Darwin and the Barnacle

by Rebecca Stott

  Where did they come from and what was their purpose? Had they been spontaneously generated, these animalcules and confervae? Some people, such as his grandfather Erasmus Darwin, argued that all life began from such aquatic fragments. Had they entered the world without parents? If not, where was their parent body? Were they plants or animals? What kept them together in such dense colonies so that the edge of the strips of discoloration were so clearly marked from the rest of the sea?

  By this point in the voyage Darwin was preoccupied with geological puzzles as well as zoological ones. The two had become impossible to separate, now that he was gathering information about how the Earth had begun. Shellfish on the tops of mountains told of early forms and moving seas and bodies sealed and imprinted in rocks. Charles Lyell’s new book Principles of Geology had gripped his imagination and the imaginations of geologists all over the world. Lyell was interested in volcanic landforms and raised beaches. He was puzzling out the slow, drip-on-drip formation of the Earth’s surface over eons of time and arguing that it had been formed not by sudden, violent spasms of eruption and catastrophe, as others had argued, but through forces still working in the world: river, rain, rising seas, volcanoes and wind. For the Earth to have been formed this way, it had to be millions of years old, not the presumed 4,000 years of biblical history, and land masses were still moving, invisibly metamorphosing. Wherever he travelled, Darwin found himself looking at mountain ranges and seashores through Lyell’s eyes, seeing through Lyell’s theory.

  Of the pages of Darwin’s zoology notebooks, written during his five years on board the Beagle, over half concern marine invertebrates. Over a third of the notebooks concern zoophytes.30 For Darwin and other zoologists working across Europe they were an alternative way of thinking through the beginnings of time, raising philosophical questions shared by the study of geology. In May 1833, Darwin wrote to William Darwin Fox: ‘The invertebrate marine animals are … my delight; amongst them I have examined some, almost disagreeably new; for I can find no analogy between them & any described families.’31

  8 Repairing the Beagle

  Whenever he was at sea he collected zoophytes and other creatures in his plankton net. When Captain FitzRoy ordered the Beagle to be beached in April 1834 near Santa Cruz, so that the ship’s carpenter could repair the ship’s keel and check for barnacle damage – a job he had to complete in a single tide cycle – it was Darwin who scoured the coppered underbelly of the ship for interesting marine invertebrate hitchhikers to slip into his collecting jars. Often the invertebrate dissections would continue for days at a time. Whilst a description of the dissection of a beetle or frog might take up a few lines, the dissection of a single zoophyte often ran to six or eight pages.32 ‘Most assuredly’, he wrote to Henslow, ‘I might collect a far greater number of specimens of Invertebrate animals if I took less time over each.’33 Much of this intensive research remained unpublished.

  With his powerful microscope Darwin could see further into his sea creatures’ minute bodies than almost anybody in the world had ever done before – new bodies; new worlds inside them. Now Darwin could not only continue to search for swimming eggs in simple organisms; he could perhaps even move inside the swimming eggs. He found small, moving, vibrating darting structures in the tissues of all the marine animals and plants he dissected. Darwin called these minute particles ‘granules’ or ‘granular matter’ or ‘grains’, and he was sure they had something to do with reproduction. Robert Brown, the zoophyte expert, called them ‘active molecules’. The trouble was not just with the names but with the explanations.

  By the end of the Beagle voyage, Darwin was sure that this granular matter was primordial; these grains were the building blocks of all organic life, animal and vegetable, from algae to elephants – unity in extreme diversity. The grains were common to both kingdoms, animal and vegetable. The kingdoms could be united here at this microscopic point, this common denominator. In addition, his microscopic work had proved to his satisfaction that in both kingdoms both asexual and sexual reproduction took place.34 They were kin. There were more and more points of comparison. By the end of the Beagle voyage he was convinced that: ‘All animals of the same species are bound together just like buds of plants, which die at one time. Though produced either sooner or later.’ The many buds of one parent tree; common ancestry. He made an important note to himself in his 1837 transmutation notebook on his return: ‘Prove animals like plants; trace gradation between associated & non associated animals. – & the story will be complete.’35 Yet it would be some time before Darwin began to question this assumed hierarchy in nature, a great chain of being. It was a habit of thought almost impossible to resist because it dominated the ideas of most of the philosophical naturalists, however radical. There were higher animals and lower animals and the job of the lower animals was to serve the higher animals as food or as fuel, or even as ocean lights: each to his place and purpose.

