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Darwin Correspondence Project

To J. D. Hooker   [28 February 1866]1



My dear Hooker

I have forwarded your letter to Lyell at his request: I did not do so at first on account of the nice little sentence about Mrs Busk “being no end of times better than Lyell’s friends2   I cut off this part, & told him it was about a private affair, & sent the remainder.3 I dare say there is a great deal of truth in your remarks on the glacial affair but we are in a muddle & shall never agree.4 I am bigotted to the last inch, & will not yield. I cannot think how you can attach so much weight to the physicists, seeing how Hopkins Hennessey, Haughton & Thompson have enormously disagreed about the rate of cooling of the crust;5 remembering Herschel’s speculations about cold space,6 & bearing in mind all the recent speculations on change of axis;7 I will maintain to the death that yr case of Fernando Po & Abyssinia is worth ten times more than the belief of a dozen physicists.8

Your remarks on my regarding temperate plants & disregarding the tropical plants made me at first uncomfortable, but I soon recovered.9 You say that all Botanists would agree that many tropical plants could not withstand a somewhat cooler climate. But I have come not to care at all for general beliefs without the special facts. I have suffered too often from this; thus I found in every book the general statement that a host of flowers were fertilised in the bud,10—that seeds could not withstand salt-water &c &c.—11 I would far more trust such graphic accounts, as that by you of the mixed vegetation on the Himalayas12 & other such accounts. And with respect to Tropical plants withstanding the slowly coming on cool period I trust to such facts as yours (& others) about seeds of same species from mountains & plains having acquired a slightly different climatal constitution.13 I know all that I have said will excite in you savage contempt towards me. Do not answer this rigmarole, but attack me to your heart’s content & to that of mine, whenever you can come here, & may it be soon.—14

Hearty thanks, my dear kind friend for all that you say about my improved health; but it is hardly so good as you suppose. Twenty-four hours never pass without 5 or 6 paroxysms of great discomfort of stomach & singing head

Here is a horrid bore (though at same time it pleases me a little) my work on Domestication is stopped for a month or two by a new Edit. of Origin being wanted.15

