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Darwin Correspondence Project

To J. D. Hooker   17 March [1867]1


Mar 17

My dear Hooker

It is a long time since I have written, but I cannot boast that I have refrained from charity towards you, but from having lots of work. I am so much obliged to you for telling me about the palm seeds. I have got a whole string of cases equally, or perhaps more curious, but yours is infinitely the most valuable from having been observed by first rate judges.2 The subject is of paramount importance for my beloved Pangenesis.3 Now cd you obtain permission for me from Naudin to insert some such paragraph as the enclosed.4 My book will not appear till next Nov. but I shd have to insert the passage in the proof sheet in about a month’s time. Help me if you can. Are they seeds or nuts? Correct the word if they are not seeds.

It is great news about the presidentship; I am very sorry for it, tho’ you seem to keep up your spirits.5 You ask what I have been doing; nothing but blackening proofs with corrections.6 I do not believe any man in England naturally writes so vile a style as I do. The only fact which I have lately ascertained, & about which I dont know whether you wd care, is that a great excess of, or very little pollen produced not the least difference in the average number, weight, or period of germination in the seeds of Ipomœa.7 I remember saying the contrary to you & Mr Smith8 at Kew. But the result is now clear from a great series of trials. On the other hand seeds from this plant, fertilised by pollen from the same flower, weigh less, produce dwarfer plants, but indisputably germinate quicker than seeds produced by a cross between two distinct plants.9

In your paper on Insular Floras (p. 9) there is what I must think an error, which I before pointed out to you; viz you say that the plants which are wholly distinct from those of nearest continent are often very common, instead of very rare.10 Etty,11 who has read your paper with great interest, was confounded by this sentence. By the way I have stumbled on two old notes, one that 22 species of European birds occasionally arrive as chance wanderer, to the Azores, & secondly the trunks of American trees have been known to be washed on shores of Canary isld, by gulf stream, which returns southward from the Azores.12

What poor papers those of A. Murray are in G. Chronicle: what conclusions he dreams from a single Carabus & that a widely ranging genus!13 He seems to me conceited: you & I are fair game geologically, but he refers to Lyell, as if his opinion on a geological point was worth no more than his own.—14 I have just bought, but not read a sentence of, Murray’s big book, second-hand for 30s, new, so I do not envy the publishers.15 It is clear to me that the man cannot reason.—

I have had a very nice letter from Scott at Calcutta:16 he has been making some good observations on the acclimatisation of seeds from plants of same species, grown in different countries; & likewise on how far European plants will stand the climate of Calcutta; he says he is astonished how well some flourish, & he maintains, if the land were unoccupied, several could easily cross, spreading by seed, the Tropics from N. to South; so he knows how to please me, but I have told him to be cautious, else he will have Dragons down on him.—17

I was going to have asked you what sort of a man Benj. Clarke was (I bought his book out of kindness) but I see A. Gray calls him “that ass”. He is now going to publish analogous views on Animals, & I have subscribed.18 He tells me that no single person has or can object to his views on plants; I suspected that perhaps no one noticed them.19 He tells me a wonderful story of the effects of an inherited mutilation from cutting off the upper half of the ears of wheat for only 3 generations, which I cannot believe; & I have told him no one would believe it, unless he repeat & rerepeats his experiment.—20

