The correspondence of Charles Darwin, volume 11: 1863

Edited by Frederick Burkhardt, Duncan Porter, Sheila Ann Dean, Jonathan R. Topham, Sarah Wilmot. (Cambridge University Press 1999)

Order this volume online from Cambridge University Press.


At the start of 1863, Charles Darwin was actively working on the manuscript of The variation of animals and plants under domestication, anticipating with excitement the construction of a hothouse to accommodate his increasingly varied botanical experiments, and continuing a massive scientific correspondence. Six months later the volume of his correspondence dropped markedly, reflecting a decline in his already weak health. Darwin then began punctuating letters with explanations that he was ‘unwell & must write briefly’ (letter to John Scott, 31 May [1863]), and in a letter of 23 [June 1863] he wrote to his close friend Joseph Dalton Hooker: ‘I am languid & bedeviled … & hate everybody’. Although Darwin did continue his botanical pursuits over the summer, and persevered with his work on Variation until 20 July, his letter-writing dwindled considerably. The correspondence and Darwin’s scientific work diminished even further when he and his family departed on 2 September for more than a month at a hydropathic establishment in Malvern Wells, Worcestershire, where he underwent a course of the water-cure. The treatment was not effective and Darwin remained ill for the rest of the year.

The first five months of 1863 contain the bulk of the correspondence in this volume. In the first part of the year, the letters illustrate Darwin’s preoccupation with the challenges presented by the publication in February of books by his friends Charles Lyell, the respected geologist, and Thomas Henry Huxley, the zoologist and anatomist. Lyell’s Antiquity of man and Huxley’s Evidence as to man’s place in nature both had a direct bearing on Darwin’s species theory and on the problem of human origins. Specifically, Darwin wondered how far the public had been led by his theory to accept the notion of human descent from ‘some Quadrumanum animal’, as he put it in a letter to J. D. Hooker of 24[–5] February [1863]. When Huxley’s book described the detailed anatomical similarities between humans and apes, Darwin was full of praise. He especially admired its discussion of the implications of ape ancestry for prevailing views of human dignity and intelligence, exclaiming to Huxley: ‘I declare I never in my life read anything grander’ (letter to T. H. Huxley, 26 [February 1863]). In the same letter, he gave his reaction to the Antiquity of man, complaining that he was ‘fearfully disappointed at Lyells excessive caution in expressing any judgment on Species or origin of man’. Darwin’s concern about the popular reception of his transmutation theory led him, after some consideration, to briefly play a public role in the controversies that embroiled Britain’s scientific circles following the publication of Lyell’s and Huxley’s books.

Three years earlier Darwin had predicted that Lyell’s forthcoming discussion of human antiquity would ‘horrify the world’ far more than Origin had (see Correspondence vol. 8, letter to Charles Lyell, 10 January [1860]). In the same letter he reminded Lyell of his belief that human beings were ‘in the same predicament with other animals’ and that he had made this suggestion in Origin with the famous line: ‘Light will be thrown on the origin of man and his history’ (p. 488). Since the publication of Origin in 1859, new evidence that early humans had coexisted with animals now extinct had been rapidly accumulating. Lyell’s argument for a greater human antiquity than was commonly accepted was based on recent discoveries in England and France of primitive stone tools in association with the bones of extinct mammals, as well as on evidence collected earlier in the century. Lyell’s Antiquity of man and Huxley’s Evidence as to man’s place in nature directly confronted experts and non-experts alike with the possibility of human descent from an ape-like animal, while dating human origins to a time far earlier than that decreed by scripture. Victorian anxiety regarding human origins was further increased by the discovery in March 1863 of the Moulin-Quignon jaw, the first human fossil found in association with bones from animals like the woolly mammoth and cave bear (see letter from Jacques Boucher de Perthes, 23 June 1863). Although English experts subsequently decided the jaw was a forgery, publications in learned journals and the press during the first half of 1863 focused attention even more closely on Darwin’s arguments for species change.

In this context, Lyell’s discussion of the origin of species particularly dismayed Darwin. In the first and most detailed of several letters to Lyell discussing Antiquity, Darwin made a list of criticisms, including the objection that one statement led the reader to think that the author was ‘far from believing that man was descended from any animal’. Another sentence suggesting that human intelligence appeared in a sudden leap from that of inferior animals made him ‘groan’ (letter to Charles Lyell, 6 March [1863]). Darwin reiterated in a later letter that it would not have mattered if Lyell had thrown doubt on the significance of variation and natural selection, if only he could have permitted himself to say ‘boldly & distinctly out that species were not separately created’ (letter to Charles Lyell, 17 March [1863]). Public perceptions of creation, and the origin of species particularly, worried Darwin; he told Hooker that he had once thought Lyell ‘could do more to convert the Public than all of us’, but that after reading the book he wished his one-time mentor had not said a word (letter to J. D. Hooker, 24[–5] February [1863]).

