To J. D. Dana   6 December [1853]

Down Bromley Kent.

Dec. 6th.—

My dear Sir

I must thank you for your letter, received about a fortnight ago— It was extremely kind of you to write to Mr. Lubbock, & I think he was much pleased & flattered at receiving your letter.—1 I am very glad you mentioned your objection to my views on the nature of the three pairs of appendages in the earliest stage of cirripedes;2 by an odd chance I was at the time searching for all sorts of evidence, & had just dissected the larva of an Hippolyte (sent me by Mr C. S. Bate) & as far as sequence goes, I find M. Joly’s views, that the three natatory pairs of legs are the 3 pairs of maxillipeds, are true for they closely follow the 2 pairs of jaws & mandibles.—3

Since my former volume I have gone into the curious case of a S. American cirripede in which the larvæ in all the first stages are typified by an egg-like larva, with the pairs of anterior horns, & posterior horn including the abdomen: & in this case I actually dissected out of the anterior horns the usual prehensile antennæ, with every part perfect. Indeed it is very certain that the larva in the first stage has 2 pairs of antennæ in process of development;4 a mouth as yet without the 3 pairs of gnathites; & the 3 pair of natatory legs, which may be, as in Hippolyte, the 3 pairs of maxillipeds, & Caridina, but which I fully believe are the 2d. 3d. 4th thoracic limbs.5

I have entered all these points with care in my present volume; & I cannot say, how I shd. be gratified if you could ever find time to criticise it. I presume I shall not get it printed for 4 or 5 months, but I will, when printed, of course send you a copy.6 It will be more fully illustrated than the last.— I shd. say that I have found many useful hints & cautions in your great work.—7 By the way I have received the duplicate page.—8

I am not much surprised at your correspondence with A. White having failed: I am told by some of his friends, poor fellow, that he has been for some considerable time, somewhat flighty in his head:9 I have long perceived that though very clever, that he wd. not do much from his fickleness.— There is, I hope, a rising Crustaceologist in Mr C. S. Bate (to whom I am soon going to lend your Book): he is an ardent observer, though I apprehend rather rash in theorising, & what is worse in observing: I suspect he trusts to the compound microscope & does not dissect enough, which I believe to be a fatal habit— He is intending to publish with Mr. Westwood, a monograph of sessile-eyed crustaceans of Britain.10 Bell is too busy ever I fear to do much;11 he is a delightful, kind-hearted person. Dr. Baird is a very goodnatured man, but rather indolent, & occupied with routine business at the B. Museum & I doubt whether very original,12 and this includes, as far as I know, all the English Crustaceologists; & I have confidentially given you what I think of them.

Sir C. & Lady Lyell were staying here a short time since: they start in two days time for Madeira & the Canaries, to work out Craters of Elevation or of Denudation; & he is well charged with points to observe.—13

To return to Crustacea were you not rather surprised at Milne Edwards new classification in the Annales for 185⁠⟨⁠  ⁠⟩⁠?—14 I was astonished at parts & could not at all, understand his reasons:— But I have an unbounded respect for M. Edwards as a Naturalist15 From some old theoretical notions, I was interested by what you say about Crustacea not having been most developed in Tropics:16 should you ever work this out in other branches, either in regard to mere numbers of species, or their rank I shd. be particularly glad to hear the result. At one time Dr. Hooker (who is a first rate naturalist, after your own heart) thought that a greater number of species of plants existed in the warmer temperate lands than under torrid zone; but he now doubts whether there are materials to determine this point.

