The year 1871 was an extremely busy and productive one for Darwin, seeing the publication of his long-awaited book on human evolution, Descent of man and selection in relation to sex. He wrote to his indexer, William Sweetland Dallas, on 27 January, ‘Good God how glad I shall be when I can drive the whole of the confounded book out of my head’. But a large proportion of Darwin’s time for the rest of the year was devoted to correspondence about Descent, as he discussed the details of its publication in February, the reprintings at intervals throughout the year, the various translations that were already under way, and the initial reception of the book in the press. Darwin fielded numerous letters from readers who were eager to contribute new facts and observations to his work, and who occasionally offered sharp criticism or even condemnation.
Darwin had expected controversy. ‘I shall be well abused’, he wrote to his friend Joseph Dalton Hooker on 21 January, ‘for as my son Frank says, “you treat man in such a bare-faced manner.”‘ The most lively debate centred on Darwin’s evolutionary account of the ‘higher’ faculties of human nature: reason, conscience, and aesthetic taste. Correspondence with his readers and critics helped Darwin to clarify, and in some cases modify, his conclusions.
The other main preoccupation of the year was the preparation of his manuscript on expression. Darwin continued to investigate the mechanisms of various emotions, such as grief, shame, and astonishment, drawing on the expertise of physicians and physiologists, as well as zoo-keepers, pet owners, and parents of young children. He also made contact with commercial photographers, hoping that various expressions might be captured with this relatively new technology for the purpose of illustrating his book.
The year also brought a significant milestone for the family, as Darwin’s eldest daughter Henrietta was married in August. The event was bittersweet for Darwin, as feelings of hope for her future happiness combined with a sense of loss.
Descent of man
As Darwin was finishing corrections to the page-proofs of Descent, he wrote to Philip Lutley Sclater on 4 January, ‘Heaven knows, whether the book is worth one quarter of the labour which it has cost me, though the collecting [of] the facts, during several past years, has been a great amusement’. Darwin had been working fairly continuously on the book since the publication of Variation in February 1868, but many of the topics, such as the evolution of mind, language, and morality, had been long-running interests, beginning with his work on species theory in the late 1830s. In recent years, Darwin had collected a wealth of material on sexual selection across the animal kingdom. He had briefly mentioned sexual selection in Origin, and had increasing come to regard it as important for explaining characteristics that distinguished males from females of the same species, as well as the physical features of different human races. The material on this subject became so extensive that it filled nearly two-thirds of the book. Indeed the number of pages devoted exclusively to human evolution was comparatively small, reflecting Darwin’s aim of showing kinship with animals at every level of structure and behaviour.
Descent was published on 24 February, and all 2500 copies were sold in a week. ‘Murray says he is “torn to pieces” by people wanting copies’, Darwin wrote to his son Francis on 28 February. Demand continued throughout the year, and Murray produced three more printings, 2000 in March, 2000 in April, and a further 1000 in December. The level of interest in the book overseas was shown by the number of foreign editions and translations, and the speed at which they appeared. Arrangements for a US edition had been in place since December 1869, while German, Russian, French, and Dutch translations were being prepared from the proof-sheets, rather than waiting for the bound copies. Hooker suggested one of the reasons behind the book’s popularity: ‘I hear that Ladies think it delightful reading, but that it does not do to talk about it, which no doubt promotes the sale’ (letter from J. D. Hooker, 26 March 1871). The profits for Darwin were considerable. After receiving sums totalling £1470 for the first two printings, Darwin wrote to Murray on 20 March 1871, ‘It is quite a grand trade to be a scientific man.’
Promoting the book
As usual, Darwin did his best to obtain a wide and favourable reception. He suggested various journals for review, and ordered a large number of presentation copies, sending around eighty books to leading men of science and collaborators who had assisted him, as well as to his extended family and friends (see Correspondence vol. 19, Appendix IV). Four of Darwin’s five sons received a copy, and his daughter Henrietta, who had contributed substantially as a critic and commentator, received a special acknowledgment in the form of a gift. Darwin credited her for whatever he had been able to achieve in ‘lucid vigorous style’, as well as for the book’s ‘arrangment, not to mention still more important aids in the reasoning’. He decided to give her around £25 so that she might buy something to her liking, ‘to keep in memory of the book’ (letter to H. E. Darwin, 20 March 1871).
