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Letter 1481

Darwin, C. R. to Dana, J. D.

8 May [1852]

    Summary Add

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    Gratified by JDD's opinion of his work.

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    Discusses problem of homologies of cirripede larva in first stage and reasons for his view.

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    JDD's information on corals was just what CD needed.

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    Would like specimen of blind cave rat described by B. Silliman [Jr] ["On the Mammoth Cave of Kentucky", Am. J. Sci. 2d ser. 11 (1851): 336] for Waterhouse to examine.

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    Discusses origin of Australian valleys; he disagrees with JDD's river-erosion hypothesis.

Transcription

Down Farnborough Kent

May 8th

My dear Sir

Your letter has given me much pleasure,—more than you would anticipate, & more perhaps than it ought to do,—though I put down part of what you say to the kindness of disposition, which I have observed in your memoirs & in your letters to me. I have had a short letter from M'{u}ller of Berlin, expressing interest in my Book, and now, with what you have said, I feel highly satisfied, & can go on with my work with a good heart: You will perhaps be surprised at all this; but I think everyone wants sympathy in their pursuits, & I live a very retired life in the country, & for months together see no one out of my own large family.

With respect to what you say on the homologies of the larva in the first stage, I confess to have gone through more doubt than on any other part: for some time I thought the three pairs of legs corresponded with the mandibles, the inner & outer maxillæ, for I must still believe in there being (potentially) two pairs of antennæ in the earliest stage; but the description of the larva in the second stage by Burmeister (whose paper by the way is dreadfully incorrect) & the somewhat varying position of the mouth in the first stage, led me to the view which I have taken.— I hope that, whenever you have an opportunity that you will attend to the adhesion of the Lerneidæ:— the method of attachment, which I have described is certainly the great character of the class of Cirripedia.—

I thank you much for your wish for me to have the Cirripedia of the Expedition, but I know well how impossible it is. Your information on the Corals has been most useful; for in the two cases in which you speak most positively, are the very two, to which I have not the smallest clue for habitat.

I am most vexed at the wooden-pill Box with the Crustacean having been lost: I put it in the parcel myself: I suppose the parcel must have been opened at your Custom House & so the little Box lost: I have got Bailliere to write to New York to enquire: I had hoped this would have turned out of some interest to you.—

I have lately been reading the vols. for the last dozen years of Silliman's Journal, with great interest: What a curious account is that on the blind Fauna by Mr Silliman, of the caves.— I feel extreme interest on the subject, having for many years collected facts on variation, &c &c.— Would it be possible to procure one of the Rats for the British Museum? I should so like my friend Mr Waterhouse to examine the teeth & see whether it is an old or new world form. If ever you could oblige the naturalists on this side of the water by getting so interesting a specimen, would you send it to me to give to Waterhouse; for (privately between ourselves) it would be of little use to real science, if once in the hands of Mr Gray; —but very likely I am asking for an impossibility; the rats may be very rare. It is not stated whether the optic nerve was dissected out, which would be a curious point.—

I read over again in the Journal several of your papers; if I had space I should have liked to have fought a friendly battle with you on the Australian valleys; I see I have not stated my side versus fresh water in nearly enough detail.

Did you not observe the great high plain forming peninsulas running laterally into the valleys, (& I suspect almost truly insulated masses); and these seem to me to be very improbable on the running water theory. Again, as far as I saw, [DIAGRAM HERE] Stream & as appears on maps, the line of drainage never seems to lie at foot of precipices on either side; & it appears to me that this might be expected to occur here & there, if the valleys were still in process of excavation.— but I had no intention to discuss this subject when I began, or to trouble you with so very long a letter.

Accept my thanks for your very kind letter, & believe me | Very sincerely your's Charles Darwin.—

