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Darwin Correspondence Project

From Asa Gray   7 July 1863

Cambridge. [Mass.]

July 7, 1863

Dear Darwin,

My last from you is May 31.1

I had arranged to reprint most of Bates on Mimetic analogy in Sill. Jour. but my long review of A. DC. crowded it out.2 I then thought of a brief abstract, but have had no time to prepare it.3 I wrote remarks & arranged long extracts of your Linum paper, and insisted on it for July no. of Sill. Jour.— But it too was laid over.4—not for any thing I had, for I have little in July no.

I like and agree to your remark that in Bates’s Geographical varieties, etc. etc. we get about as near to seeing a species made as we are ever likely to get:5—and so believing I think your gradual way more likely than Heer’s jumps.6

A propos to Heer, you ask me if it is not impossible to imagine so many & nice coadaptations as we see in Orchids being formed all by a chance blow.

I reply yes, perfectly impossible to imagine (and much the same by any number of chance blows).

So I turn the question back upon you, is not the fact that the co-adaptations are so nice” next to a demonstration against their having been formed by chance blows at all, one or many!

Here lives, I suppose the difference between us. When you bring me up to this point, I feel the cold chill.7

I have been doing nothing but attend to my daily work, & had got so fagged that I really thought I was about to have softening of the brain, or some other break down. But a week of respite—caused by the death of an aged relative of my wife’s8—a dear old soul—taking us away from here perforce, has nearly set me up very nearly. And now after a week since comes my vacation, and we are off into the quiet country for 3 weeks.—

A little legacy of about £2000 to my wife comes in opportunely to relieve us of anxiety for the future. We have no children—(which I regret only that I have no son to send to the war),9 and this with a little income—rather precarious, of about £200 a year would support us in our very simple way, if I were to throw up my place here. But I cannot do that yet.10

Hooker11 writes that you have been ill. I am very sorry to hear it.

Look at Impatiens flowers. See if the most fertile “precociously fertilized” ones ever get crossed!12

I have asked in three directions for seeds of the Specularia perfoliata.13 Enclosed are depauperate specimens.

It is pretty to see Honey bees cross-fertilize Locust (Robinia) much as you say of Broom.14 One of my students has been noticing the way bees act on Kalmia15

Now for my best thing for to-day.

An Orchid which I missed last year Platanthera flava, I knew would be curious, for I remembered a strong protuberance on base of labellum, on the median line. I have not time left to describe it now—having been sadly interrupted— But it is pretty.—equal to anything you have yet seen in British Orchids   The process turns proboscis of insect either to right or left—where it will slip in to an imperfect ring (as seen from above) or deep groove (as seen from before)—in which lies the disk,—not flat but coiled up—ready to catch proboscis— It is like the eye of needle to re⁠⟨⁠ce⁠⟩⁠ive the thread.—16

Perhaps I will send you, or print—a sketch of the thing.