Darwin did not relish telling Lyell of his disappointment; when he did write, he tempered his criticisms by acknowledging: ‘I know you will forgive me for writing with perfect freedom; for you must know how deeply I respect you, as my old honoured guide & master’ (letter to Charles Lyell, 6 March [1863]). Nevertheless, Darwin’s regret was profound that the colleague and friend who had first advised him in 1856 to write his essay on species could not now support his theory more definitively.

Lyell, for his part, admitted that his feelings prevented him from discussing human descent from the ‘brutes’, but added that he would bring many towards Darwin who would have rebelled against stronger statements regarding species change (letter from Charles Lyell, 11 March 1863). The botanist Asa Gray, Darwin’s friend in the United States, agreed that Lyell’s approach would sway many towards a new way of thinking, while Huxley’s book would scare them off (see letter from Asa Gray, 20 April 1863). In May, Darwin responded to Gray that Lyell’s and Gray’s indecision regarding change of species by descent put him ‘into despair’ (letter to Asa Gray, 11 May [1863]). In the same letter, he assured Gray that the essential question was not natural selection, but ‘Creation or Modification,’.

Darwin was not alone in feeling disaffected towards Lyell and his book. In a February letter to the Athenæum, a weekly review of science, literature, music, and the arts, the prominent anatomist Richard Owen denounced the account provided in Antiquity of man of the ongoing debate between Owen, Huxley, and others concerning the comparative anatomy of the human and simian brain. He charged Lyell with failing to put across Owen’s position, a failure which he attributed to Lyell’s lack of expertise in the subject. ‘The worst of it is’, Hooker wrote to Darwin, ‘I suppose it is virtually Huxley’s writing, & that L. will find great difficulty in answering Owen unaided’ (letter from J. D. Hooker, [23 February 1863]). Hugh Falconer was also preparing a denunciation of Lyell’s book on the grounds that it gave insufficient credit to his own research and that of Joseph Prestwich. Hooker wrote: ‘I fear L. will get scant pity even from his own side, for F spoke to me the other night in the most strongly slighting terms of so much of Lyell’s book being written by others’ (letter from J. D. Hooker, [23 February 1863]). Falconer published his criticisms in a letter in the Athenæum, on 4 April, concluding with an invitation to Lyell to present a single fact or original observation that he had contributed to the proofs of human antiquity. Darwin and Hooker repeatedly exchanged regrets about Falconer’s action towards Lyell, with Darwin commenting: ‘It is wretched to see men fighting so for a little fame’ (letter to J. D. Hooker, 17 March [1863]).

Falconer and Owen were already engaged in a dispute over whose name for a recently discovered fossil elephant should have priority. When Falconer’s account of the elephant appeared in the Natural History Review in January, Darwin, who was already ill-disposed towards Owen following his 1860 review of Origin, wrote to Falconer: ‘You would laugh, if you could have seen how indignant all Owen’s lies and mean conduct about E. Columbi made me… . The case is come to such a pass, that I think every man of science is bound to show his feelings by some overt act, and I shall watch for a fitting opportunity’ (letter to Hugh Falconer, 5 [and 6] January [1863]).

Falconer, Darwin, and others found an additional reason to be annoyed with Owen when it became clear that Owen’s November 1862 description of the recently discovered Archaeopteryx had missed some essential elements of the Jurassic fossil. When informed by Falconer of Owen’s ‘slip-shod and hasty account’ of the find, Darwin asked, ‘Has God demented Owen, as a punishment for his crimes … ?’ (letter from Hugh Falconer, 3 January [1863], and letter to Hugh Falconer, 20 [January 1863]). Aside from Owen’s apparent oversights, Falconer enthusiastically observed that the fossil was ‘a strange being à la Darwin’, a transitional form between reptiles and birds (letter from Hugh Falconer, 3 January [1863]). Darwin was delighted by Falconer’s description of the ‘wondrous Bird’, commenting that: ‘no group is so isolated as Birds’; Darwin thought that now perhaps a significant gap had been filled in the fossil record (letter to Hugh Falconer, 5 [and 6] January [1863]). Only until March did Darwin take much notice of the now famous fossil in his correspondence and publications; Owen’s perceived failings, however, continued to capture his and others’ attention (see letter to J. D. Dana, 20 February [1863], and letter to Charles Lyell, 6 March [1863]).

In March, after hearing from Lyell that Owen in his paper on the aye-aye claimed the ‘whole credit of making out the derivation or origin of species’, Darwin considered writing a letter to the Athenæum in response (letter to J. D. Hooker, 5 March [1863]). He later expressed disappointment that the paper gave him no scope to attack Owen even though he ‘had partly composed such a good letter(!)’ (letter to J. D. Hooker, 17 March [1863]). At the same time Darwin admitted his mixed feelings: ‘I long to be in the same boat with all … my friends ie at open war; but at same time I rejoice not to be annoyed at public quarrel, & it would annoy me much.