Recipients of his presentation copies began to write in February, usually sending their compliments and praise. The asylum director James Crichton-Browne described the book as ‘strong as iron and clear as crystal’, and had forsaken his lunch and dinner in order to read it (letter from James Crichton-Browne, 19 February 1871). The African explorer and writer William Winwood Reade thought the publication of so bold a theory would ‘encourage many in their writings to tell what they believe to be the truth, whether pleasant or not’ (letter from W. W. Reade, 21 February 1871). The geologist William Boyd Dawkins remarked on Darwin’s books’ reception amongst ‘artisans and mill-hands of Manchester and Oldham … They club together to buy them’ (letter from W. B. Dawkins, 23 February 1871). Thomas Henry Huxley marvelled that Darwin had been able to link the periodicity of certain bodily phenomena with the lunar cycle: ‘Fancy lunacy & menstruation coming out of the primary fact that one’s nth. ancestor lived between tide-marks!’ (letter from T. H. Huxley, 20 February 1871). Asa Gray remarked, somewhat reservedly:
almost thou persuadest me to have been “a hairy quadruped, of arboreal habits, furnished with a tail and pointed ears”
(letter from Asa Gray, 14 April 1871)
Like his previous book, Variation, Descent inspired many to write to Darwin with small corrections or contributions.
A German emigrant in St Louis claimed that new races arriving in America began to ‘elongate’ owing to sheer ‘will-power’ and the heavy use of their arms and legs (letter from C. L. Bernays, 25 February 1871). Samples of hair arrived from several correspondents, including William Bernhard Tegetmeier, who remarked that he had often been falsely accused of dying his beard in order to make it darker than the hair on his head (letter from W. B. Tegetmeier, [before 25 April 1871])). Hinrich Nitsche, ‘the lucky owner of a pair of well developed atavistic ears’, enclosed photographs together with an image of an orang-utan foetus (letter from Hinrich Nitsche, 18 April 1871). Darwin thought he might use the photographs in a second edition of Descent, and enclosed one of himself, adding that it made a ‘very poor return’ (letter to Hinrich Nitsche, 25 April ).
Animal anecdotes appeared in great quantity: a koala who smoked pipe tobacco ‘in a state of dreamy enjoyment’, a parrot who addressed family members by name and scolded another parrot who escaped his cage and helped himself to food (‘how dare you Sir’), a perfidious dog who crept silently onto a forbidden sofa each night, returning to its allotted space each morning (letter from Arthur Nicols, 7 March 1871; letter from B. J. Sulivan, 11 March 1871; letter from Hermann Hoffmann, 17 April 1871).
Disagreements with old friends
A number of correspondents took issue with Darwin’s evolutionary explanation of the ‘higher’ faculties and his insistence that the differences between humans and other animals were differences only in degree, not kind. Several objected to his attribution of aesthetic sense to animals, arguing that beauty for humans involved reasoned judgement. The American poet Emily Pfeiffer suggested that beauty might have evolved as an ‘incidental result’ of the selection of characteristics that ‘fascinate and allure’, thus birds might be captivated by particular objects, as if under a spell, without having a high aesthetic appreciation of beauty (letter from E. J. Pfeiffer, [before 26 April 1871]). Roland Trimen, a long-time correspondent and contributor of observations on South African butterflies and beetles to Descent, could not extend Darwin’s evolutionary theory beyond man’s ‘bodily frame’, maintaining that humans must have received a ‘special endowment of spiritual life’ at some time in the past (letter from Roland Trimen, 17 and 18 April 1871).
Candid disagreement regarding human ancestry was expressed by Darwin’s old friend, the former vicar of Down John Brodie Innes. Darwin and Innes had remained on good terms over the years despite their widely divergent views on politics, religion, and science. Darwin had written to Innes on 18 January, ‘you are one of those rare mortals, from whom one can differ & yet feel no shade of animosity,—& that is a thing which I shd feel very proud of, if anyone cd. say of me.’ After the publication of Descent, these differences were raised to a high pitch, as Innes wrote on 26 May 1871 about the darker races arising through degeneration: ‘I hold to the old belief that a man was made a man though developed into niggurs who must be made to work and better men able to make them, if those radicals did not interfere with the salutary chastisment needful, neglecting the lesson taught by the black ants slaves to the white’. Darwin thanked Innes for his ‘pleasant letter’, but asserted his antipathy to human bondage: ‘my views do not lead me to such conclusions about negros & slavery as yours do: I consider myself a good way ahead of you, as far as this goes’ (letter to J. B. Innes, 29 May ).
