Darwin and the Barnacle

by Rebecca Stott

  Darwin’s collectors, Hancock and his friends on the Northumbrian shores and Bate down on the Devonshire coast, persisted, despite snow, ice, driving winds and mountainous waves. Postmen persisted, struggling through snowdrifts. Railway workers persisted, clearing railway tracks of snow. Barnacles continued to arrive at Down throughout February, and Darwin continued to write.

  With the study fire banked higher than usual, Darwin struggled to make out the Alcippe, hoping that here he had found the closest kin for Mr Arthrobalanus, for the two species had several features in common: they both burrowed, they had approximately the same number of limbs, arranged in similar patterns; but Alcippe was difficult to link to any other kind of barnacle, almost impossible to compare because of the scale of its deviation from the barnacle archetype. He could not decide how to place the species and Hancock could not offer any help when Darwin wrote to ask for it with desperation: ‘My surmises are too vague & too long to tell in this note, & perhaps all of a blunder, but I am dreadfully perplexed,’ he wrote, worriedly.41 Hancock wrote to assure Darwin that he had confidence in the direction that Darwin’s conclusions were taking him, ‘but my knowledge of the Class is so imperfect that I have no great confidence in my own opinion on the subject. I am therefore well pleased that this curious animal is now in such competent hands, and have no doubt that you will find for it its proper place in the Classification, how difficult soever the task.’42 Darwin was on his own. By now no one knew the order as well as he did. No one could make this decision with him.

  As he prevaricated, a letter arrived from Edwin Lankester from the Ray Society asking – politely but with some insistence – when the third volume was due to arrive. Darwin replied desperately, ‘I have at least 6 weeks of dissection to do. Before going to press, I must have a few weeks rest, & I do not think I shall be able to send you my M.S. till the beginning of August: but I will & can make no other pledge, except that I will work every day without exception, on which I can.’43

  Now he had to turn his mind to Mr Arthrobalanus. It had been eighteen years and two months since his first encounter with this monster in its conch shell on the Chilean beach – nearly as long as the entire life span of the young John Lubbock, who had turned eighteen the year before. Nearly seven years ago he had thought that a month would solve the questions Mr Arthrobalanus’s aberrant body raised. Where had the time slipped away to? Would all the knowledge he had accumulated in those seven long years equip him any better for understanding Mr Arthrobalanus?

  Notes

  1 In October 1852 Darwin wrote to his cousin William Fox about the pears he had in his garden and which Fox had recommended ten years before. See CD to W. D. Fox, 24 October 1852, Correspondence 5, p. 100.

  2 This section is based on Darwin’s analysis of pear and apple tree cultivation in Origin of Species.

  3 Justus von Liebig, Familiar Letters On Chemistry, In Its Relations To Physiology, Dietics, Agriculture, Commerce, And Political Economy (3rd ed., London: Taylor, Walton & Maberly, 1851), Letter 11.

  4 See CD to J. S. Bowerbank, 28 September 1851, Correspondence 5: p. 62.

  5 CD to J. J. S. Steenstrup, 16 October 1851, Correspondence 5: p. 66.

  6 CD continued to write polite and exasperated notes to Steenstrup throughout late 1851.

  7Throughout 1851 and 1852 Darwin sent out his complimentary copies of the Fossil Stalked Barnacles (1851) and the Living Stalked Barnacles (1851). He particularly targeted those men who who were not members of the Ray Society, who would automatically receive their copy. One man whom Darwin knew would not be able to afford the Ray Society subscription was Thomas Huxley. He sent Huxley a copy of Living Stalked Barnacles in 1852 and drew his attention to the Ibla and Scalpellum discoveries.

  8 Joseph Dalton Hooker with Thomas Thomson, Flora Indica, Introductory essay (London, 1855) p. 12.

  9 See the interesting discussion of this period of Hooker’s life in Desmond Ray, Sir Joseph Hooker: Traveller and Plant Collector (London: Antique Collectors Club and the Royal Botanical Gardens, Kew, 1999), pp. 200–9.

  10 Letter from Hooker to CD, November 1851, Correspondence 5: p. 68.

  11 In a letter CD wrote to Richard Owen on 17 July 1852 Darwin admitted to having been ‘frightened at the thoughts of all the sessile species’, so frightened that he had neglected to develop some of his thoughts on the anatomical structures of the stalked living barnacles in volume 2. Correspondence 5: p. 95.

