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Darwin Correspondence Project

From J. D. Dana   8 September 1856

New Haven,

Sept. 8, 1856.

My dear Sir:—

I received your most welcome letter a few days before the meeting of our Scientific Association:1 and as I should meet Prof. Agassiz2 there, who could best answer your queries respecting the Mammoth Cave Animals, I concluded to defer my answer till my return. Here I am, back again, at last and I seat myself for a few words with you, socially and Scientifically.—

First as to the Mammoth Cave.— Professor Agassiz told me that the family to which the Fishes belong—the Cyprinodonts—was rather strikingly American.3 With regard to the Insects, Dr John L. LeConte an Excellent Entomologist says that the genera of beetles are not American, but the same that occur in Caverns in Europe & elsewhere.4 The genus of fly Anthomyia is common in Europe.5 The Crustacean, Astacus pellucidus, belongs to that subdivision of the genus, (Cambarus, as it has been called), which is peculiarly American. Cambarus is made a distinct genus by some writers: the only difference is in the number of branchiæ: Cambarus has 17, on a side or one less than Astacus.— The Crustacean genus Triura, has not been found any where except at the Mammoth Cave. You may have seen some notice of the species of the Cave in the Amer. Jour. Sci., vol. xi, p. 127 (1851).—6 Of the spiders I cannot speak definitely.— I would add respecting the genus Cambarus, that its Species are very numerous and widely spread over North America. Agassiz has collected a large amount of information on the peculiarities of the North American Fauna, but he has not yet embodied them in any work or article. One of the most interesting of our peculiar tribes, as you undoubtedly know, is that of the Gar-pikes, of which there are several genera & near two dozen known species occurring over the Continent between Cuba & the northern Lakes—and not represented elsewhere over the globe.— It is not to the point in view, yet I may mention here a fact of geological interest brought out by Agassiz at our Assoc. meeting a fortnight since. There were some young individuals, alive, shown, which had the tail of the Ancient Ganoids— That is, the vertebræ were actually continued to the extremity of the upper lobe—7 This upper lobe, as here drawn, drops off as the animal grows & the fish then is of the modern type of form.8


It was a striking illustration of the principle discussed by Agassiz—that the earliest species in Geological history often have relations to the early or embryonic forms of existing species.—9

With respect to Genera represented by both northern & Southern species and not by tropical:—10

There are several which may be as correctly considered northern as southern, or the reverse.

Lithodes is a cold water genus, found about the South Extremity of S. America, and also in the N. Atlantic & N. Pacific. There are 2 known northern species, & 4 Southern. Still I should doubt the propriety of calling it a Southern genus. There is also another closely related genus described by Adam White11 called Echidnocerus found near the mouth of the Columbia R.— I have not seen the species

(The Genus Eurypodius of Southern S. America is represented in Puget’s Sound, by the Genus Oregonia (D.) differing but little.)

Cancer (Platycarcinus of Edw.) occurs about Britain, Eastern North America (northern part of the U.S.), also along the coast of Chili, and about New Zealand & Tasmania; but not in the Tropics. There are 5 species in the N. Temperate Zone, and as many in the South Temperate.

Atelecyclus is found about Britain (3 species), on the coast of Chili (1 sp.), and along Japan (1)   Peltarion is a closely related genus found at the Falkland’s.

Bernhardus, of the Paguridea, is represented quite largely in the North and South temperate zones and not in the warmer tropical zone, as far as known.

Homarus has two species in the North Atlantic, (one American & one European,) and one near Cape Town, in the South Atlantic.

Crangon is one of the northern genera not yet found south.

Portunus is eminently north temperate: but like Cancer, has species both in Britain, and in New Zealand & Tasmania; in no other parts of the globe as far as ascertained do these two genera occur together (see p. 1578 of my work)—12 we may say that it is a northern genus, as the larger part of the known species are in the north. Yet it is possible that if there had been as much coastline in the South, there would have been as many Southern species. In such comparisons the amount of coast line—that is, the extent of possible habitats—is an important element.