On religion and morality
Others objected to Darwin’s theory on purely religious grounds. The Christian publisher George Morrish urged Darwin to rest the uniqueness of humans on their fallen nature: sin has infected the being of humans, ‘whereas the baboon is as the Creator made it’ (letter from George Morrish, 18 March 1871). Darwin received an anonymous letter headed ‘A Message, from God unto thee’, accusing him of trying to prove God a liar, and promising that He who had redeemed the world, could also redeem the wayward author of Descent (letter from a child of God, [after 24 February 1871]).
Yet some continued to find Darwin’s theories consistent with religious belief, whether liberal or orthodox. The American philosopher and journalist Francis Ellingwood Abbot incorporated Darwinian theory into his campaign for ‘free religion’: ‘it contains nothing inconsistent with the most deep and tender religious feeling’ (letter from F. E. Abbot, 20 August 1871). The Anglican clergyman and naturalist George Henslow reported that he had been defending Darwin against charges of atheism amongst his ‘clerical brethren’ (letter from George Henslow, 5 December 1871). Ernst Haeckel boasted of his month spent at a Franciscan monastery while working on sponges in Dalmatia, having been hosted by a monk who announced on his arrival, ‘Darwin is right . . . we are all of us descended from one and the same catarrhine monkey!’ (letter from Ernst Haeckel, 21 December 1871).
Descent was extensively reviewed in the periodical press, including religious journals, literary magazines, and daily newspapers (see Appendix V). Not surprisingly, it was Darwin’s naturalistic theory of the evolution of morals from the animal instincts of sympathy and love that proved most controversial. The Times rebuked Darwin for undermining the foundations of social order, namely ‘those elementary principles of duty which are independent of all times and all circumstances’ (8 April 1871, p. 5). Darwin condemned the author of the review as ‘a windbag full of metaphysics & classics’ (letter to John Murray, 13 April ).
But a similar point was made by the religious writer Frances Power Cobbe, who praised the charm of Darwin’s book, but found highly objectionable his suggestion that, if, for example, bees developed moral instincts, they might consider the killing of some members of a hive a duty (Cobbe 1871, pp. 174, 188–9). Darwin was particularly interested in an anonymous review in the Pall Mall Gazette, and wrote to its author, who turned out to be John Morley, a leading advocate of associationist philosophy and utilitarian ethics. Morley thought that Darwin had attributed to natural selection what was properly due to ‘Social Selection’. Moral progress, he held, was achieved through ‘the medium of opinion, positive law &c’, and transmitted by culture, not biology (letter from John Morley, 30 March 1871).
Reaction at home
Darwin engaged with critical readers from within his own family circle, especially his cousin Hensleigh Wedgwood, whom Darwin had cited on the origin of language in animal sounds. In Descent, Darwin had argued that conscience arose in humans through a conflict between enduring social feelings and more fleeting desires and passions. He had used the example of an English pointer, who ‘if able to reflect on his past conduct would say to himself, I ought (as indeed we say for him) to have pointed at that hare and not have yielded to the passing temptation of hunting it’ (Descent 2: 392). Wedgwood, however, denied that a simple comparison between instincts, one enduring and one fleeting, could produce regret or remorse. The true essence of conscience, according to Wedgwood, was shame, and he went so far as to attribute ‘a distinct sense of sin’ to the naughty dog when it was confronted by the presence of its master. (Letter from Hensleigh Wedgwood, [3–9 March 1871].)
Some of Darwin’s correspondence on evolution and ethics was circulated within the family and commented upon by his wife and children. William offered his assessment of John Stuart Mill’s theory of utilitarianism to assist his father in answering Morley. George and Henrietta remarked upon his dispute with Wedgwood. Darwin’s theory of the moral sense was especially troubling to Emma, as indicated in a letter that she wrote to Cobbe on 25 February: ‘Speaking in my private capacity … I think the course of all modern thought is `’desolating’’ as removing God further off…. So you see I am a traitor in the camp’.
Because Darwin’s scientific work was situated in the home, and because he relied extensively upon friends and family for scientific assistance, he was acutely mindful of this immediate circle of readers to whom he was emotionally and morally bound. In one particularly long letter to Wedgwood, Darwin alluded to the pain of disagreement and the pleasure of consensus, as he tried to establish common ground with his cousin, often through considerable labour: ‘Every point of agreement is a satisfaction to me’ (letter to Hensleigh Wedgwood, 9 March 1871).