I am waiting for Gymnadenia tridentata to come on.17

But the post-hour has come, Good Bye | Ever | A Gray


Gray had planned to reprint extracts from Bates 1861 in the May 1863 issue of the American Journal of Science and Arts, commonly known as ‘Silliman’s Journal’ after its founder Benjamin Silliman (see letter to H. W. Bates, 4 March [1863], and letter from Asa Gray, 22–30 March 1863). Gray also refers to his review of A. de Candolle 1862a (A. Gray 1863d). See also letter from Asa Gray, 13 April 1863.
Gray prepared a review abstract of Bates 1861 for the September 1863 issue of the American Journal of Science and Arts (A. Gray 1863a; see also letter from Asa Gray, 21 July 1863).
Gray’s review abstract of ‘Two forms in species of Linum was published in the September 1863 issue of the American Journal of Science and Arts (A. Gray 1863c).
In his review of Bates 1861 (‘Review of Bates on mimetic butterflies’, p. 223 (Collected papers 2: 92)) CD observed: It is hardly an exaggeration to say, that whilst reading and reflecting on the various facts given in this Memoir, we feel to be as near witnesses, as we can ever hope to be, of the creation of a new species on this earth.
Gray had expounded his interpretation of natural selection as consistent with design in a series of articles published in 1860 in the Atlantic Monthly (A. Gray 1860b). For Gray and CD’s extended correspondence on the question of design in nature, see Correspondence vols. 8–10. See also Dupree 1959.
The relative was a great aunt of Jane Loring Gray’s, ‘one of the country kin in Connecticut’ (Dupree 1959, p. 332; see letter from Asa Gray to J. D. Hooker, 6 July 1863); she has not been further identified.
The reference is to the American Civil War.
Gray did not retire as Fisher Professor of natural history at Harvard University until 1873 (DAB).
CD and Gray had discussed the occurrence of what Gray called ‘precociously fertilized’ flowers in Impatiens over a number of years (see Correspondence vols. 9 and 10). The reference is to small, unopening flowers in which self-pollination occurs (a phenomenon later known as ‘cleistogamy’). CD discussed his experiments on the cleistogamic flowers of Impatiens noli-me-tangere in Forms of flowers, p. 328 and Cross and self fertilisation, p. 367.
CD asked for seeds of the dimorphic plant Specularia perfoliata (which he called Campanula perfoliata) in his letters to Gray of 20 March [1863] and 31 May [1863]; it is a North American species that bears cleistogamous flowers.
The reference is apparently to William James Beal, a teacher in Union Springs, New York, who studied botany with Gray at Harvard University during his vacations (DAB). Beal published his observations of the role of bees in the pollination of Kalmia in Beal 1868, pp. 257–8.
Gray gave an account of the pollination mechanism of Platanthera flava in A. Gray 1863b, pp. 292–3, which CD cited in ‘Fertilization of orchids’, p. 148 (Collected papers 2: 145).
In the summer of 1862, Gray observed that Gymnadenia tridentata (a synonym of Platanthera clavellata, the small green wood orchid) was adapted for self-pollination, reporting his results in A. Gray 1862a, p. 426, and A. Gray 1862c, p. 260 n. However, Gray introduced his more detailed account with the comment: ‘we hesitate to bring forward our too scanty observations until another summer affords an opportunity to test them’ (A. Gray 1862a, p. 426); he confirmed his observations in A. Gray 1863b, pp. 293–4. See also Correspondence vol. 10, letter to Asa Gray, 26[–7] November [1862] and n. 27.


Bates, Henry Walter. 1861. Contributions to an insect fauna of the Amazon valley. Lepidoptera: Heliconidæ. [Read 21 November 1861.] Transactions of the Linnean Society of London 23 (1860–2): 495–566.

Collected papers: The collected papers of Charles Darwin. Edited by Paul H. Barrett. 2 vols. Chicago and London: University of Chicago Press. 1977.

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

Cross and self fertilisation: The effects of cross and self fertilisation in the vegetable kingdom. By Charles Darwin. London: John Murray. 1876.

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.

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

‘Fertilization of orchids’: Notes on the fertilization of orchids. By Charles Darwin. Annals and Magazine of Natural History 4th ser. 4 (1869): 141–59. [Collected papers 2: 138–56.]

Forms of flowers: The different forms of flowers on plants of the same species. By Charles Darwin. London: John Murray. 1877.

‘Review of Bates on mimetic butterflies’: [Review of "Contributions to an insect fauna of the Amazon valley", by Henry Walter Bates.] [By Charles Darwin.] Natural History Review n.s. 3 (1863): 219–24. [Collected papers 2: 87–92.]

‘Two forms in species of Linum’: On the existence of two forms, and on their reciprocal sexual relation, in several species of the genus Linum. By Charles Darwin. [Read 5 February 1863.] Journal of the Proceedings of the Linnean Society (Botany) 7 (1864): 69–83. [Collected papers 2: 93–105.]


Has extracted CD’s Linum paper [Am. J. Sci. 2d ser. 36 (1863): 279–84].

Elaborate co-adaptations of orchids and insects demonstrate against "chance blows", whether few, as Oswald Heer would have, or many and slight as CD proposes.

Letter details

Letter no.
Asa Gray
Charles Robert Darwin
Sent from
Cambridge Mass.
Source of text
DAR 165: 127, 137
Physical description
ALS 6pp

Please cite as

Darwin Correspondence Project, “Letter no. 4234,” accessed on 4 March 2024,

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