  12 See letter from CD to J. D. Dana, 8 May 1852, Correspondence 5: p. 91: ‘I am most vexed at the wooden pill Box with the Crustacean having been lost: I put it in the parcel myself.’

  13 CD to W. D. Fox, 7 March 1852, Correspondence 5: p. 83.

  14 CD to John Stevens Henslow, 11 December 1851, Correspondence 5: p. 75.

  15 The Annual Register, vol. 44, 1852, pp. 478–81.

  16 Philip Henry Gosse, A Naturalist’s Sojourn in Jamaica, assisted by Richard Hill (London: Longman Brown, Green and Longmans, 1851). Darwin lists the book in his reading notebooks.

  17 Emma Darwin letter to William Darwin, 23 April 1852: DAR 219.1.4.

  18 In 1858, Hooker wrote to Asa Gray that he was ‘most thankful … that I can now use Darwin’s doctrines – hitherto they have been kept secrets I was bound to honour to know, to keep, to discuss with him in private – but never to allude to in public, & I had always in my writings to discuss the subjects of creation, variation &c &c as if I had never heard of Natural Selection – which I have all along known & feel to be not only useful in itself as explaining many facts in variation, but as the most fatal argument against “Special Creation” & for “Derivation” being the rule of all species.’ Quoted in Duncan Porter, ‘On the road to the Origin with Darwin, Hooker, and Gray’, Journal of the History of Biology, vol. 26 (1993), pp. 33–4.

  19 Quoted ibid., p. 13.

  20 Hooker later told Francis Darwin: ‘It was an established rule that he every day pumped me, as he called it, for half an hour or so after breakfast in his study, when he first brought out a heap of slips with questions botanical, geographical, &c, for me to answer. And concluded by telling me of the progress he had made in his own work, asking ray opinion on various points.’ Cited in Mea Allen, The Hookers of Kew, 1785–1911 (London: Michael Joseph, 1967), p. 194. He also remembered: ‘long walks, romps with the children on hands and knees, music that haunts me still’. I am indebted to Jim Endersby, of the History and Philosophy of Science Department at Cambridge University, for long discussions about the relationship between Darwin and Hooker and Hooker’s struggles to make botany philosophical.

  21 CD to Richard Owen, 17 July 1852, Correspondence 5, p. 95.

  22 CD to William Fox, 24 October 1852, Correspondence 5, p. 100.

  23 Henry Holland, Chapters on Mental Physiology (London: Longman, Brown, Green and Longmans, 1852), Preface, pp. i–x& for an analysis of Holland’s place in the development of theories of Victorian psychology see Rick Rylance, Victorian Psychology and British Culture 1850–1880 (Oxford: Oxford University Press, 2000), pp. 127–43.

  24 Henry Holland, Chapters on Mental Physiology (London: Longman, Brown, Green and Longmans, 1852), pp. 83–4.

  25 Holland (1852), p. 209.

  26 CD to William Fox, 24 October 1852, Correspondence 5: p. 101.

  27 Ibid., p. 100.

  28 Ibid., p. 101, note 3.

  29 According to Lubbock, CD had ‘induced my father to give me a microscope, he let me do drawings for some of his books, and I greatly enjoyed my talks and walks with him. My first scientific original work was on some of his collections.’ Cited in Horace Gordon Hutchinson, Life of Sir John Lubbock, Lord Avebury, 2 vols (London: Macmillan, 1914), vol. 1, p. 23.

  30 John Lubbock, Natural History Notebook, 1852–1855; Royal Society LUA.1 Location xxvii. d–e.

  31 John Lubbock published several infusoria and crustacean articles in 1853: ‘On Labidocera’, Annals and Magazine of Natural History, vol. xi (1853), and several articles on Calanidae in the Annals and Magaz
ine of Natural History, vols xii, lxvii and lxix.