A widening rift
By far the most vexing critic for Darwin was the zoologist St George Jackson Mivart. An expert on primates and a former protegé of Huxley’s, Mivart had written several articles the previous year that questioned the capacity of the theory of natural selection to explain various animal structures and homologies. Mivart’s views were published in expanded form in Genesis of species (Mivart 1871a), which appeared just prior to Descent in early 1871. ‘I daresay it will tell heavily against natural selection’, Darwin wrote to Hooker on 21 January. Darwin read the book in just a few days, and was particularly concerned that his own views on evolution had been misrepresented. Mivart had ignored his continued reliance on mechanisms other than natural selection, such as the inherited effects of use and disuse, and the direct action of ‘conditions of life’. He had also accused Darwin of being ‘dogmatic’ in his assertions. Darwin pressed this last point with Mivart, insisting that he had hunted through two chapters of Variation and the fifth edition of Origin and found only the ‘most guarded expressions’ (letter to St G. J. Mivart, 23 January ).
Darwin’s letter to Mivart was part of a long exchange in which the men sought with increasing difficulty to remain on cordial terms. Mivart repeatedly affirmed his deep respect for the elder naturalist, inquired after Darwin’s health, and expressed his desire to meet so that their differences might be patched up. He claimed that his attacks on the theory of natural selection were directed primarily against some of Darwin’s supporters and their ‘irreligious deductions’ (letter from St G. J. Mivart, 24 January 1871). The men did meet in London at the end of February, and Darwin’s impression was highly favourable: ‘He is really a charming man & we were the best of friends’, he wrote to his son Francis on 28 February. However, later in the year, Mivart wrote an even more hostile article in the Quarterly Review ([Mivart] 1871c]). It was published anonymously, as was common practice, but Darwin quickly guessed the author from the tone and manner of argumentation, full of the ‘greatest scorn & animosity’. ‘He makes me the most arrogant, odious beast that ever lived,’ Darwin wrote to Hooker on 16 September. Darwin suspected that Mivart’s sense of honour and fairness had been corrupted by his devotion to Roman Catholicism: ‘I suppose that accursed religious bigotry is at the root of it’ (letter to J. D. Hooker, 16 September ).
While struggling to maintain politeness in his private correspondence, Darwin took measures to address Mivart’s objections to the theory of natural selection. He arranged for a highly critical review of Genesis of species to be reprinted in London (Wright 1871b). The article was by the American mathematician Chauncey Wright, a colleague of Asa Gray’s at Harvard University. Darwin financed the publication of 750 copies, requesting 250 for himself so that he could distribute them privately, for he suspected that very few would actually sell (letters to John Murray, 17 August  and 13 September 1871).
Darwin also began to gather new material to answer Mivart’s criticisms. Alexander Agassiz, Abraham Dee Bartlett, Albert Günther, George Busk, T. H. Huxley, Osbert Salvin, and William Henry Flower all provided Darwin with information on transitional forms and modified structures. Darwin eventually incorporated this material into a new chapter of the sixth edition of Origin, published the following year. Darwin was also pleased that Huxley took up the defence in an article in the Contemporary Review attacking Mivart’s misreading and misquoting of both Darwin and Catholic theology (T. H. Huxley 1871). Huxley judged Mivart to be not ‘a bad fellow’, but thought his mind had been poisoned by ‘accursed Popery and fear for his soul’ (letter from T. H. Huxley and H. A. Huxley, 20 September 1871).
Darwin’s other main preoccupation of the year was the completion of Expression. ‘I care for nothing in the world except. laughing. crying grinning pouting &c. &c’, he wrote to Hooker on 21 March. Darwin engaged leading anatomists and eye specialists Frans Cornelis Donders, William Bowman, and Erasmus Wilson, to investigate the mechanisms of weeping and the production of tears during spasmodic movements of the eye-muscles, apologising for troubling his correspondents with his ‘ludicrous’ or ‘absurd & trifling’ questions (letter to William Bowman, [before 26] January ). He was particularly keen to get photographs of infants crying, and wrote to the studio photographer Adolphe Diedrich Kindermann of Hamburg on 27 March for one of a baby of one or two months ‘screaming with the eyes firmly closed’. He consulted another photographer, Oscar Gustaf Rejlander, who had gained notoriety for images of ragged children, paying a visit to his studio in April. Rejlander took a keen interest in Darwin’s work, sending him notes on various emotional expressions. He eventually contributed a number of photographs to Darwin’s book, and persuaded Darwin to pose for him in turn, as partial exchange for his services.