  Darwin’s marine zoology research on the Beagle demonstrated again and again how interdependent and symbiotic life was. Every living marine organism had a part to play in supporting the life of other species. Just as he marvelled at what we might call the ‘ecosystem’ of the tropical forests of Tierra del Fuego, so he found giant aquatic forests growing on all the submerged rocks around the coast of the Falkland Islands and Tierra del Fuego. Sailors navigated around these kelp forests, which warned of dangerous rocks beneath; but the fact that these forests not only saved the lives of sailors, by acting as lighthouses, seemed inconsequential compared to the fact that they also supported hundreds of species of corals, polyps, and sea anemones: ‘On shaking the great entangled roots, a pile of small fish, shells, cuttle-fish, crabs of all orders, sea-eggs, starfish, beautiful Holuthuriae … Planariae, and crawling nereidous animals of a multitude of forms, all fall out together.’36

  Yet this agent of life could also be an agent of death. In March 1833 the ship’s clerk, Hellyer, was reported missing. He had gone ashore on to the Falkland Islands to shoot birds, for he was building up a collection of rare bird skins that he would have stuffed on his return to England. The search party found his clothes, gun, watch and a pile of dead birds on the rocky beach. But they were too late. They found his naked body as the tide retreated, half-submerged in the water. Swimming to retrieve a shot bird that had fallen into the water, his feet had become entangled in the kelp. His drowned and swollen body had to be cut out of the seaweed. These aquatic forests were both fertile and dangerous.37 The grave of the man drowned by seaweed is still visible on a desolate outcrop of rock on the Falkland Islands.

  Without the kelp, however, the marine food cycle of this particular coastline would be broken. Without shelter the fish and other marine creatures that lived in the giant kelp forests would not flourish. Without these creatures, cormorants, divers, seabirds, otters, seals and porpoises would die; and shoreline man was entirely dependent on this food chain too. It marked out his separation from cannibalism and from extinction. Without it, ‘the Fuegian savage, the miserable lord of this miserable land, would redouble his cannibal feast, decrease in numbers, and perhaps cease to exist’.38

  Darwin was both fascinated and disgusted by the Fuegians. Half-naked, they scratched a miserable existence on the rainy shores of Tierra del Fuego, living on fish and limpets. These were shore people who depended entirely on food from the sea, food nurtured in the kelp forests. From the deck of the Beagle, in February 1834, he watched a colony of Fuegians living on the beach: ‘Here 5 or 6 human beings, naked & uncovered from the wind, rain & snow in this tempestuous climate sleep on the wet ground, coiled up like animals. – In the morning they rise to pick shell fish at low water; & the women winter & summer dive to collect sea eggs; such miserable food is eked out by tasteless berrys & Fungi.’39 Life was in a state of complex entanglement, yet the practice of so many zoologists was to separate organisms from their environment and from the other organisms with which they were entangled and to box and pin them in splendid isolation.


  It seemed to be something about the Fuegians’ exposure to the elements that disgusted and disturbed Darwin. He wrote that he had never felt the division between a savage and a civilized state so acutely as in watching the Fuegians, particularly watching the women in the rain:

  But these Fuegians in the canoe were quite naked, and even one full-grown woman was absolutely so. It was raining heavily, and the fresh water, together with the spray, trickled down her body. In another harbour not far distant, a woman, who was suckling a recently-born child, came one day alongside the vessel, and remained there whilst the sleet fell and thawed on her naked bosom, and on the skin of her naked child. These poor wretches were stunted in their growth, their hideous faces bedaubed with white paint, their skins filthy and greasy, their hair entangled, their voices discordant, their gestures violent and without dignity.40

  This was no South Seas golden-sands idyll complete with flower garlands and conch shells. The beach the Fuegians lived on was covered with boulders, and because the cliffs were so steep in places, they could only move about in their canoes. They had no homes, he noted, and no domestic affection. They lived like animals. But they had survived – and continued to survive – here in this inhospitable, cold and wet place. Whatever his own judgements, Darwin was aware that their survival here meant that they had successfully adapted to their environment: ‘Nature by making habit omnipotent, and its effect hereditary, has fitted the Fuegian to the climate and the productions of his country.’41 No one knew what effect the transplantation of the ‘civilised’ Fuegians would make on these communities.42

  Darwin and the other officers on the ship also had to adapt to their changing environment. Frock coats and clean-shaven faces would not help them survive against the biting insects and elements. They grew beards before they sailed for Patagonia.43 That August, Darwin wrote to a friend from Montevideo: ‘If you were to meet me at present I certainly should be looked at like a wild beast, a great grisly beard and flushing jacket would disfigure an angel.’44 He ate roast armadillos on tropical shores, swam in warm seas, slept in makeshift tents on mattresses of putrefying seaweed on rocky coasts, and slaughtered scores of seabirds with his geological hammer. In Tahiti he chewed on hallucinogenic plants so powerful that even the local people wouldn’t touch them.45 ‘With my pistols in my belt and geological hammer in hand, shall I not look like a grand barbarian?’ he asked in 1832.46

