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Darwin Correspondence Project

To Asa Gray   20 March [1863]1

Down Bromley Kent

March 20th

My dear Gray.

I have very little to say, but will amuse myself by scribbling a few lines to thank you for information in last note of Feb. 9th 2 & to thank you in my dear little man’s name for two precious stamps.3 He told me with joyful triumph that in American stamps he equalled all other collections put together in the school. He exchanged a duplicate Blood’s stamp for a whole lot of treasures.4 He says there is an envelope of same value as the stamps you put on your letter, which would be of value to him.—

I have one request to make for myself, viz seed of Campanula perfoliata: I have tried in vain at Kew & elsewhere for some.—5

I am very glad you like Bates’ paper;6 I expect his Amazonian Travels will be good.7 If you read Lyell’s book, tell me what you think of it;8 I (& Hooker) have told him that we regret much that he did not speak more boldly out about Species.9 He answers that his belief in change fluctuates.—10 His Book has made me reread your essay; & I admire it as much as ever.11 What a dead hand you are in parrying a lounge & transfixing your adversary! You ask about Sprengels “Dichogamy”:12 he means by this a plant in which each flower first matures & sheds its pollen & then has its stigma mature; & much more rarely matures its stigma first & subsequently its pollen: so that these plants are in function monoœcious. I am sure his observations are to large extent correct, & the case is very common.13 In the Primula-like cases the plants are in function Diœcious.—14

A couple of days ago I had an interesting letter from Dr. Cruger of Bot. Gardens of Trinidad,15 & he tells me odd facts of native species (& only native species) of Cattleya &c which never open their flowers, & yet set seed-capsules. Happy man he has actually seen crowds of Bees flying round Catasetum with the pollinia sticking to their backs! I wrote to him to ask him to observe what insects did in flowers of Melastomaceæ;16 he says not proper season yet, but that on one species a small Bee seemed busy about the horn-like appendages to the anthers. It will be too good luck if my study of the flowers in the green-house has led me to right interpretation of these queer appendages.17 By the way, I have just built a hot-house & got some orchids, & it amuses me much.—18 Some plants of Amsinckia spectabilis, at least the seed was so named (small dark orange flowers, elongated hairy leaves) have just begun to flower, & I find in two plants that stigma stands on exact level with anthers; hence I fear they cannot be dimorphic.—19

Your Mitchellas look healthy: I hope they will not flower very soon;20 for my health (& that of my youngest Boy) has been of late so bad, that we have resolved all to go about middle of April for 6 or 8 weeks to Malvern for Water-Cure for me & change for my Boy.—21 It breaks my heart: I shall never get my present Book on Variation under Domestication finished; yet it interests me much & I am now in middle of long chapter on Inheritance Reversion &c, giving results of my own & other Breeders’ Experiments.—22

