirripedia (1851): 26 n.). Dana also believed that, analogous to the Crustacea, the inferior pair of larval antennae, rather than the superior, were developed in cirripedes (see Correspondence vol. 4, letter from J. D. Dana, [before 29 December 1850]). CD had apparently convinced Dana that the superior antennae were actually the pair that were developed in the Cirripedia and which later became the prehensile antennae of the adult (see Living Cirripedia (1854): 114). Dana presumably also agreed with CD's view that ‘All that we externally see of a Cirripede, whether pedunculated or sessile, is the three anterior segments of the head of a Crustacean, with its anterior end permanently cemented to a surface of attachment, and with its posterior end projecting vertically from it.’ (Living Cirripedia (1851): 28).
- f8 1484.f8According to Emma Darwin's diary, CD was in London from 2 to 5 June 1852, but was unwell for part of the time.