Darwin did find an opportunity to enter his own protest against Owen with the appearance of an anonymous review in the Athenæum of William Benjamin Carpenter’s book on Foraminifera (see letter to J. D. Hooker, [29 March 1863], and Appendix VII). The reviewer, soon identified as Owen, accused Carpenter, a physician and naturalist, of slavishly following Darwin’s ideas by concluding that the varied Foraminifera probably derived from a few ancestral types. Owen also censured Darwin for subscribing to an ‘occult cause’ when he wrote that all organic forms had probably ‘descended from some one primordial form, into which life was first breathed’ ( Origin, p. 484). Owen preferred Jean Baptiste de Lamarck’s explanation of the origin of life: heterogeny, or the spontaneous generation of species from non-living matter; and he referred to the beginning of life in the ‘vitally acting slime’ settled at the bottom of seas, lakes, and rivers (Appendix VII).

Darwin told Hooker of his regret that he had ‘truckled to public opinion & used Pentateuchal term of creation, by which I really meant “appeared” by some wholly unknown process.— It is mere rubbish thinking, at present, of origin of life; one might as well think of origin of matter.—’ (letter to J. D. Hooker, [29 March 1863]). Owen’s endorsement of Lamarck rankled all the more because Darwin was already disturbed by Lyell’s presentation of his theory in Antiquity of man as a modification of Lamarck’s. In complaining of this to Lyell, he described Lamarck’s 1809 publication as a ‘wretched book’ from which he had ‘gained nothing’ (letter to Charles Lyell, 12–13 March [1863]).

When Carpenter’s answer to Owen’s review was judged too weak a response to the man whom Hooker referred to as a ‘poor miserable devil of a scotched viper’, Darwin wrote a letter to the Athenæum in opposition to Owen’s review, in which he sought to advance his theory by making clear the difference between his view of transmutation and Lamarck’s and by softening the effect of Lyell’s failure to fully support him in the first edition of Antiquity of man (letter from J. D. Hooker, [23 February 1863], and letter to Athenæum, 18 April [1863]). He told Gray: ‘Under the cloak of a fling at Heterogeny I have sent a letter to Athenæum in defence of myself, & I take sly advantage to quote Lyells amended verdict on the Origin’ (letter to Asa Gray, 20 April [1863]). Darwin quoted a sentence from the second edition of Antiquity of man (C. Lyell 1863b, p. 469), published in April, in which Lyell had added that he fully expected it would become the ‘generally received opinion of men of science’ that organic change had ‘been brought about by the subordinate agency of such causes as Variation and Natural Selection’. Darwin explained his use of the quote to Lyell: ‘you see that I am determined, as far as I can, that the Public shall see how far you go’ (letter to Charles Lyell, 18 April [1863]).

Hooker implored him not to write any more letters to the Athenæum, stressing how much he disliked bringing science before the public in this way (see letter from J. D. Hooker, [7 May 1863], and Appendix VII). He also suspected that Owen’s reply had won favour with the public. Darwin agreed, and regretted that he had written to the Athenæum in response to Owen: ‘I have been gnashing my teeth at my own folly’ (letter to J. D. Hooker, [9 May 1863]). After his venture into the popular press, he admired a satiric rendition in Public Opinion of the recent quarrels that he thought showed that ‘a scientific man had better be trampled in dirt than squabble’ (see Appendix VIII).

While Darwin worried about the effect of the quarrels on public perceptions, his theory was gathering support in influential scientific circles. George Bentham devoted the first part of his presidential address at the Linnean Society of London to British and foreign evaluations of Darwin’s theory. While preparing the lecture, Bentham had warned Darwin that though he appreciated the force of Darwin’s arguments, he still could not satisfy himself on all points (see letter from George Bentham, 21 April 1863). However, when he read the address, Darwin was greatly pleased with its positive approach to both transmutation and natural selection: ‘I verily believe that your address, written as it is, will do more to shake the unshaken & bring on those leaning to our side, than anything written directly in favour of transmutation. I can hardly tell why it is, but your address has pleased me as much as Lyell’s book disappointed me,—that is the part on species, though so cleverly written’ (letter to George Bentham, 19 June [1863]).

Darwin was also pleased by the publication of The naturalist on the river Amazons, a book that he had encouraged Henry Walter Bates to write. When the book appeared in April 1863, Darwin gave it fulsome praise: ‘My criticisms may be condensed into a single sentence, namely that it is the best book of Natural History Travels ever published in England.’ He added that Bates had ‘spoken out boldly on Species; & boldness on this subject seems to get rarer & rarer’ (letter to H. W. Bates, 18 April [1863]), dismissing a reviewer in ‘that d——d Athenæum’ who accused Bates of bending his facts to support Darwin’s theory (letter to J. D. Hooker, [17 April 1863]). Darwin felt equally strongly about the quality of Bates’s work on mimicry in butterflies, which had been published in 1862 (see Correspondence vol. 10). He sent a copy to Asa Gray to review in an American journal, and also wrote a long unsigned review of it himself (‘Review of Bates on mimetic butterflies’) for the Natural History Review (see letter to H. W. Bates, 12 January [1863]). Darwin added Bates’s name to his list of the ‘half-a-dozen real downright believers in modification of Species in all England … who dare speak out’ (letter to J. D. Hooker, [9 May 1863]). The others listed were himself, Hooker, Huxley, Alfred Russel Wallace, and John Lubbock.