I do not know that the facts here stated meet precisely the question you have under consideration: and if not, do not hesitate to put more enquiries, and I will do my best to answer them.— In my Chapter on the subject of Geog. Distribution I should not have used the word Kingdom as I have done.13 Some other term for the great sections of the globe would have been better.

You may have noticed that in citing the chapter in the Amer. Jour. Sci., I changed the name Nova Scotia Province, to Acadian Province14   I have always looked on my review of the Distrib. of Crustacea, as only a beginning, which the future would extend & correct—a first effort, as regards Crustacea, in a field that will yet afford great results. For want of a knowledge of the difference of temperature between the waters of the coasts of Europe & N. America Milne Edwards made poor work in his “Crustacés” (1834) in a chapter on the Distribution of Species;15 and for a like reason, naturalists generally had failed to appreciate the wide difference, in water & land distribution on the same coasts. It is something to know that the plants and birds may have equatorial heat, when the fishes of the neighboring waters are in the temperate zone: & this at least is clear from my survey of the subject.—

As to fossil trees in the South Shetland’s— Dr James Eights says (Transactions of the Albany Institute vol. ii, p. 64)16—(after describing the rocks of the Islands as basalt & a conglomerate, passing into a tufa (if I may judge from his description) and farther into “a fine argillaceous substance with an imperfect slaty structure and a Spanish-brown aspect” often containing zeolites especially near “the incumbent amygdaloid”)— “The only appearance of an organized remain that I any where saw, was a fragment of Carbonized wood, imbedded in this conglomerate. It was in a vertical position, about 212 ft. in length and 4 inches in diameter   Its color is black, exhibiting a fine ligneous structure; the concentric circles are distinctly visible on its superior end; it occasionally gives sparks with steel and effervesces slightly in nitric acid.”—17

The part of your letter which afforded special pleasure was that alluding to your home group—18 I cannot speak of mine as “large”, yet I may as “good & happy”—Fanny the oldest 10 years—Edward, 6 (nearly 7) and James, 3.—19 I was also pleased to hear of Mr Lubbock’s happiness.20 A long life to them full of joys.— Please thank him from me for the pamphlets which he has sent. He is doing excellent work among the Entomostracas,21 and dear little things they are.

—You query as to my whereabouts. My Professorship is here at New Haven where I have been living since the return of the Expl. Expedition after the first two years—in other words, since 1844—the year in which I was married at this place.

I have been interested recently in the “Embryogeny” of N. America, and before many months have past will send you a pamphlet on the subject.— That title sounds queer, yet is not inappropriate: I entitle the article “On the plan of development in the Geological History of N. America”—22 I have not space or time for explanations now and therefore must ask you to wait a little before you set me down as a mere speculator.

With warm wishes for your welfare, I remain | Sincerely your friend | James D. Dana

Ch. Darwin Esq.

CD annotations

0.1 New Haven ... Cave.— 2.1] crossed pencil
2.2 Cyprinodonts] underl pencil
2.2 rather strikingly American] underl pencil
2.7 peculiarly American] underl pencil
3.1 It was ... species.— 3.3] crossed pencil
4.1 With respect ... reverse 5.2] ‘See that I am correct about Crustacea N & S’23 ink
8.1 Platycarcinus] underl pencil
14.1 I do not know ... subject.— 15.11] crossed pencil
15.1 You may ... same coasts 15.9] ‘Silicified Tree Shetlands’ ink
16.1 (Transactions ... p. 64) 16.2] cross in margin pencil
16.7 a fragment ... structure; 16.9] double scored pencil
16.8 vertical position] underl pencil
17.1 The part ... Ch. Darwin Esq. 21.1] crossed pencil
Top of first page: ‘Dana’ pencil; ‘19’24 brown crayon