    Footnotes Add

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    f1 1481.f1
    CD had sent both Dana and Johannes Peter M'{u}ller presentation copies of Living Cirripedia (1851) (MS attached to CD's copy of Living Cirripedia (1854) in the Cambridge University Library).
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    f2 1481.f2
    Burmeister 1834. CD's unannotated copy is in the Darwin Library–CUL. CD summarised Karl Hermann Konrad Burmeister's description of the second larval stage in Living Cirripedia (1851): 13–14 and Living Cirripedia (1854): 109–10, the latter also including a figure taken from Burmeister 1834 (Plate XXX, fig. 1). In fact, Burmeister's figure does not correspond to any cirripede larval stage. It shows a settled cyprid larva, but with only three pairs of legs instead of the six pairs it should have. CD believed the figure represented an intermediate between the nauplius, with three pairs of appendages, and the final cyprid larva, with six.
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    f3 1481.f3
    See Correspondence vol. 4, letter from J. D. Dana, [before 29 December 1850], n. 4. See also Living Cirripedia (1851): 9–13, where CD discussed his views on the homologies of the two larval antennae, the mouth, and the legs. He held that the eyes, prehensile antennae, and therefore the peduncle were homologous with the first three (cephalic) segments of Crustacea (ibid., p. 25). Concerning the homologies of the larval legs, see letter to J. D. Dana, 6 December [1853], n. 2.
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    f4 1481.f4
    The Lerneidae, an order of parasitic copepods, share several characteristics with the Cirripedia. Like cirripedes, they hatch as a free-swimming nauplius and at the first cyclops stage they settle as parasites on the gills of a flat-fish; later they are transformed again into free-swimming sexual forms. The means by which the larvae, and later the female, attach to the host was obscure in the 1850s, as were their precise taxonomic affinities. See Baird 1851, pp. 307–22 for a contemporary historical account of the systematic arrangement of this group. See also Correspondence vol. 4, letter to Henri Milne-Edwards, 18 November [1847].
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    f5 1481.f5
    See Living Cirripedia (1851): 37 and Living Cirripedia (1854): 151. For CD's attempt to show how the unique cementing system of the cirripedes originated from modifications of an existing organ system, see Correspondence vol. 4, Appendix II, pp. 398–9. CD's belief that the cement gland was a modified ovarian tube led him to misunderstand the structure of the ovaries, the routes of the oviducts, and the function of an organ he identified as an acoustic sac (see Crisp 1983). August David Krohn later correctly recognised that CD's ovarian glands were salivary glands and traced the oviducts to their true openings, CD's so-called auditory sacs (see Krohn 1859 and CD's ‘On the so-called “auditory-sac” of cirripedes’, Collected papers 2: 85–7).
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    f6 1481.f6
    Presumably the specimens were the property of the United States government, sponsor of the expedition on which Dana served as naturalist.
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    f7 1481.f7
    See letter to J. D. Dana, 15 February [1852], n. 5.
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    f8 1481.f8
    The crustacean had accompanied copies of Living Cirripedia (1851) and Fossil Cirripedia (1851) (see letter to J. D. Dana, 15 February [1852]).
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    f9 1481.f9
    Hippolyte Baillière, a bookseller at 219 Regent Street, London. The company of Jean Baptiste Marie Baillière et ses fils had offices in London, Paris, and New York.
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    f10 1481.f10
    American Journal of Science and Arts, edited by Benjamin Silliman Jr and Dana. Dana had married Henrietta Frances Silliman, third daughter of the elder Benjamin Silliman who had founded the American Journal of Science and Arts.
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    f11 1481.f11
    Silliman 1851, pp. 336–7.
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    f12 1481.f12
    CD refers to the blind cave rat in both Natural selection, p. 296, and Origin, pp. 137–8, pointing out that rather than having no eyes or rudimentary eyes, it has eyes of an enormous size. Silliman, who kept one of the rats, thought that, after a few days in light, it regained a slight power of vision. CD concluded that ‘in the case of the cave-rat natural selection seems to have struggled with the loss of light and to have increased the size of the eyes; whereas with all the other inhabitants of the caves, disuse by itself seems to have done its work.’ (Origin, pp. 137–8).
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    f13 1481.f13
    George Robert Waterhouse was considered an authority on the Rodentia.
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    f14 1481.f14
    John Edward Gray, keeper of the zoological department at the British Museum, 1840–74, was notoriously slow in describing specimens sent to him (see Correspondence vol. 2, letter to Leonard Jenyns, 3 December [1837]).
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    f15 1481.f15
    Dana's discussion of the Australian valleys is in Dana 1849, pp. 526–33. His conclusion was that: ‘The idea that running water was the agent in these operations appears not so “preposterous” to us, as it is deemed by Mr. Darwin; and we think it may be shown that Major Mitchell was right in attributing the effects to this cause’ (p. 528). CD's view that the valleys were formed by sea action is in Volcanic islands, pp. 134–7. See also Correspondence vol. 4, letter to Charles Lyell, 4 December [1849]. For his earlier correspondence with Thomas Livingstone Mitchell on Australian valleys, see Correspondence vol. 2, letter to T. L. Mitchell, [1838].
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