Darwin had also found a supporter in New Zealand. Julius von Haast, a German working as a provincial geologist in the British colony, paid tribute to Darwin’s work when he spoke to the Philosophical Institute of Canterbury in September 1862 (see letter to Julius von Haast, 22 January 1863); he discussed the importance of applying Darwin’s theory to geological and palaeontological discoveries made in New Zealand. Haast’s arduous explorations and geological, zoological, and botanical observations greatly interested Darwin, who applauded him as a ‘glorious species man’, while Haast extolled Darwin as the ‘noble champion of true philosophic enquiry’ (letter to J. D. Hooker, 23 April [1863], and letter from Julius von Haast, 21 July [–7? August] 1863). Darwin was subsequently elected an Honorary Member of the Philosophical Institute of Canterbury, New Zealand, of which Haast was a founding member (see letter from the secretary of the Philosophical Institute of Canterbury, New Zealand, 14 September 1863).

Additional notices of honours arrived at Down House in 1863. From Shropshire, where Darwin first began observing nature, he was invited to become an honorary member of the Severn Valley Naturalists Field Club (see letter from George Maw, 19 February 1863). Other honours included his election as a corresponding member of the Royal Prussian Academy of Sciences, Berlin (see Appendix III), and of the Société des Sciences Naturelles de Neuchâtel (see letter from La Société des Sciences Naturelles de Neuchâtel, 14 May 1863).

The foreign reception of Origin was reflected not only in awards, but in Darwin’s correspondence. When Darwin felt that Lyell failed to uphold his views on transmutation in Antiquity of man, he did not hesitate to tell him of recent reports from other countries suggesting growing international interest in his theory (see letter to Charles Lyell, 17 March [1863]). In January 1863, the geologist Friedrich Rolle, who had recently published a popular exposition of Darwin’s views, wrote with positive news of reactions to his theory in Germany (see letter from Friedrich Rolle, 26 January 1863). Darwin was not surprised to hear from Hooker that the French botanists Joseph Decaisne and Charles Naudin thought little of his theory (see letter to J. D. Hooker, 30 January [1863]), but he was happy that the respected Swiss botanist Alphonse de Candolle sent information on the ‘progress of species-question’, citing the French palaeontologist Gaston de Saporta’s prediction that the role of natural selection would ultimately be accepted in France. Candolle had sent his monograph on oaks (A. de Candolle 1862b), which included a generally favourable discussion of Origin with what Darwin called ‘prudent reservations’ (letters to Alphonse de Candolle, 14 January [1863] and 31 January [1863], and letter to Asa Gray, 31 May [1863]). Asa Gray reviewed Candolle’s memoir in the American Journal of Science and Arts (A. Gray 1863e), continuing his practice of making discussions of Darwin’s views known to American readers.

Less encouraging news arrived in November when Darwin heard that his nomination for the Royal Society’s Copley Medal had been unsuccessful (see letter from E. A. Darwin to Emma Darwin, 11 November [1863]). The council of the Royal Society voted instead for the geologist Adam Sedgwick; Darwin suspected that Owen, a member of the council, had placed Sedgwick in opposition to him (see letter to J. D. Hooker, [22–3 November 1863]). However, it is certain that one influential figure in Darwin’s failure to win the award was Edward Sabine, President of the Royal Society (see letter from Edward Sabine to John Phillips, 12 November 1863). Characteristically, Darwin claimed to care more about the resulting sympathy and praise from close friends than about honours like the Copley Medal (see letter to J. D. Hooker, 5 [December 1863]).

Darwin continued to pay particularly close attention to specific criticisms from supporters or near-supporters of his theory. Hugh Falconer suggested that a ‘law of Phyllotaxis’ governed the arrangement of leaves around a stem in a series of fixed angles for every plant, and stated that there must then be ‘in nature, a deeper seated and innate principle, to the operation of which “Natural Selection” is merely an adjunct’ (Falconer 1863a, p. 80). Darwin, challenged by this statement, began puzzling over the angles of leaves, asking the professional botanists Gray, Hooker, and Daniel Oliver for references on phyllotaxy, and setting his son George, the mathematician in the family, to explaining the phenomenon (see letter from Daniel Oliver, 17 February 1863, letter to Asa Gray, 20 April [1863], letter to J. D. Hooker, [9 May 1863], and memorandum from G. H. Darwin, [before 11 May 1863]). As he struggled with leaf angles, fractions, diagrams, and shoot dissections, his letters grew full of complaints that the problem was ‘enough to drive the quietest man mad’ (letter to Asa Gray, 11 May [1863]). Hooker and Gray agreed wholeheartedly, but Hooker sent another reference, acknowledging that Darwin was a ‘hard headed man’ (letter from J. D. Hooker, [24 May 1863]). Darwin finally decided that Falconer’s remark was much exaggerated; he conceded to his critic that it was a ‘wonderful problem’ but he himself had ‘made out … nothing’ and wished someone could give a rational explanation of phyllotaxy (letter to J. D. Hooker, 29 May [1863], and letter to Hugh Falconer, [25–6 August 1863]).