Letter to J. D. Dana, 14 July [1856] (Correspondence vol. 6). The meeting of the American Association for the Advancement of Science was held in Albany, New York, from 20 to 28 August 1856.
See letter to J. D. Dana, 14 July [1856] and n. 5. The information on fish from the Mammoth Cave, Kentucky, had already been given in J. L. R. Agassiz 1851. CD referred to Dana and Agassiz in his discussion of blind cave animals in Origin, pp. 137–9.
John Lawrence Le Conte was recognised in the United States and elsewhere as the leading American entomologist (DAB).
This sentence was added in the margin.
For the work of Agassiz and others on the classification of the blind crayfishes (Triura), see Winsor 1991, pp. 107–15. Dana refers to J. L. R. Agassiz 1851.
This fact was eventually published in J. L. R. Agassiz 1857.
This letter was published to here, including the drawing, in Correspondence vol. 6. The remaining eight pages in DAR 162: 38 were subsequently discovered to be part of this letter.
Agassiz’s contribution to the theory that the development of a class of organisms as recorded in geological evidence was recapitulated in the development of the embryo was first published in J. L. R. Agassiz 1848. For CD’s assessment of Agassiz’s view, see Origin, pp. 338, 449–50. See also Lurie 1960, pp. 162–3, 285–91.
In the letter to J. D. Dana, 14 July [1856] (Correspondence vol. 6), CD had asked for information on the geographical distribution of northern and southern species of Crustacea. See also Origin, pp. 374–81, and Natural selection, pp. 556–7.
Adam White was a naturalist employed in the zoological department of the British Museum (DNB).
Dana refers to his Crustacea (Dana 1852), volume 13 of the reports of the United States exploring expedition between 1838 and 1842. The page reference given is part of a discussion of the geographical distribution of Crustacea. This section of Dana 1852 is cited in Natural selection, p. 556; see also Origin, pp. 372, 376. The parts of Dana 1852 on the classification and geographical distribution of Crustacea were reprinted separately as Dana 1853a. There is an annotated, inscribed copy of Dana 1853a in the Darwin Library–CUL (see Marginalia 1: 178–9).
See Dana 1852 and 1853a, p. 1554; Dana divided the world into the Occidental, European, Oriental, Arctic, and Antarctic kingdoms. See also Correspondence vol. 5, letter from J. D. Dana, [before 6 December 1855].
Abstracts of Dana’s report on the geographical distribution of Crustacea (Dana 1852) were published in the American Journal of Science and Arts (Dana 1853b and Dana 1854–5). For the reference to the Acadian province, see Dana 1853b, p. 325, and compare Dana 1852 and 1853a, p. 1564.
The reference is to Henri Milne-Edwards and to Milne-Edwards 1834–40, 3: 555–91, ‘De la distribution géographique des crustacés’. CD’s annotated copy of Milne-Edwards 1834–40 is in the Darwin Library–CUL (see Marginalia 1: 579–81). CD had been strongly influenced by Milne-Edwards’s work on classification in his own studies on cirripedes (see Correspondence vol. 4, Appendix II), and dedicated Living Cirripedia (1854) to him.
In his letter to J. D. Dana, 14 July [1856] (Correspondence vol. 6), CD had asked whether any author had described fossil trees in the South Shetland Islands off the coast of Antarctica, and suggested ‘Mr Eights whose writings I have never seen’. James Eights was an American naturalist who had accompanied a voyage of discovery to the South Shetland Islands and published a number of papers on the specimens he brought back (American medical biography, Stewart 1990). The work Dana refers to is Eights 1833–52.
For CD’s interest in this fossil wood, see CD annotations, and Natural selection, p. 579, n. 3.
CD had written, ‘As for myself I live a very quiet & retired life, with a large set of very happy & good children round me’ (Correspondence vol. 6, letter to J. D. Dana, 14 July [1856]).
Dana and his wife, Henrietta Frances, eventually had six children, of whom four survived. Edward Salisbury Dana became the leading mineralogist of the United States. (DAB, ANB.)
Entomostraca was the name used to refer to all crustaceans other than Malacostraca (Leftwich 1973).
Dana’s paper ‘On the plan of development in the geological history of North America’ was published in the American Journal of Science and Arts (Dana 1856); it was also published together with Dana 1855 as a pamphlet, ‘On American geological history’ (New Haven: Ezekial Hayes, 1856). There is an annotated copy of the pamphlet in the Darwin Pamphlet Collection–CUL. CD wrote on the back, ‘(Very poor Pamphlet)’.
See Natural selection, p. 556.
The annotation refers to a portfolio of notes on the distribution of animals. CD kept a number of such portfolios, amassed over a long period of time and since dispersed. The likely contents of some portfolios were reconstructed when some of CD’s papers were catalogued in 1932 (see DAR 220: 13).


