skip to content

Darwin Correspondence Project

To Asa Gray   19 October [1865]1

Down. | Bromley. | Kent. S.E.

Oct. 19th

My dear Gray

I received yesterday your article on Climbers2 & it has pleased me in an extraordinary & even silly manner. You pay me a superb compliment & as I have just said to my wife I think my friends must perceive that I like praise, they give me such hearty doses.3

I always admire your skill in reviews or abstracts, & you have done this article excellently & given the whole essence of my paper.— I daresay you are right about the climbing roses; I never thought about spring shoots behaving differently from others.4 I have had a letter from a good zoologist in S. Brazil, F. Müller, who has been stirred up to observe climbers & gives me some curious cases of Branch-climbers, in which branches are converted into tendrils, & then continue to grow & throw out leaves & new branches & then lose their tendril character.5

I am certainly better & have not vomited for above 5 weeks. This is certainly due to not having eaten any thing but toast & meat for the last 2 months. But I cannot recover mental strength & I do no regular work.6 I have had some flowers crossed for me this summer & have lately been counting seeds.7

You might like to hear that Mitchella behaves exactly like the Cowslip.8 Did I ever tell you that a year or two ago I ascertained that Pulmonaria offers a curious case. The long-styled form being absolutely sterile with its own pollen, whilst the short-styled is almost perfectly with its own pollen.9 I have also ascertained that plants raised from Dimorphic species fertilized by their own pollen, are themselves generally sterile, & are often dwarfs, so that they offer the closest analogy with Hybrids; the first cross & the product both being more or less sterile; this seems to me a very curious fact.10

I do not know when I shall be able to publish any of these results, for I have resolved, whenever able to do any thing, to publish my next book.11 I have not heard very lately from Hooker, who I believe returns tomorrow to Kew. His illness has been very serious.12 To me the loss of his correspondence has been very great.

My wife has read aloud to me Stephens’s 2 books on Central America.13 What a remarkably pleasant writer he is! & how singularly deficient in the spirit of a naturalist. Who is he & is he still alive14   we liked his books extremely.

With cordial thanks for all your kindness & you are enough to stimulate a dead man to work.