Another criticism that continued to exercise Darwin was Huxley’s assertion, first made in his 1860 review of Origin, that in order to prove the emergence of new species by natural selection, it was necessary to provide a case in which two forms of the same species of plant or animal, produced by selective breeding, were either unable to cross or else formed sterile hybrids. Huxley made this point again in his six lectures to working men, given at the Museum of Practical Geology at the end of 1862, and published as a book in early 1863 (T. H. Huxley 1863a). Though Darwin was otherwise extremely pleased with the book, he continued to disagree with Huxley about sterility as a fair test for species, pointing out that in his work on domesticated animals he had come to the conclusion that ‘there are almost certainly several cases of 2 or 3 or more species blended together & now perfectly fertile together’ which led him to believe ‘that there must be something in domestication … which eliminates the natural sterility of species, when crossed’ (letter to T. H. Huxley, 10 [January 1863]). He reminded Huxley again of the German botanist Karl Friedrich von Gärtner’s experiments, which had produced infertile hybrids in Verbascum and Zea (see Correspondence vol. 10, Appendix VI). However, when Evidence as to man’s place in nature was published in February 1863, Huxley again argued that natural selection required experimental proof that physiological species could be produced by selective breeding.

Huxley’s criticism provided additional impetus for Darwin to continue the work on dimorphic plants, and on cross and hybrid sterility, that had already occupied much of his time in 1861 and 1862. With the publication in 1862 of his paper on Primula (‘Dimorphic condition in Primula’), he had demonstrated that two different flower forms, one with a long style and short stamens, the other with a short style and long stamens, were only fully fertile when crossed with each other. In February 1863, his paper on Linum (‘Two forms in species of Linum’) was read before the Linnean Society. In the paper, Darwin presented experimental results that suggested a high degree of sterility when the same flower forms were crossed (see Appendix IV). Darwin continued to investigate the true nature of sterility, a question he had been struggling with in 1861 and 1862; he wanted to determine experimentally whether it was selected for or whether, as he had argued in Origin (p. 245), it was ‘incidental on other acquired differences’ (see Correspondence vol. 10, Appendix VI). In addition to crossing varieties of Primula in 1863, he continued working with a plant in another genus, the purple loosestrife, Lythrum salicaria. This species provided the ‘oddest case of reproduction ever noticed.—a triple marriage’ between three hermaphrodite flower forms; during the summer of 1863, Darwin worked ‘like a Trojan’ to finish the large series of crosses between the three forms that he had started the previous year (letter to Asa Gray, 4 August [1863]). The results were published in his 1865 paper ‘Three forms of Lythrum salicaria’.

In the process of acquiring botanical specimens, as well as sharing observations and experimental results, Darwin continued corresponding with a wide range of gardeners, horticulturists, and hobbyists, in addition to professional botanists. Lydia Ernestine Becker, who was soon to be involved in the women’s suffrage movement, began writing to him in 1863 with field observations and specimens of the dimorphic Lychnis. A correspondence also began with the Scottish hybridiser Isaac Anderson-Henry, and Darwin continued the exchange of letters that had started the previous year with the Hertfordshire nurseryman Thomas Rivers.

Darwin had found a protégé and collaborator in the examination of hybridity and sterility at the end of the previous year. John Scott, a gardener at the Royal Botanic Garden, Edinburgh, had initiated the correspondence in November 1862 with a letter correcting Darwin’s description of reproduction in the orchid genus Acropera (see Correspondence vol. 10). Their 1863 letters reveal Darwin’s excitement at finding another person in Britain who shared his interests in hybridity, and who was more than willing to carry out breeding experiments. Though the two men discussed a multitude of botanical subjects, the crossing experiments that Scott had begun on the primrose family after reading Darwin’s paper, ‘Dimorphic condition in Primula’, as well as investigations of orchid pollination, occupied much of their detailed and lengthy botanical correspondence in 1863. Darwin eventually communicated Scott’s Primula work to the Linnean Society in a paper that was read in February 1864. He had already promised Scott that he would delay publication of his own continuing work with Primula crosses, the results of which were published in 1868 (see letter to John Scott, 25 and 28 May [1863]). Scott’s experiments confirmed the results of Darwin’s earlier paper on Primula ; his additional crosses between differently coloured varieties of P. vulgaris, in which he found ‘the very zero of fertility between varieties of a species’, were the sort of result that both he and Darwin hoped would counteract Huxley’s criticism (letter from John Scott, 23 July [1863]). Darwin reviewed the draft of Scott’s paper with satisfaction (see letter to John Scott, 7 November [1863]).