  32 CD to J. D. Dana, 25 November 1852, Correspondence 5: p. 103.

  33 CD to Albany Hancock, 25 December 1852, Correspondence 5: pp. 106–8.

  34 CD to Albany Hancock, 10 January 1853, Correspondence 5, p. 111.

  35 CD to Albany Hancock, 12 February 1853, Correspondence 5: p. 116.

  36 CD to W. D. Fox, 29 January 1853, Correspondence 5: p. 113.

  37 CD to Albany Hancock, 12 February 1853, Correspondence 5: pp. 116–7.

  38 CD to William Darwin, 1 March, 1853, Correspondence 5: p. 121.

  39 See Annual Register vol. 95, 1853, pp. 32–3.

  40 Ibid., pp. 28–32.

  41 CD to Albany Hancock, 29 January 1853, Correspondence 5: p. 114.

  42 Albany Hancock to CD, 25 February 1853, Correspondence 5: p. 121.

  43 CD to Edwin Lankester, Ray Society, 19 March 1853, Correspondence 5: p. 123.

  11

  Manoeuvres and Skirmishes

  Do not despise the creatures

  because they are minute …

  doubt not that in these tiny

  creatures are mysteries more

  than we shall ever fathom

  Charles Kingsley, Glaucus or the

  Wanders of the Shore, 1855

  Early March 1853. The snowstorms abate for long enough for a few snowdrops to flower and the village pond to thaw, but on 15 March the winter winds and snows return with great severity. The Darwin children have tired of playing snow angels, skating and sliding, tired of the white light and picturesque snow-muffled fields, and the Down servants complain about the incessant extra work the snows have brought. The fields are covered again. The children, confined to the house, are listless and bored. Everything is more difficult. The rooms feel cold and draughty even with the fires banked up. Parslow polishes snow-stained or mud-encrusted shoes, digs out the drive, removes the icicles that have grown dangerously long. Everywhere the light is intense and shadows hard and sharp – Skimmed Milk White, Blue White, ghostly white – but at dawn, when Darwin walks the Sand Walk, the rising sun stains the snow a soft pink: Aurora Red.

  Darwin holds a glass specimen bottle up to the study window, blows off the dust and shakes it slightly so that the yellow-flecked fluid swirls angrily like a tiny whirlpool held within his hand. Beyond the window, a fresh snowstorm breaks, wind-blown across the driveway; the sky is swollen dark grey washed thinly with carmine. The label on the bottle in his hand has yellowed and the brown ink faded, but he can still make out the words written in the cabin of the Beagle: Bolanidae; Mr Arthrobalanus. ‘Our little fellow,’ he and Hooker used to call him – our little invisible fellow – but under the microscope such a grand and curious monster. Mr Arthrobalanus. He liked the name. He hadn’t quite been able to adopt the Latin name he and Hooker had invented: Cryptophialus minutus – too many syllables; and if he, Charles Darwin, unique in all the world for his knowledge of barnacle anatomy, the man whose eyes had seen and described more barnacles than any person living or dead – if he could not puzzle out this anomaly, then no one could. He had two weeks to do it – two weeks according to the tight barnacle schedule he had reworked since Lankester’s pressing letter.

  There must be about eight or nine specimens still floating in the jar, he estimates – enough to make up several slides. He will need separate specimens to produce a slide each for the cirri, pupae, reproductive parts, stomach and mouth. He gathers his materials: the boxes of glass slides and glass cover slips, the jar of asphalt for sealing, the caustic potash for dissolving the shell, the microscope and micrometer, the notes and papers and drawings, the microscope slide catalogue, which now lists 254 separate slides, a sheaf of fresh paper and a jar of cobalt-blue ink.1 All around him hundreds of barnacle valves and body parts, some as ancient as dinosaur bones, sit in their labelled coffin-Like pill boxes, waiting to be returned to their owners or posted to the British Museum. Philip Gosse had complained in his last book that zoology was too much like a necrology – a science of dead things: dry skins, furred and feathered, blackened, shrivelled and hay-stuffed, bleached and shrunken, suspended by threads and immersed in spirit in glass bottles. Zoologists should study their creatures alive and going about their business, he said, in order to really understand them.2 Mr Arthrobalanus, though, was almost invisible to the naked eye and almost invisible within his conch-shell home. There was nothing to see, and its barnacle business all went on down there, invisibly, in the hole of the shell. Mr Arthrobalanus didn’t walk, sing, fly, migrate or change his colours. The structure and layout of his body was his singular miracle and this was only made visible by using acid to dissolve the shell, dissecting pins to open up his body and a microscope to enlarge it.