Darwin made extensive inquiries about blushing, trying to establish whether it was a purely instinctual response, and whether it could be produced by an operation of the mind. He wrote to James Crichton-Browne on 28 March to ask whether blushing was evident in asylum patients, and later wondered whether Crichton-Browne’s sister-in-law had ever blushed when alone in the dark (Crichton-Browne had reported some of her remarks on the subject of blushing to Darwin): ‘I have long thought that Shakspear was in error (though this is high treason) when he makes Juliet say to Romeo `’Thou knowest the mask of night is on my face, else would a maiden blush bepaint my cheek’’‘ (letter to James Crichton-Browne, 18 April 1871).
He pursued a similar query with the artist Thomas Woolner, inquiring on 7 April whether ‘young and inexperienced’ models blushed and how far down the body the blush extended. He asked more difficult questions regarding the possible effects of the mind on the circulation of the blood. The physiologist Michael Foster offered a lengthy speculation about how the exercise of attention might alter the flow of blood to various parts of the body indirectly, by giving rise to a particular emotion (such as embarrassment) that could then produce physiological changes (letter from Michael Foster, 4 June ).
Pangenesis under siege
For over a year, Darwin had been receiving regular reports from his cousin Francis Galton on the progress of experiments that were designed to test Darwin’s hypothesis of heredity, pangenesis. The experiments involved transfusing blood between rabbits that were differently coloured, and then observing any changes in coloration in the offspring. In a paper presented at the Royal Society of London in March, Galton announced that the results of his experiments tended to disprove Darwin’s hypothesis. Darwin quickly responded with a letter to Nature, questioning one of the central assumptions of Galton’s work, namely that the material of hereditary transmission (what Darwin had called ‘gemmules’) was located in the blood. Darwin insisted that he had never made such an assumption, for he had intended his theory to apply to plants as well as animals. He remarked, however, that he had not reflected sufficiently on the subject when he first learned of Galton’s experiments and he praised Galton’s ‘ingenuity and perseverance’, adding that pangenesis had not yet ‘received its death blow’ (letter to Nature, [before 27 April 1871]). The misunderstanding seems to have caused no ill feelings between the cousins. Galton continued to pursue his experiments, and described in graphic detail how he was turning his attention to rats, and employing a surgical assistant to ‘siamese’ them together in order to facilitate cross-circulation (letter from Francis Galton, 13 September 1871).
A return to poor health
During the summer months, Darwin was plagued by illness, and he complained more about poor health than he had done in recent years. The family rented a house in Albury, Surrey, from 28 July to 25 August in the hope that it would improve his condition; but it only worsened, and they had to return home early. Darwin wrote very few letters in August, on one occasion penning just two lines to Alfred Russel Wallace, ‘I am so giddy I can hardly sit up, so no more’ (letter to A. R. Wallace, 4 August ). On 23 September he informed Murray that owing to poor health he had done nothing for six weeks.
Danger: botanist at work
Despite his bouts of illness, his considerable work on Expression, and the extensive correspondence about Descent, Darwin found time to devote to some of his other long-standing interests in natural history. He obtained a bottle of curare from Michael Foster in June. Curare was a paralysing agent more commonly used in animal experiments, but Darwin wanted to apply it to the leaves of Drosera rotundifolia as part of his research on the habits and physiology of insectivorous plants. Foster described the effects of the poison on frogs, but doubted that it would work on organisms without a nervous system (letter from Michael Foster, [26 June 1871]).
Coincidentally, Darwin received a letter from the American botanist Mary Treat including her observations on the fly-catching activity of Drosera. This was the first of a series of letters extending over five years. ‘A life time of observation and experiments’, she wrote, ‘could not repay the debt of gratitude we owe you’ (letter from Mary Treat, 20 December 1871).