Scott had referred directly to Huxley’s reservations about natural selection in the introduction to his paper on orchids (Scott 1863a), completed earlier in 1863, which Darwin had also encouraged him to write (see letter to John Scott, 12 April [1863]). In this paper, Scott provided evidence of self-sterility in Maxillaria species that were fertile when crossed with another species in the same genus. Darwin’s reaction was enthusiastic: ‘The facts will be of highest use to me: I feel convinced that your paper will have permanent value’ (letter to John Scott, 31 May [1863]). Scott received a different response in Scotland; he warned Darwin that at the Edinburgh Botanical Society, where he read his orchid paper, anything that ‘savours of the “Origin” is not at all palatable!’ (letter from John Scott, [3 June 1863]).

Darwin’s early confidence in Scott rested not only on their common theoretical interests but on Scott’s powers of experimental observation. When Scott expressed growing frustration with his position as gardener, hoping for a foreign appointment that would offer more independence and opportunity for his experimental work, Darwin was sympathetic. He consulted Hooker on the advisability of this ‘truly remarkable man’ taking a position offered in Darjeeling, India (see letter from John Scott, 22 May 1863, and letter to J. D. Hooker, 23 May [1863]). Hooker advised against the appointment; Darwin replied that if Scott ‘had leisure he would make a wonderful observer; to my judgment I have come across no one like him’ (letter to J. D. Hooker, 29 May [1863]).

Darwin continued his own study of orchid pollination and was aided by the completion of his new hothouse in February; this enabled him to grow more tropical plants than before (see Appendix VI). He was fascinated with the adaptations in orchids for cross-pollination by insects because of his conviction that natural selection had brought about modifications leading to an apparent perfection of structure and coadaptation. The cross-pollination of orchids, as well as dimorphism in other flowers, provided evidence for his assertion that nature ‘abhors perpetual self-fertilisation’ (Orchids, p. 359); he had discussed the indispensibility of intercrossing to natural selection in Origin, pp. 96–109, and he continued to observe individuals of the same species crossing with one another in a variety of plants. With additional study of Cypripedium, Acropera, and the bee orchid, Ophrys apifera, he gathered information that would ultimately be published in his paper ‘Fertilization of orchids’ and the second edition of Orchids. Darwin also exchanged information on orchids, melastomas, and other tropical and sub-tropical plants with observers from warmer parts of the world. Correspondence was established in 1863 with Roland Trimen, a civil servant in Cape Town, whose work on Disa and Herschelea Darwin communicated to the Linnean Society (see letter to Roland Trimen, 23 May [1863]). Darwin began to exchange letters with Hermann Crüger, a German botanist in Trinidad, and continued writing to George Henry Kendrick Thwaites, the director of the Peradeniya botanic gardens in Ceylon. Closer to home, Darwin arranged for a paper on orchids written by a German correspondent, the botanist Friedrich Hildebrand, to be published in the English journal Annals and Magazine of Natural History. In addition to following Darwin’s orchid work, Hildebrand told him he had repeated all Darwin’s Linum experiments with the same results (see letter from Friedrich Hildebrand, 16 July 1863). In England, Darwin asked Philip Henry Gosse, a writer and naturalist in Torquay, about reproduction in Ophrys apifera, his ‘greatest puzzle’, an orchid that seemed perfectly adapted for both self-pollination and cross-pollination (letter to P. H. Gosse, 2 June [1863]). The observation of insects entering and leaving flowers filled Darwin with pleasure. After describing a bee’s movements in relation to the pollinia, movements that confirmed Gray’s theory that Cypripedium was pollinated by insects crawling through the flower, Darwin concluded: ‘It was beautiful’ (letter to Asa Gray, 20 April [1863]).

Darwin was also investigating different mechanisms for cross-pollination by searching for and studying dichogamous flowers, those in which the stamens and pistils mature at different times (see letter to Asa Gray, 11 May [1863]). The fertility of unopening, self-pollinated flowers (later called cleistogamic flowers) relative to that of the opening, cross-pollinated flowers on the same plant, as in some Oxalis and Viola species, had interested Darwin since 1860; it continued to capture his attention (see letter to John Scott, 12 April [1863]). Additionally, Darwin investigated the fertility of peloric flowers to determine whether the change in flower structure from irregular to regular was associated with a change in fertility when crossed with other plants in the same species (see letter to Isaac Anderson-Henry, 20 January [1863]). These botanical observations contributed to his understanding of intercrossing, the subject of several papers published later, and of Forms of flowers and Cross and self fertilisation, both published in the 1870s.