  Arthrobalanus was distinctly deviant, Darwin remembered, leafing through the pages of notes gathered in his files, the drawings he and Hooker had put together at Kew, his own notes from the Beagle and the final paper he had written about the barnacle and sent to Richard Owen for comments, still unpublished because still incomplete. Back then, in 1835, scribbling his first microscope notes in the Beagle cabin, he had thought Mr Arthrobalanus unique – the only naked burrowing barnacle ever discovered; but since then his collectors had brought him other burrowing barnacle deviants, Alcippe, Verruca and Proteolepas. He remembered his amazement at discovering that one of the Arthrobalanus specimens he had dissected had what seemed to be a double penis, but no ovisac, which seemed to suggest it was not hermaphrodite but fully male. Now that he had found fellow deviants from the barnacle hermaphrodite norm – the spectacular Ibla and Scalpellum complemental males – he was able to return to Arthrobalanus with different expectations and a more open mind about their reproductive arrangements. When he looked again he discovered now that Mr Arthrobalanus was actually female. What he had assumed to be a double penis was part of the cirri, and, as in Ibla and Scapellums, the males lived parasitically upon the much larger females, mere bags of spermatazoa embedded in female flesh. Mr Arthrobalanus was now an ‘it’, with male and female parts separated out yet mutually interdependent. Nevertheless, Mr Arthrobalanus had assumed a male identity since Darwin’s first presumptions and would continue to be imagined and referred to as male in Darwin’s correspondence.

  What more could he find here? What more could he say? He needed to determine Mr Arthrobalanus’s place amongst fellow barnacles, find a family for him; and what would Mr Arthrobalanus’s presumed relation to Alcippe finally be – if there was a relation at all? In all the world Alcippe, fellow burrower, was most likely to be his nearest kith and kin. This was why he had placed them together in the barnacle list and dissection schedule.

  First Darwin used his pins to dissect Arthrobalanus’s impossibly minute egg-shaped larvae, teasing out developing adult parts, searching even inside the anterior horns, in which he found prehensile antennae, every part perfect. This is where the secrets began – in the larvae. There, pleasingly, were the swimming legs that corresponded to the second, third and fourth thoracic limbs of the crustacean archetype – as he had expected. All was going to plan; but as he examined more larva specimens in different stages of maturity over the next few days, he was astonished to find that Arthrobalanus metamorphosis was utterly unlike that of the Alcippe. Although barnacle young were generally free-swimming, the young Arthrobalanus larvae never developed swimming legs, and could only crawl about using their antennae. Structurally, despite their superficial adult similarities, they were quite different from Alcippe larvae and now he would have to go back and rethink Alcippe again as a consequence. He wrote to Hancock in frustration: ‘This has utterly confounded my previous confusion how to rank Alcippe & it; for they present some most remarkable similarity, for instance they are both bisexual, with the males remarkably alike. & yet in what I must consider their fundamental organisation, & in their metamorphosis, they are so totally unlike that I cannot place them in the same order!’3 Compare the adults and they seemed like doubles; compare the pupae and process of me
tamorphosis and they were as dissimilar as a lizard and a leopard.

  Some of the analogies between these two deviants, though, were bizarre and wonderful. A week before, he had looked carefully at the cirri on the legs of the Alcippe, noting crenated ridges on them, like teeth. He had a hunch, a flash of inspiration, that these toothed ridges were not used for grasping but for tearing up food for digestion. So these were swimming legs with teeth – multi-functioning like a penknife. Then – wonder of wonders – only days later, searching inside Mr Arthrobalanus’s oesophagus, the canal from mouth to stomach, he found, he wrote to Hancock: ‘The most beautiful discs set with teeth, & brushes of hairs worked by muscles, certainly for triturating food; which strengthens my notion.’4 So, despite the fact that these barnacles were not of the same species, nor of the same order – despite the fact that they came from different oceans – they had evolved similar bizarre devices for digestion: one had developed toothed legs and the other toothed stomach walls.

  The minute Arthrobalanus males also had quite the largest genitalia he had ever seen in the barnacle world, he wrote in the manuscript, allowing himself a rarely used exclamation mark:

  the probosciformed penis is wonderfully developed, so that in Cryptophialus, when fully extended, it must equal between eight and nine times the entire length of the animal! These males … consist of a mere bag, lined by a few muscles, enclosing an eye, and attached at the lower end by the pupal antennae, it has an orifice at its upper end, and within it there lies coiled up, like a great worm, the probosciformed penis … there is no mouth, no stomach, no thorax, no abdomen, and no appendages or limbs of any kind … I know of no other animal in the animal kingdom with such an amount of abortion.5