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Darwin Correspondence Project

From Asa Gray   [10–16] June [1863]1

Cambridge. [Mass.]

June ⁠⟨⁠    ⁠⟩⁠

My Dear Darwin,

I am kept distracting⁠⟨⁠ly⁠⟩⁠ busy. So look for nothing of any use from me yet a while

Your Ohio case of law against marrying of cousins, I put to my neighbor, Prof. Parsons, who had it looked up.2 He tells me there is no such law at all on the Ohio Statute-books—nor is there a trace of any law on the subject to be found in the laws of any State in U.S. He doubts if there can really be any statistics which tell on the point, because 1. the marriage of 1st cousins is a rare thing in this country.— 2. the U.S. decennial Censuses do not afford any information on the matter.— 3. Nor any of the ⁠⟨⁠states’⁠⟩⁠ Census that he knows ⁠⟨⁠of.⁠⟩⁠

Campanula perfoliata seed I am trying to procure for you.3

Phloxes.4 Last spring Dr. Torrey5—who has been examining Polemoniaceæ—told me that—the stamens remaining the same—some species have long styles, and other nearly related species short styles. I suggested dimorphism,—but he said they varied also in the no. of ovules. I have wished to look at Phloxes in this light—being confident that this means dimorphism.— But no wild ones grow in this region. Perhaps I can get seed from the West.—

Engelmann is the only reliable man,—probably because he is very busy.6 I shall ask him. As I have lately been taking trouble for him, he will probably reciprocate.

Pray dont run mad over phyllotaxis! I can’t save you, I am sure.7

George’s ‘Converging sines’ is the same, perhaps, as what Bravais was after. His memoir may help you. (See Bot. Text Book, p. 141, par. 248)8 Or, if you want something thoroughly mathematical, consult Neumann, of Berlin, in some paper—which I have no reference to.9

I have never meddled with this mathematical stuff. Hooker is quite mistaken.10 But Prof. Peirce (our mathematical Prof. did so years ago, but ran off into the sky, dementedly—for which folly see Agassiz Contrib. vol. 1.—11 It is not by me now.

—Oh, I see what Hooker was referring to. See the last pages of Proceedings of the American Association for the advancement of Science, 1849, vol. 2.12

You ask me for copy of article on De Candolle—on species.—13 Why, I posted a copy to you—at the time, and you seem to refer to it. Do you mean to ask for a 2d copy. But my copies are exhausted quite.

If yours failed, I will try to get the sheets for you.— I dare say I can do so.

Never had I so much work to do in the University—lecturing & teaching all the while.14 It quite uses me up.

I am sorry you do not give a better account of yourself. Be careful, and do not work too hard

Ever Yours | A. Gray


This letter was written before Gray received CD’s letter of 31 May [1863], and was received by CD on or before 26 June (see letter to Asa Gray, 26 June [1863]); allowing ten to eleven days for the crossing of the Atlantic by mail packet, it was therefore probably written between 10 and 16 June 1863.
See letter to Asa Gray, 20 April [1863]. Theophilus Parsons was Dane Professor of law at the Harvard Law School (WWWA).
CD thought that some species of Phlox might be dimorphic (see letter from Isaac Anderson-Henry, 24 April 1863, and letter to Isaac Anderson-Henry, 2 May [1863]); he probably asked Gray his opinion either in a missing postscript to his letter to Gray of 11 May [1863], or in a letter that has not been found.
The botanist John Torrey was Gray’s friend and mentor (Dupree 1959).
The botanist George Engelmann was a very successful physician practising in St Louis, Missouri (DAB).
Gray refers to George Howard Darwin, who was assisting his father in analysing the arrangement of leaves around the stems of plants (see letter to Asa Gray, 11 May [1863]). Gray discussed the work of ‘M. Bravais’ on phyllotaxy in A. Gray 1858a, p. 141; a specific publication is not cited, but the reference is evidently to the numerous papers on phyllotaxy published by Auguste and Louis Bravais in the 1830s (see Royal Society catalogue of scientific papers and DSB).
Gray probably refers to Karl Friedrich Naumann, who published several papers on phyllotaxy, beginning with Naumann 1842 (Royal Society catalogue of scientific papers). See also Naumann 1845.
See letter to Asa Gray, 11 May [1863] and n. 12; the reference is to Joseph Dalton Hooker.
Benjamin Peirce was Perkins Professor of astronomy and mathematics at Harvard University (DAB). In the first volume of his Contributions to the natural history of the United States of America (Agassiz 1857–62, 1: 128–9), Louis Agassiz stated that Peirce had discovered ‘the most perfect identity’ between the laws regulating the arrangement of the leaves in plants, and the revolutions of the planets in the solar system.
Gray reviewed A. de Candolle 1862a in the May 1863 number of the American Journal of Science and Arts (A. Gray 1863d). See letters to Asa Gray, 11 May [1863] and 31 May [1863].
Gray had been Fisher Professor of natural history at Harvard University since 1842 (Dupree 1959).


Agassiz, Louis. 1857–62. Contributions to the natural history of the United States of America. 4 vols. Boston, Mass.: Little, Brown & Company. London: Trübner.

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.

DSB: Dictionary of scientific biography. Edited by Charles Coulston Gillispie and Frederic L. Holmes. 18 vols. including index and supplements. New York: Charles Scribner’s Sons. 1970–90.

Dupree, Anderson Hunter. 1959. Asa Gray, 1810–1888. Cambridge, Mass.: Belknap Press of Harvard University.

Gray, Asa. 1849. On the composition of the plant by phytons, and some applications of phyllotaxis. Proceedings of the American Association for the Advancement of Science; second meeting, held at Cambridge, Massachusetts, August 1849, pp. 438–44.

Naumann, Karl Friedrich. 1842. Uber den Quincunx, als Grundgesetz der Blattstellung im Pflanzenreiche. Annalen der Physik und Chemie 2d ser. 56: 1–37.

Naumann, Karl Friedrich. 1845. Ueber den Quincunx als Grundgesetz der Blattstellung vieler Pflanzen. Dresden and Leipzig: Arnoldische Buchhandlung.

Royal Society catalogue of scientific papers: Catalogue of scientific papers (1800–1900). Compiled and published by the Royal Society of London. 19 vols. and index (3 vols.). London: Royal Society of London. Cambridge: Cambridge University Press. 1867–1925.

WWWA: Who was who in America. A companion to Who’s Who in America. 9 vols., historical vol., and index. Chicago: A. N. Marquis. 1943–89.


Possible dimorphism in Phlox.

Knows of no U. S. law prohibiting marriage of cousins.

Gives references to papers on phyllotaxy.

Letter details

Letter no.
Asa Gray
Charles Robert Darwin
Sent from
Cambridge Mass.
Source of text
DAR 165: 136
Physical description
ALS 4pp damaged

Please cite as

Darwin Correspondence Project, “Letter no. 4198,” accessed on 4 October 2023,

Also published in The Correspondence of Charles Darwin, vol. 11