Believe me, Your’s very sincerely & cordially | C. Darwin

1
In his letter to J. D. Dana, 27 September [1853], CD wrote about John Lubbock: ‘if you can ever give him a little encouragement it would really be a good service, for he … may do good work in Natural History.’
2
In Living Cirripedia (1854): 107, CD wrote ‘With regard to the homologies of these three pairs of limbs, my first impression was that they were the mandibles and the two pairs of maxillæ in their earliest condition; but I consider this view as quite untenable, for several reasons’ and he cited a passage from Dana 1852–3, pt 2, p. 1386, in which Dana stated that he knew of ‘no instance of a mandible becoming so completely a leg, as to lose wholly the mandibular function, even of its basal portion.’ The French philosophical anatomists, followers of the work of étienne Geoffroy Saint-Hilaire, had first suggested a homology between certain mouth parts of Crustacea and the legs of insects (Appel 1987, p. 94). The homologies of the ‘pied-machoirs’ were current in the classification of Crustacea and were used by CD in classifying the barnacles.
3
This notion is expressed in Living Cirripedia (1854): 107–8 n.: ‘A far more tenable view is that these three pairs of legs are the three pairs of maxillipeds, in their earliest condition, in accordance with the view of M. Joly on the nature of the three very similar pairs of natatory legs in the larva of Caridina, a macrourous Crustacean.’ CD cited Joly 1843 and thanked Charles Spence Bate for providing him with specimens of an allied genus, Hippolyte varians.
4
CD refers to Cryptophialus minutus; this description was repeated in Living Cirripedia (1854): 106, 580. CD and Dana had earlier disagreed over the homologies of the two pairs of larval antenna. See Correspondence vol. 4, letter from J. D. Dana, [before 29 December 1850], and letter to J. D. Dana, 29 December [1850]; see also letter to J. D. Dana, 8 May [1852].
5
Living Cirripedia (1854): 106–8 and nn.
6
Dana’s name appears on CD’s list of presentation copies of Living Cirripedia (1854) (MS attached to CD’s copy of Living Cirripedia (1854) in the Cambridge University Library). Dana had earlier reviewed Living Cirripedia (1851) for the American Journal of Science and Arts (see letter to J. D. Dana, 25 November [1852]). Living Cirripedia (1854) was noticed in American Journal of Science and Arts 2d ser. 19 (1855): 272.
7
Dana 1852–3.
8
Probably from Dana 1853 (see letter to J. D. Dana, 10 October [1853]). One leaf in CD’s copy (pp. 1475–6) is a different size from the others.
9
Adam White was an assistant in the zoology department of the British Museum. In 1851 CD wrote a testimonial for him (letter to Adam White, 26 December 1851). In 1863, White became an inmate of a Scottish asylum (DNB).
10
Bate and Westwood 1863–8, a treatise on the sessile-eyed Crustacea, intended to supplement Bell 1853, on the stalk-eyed Crustacea.
11
Thomas Bell was at this time serving as president of the Linnean Society and president of the Ray Society, as well as performing his professional duties at Guy’s Hospital and King’s College, London.
12
William Baird, a Scottish physician practising in London and employed in the zoological department of the British Museum. He was the author of a monograph on the British Entomostraca, the lower Crustacea (Baird 1850).
13
Lyell had published a paper on ‘Craters of denudation’ in 1850 in which Dana’s geological work was discussed (C. Lyell 1850; see Correspondence vol. 4, letter to Charles Lyell, [1 November 1849]). He and Mary Lyell, together with Frances Joanna and Charles James Fox Bunbury, arrived in Madeira on 18 December. On 18 February 1854 they landed in Tenerife and remained in the Canary Islands until mid-April (F. J. Bunbury ed. 1891–3, Middle Life 2: 161, 225, 275). Just before leaving Madeira, Bunbury commented: ‘As for Lyell, I do not think that, except when asleep, he has been stationary anywhere for two hours, since we arrived.’ (ibid., p. 211).
14
In Milne-Edwards 1852, Henri Milne-Edwards revised his earlier classification of Crustacea (Milne-Edwards 1834–40), placing high taxonomic value on the mouth parts in determining orders and on his principle of retrograde development in viewing some forms as degraded members of a certain type. Both Dana (Dana 1852–3, pt 1, p. 9) and CD (Living Cirripedia (1854): 565 n.) had reservations about using these criteria. In his general discussion of the classification of Crustacea (ibid., p. 11), CD compared Milne-Edwards’s and Dana’s views: In the classification of Crustacea, the relation and number of the segments of the different parts of the body, are viewed both by Prof. Milne Edwards and Mr. Dana, as of the highest importance. I may premise that both these authors divide the Crustacea into Podophthalmia, Edriophthalmia, and Entomostraca; Milne Edwards making a fourth legion, the Branchiopoda, and another division, including Limulus, of equal value to the above four legions altogether; whereas Dana sinks Limulus and the Branchiopoda under his Entomostraca. As far as concerns our present discussion on Cirripedes, the first three divisions, as valued by Dana, will best serve as standards of comparison; but it is not unimportant to our present purpose, as showing how difficult it is to weigh the value of the higher divisions of a Class, to observe the wide difference in opinion of two naturalists, so eminent for their knowledge of the class in question and for their high abilities.
15
CD dedicated Living Cirripedia (1854) to Milne-Edwards, ‘with the most sincere respect, as the only, though very inadequate acknowledgment which the author can make of his great and continued obligations to the “Histoire Naturelle des Crustacés,” and to the other memoirs and works on natural history published by this illustrious naturalist.’ See also Correspondence vol. 4, Appendix II.
16
In Dana 1853, p. 1501, Dana stated that ‘the highest development of the class Crustacea takes place, not in the Torrid zone, the most profuse in life, but beyond the tropics and coral-reef seas, in the middle Temperate Regions.’

Manuscript Alterations and Comments

1.1 ago—] ‘—’ over ‘:’
1.7 find] over ‘found’
1.8 are true] interl
2.8 & Caridina,] after del ‘as in Hippolyte’
3.5 found] above del ‘marked’
4.1 having failed] interl
6.3 all,] added
6.6 either … rank 6.7] interl
6.9 lands] interl

Please cite as “DCP-LETT-1542,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-1542