Darwin regularly discussed a wide range of botanical topics with Hooker, Gray, and Oliver. These correspondents were the first to hear about Darwin’s ‘chief Hobby-horse’ of the summer, one that he said he owed to Gray’s 1858 paper on the coiling of tendrils in Echinocystis. Darwin had placed the gourd Echinocystis lobata in his study to watch the spontaneous gyratory movements of its tendrils (see letter to J. D. Hooker, 25 [June 1863]). Darwin observed: ‘their irritability is beautiful, as beautiful in all its modifications as anything in orchids’ (letter to Asa Gray, 4 August [1863]). He acquired tropical ‘tendrilliferous’ plants that could grow in his hothouse from Hooker, and set about studying the various types of movement of tendrils, stems, and leaves in different plants (see letter from J. D. Hooker, [31 July 1863]). When he tried to determine the originality of his observations, Hooker and Oliver responded that they knew little; Hooker suggested that Darwin’s discoveries were ‘most curious & novel’ (letter from J. D. Hooker, [21 July 1863]). Gray had noticed more tendril movements and supplied additional references, expressing astonishment at his English colleagues’ lack of knowledge about these types of plant movements: ‘What are Hooker & Oliver (the latter a Professor too) about, and where have they lived not to know anything of them?’ (letter from Asa Gray, 1 September 1863). Gray encouraged Darwin’s work, assuring Darwin: ‘it will be fruitful in your hands’.

Darwin was considering the movements as adaptations for climbing, and was beginning to puzzle over the various types of sensitivity in different plant parts. The detail of his note-taking, the diagrams, and the careful timing of the oscillations, suggest how important the observations would be to the later publications ‘Climbing plants’ and Movement in plants. At the same time, he explained to Hooker: ‘it is just the sort of niggling work which suits me & takes up no time & rather rests me whilst writing’ (letter to J. D. Hooker, 14 July [1863]). Darwin’s pleasure in watching these ‘wonderfully crafty & sagacious’ plants was cut short in September by his departure with his family for Malvern Wells, but even when ill at home in November, he watched them in his study as they twined past volumes on the bookcase and around the head of the sofa (letter to W. E. Darwin, [25 July 1863], and letter to J. D. Hooker, [22–3 November 1863]).

Many of Darwin’s botanical observations and experiments of 1863 naturally overlapped with his writing of Variation, particularly when he was working on the chapter he called ‘Crossing & Sterility’ (see Appendix II). When Darwin finished, by 23 January 1863, a chapter on bud-variation, or sports, he had completed the first half of the book, which was to amass ‘a large body of facts’ on variation in domestic animals and plants (Variation 1: 1). He then turned to general discussions, completing three sections, on inheritance, crossing and sterility, and selection, by the end of July 1863. While it was not unusual for Darwin to complain to his correspondents about how slowly the writing was going, and how he feared he would never finish, he struck a more optimistic note in a letter to Julius von Haast of 18 July [1863], in which he said he was working very hard at Variation and hoped to begin printing in six months. However, the two-volume work was not published until 1868.

Darwin relied on members of his family for help in his research throughout the year. His eldest son, William Erasmus Darwin, a banker in Southampton, had been pressed into service to make observations in the field on dimorphic plant species. William was a conscientious observer, as is indicated by his botanical notebook and sketchbook (DAR 117 and DAR 186: 43). Many of his observations were later cited in Forms of flowers, and his help with the examination of the trimorphic genus Lythrum was noted in ‘Three forms of Lythrum salicaria’. George contributed his mathematical expertise to his father’s investigation of phyllotaxy, while Henrietta was often at her father’s side in the hothouse and garden. Henrietta took an interest in science, reading and commenting on Huxley’s books and Lyell’s Antiquity of man (see letter from T. H. Huxley, 25 February 1863, and letter to Charles Lyell, 12–13 March [1863]). Emma was a steady help to Darwin, writing many letters that her husband dictated when he was too ill to hold a pen. During the autumn of 1863, they collaborated in a new endeavour, producing an appeal against the use of steel vermin traps and the animal suffering caused by them (see Appendix IX). Francis Darwin later wrote of his father’s strong feelings regarding torment of both animals and humans: ‘It was indeed one of the strongest feelings in his nature, and was exemplified in matters small and great, in his sympathy with the educational miseries of dancing dogs, or in his horror at the suffering of slaves’ (LL 3: 199).

Darwin’s aversion to slavery had led him to side with the Union cause in the American Civil War, discussion of which figured prominently in his correspondence with Asa Gray in Cambridge, Massachusetts. At the start of the year, Darwin displayed an interest in war-related issues, particularly after reading a tract written on relations between Britain and the United States by Gray’s father-in-law, the lawyer Charles Greely Loring (see letter to Asa Gray, 23 February [1863], and Loring 1862). However, his tolerance of Gray’s fervent approach to the war declined in 1863. In April, he complained that a note of Gray’s sounded ‘very savage against England’ (see letter to Asa Gray, 20 April [1863]). Darwin evidently refrained from discussing the subject again until he read Gray’s statement that he wished he had a son so that he could send him to the war (see letter from Asa Gray, 7 July 1863). Darwin shared this letter with Hooker, who had long since ceased to discuss politics or the American Civil War in his correspondence with Gray: ‘What pleasant letters Asa Gray writes. One might as well write to a madman as to him about the war. It is a holy war & everything sh d. be sacrificed to it’ (letter to J. D. Hooker, 26 [July 1863]). Darwin then confessed to Gray that he could not eagerly support the north owing to the boasting and the abuse of England, and added that ‘the treatment of the free coloured population, and the not freeing Maryland slaves stops all my enthusiasm’ (letter to Asa Gray, 4 August [1863]). He urged Gray not to hate England too much, claiming: ‘she is the mother of fine children all over the world’.