Yours affect | C. Darwin


The year is established by the reference to A. Gray 1865–6; see n. 2, below.
CD refers to the first of a two-part review Gray had written of ‘Climbing plants’ in the American Journal of Science and Arts (A. Gray 1865–6). The first part of the review was published in September 1865 and the conclusion in January 1866.
Gray described CD’s botanical works as showing ‘a genius for biological investigation, and a power of turning common materials and ordinary observations to high scientific account’, which had not been surpassed ‘since the days of Hunter and Charles Bell’ (A. Gray 1865–6, pp. 273–4). Gray referred to the surgeons and anatomists John Hunter and Charles Bell.
In his review, Gray noted that CD had difficulty understanding how the shoots of climbing roses could ‘get under a trellis close to a wall’ (‘Climbing plants’, p. 105). Gray commented that he had observed (A. Gray 1865–6, p. 282): the strong summer-shoots of Michigan Rose (Rosa setigera Mx., R. rubifolia R. Br.), trained on a latticed wall, are strongly disposed to push into dark crevices and away from the light; they would, many of them, pretty surely place themselves under the trellis, and the lateral shoots of the next spring would emerge as they seek the light. CD added Gray’s explanation in a note to Climbing plants 2d ed., p. 184.
CD had recently received a second letter from Fritz Müller on Brazilian climbing plants, written after receiving a copy of CD’s ‘Climbing plants’ in August 1865 (see letters from Fritz Müller, 12 August 1865 and n. 11, [12 and 31 August, and 10 October 1865], and 31 August 1865; see also letter to Fritz Müller, 17 October [1865]). Müller paid particular attention to branch climbers because CD had not observed any among the species he had studied for ‘Climbing plants’. CD added many of Müller’s observations to Climbing plants 2d ed.
CD attributed his improved health to the strict diet recommended by Henry Bence Jones (see letter to T. H. Huxley, 4 October [1865] and n. 3). By ‘regular work’ CD typically meant writing; he was engaged in experimental work at the time (see n. 7, below; see also Bowlby 1990, pp. 378–80).
Henry Lettington, the under-gardener CD once described as a ‘skilful crosser’, probably made the crosses (see Correspondence vol. 12, letter to J. D. Hooker, 19 [April 1864] and n. 4). In 1865, CD conducted crossing experiments with primroses (Primula vulgaris) and cowslips (P. veris) grown from seeds he had received from John Scott (see Correspondence vol. 11, letter from John Scott, [26 July – 2 August 1863], and this volume, memorandum from W. E. Darwin, [late February–May 1865], and letter from B. D. Walsh, 29 May 1865, n. 3). He counted seeds from crosses he made of long-styled purple or red primroses with common wild primroses, and of red cowslips with common cowslips. CD’s notes on these crosses are in DAR 108: 89b–110. He continued crossing experiments on these plants in 1866 and 1867 (notes in DAR 108: 111–24). He reported his findings in ‘Illegitimate offspring of dimorphic and trimorphic plants’, pp. 416–30, and in Forms of flowers, pp. 224–38.
CD may be referring to the relative rates of fertility of legitimate and illegitimate crosses in Mitchella and the cowslip. Gray had sent CD plants of Mitchella repens early in 1863 (see Correspondence vol. 11, letter to Asa Gray, 2 January [1863] and n. 5). CD’s results of crosses with M. repens are reported in Forms of flowers, pp. 125–7.
CD and his son William had made observations on Pulmonaria in 1863 and in April and May 1864 (see Correspondence vol. 11, letter from W. E. Darwin, 8 May [1863] and n. 4, and Correspondence vol. 12, letters from W. E. Darwin, 14 April 1864 and 18 April [1864], and letter to W. E. Darwin, 14 May [1864]). CD’s notes on Pulmonaria, made between 1864 and 1866, are in DAR 110: A40–94 and B15–17; his findings are discussed in ‘Illegitimate offspring of dimorphic and trimorphic plants’ and in Forms of flowers, pp. 101–10, 239, 252, and 287.
CD was intrigued by the similarity between hybrid sterility and the sterility of plants that were the result of illegitimate unions among dimorphic and trimorphic plants (see letter to Max Wichura, 3 February [1865] and n. 9).
CD hoped to resume work on Variation, which was not published until 1868 (see letter to John Murray, 2 June [1865], n. 1).
Joseph Dalton Hooker had suffered an attack of rheumatic fever in August, around the time of his father’s death (see letter from F. H. Hooker, [17 August 1865]). He had been offered leave until the end of the month, but told CD he was returning to Kew about 20 October 1865 (see letter from J. D. Hooker, 6 October 1865); Daniel Oliver later told CD that he was expected to return to Kew on 26 October (see letter from Daniel Oliver, 23 October 1865 and n. 6).
The reference is to John Lloyd Stephens and to his travel narratives, Incidents of travel in Central America, Chiapas and Yucatan (Stephens 1841), and Incidents of travel in Yucatan (Stephens 1843).
Stephens died in 1852 (DAB).


Bowlby, John. 1990. Charles Darwin: a biography. London: Hutchinson.

Climbing plants 2d ed.: The movements and habits of climbing plants. 2d edition. By Charles Darwin. London: John Murray. 1875.

‘Climbing plants’: On the movements and habits of climbing plants. By Charles Darwin. [Read 2 February 1865.] Journal of the Linnean Society (Botany) 9 (1867): 1–118.

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.

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

Gray, Asa. 1865–6. On the movements and habits of climbing plants; by Charles Darwin. American Journal of Science and Arts 2d ser. 40: 273–82, 41: 125–30.

‘Illegitimate offspring of dimorphic and trimorphic plants’: On the character and hybrid-like nature of the offspring from the illegitimate unions of dimorphic and trimorphic plants. By Charles Darwin. [Read 20 February 1868.] Journal of the Linnean Society of London (Botany) 10 (1869): 393–437.

Stephens, John Lloyd. 1843. Incidents of travel in Yucatan. 2 vols. London: John Murray.

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


AG’s article on climbing plants [Am. J. Sci. 2d ser. 40 (1865): 273–82] is admirable and complimentary.

Reports Fritz Müller’s observations on climbers.

Experiments on dimorphism with Mitchella and Pulmonaria.

Letter details

Letter no.
Charles Robert Darwin
Asa Gray
Sent from
Source of text
Gray Herbarium of Harvard University (93)
Physical description
LS(A) 4pp

Please cite as

Darwin Correspondence Project, “Letter no. 4919,” accessed on 19 April 2024,

Also published in The Correspondence of Charles Darwin, vol. 13