Farewell my dear old friend | C. Darwin


The year is established by the relationship between this letter and the letter from J. D. Hooker, 14 March 1867.
CD refers to seeds that had recently been sent to Hooker by Charles Victor Naudin from a fan palm pollinated by a date palm (see letter from J. D. Hooker, 14 March 1867 and n. 5).
In Variation 1: 397–403, CD discussed cases in which the pollen of one plant, when applied to another species or variety, affected the shape, colour, or flavour of its fruit. In the chapter on pangenesis, CD concluded, ‘We here see the male element affecting and hybridising not that part which it is properly adapted to affect, namely the ovule, but the partially-developed tissues of a distinct individual’ (Variation 2: 365). For more on the development of the theory of pangenesis, see Correspondence vols. 13 and 14.
The enclosure has not been found, but CD added a description of the fruit and seeds, citing Naudin’s report to Hooker, in Variation 1: 399.
CD refers to Hooker’s decision to accept the presidentship of the British Association for the Advancement of Science for 1868 after initially turning down the invitation (see letters from J. D. Hooker, 4 February 1867 and 14 March 1867).
CD had received the first proof-sheets of Variation on 1 March 1867 (CD’s ‘Journal’ (Correspondence vol. 15, Appendix II)).
CD began a series of experiments with Ipomoea in 1866; at the end of a note dated 1866 he commented, ‘too much pollen?’ (DAR 78: 71). In Cross and self fertilisation, pp. 24–5, CD described experiments with I. purpurea to ascertain whether fertility rates were affected by the amount of pollen used and concluded, ‘flowers fertilised with little pollen yielded rather more capsules and seeds than did those fertilised with an excess; but the difference is too slight to be of any significance’ (ibid., p. 25).
John Smith was curator of the Royal Botanic Gardens, Kew (R. Desmond 1994).
CD’s notes on the germination of seeds from cross-pollinated and self-pollinated plants of Ipomoea purpurea, dated between 1 and 10 March 1867, are in DAR 78: 77.
In his letter to Hooker of 21 January [1867], CD had pointed out the apparent misprint of ‘commonest’ for ‘rarest’ in the latest instalment of Hooker’s paper on insular floras in the Gardeners’ Chronicle (J. D. Hooker 1866a); in Hooker’s pamphlet version of the paper, he changed ‘the commonest of all’ to ‘very common’ (see Williamson 1984, p. 70).
Henrietta Emma Darwin.
The notes referred to have not been found. In a letter to Hooker of 5 August [1866] (Correspondence vol. 14), CD mentioned looking for a ‘note about Birds being blown to the Azores from Europe’, but had not found it on that occasion.
Andrew Murray’s paper, ‘Dr. Hooker on insular floras’, appeared in two parts in Gardeners’ Chronicle (16 and 23 February 1867, pp. 152, 181–2; A. Murray 1867). Murray cited the case of a species of beetle of the family Carabus (now Carabidae), Aplothorax burchelli, found only on St Helena. Murray argued that it showed the greatest affinity to species found in Switzerland and Asia Minor, and further, that as the species could not have arrived by means of occasional transport, it indicated a connection between Europe and the coast of Africa that might have extended to St Helena (ibid., p. 182).
Murray made two references to Charles Lyell’s geological theories, in both cases associating them with CD’s views. He argued that Lyell and CD were unduly cautious in not allowing for the former existence of land-bridges between Europe and the Americas because of the great depth and width of the Atlantic ocean (A. Murray 1867, p. 152).
CD refers to Murray’s recently published book, The geographical distribution of mammals (A. Murray 1866). CD’s annotated copy is in the Darwin Library–CUL (see Marginalia 1: 624). In 1864, Murray had produced a prospectus for the work, and asked CD for suggestions on the content, but CD had been sceptical of Murray’s ability (see Correspondence vol. 12, letter from Andrew Murray, 31 October 1864, and letter to J. D. Hooker, 3 November [1864]).
CD’s response to Scott’s letter of 22 January 1867 has not been found.
CD refers to Benjamin Clarke and Asa Gray. The source of Gray’s comment has not been identified, but Hooker frequently passed on letters he received from Gray to CD. CD had bought a copy of Clarke’s work on plant taxonomy and Clarke had recently written to tell CD of his plan to produce a similar work including animals (Clarke 1866 and Clarke 1870; see letter from Benjamin Clarke, 12 March 1867 and nn. 1 and 2).
See enclosure to letter from Benjamin Clarke, 12 March 1867. CD’s reply to Clarke’s letter has not been found.


The date-palm seed case is important for Pangenesis.

Reports experiments on pollination of Ipomoea.

"Insular floras": A. Murray’s paper in Gardeners’ Chronicle is poor.

John Scott’s work on acclimatisation of plants.

The anomaly of the Azores flora on the migration theory.

Letter details

Letter no.
Charles Robert Darwin
Joseph Dalton Hooker
Sent from
Source of text
DAR 94: 13a–e
Physical description
8pp, CD note

Please cite as

Darwin Correspondence Project, “Letter no. 5445,” accessed on 19 June 2019,

Also published in The Correspondence of Charles Darwin, vol. 15