Your’s ever affectionately | Ch. Darwin


The date is established by the relationship between this letter, the letter from J. D. Hooker, [26 or 27 February 1866], and the letter from Charles Lyell, 1 March 1866. See also letter from J. D. Hooker, [26 or 27 February 1866], n. 1. In 1866, 28 February was a Wednesday.
CD had been informed by Hooker that Charles Lyell wished to read Hooker’s letter of 21 February 1866 (see letter from J. D. Hooker, [26 or 27 February 1866]). CD refers to Ellen Busk.
No accompanying letter from CD to Lyell has been found. The letter from J. D. Hooker, 21 February 1866, is in the Darwin Archive–CUL (DAR 102: 59, 62–4); a copy of the first page, omitting the opening paragraph in which Hooker referred to Ellen and George Busk and Mary Elizabeth and Charles Lyell, is at DAR 102: 61.
CD refers to William Hopkins, Henry Hennessy, Samuel Haughton, and William Thomson (later Lord Kelvin), all of whom contributed to research on the rate of cooling of the earth’s crust. See Hennessy 1864 for a discussion of the differing positions of Hopkins, Hennessy, and Thomson. In 1865, Haughton estimated the earth to be at least 1280 million years old by calculating the rate of cooling of the crust (Haughton 1865, pp. 99–102). See also letters to Charles Lyell, 7 February [1866] and n. 12, and 15 February [1866] and n. 4.
In 1830, in a paper read before the Geological Society of London, John Frederick William Herschel had considered uncertainties about the temperature of space in relation to the changes in the earth’s climate that were implied by evidence from palaeontology (Herschel 1830, pp. 297–9).
CD probably refers to discussions arising from James Croll’s astronomical explanations of climate change (Croll 1864; see also Imbrie and Imbrie 1979, pp. 81–96). In letters to the Reader (for example, Croll 1865a and 1865b), Croll had developed his views, prompting further discussion in the review’s ‘Scientific correspondence’ columns between September and December 1865. Hooker had drawn CD’s attention to Croll’s work on shifts in the earth’s centre of gravity caused by the weight of ice during the glacial period in the letter from F. H. Hooker, 6 September [1865] (Correspondence vol. 13). The subject was expanded further in Croll 1866a and 1866b, the latter appearing with a short introductory note by Lyell. All but one issue of the Reader in January and February 1866 contained comments by correspondents who made implicit or explicit references to Croll’s work. In 1860, CD had commented on Sir Henry James’s ‘wild speculations’ about climate change in relation to change of the earth’s axis (Correspondence vol. 8, letter to Charles Lyell, 8 October [1860] and n. 7). CD cited Croll on climate change in Origin 5th ed., pp. 451–2.
In a paper read before the Linnean Society in 1861 (J. D. Hooker 1861), Hooker had emphasised the affinity between the vegetation of Clarence Peak, Fernando Po, off the coast of West Africa, and that of Abyssinia, 1800 miles distant on the other side of Africa. On the inferences that CD drew from this affinity in relation to a possible former cold period, see Correspondence vol. 10, letter from J. D. Hooker, 28 June 1862, n. 9.
In ‘Two forms in species of Linum, pp. 80–1 (Collected papers 2: 103), CD had written: ‘In botanical works many flowers are said to be fertilized in the bud. This rests solely, as far as I can discover, on the anthers opening in the bud.... I have reason to believe that some flowers are frequently fertilized without expanding; but my observations lead me to disbelieve that this is ever the invariable course with all the flowers of any species whatever.’
In the 1850s, CD had conducted a series of experiments, the results of which were published in his 1857 paper ‘On the action of sea-water on the germination of seeds’ (Journal of the Proceedings of the Linnean Society (Botany) 1: 130–40; Collected papers 1: 264–73).
See, for example, J. D. Hooker 1853–5, p. xi.
Hooker next visited Down from 24 to 26 March 1866 (Emma Darwin’s diary (DAR 242)).
CD refers to Variation. John Murray had proposed that CD produce a fourth edition of Origin (see letter from John Murray, 21 February [1866]).


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–.

Croll, James. 1864. On the physical cause of the change of climate during geological epochs. Philosophical Magazine 4th ser. 28: 121–37.

Haughton, Samuel. 1865. Manual of geology. London: Longman, Green, Longman, Roberts, and Green.

Hennessy, Henry. 1864. On the possible conditions of geological climate. Report of the thirty-fourth meeting of the British Association for the Advancement of Science, held at Bath, Transactions of the sections, pp. 55–7.

Hooker, Joseph Dalton. 1852. On the climate and vegetation of the temperate and cold regions of East Nepal and the Sikkim Himalaya Mountains. Journal of the Horticultural Society of London 7: 69–131.

Hooker, Joseph Dalton. 1853–5. Flora Novæ-Zelandiæ. 2 vols. Pt 2 of The botany of the Antarctic voyage of HM discovery ships Erebus and Terror, in the years 1839–1843, under the command of Captain Sir James Clark Ross. London: Lovell Reeve.

Imbrie, John and Imbrie, Katherine Palmer. 1979. Ice Ages: solving the mystery. London and Basingstoke: Macmillan Press.

Origin 5th ed.: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. 5th edition, with additions and corrections. By Charles Darwin. London: John Murray. 1869.

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.

‘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.]


Refers to part of JDH letter on glacial period sent on to Lyell. CD will not yield. Cannot think how JDH attaches so much attention to physicists. Has "come not to care at all for general beliefs without the special facts".

His health is improved but not so good as JDH supposes.

Letter details

Letter no.
Charles Robert Darwin
Joseph Dalton Hooker
Sent from
Source of text
DAR 94: 31–2
Physical description
ALS 4pp

Please cite as

Darwin Correspondence Project, “Letter no. 5020,” accessed on 13 September 2023,

Also published in The Correspondence of Charles Darwin, vol. 14