Good Night.— | My dear Gray | Yours most truly | Ch. Darwin

Many thanks for Pamphlet Chapters on History of war & newspaper just arrived.23


The year is established by the relationship between this letter and the letter from Asa Gray, 13 April 1863.
Gray’s letter has not been found; however, a portion of the letter is quoted in CD’s letter to H. W. Bates, 4 March [1863] (see n. 6, below).
CD refers to his twelve-year-old son, Leonard Darwin; at CD’s request, Gray had been sending United States postage stamps for Leonard’s collection since the summer of 1862 (see Correspondence vol. 10).
The reference is to a stamp issued by the Philadelphia carriers, D. O. Blood & Co. (see Sutton 1966, p. 41). See also letter to Asa Gray, 2 January [1863].
Campanula perfoliata (also called Specularia perfoliata) is native to the eastern United States (Bailey and Bailey 1976). CD had been interested in the plant since learning from Gray that it bore unopened flowers in which self-pollination occurred, a phenomenon later known as cleistogamy (see, for example, Correspondence vol. 9, letter from Asa Gray, 11 October 1861, and Correspondence vol. 10, letters to Asa Gray, 10–20 June [1862] and 26[–7] November [1862], and letters from Asa Gray, 18–19 August 1862 and 29 December 1862).
Gray evidently discussed Bates 1861 in a letter to CD written on 9 February 1863 that has not been found; CD quoted Gray’s comments in a letter to Henry Walter Bates of 4 March [1863]. Bates sent a copy of his paper to Gray in January, after CD had persuaded Gray to attempt to have it reviewed in the American Journal of Science and Arts, of which he was one of the contributing editors (see letter to H. W. Bates, 12 January [1863], and letter from H. W. Bates, 17 January [1863]).
Bates’s account of his eleven years as a naturalist in the Amazon region of South America (Bates 1863) was published between 1 and 14 April 1863 (Publishers’ Circular 26 (1863): 193).
A. Gray 1861a.
See Correspondence vol. 10, letter from Asa Gray, 29 December 1862. The reference is to Sprengel 1793, in which the term ‘dichogamie’ was first used (Baillon et al. 1876–92).
CD cited Sprengel 1793 extensively in Orchids, adding (p. 340 n.): I am aware that this author’s curious work … has often been spoken lightly of. No doubt he was an enthusiast, and probably carried some of his ideas to an extreme length. I feel sure, from my own observations, that his work contains a large body of truth. Although little regarded by botanists, the work was notable for its statement of two related doctrines, namely, that flowers were generally adapted to be cross-pollinated, and that floral structures were often adapted for insect visitation (DSB). These doctrines related closely to CD’s own belief that it was a ‘law of nature … that no organic being self-fertilises itself for an eternity of generations; but that a cross with another individual is occasionally … indispensable’ (Origin, p. 97).
In his letter to Gray of 26[–7] November [1862] (Correspondence vol. 10), CD objected to Gray’s use of the term ‘Diœcio-dimorphism’ to describe cases of flower dimorphism like those occurring in several species of Primula, on the grounds that he doubted the implied evolutionary transition between such dimorphism and dioeciousness. In his reply of 29 December 1862 (Correspondence vol. 10), Gray drew on CD’s account of the functional similarity of dimorphic and dichogamous plants, suggesting that CD extend the meaning of the word ‘dichogamy’ to include such cases of dimorphism as that in Primula.
CD’s new hothouse was completed by 15 February 1863 (see letter to J. D. Hooker, 15 February [1863] and n. 5); Joseph Dalton Hooker had sent CD orchids and other plants for cultivation from the Royal Botanic Gardens, Kew (see letter to J. D. Hooker, [21 February 1863]). See also Appendix VI.
Gray had suggested that Amsinckia spectabilis might be dimorphic, a view CD endorsed, having seen dried specimens sent by Gray (see Correspondence vol. 9, letter from Asa Gray, 9 November 1861, and letter to J. D. Hooker, 18 [December 1861]). CD subsequently grew plants from seed in order to experiment on the species (see Correspondence vol. 10, letter to Asa Gray, 15 March [1862], and this volume, letter to Asa Gray, 2 January [1863]). He recorded his observations on these plants, and on one belonging to his neighbour, George Henry Turnbull, in notes dated 23 March and 1 April 1863 (DAR 110: B2), concluding that the plant was not dimorphic, but that the length of the stigma was very variable, and the first-formed flowers tended to have stamens somewhat arrested in development. See also Forms of flowers, pp. 110–11.
Gray sent CD live specimens of the dimorphic plant Mitchella repens in December 1862, for use in crossing experiments (see Correspondence vol. 10, letter from Asa Gray, 9 December 1862, and this volume, letter to Asa Gray, 2 January [1863]). CD deferred his experiments until 1864, because the plants did not flower abundantly in 1863 (see letters to Asa Gray, 31 May [1863] and 26 June [1863], and Forms of flowers, p. 125).
CD had been suffering ill health since the end of February (see, for example, letter to J. D. Hooker, 5 March [1863]). Horace Darwin had been ill for much of 1862 (see letter from G. V. Reed, 12 January 1863 and n. 2); on 17 March 1863, Emma Darwin recorded in her diary (DAR 242) that he was again unwell. CD refers to James Manby Gully’s hydropathic establishment in Great Malvern, Worcestershire.
According to his ‘Journal’ (see Correspondence vol. 11, Appendix II), CD wrote a draft of the section of Variation dealing with inheritance (Variation 2: 1–84) between 23 January and 1 April 1863, noting: ‘took me 612 weeks   time lost by illness & London’. Variation, which CD began writing early in 1860, was not published until 1868.
The pamphlet has not been identified. Gray periodically sent CD American newspapers, although CD told Hooker that he never read them (see Correspondence vol. 10, letter to J. D. Hooker, 29 [December 1862]).


Bailey, Liberty Hyde and Bailey, Ethel Zoe. 1976. Hortus third: a concise dictionary of plants cultivated in the United States and Canada. Revised and expanded by the staff of the Liberty Hyde Bailey Hortorium. New York: Macmillan. London: Collier Macmillan.

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.

Bates, Henry Walter. 1863. The naturalist on the River Amazons. A record of adventures, habits of animals, sketches of Brazilian and Indian life, and aspects of nature under the equator, during eleven years of travel. 2 vols. London: John Murray.

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

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.

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

Orchids: On the various contrivances by which British and foreign orchids are fertilised by insects, and on the good effects of intercrossing. By Charles Darwin. London: John Murray. 1862.

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.

Sprengel, Christian Konrad. 1793. Das entdeckte Geheimniss der Natur im Bau und in der Befruchtung der Blumen. Berlin: Friedrich Vieweg.

Sutton, R. J. 1966. The stamp collector’s encyclopaedia. 7th edition. 6th edition revised by K. W. Anthony. London: Stanley Paul. [Vols. 10,11]

Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.


Discusses the meaning of C. K. Sprengel’s term "dichogamy". Dichogamous plants are functionally monoecious; Primula is functionally dioecious.

Reports Hermann Crüger’s observations of Cattleya and of bees pollinating Catasetum. Crüger will observe Melastomataceae.

Has built a hothouse.

Fears Amsinckia cannot be dimorphic.

Ill health slows his work on Variation.

Letter details

Letter no.
Charles Robert Darwin
Asa Gray
Sent from
Source of text
Gray Herbarium of Harvard University (58)
Physical description
ALS 8pp

Please cite as

Darwin Correspondence Project, “Letter no. 4053,” accessed on 29 May 2023,

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