Despite his declining health, Darwin continued to be occupied with his various botanical subjects throughout the summer, until he told Hooker in a letter of 25 [August 1863] that after having had ‘a deal of sickness of late; every morning for a fortnight’, he had resolved to take his household to Malvern the following week. Three letters in August from John Goodsir, professor of anatomy at the University of Edinburgh, indicate that Darwin had sent him a slide and a phial of vomit for analysis. Goodsir found no micro-organisms other than normal inhabitants of the mouth and stomach. On the way to Malvern Wells, Darwin stopped in London overnight to consult George Busk, former Hunterian Professor at the Royal College of Surgeons, whom Goodsir had mentioned, and whom Hooker had recommended as having ‘the most fertile brain of any man I know in regard of all such matters as your stomach’ (see letter from John Goodsir, 21 August [1863]; letter from J. D. Hooker, [27 August 1863]). Unfortunately Darwin took a turn for the worse once he arrived in Worcestershire. Only by the end of September was he able to write a letter in his own hand and recount his condition over the summer and early autumn: ‘I got worse & worse at home & was sick every day for two months; so came here, where I suddenly broke down & could do nothing; but I hope I am now very slowly recovering, but am very weak’ (letter to A. R. Wallace, [29 September? 1863]).

Darwin wrote one other letter in his own hand before the end of October; this was a heart-felt note to Hooker, who had recently suffered the death of his six-year-old daughter (see letter to J. D. Hooker, [4 October 1863]). The Darwins’ daughter, Annie, had died at Malvern in 1851, and Hooker’s news was a powerful reminder of their loss (see Correspondence vol. 5). Unable to find Annie’s gravestone in 1863, they wrote to Darwin’s cousin, William Darwin Fox, who had visited the grave seven years earlier. Fox sent a helpful letter that guided them to where it was hidden by overgrown trees and shrubs (see letter from W. D. Fox, 7 September [1863]). Emma wrote back: ‘This has been a great relief’ (letter from Emma Darwin to W. D. Fox, [29 September 1863]).

When the Darwins returned home, Charles fared little better, and most letters were dictated to Emma. Darwin only managed one of his typically long letters to Hooker by writing while lying down (see letter to J. D. Hooker, [22–3 November 1863]). He told Roland Trimen in a letter of 25 November [1863] that he had been ‘ordered to do nothing for 6 months’ by his doctors, mentioning that even writing the letter was ‘against rules’. George Busk had diagnosed Darwin as having ‘Waterbrash’, a ‘diseased secretion of the stomach’, which accompanied ‘various kinds of general derangement’. Busk prescribed medication and also advised him to consult the physician Dr William Brinton, a stomach specialist at St Thomas’s Hospital, London (letter from George Busk, [ c. 27 August 1863]). Brinton, who visited Down House in early November, evidently advised Darwin to curtail his activities.

Dr Brinton visited Down House again in early December, when Darwin had been ‘vomiting every day for eleven days & some days many times after every meal’ (letter to J. D. Hooker, 5 [December 1863]). Nevertheless, Brinton, he said, had told him that there was no reason why he should not recover his previous state of health. Brinton’s words must have encouraged Darwin; he wrote Hooker a somewhat more lively letter than usual: ‘I sh d. like to live to do a little more work & often I feel sure I shall & then again I feel that my tether is run out’ (letter to J. D. Hooker, 5 [December 1863]). He also triumphantly informed Hooker that an Italian edition of Origin was being prepared, which would be the fifth foreign edition. Recalling the controversies of the first five months of the year, Darwin added: ‘Owen will not be right in telling Longmans that Book w d be utterly forgotten in ten years’.

However, Darwin would not return at once to gathering more support for Origin, or to the observations and experimental work that he hoped would further bolster his theory. The few remaining letters from him in December were short, and dictated to Emma. By the end of the year, Emma admitted to Hooker (letter from Emma Darwin to J. D. Hooker, 26 December [1863]) that Darwin’s health fluctuated and showed little improvement; he usually stayed in his bedroom, tolerating only short visits even from his sons. She was pessimistic about his prospects of health over the next few months: ‘When not uncomfortable his spirits are wonderfully good, but I am afraid he may remain just as he is very long before there is a struggle in his constitution & that the sickness is conquered.