To Charles Spence Bate   13 June [1851]

Down, Farnborough Kent.

June 13th—.

Dear Sir.

I am very much obliged to you for so kindly sending me the excellent drawings of the 2nd leg of the larva in the different stages,1 & for giving me permission to refer to your paper as if published;2 & that it will most likely be before my volume which will include in the introduction a mere brief abstract on the anatomy of the cirripedia.— With regard to the metamorphoses my chief work has been in the last stage—& I have done the anatomy in much detail at that period.— It has occurred to me before now, to have been working hard at a subject, & then found that my results had been previously published, & very much provoked I have felt.—3 therefore I can appreciate & admire the very pleasant manner in which you received my unpleasant tidings.—4 I think you will find it useful to preserve small objects, in a way in which I have been accustomed to preserve the results of most of my minute anatomical researches, namely in common water without any spirits, with a Bit of thin glass over the object (without any cell) & gold size all round the rough edge—objects thus prepared will sometimes keep for a long time & generally for some months.—5 If you are inclined to take the trouble to rear any larvæ to the second stage, you could so send them me or better in a very minute bottle of spirits—6 Every cirripede that I dissect I preserve the jaws &c. &c. in this manner, which takes no time & often comes in very useful. This very day I have been using preparations thus made two years since, & they are perfectly clear & with some colour preserved, As I am in the way of suggesting—I would strongly advise you to get one of the glass ruled micrometers to slip in eye piece, the whole does not cost much above half a guinea, you would only have to send medium eyepiece to London & you could measure to the 120,000th or less of an inch, without delaying your work half a minute.—7

With every good wish—Believe me | Dear Sir. | Yours faithfully. | C. Darwin

P.S. I suppose the Balanus which you call balanoides encrusts the rocks between high & low water, & are not very large— I ask as a caution, because there are three or four British species, but only one common on tidal rocks, At Tenby there is however a large, dark coloured steeply conical kind common on tidal rocks—viz—B. perforatus.8

1
CD had asked Edward Forbes to ask Bate for specimens (see letter to Edward Forbes, [1 May – 5 June 1851]). CD was particularly interested in Bate’s description of the basal segments of the legs in larvae and referred to this in Living Cirripedia (1851): 11.
2
See letter to Edward Forbes, [1 May – 5 June 1851], in which CD commented on a manuscript version of Bate 1851. Bate 1851 appeared in the October issue of the Annals and Magazine of Natural History while Living Cirripedia (1851) was in the press.
3
A reference to CD’s explanation of the geographical distribution of Arctic and alpine plants, which had been anticipated by Edward Forbes in Forbes 1846 (see Browne 1983, pp. 123–7). In his Autobiography, p. 124, CD recorded that: I was forestalled in only one important point, which my vanity has always made me regret, namely, the explanation by means of the Glacial period of the presence of the same species of plants and of some few animals on distant mountain summits and in the arctic regions.
4
See letter to Edward Forbes, [1 May – 5 June 1851], in which CD discussed the considerable literature on the developmental history of the Cirripedia of which Bate was unaware.
5
CD’s method for preserving specimens accords well with that recommended by John Thomas Quekett (Quekett 1852, pp. 283–4). Gold size was one of several cements used to fasten the cover slip to a slide. Many of CD’s cirripede preparations in the collection given by Francis Darwin in 1870 to the Cambridge University Museum of Zoology are still well preserved after 140 years, although in some cases the cement has run in and spoiled the specimens.
6
See letter to C. S. Bate, 18 August [1851]. In Bate 1851, pp. 328–9, the author stated: ‘Unfortunately … I have not been able, even with the greatest care and watchfulness, to preserve the young creature alive, so as to have the successive forms through which it passes’. CD was unaware that there is, in fact, no second stage larva as depicted in Burmeister 1834 and reproduced in Living Cirripedia (1854), Plate XXX, fig. 1 (see letter to J. D. Dana, 8 May [1852], n. 2).
7
CD presumably used the negative eye-piece micrometer designed for his Smith and Beck dissecting microscope (see Correspondence vol. 4, letter to Richard Owen, [26 March 1848], and also Beck 1865). A good example of CD’s use of the micrometer is found in the table on the generic characters of the larval prehensile antennae in Living Cirripedia (1851): 286–7. He gave the dimensions of the larval antennae in various genera to 120000 of an inch.
8
Bate’s paper treated the development of five species of Balanidae, including Balanus balanoides, B. porcatus, and B. perforatus.

Please cite as “DCP-LETT-1340,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-1340