Working on worms
Toward the end of the year, Darwin began to make calculations on the amount of earth raised by worms over long periods of time, and the effects that this activity would have on the elevation of land. In October 1870, two separate square yards of ground were marked out near the Wedgwoods’ home, Leith Hill Place in Surrey, and CD’s niece Lucy Wedgwood collected and weighed the dried castings for a year. In November 1871, Darwin estimated the amount of soil that worms could raise annually on an acre of land at 16 tons (letter from L. C. Wedgwood, [20 November 1871]). He also wrote to the leading geologists David Forbes, Arthur Crombie Ramsey, and Archibald Geikie with related questions about the denudation of the soil on cultivated land, the gradual sinking of heavy stones, and the effects of various acids on the disintegration of rocks in the soil. These inquiries, stemming from a short paper Darwin had delivered at the Geological Society of London in 1837, would culminate in Darwin’s last book, The formation of vegetable mould through the action of worms, published just six months before his death.
The emptying nest
By the close of 1871, Down House was more than usually quiet, as all but one of the Darwin children had now left the family home.
The Darwins' youngest son, Horace, entered Cambridge University. He passed his first examination toward a Bachelor of Arts degree, and planned to pursue studies in mathematics and science (letter to Horace Darwin, [15 December 1871]). Francis was now studying medicine at St George’s Hospital in London, although he still attended some lectures in Cambridge and tutored in natural science. George, now a fellow of Trinity College, planned a trip to America, and invited Francis and two Cambridge friends. Darwin agreed to pay Francis’s expenses, after being reassured that the trip would not interfere with his medical studies. Darwin had paid off Francis’s considerable debts the previous year, but he was sympathetic about the venture: ‘it wd be almost superhuman virtue to give it up’ (letter to Francis Darwin, 16 May ). Darwin asked Asa Gray to obtain introductions for his sons to ‘any pleasant & good natured persons’, and the boys were away from August to October 1871, travelling from Boston to Niagara Falls to the ‘great valleys in California’ (letter to Asa Gray, 16 July , letter to S. R. S. Norton, 23 November ).
Darwin’s eldest daughter, Henrietta, became engaged in June, and was married on 31 August. Darwin remarked to Hooker on 23 July, ‘her loss will be so terrible to us all, that I am so selfish I cannot rejoice properly over her great happiness’. He sent warm congratulations soon after the wedding, reminding her that he had been her favourite from an early age, and that she used to sit on his knee for a long time ‘looking as solemn as a little judge’, and counselling her to follow the example of her mother, who was ‘as good as twice refined gold’ (letter to H. E. Litchfield, 4 September ).
The months leading up to her marriage were evidently a period of deep reflection for Henrietta, and some of her thoughts on the foundations of religious belief, Christian charity, and the nature of sympathy are contained in her journal for part of 1871. Henrietta’s husband was Richard Buckley Litchfield, a barrister, philanthropist, and music instructor at the London Working Men’s College. A wedding party for the couple was held at the college in November, and Henrietta described the joyous occasion in great detail, her uncertain health requiring her to attend ‘fortified up to the last with quinine & sherry’ (letter from H. E. Litchfield to Charles and Emma Darwin, [5 November 1871]). Her husband quickly found himself enrolled in Darwin’s circle of scientific correspondents, providing reflections on the origin of music and the use of the human voice in emotional expression.
In the popular press
The publication of Descent brought Darwin even more into the public eye than he had been in the years following the publication of Origin of species. Murray convinced him to appear in Vanity Fair in September as part of its series ‘Men of the day’, which had featured humorous portraits of Otto von Bismarck, Roderick Impey Murchison, and the earl of Derby. Given his poor state of health for much of the summer, it is ironic that the Vanity Fair artist chose to depict Darwin in a rare and uncharacteristic pose: smiling. A more typically sober image of the naturalist appeared in the Illustrated London News in March, with deep set eyes, prominent brow, and bearded face. It prompted a reader ofDescent to write to him, commenting on his fitting resemblance to a ‘venerable old Ape’ (letter from D. Thomas, [after 11 March 1871]).
Descent and its sequel, Expression, would inspire a number of other ‘likenesses’, showing Darwin transformed, with monkey hands and tail, swinging from a tree, an incarnation of his theory of evolution. A French correspondent predicted that ‘in times to come this will be known as `’the age of Darwin’’, as we now speak of the age of Newton’ (letter from Napoleon de la Fleurière, 8 April ); while Huxley looked forward two thousand years, when Origin of species would still be read, like Plato’s Republic, by ‘earnest students’, consoling themselves with the reflection that ‘Truth doesn’t die’ (letter from T. H. Huxley, 28 September 1871).