Agassiz, Louis. 1857. On some young gar pikes from Lake Ontario. American Journal of Science and Arts 2d ser. 23: 284.

American medical biography: Dictionary of American medical biography. Lives of eminent physicians of the United States and Canada, from the earliest times. By Howard A. Kelly and Walter L. Burrage. New York and London: D. Appleton and Company. 1928.

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.

DAB: Dictionary of American biography. Under the auspices of the American Council of Learned Societies. 20 vols., index, and 10 supplements. New York: Charles Scribner’s Sons; Simon & Schuster Macmillan. London: Oxford University Press; Humphrey Milford. 1928–95.

Dana, James Dwight. 1854–5. On the geographical distribution of Crustacea. American Journal of Science and Arts 2d ser. 18 (1854): 314–26; 19 (1855): 6–15; 20 (1855): 168–78, 349–61.

Dana, James Dwight. 1856. On the plan of development in the geological history of North America. American Journal of Science and Arts 2d ser. 22: 335–49.

DNB: Dictionary of national biography. Edited by Leslie Stephen and Sidney Lee. 63 vols. and 2 supplements (6 vols.). London: Smith, Elder & Co. 1885–1912. Dictionary of national biography 1912–90. Edited by H. W. C. Davis et al. 9 vols. London: Oxford University Press. 1927–96.

Eights, James. 1833–52. Description of a new crustaceous animal (Brongniartia trilobitoides) found on the shores of the South Shetland Islands, with remarks on their natural history. Transactions of the Albany Institute 2: 53–69

Leftwich, A. W. 1973. A dictionary of zoology. 3d edition. London: Constable.

Living Cirripedia (1854): A monograph of the sub-class Cirripedia, with figures of all the species. The Balanidæ (or sessile cirripedes); the Verrucidæ, etc. By Charles Darwin. London: Ray Society. 1854.

Lurie, Edward. 1960. Louis Agassiz: a life in science. Chicago: University of Chicago Press.

Marginalia: Charles Darwin’s marginalia. Edited by Mario A. Di Gregorio with the assistance of Nicholas W. Gill. Vol. 1. New York and London: Garland Publishing. 1990.

Milne-Edwards, Henri. 1834–40. Histoire naturelle des crustacés, comprenant l’anatomie, la physiologie et la classification de ces animaux. 4 vols. Paris: Librairie encyclopédique de Roret.

Natural selection: Charles Darwin’s Natural selection: being the second part of his big species book written from 1856 to 1858. Edited by R. C. Stauffer. Cambridge: Cambridge University Press. 1975.

Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.

Stewart, John. 1990. Antarctica: an encyclopedia. 2 vols. Jefferson, N.C., and London: McFarland & Co.

Winsor, Mary Pickard. 1991. Reading the shape of nature. Comparative zoology at the Agassiz museum. Chicago and London: University of Chicago Press.


Responds to CD’s query about the blind fauna of Mammoth Cave.

Gives information from L. Agassiz. Distribution of Crustacea, especially along southern coastlines.

Letter details

Letter no.
James Dwight Dana
Charles Robert Darwin
Sent from
New Haven
Source of text
DAR 205.3: 269 (Letters), DAR 162: 38
Physical description
ALS 12pp †

Please cite as

Darwin Correspondence Project, “Letter no. 1951,” accessed on 18 May 2024,

Also published in The Correspondence of Charles Darwin, vol. 6 and 13 (Supplement)