  There were cultural and religious rituals, too, that had to be accommodated in the most bleak conditions. On Christmas Day 1834 twelve men of the ship’s company, including Darwin and Sulivan, foraged for birds’ eggs on a small island in the Chonos Archipelago off the coast of Chile in the rain. They needed enough eggs to make a plum pudding. Breaking into the padre’s house attached to the church, they hung up their clothes to dry and, half-naked, roasted a sheep and made two enormous plum puddings. Lieutenant Sulivan told the story in a letter home:

  It would have amused you if you could have seen us in a dirty room with a tremendous fire in the middle, and all our blankets and clothes hung round the top on lines, getting smoked as well as dry, while all hands were busily employed for four hours killing a sheep, picking raisins, beating eggs, mixing puddings which were so large that, in spite of two-thirds of the party being west-country men, we had enough for supper also.47

  That Christmas in 1834, Darwin had found the Chonos Archipelago one of the most beautiful places in the world: ‘I cannot imagine a more beautiful scene, than the snowy cones of the Cordilleras seen over an island sea of glass, only here & there rippled by a Porpoise or logger-head Duck.’48 Cones mirroring cones.

  Lowe’s Harbour, Chonos Archipelago, January 1835. Darwin, twenty-six years old, walked along a sandy beach covered with small shells on an island off the coast of southern Chile. The Beagle was moored in the harbour nearby. Lush forests lined the beach where he walked, hanging down like an evergreen shrubbery over a gravel walk. In the distance he could see the four great snowy cones of the range of mountains called the Cordillera, There were clumps of wild potatoes growing nearby on the sandy, shelly soil near the beach, and out in the bay sea otters hunted small red crabs, which swam in shoals near the surface of the water. Here on the Chilean beach he turned over another object worth adding to his collection: a thick conch shell shot through with hundreds of unusual and tiny boreholes. This shell would become one of his most prized possessions. However, it was the holes in the shell rather than the shell itself that interested him. What creature had made them and why? He peered into one of the tiny holes but could see nothing. He slipped the shell into his pocket. It was a zoological encounter that would preoccupy him for much of the next twenty years of his life.

  Back on the Beagle he placed the shell under his microscope and peered down into one of the holes, adjusting his lens. There was a tiny creature at the base of the hole with a soft, cream-coloured body. Cemented into the hole by its head, it was upside down, waving six pairs of jointed legs in the air. Darwin was hesitant; this ‘ill-formed monster’ looked like an acorn barnacle, he reflected. But how could that be? The one accepted common feature of the acorn barnacle was that it built a house for itself, a cone-shaped house glued to the rocks. If it was a barnacle and, looking more closely, Darwin was more and more convinced it – was unclassified, up until this point: ‘undiscovered’. Darwin jotted down a few thoughts in his notebook but hesitated about what to call this unnamed monster. This creature had personality and a past worth investigating.

  Darwin will carry this Chilean barnacle on a journey around the world, from the South American beach back to London, preserved in a jar of wine spirits. When he has finished finding homes for all the 1,529 species he has collected and preserved in spirits on the Beagle, he will return to the puzzle that the creature’s strange anatomy presents; and then he will write this Chilean barnacle’s evolutionary biography – a puzzle that will take him eight years to think through.

  Days later the barnacle-shaped volcano in the distance began to erupt. It reminded FitzRoy and Darwin of the brick glasshouses on Leith shore. FitzRoy described it in his narrative:

  In the night, or rather from two to three the following morning, Osorno was observed in eruption, throwing up brilliant jets of flame or ignited matter, high into the darkness, while lava flowed down its steep sides in torrents, which from our distance (seventy-three miles) looked merely like red lines…. The apex of this cone being very acute, and the cone itself regularly formed, it bears a resemblance to a gigantic glass-house; which similitude is increased not a little by the column of smoke so frequently seen ascending.49

  The volcano was a warning of the earthquake to follow a few days later. Darwin, in a Chilean forest flanking the sea with Syms Covington, his assistant, felt the earth tremble and a breeze move through the trees. The sea surged high on the beach. A few miles away the town Concepción was devastated. A tidal wave swept through the town, shedding wreckage everywhere. The ground opened up, rocks shattered and splintered, the Cathedral collapsed. Darwin was sympathetic to the inhabitants who had lost their relatives or their homes, but fascinated by the geological phenomena opening up in front of him. Nothing on the Beagle voyage had been as interesting as this, he claimed. The earthquake had raised the beach ten feet above high-water mark, leaving mussels and shellfish drowned in the air.

  On the Beagle voyage Darwin spent a good deal of time inland, up mountains, climbing into hanging valleys, surveying extraordinary geological landscapes, speculating. Yet every where he went he found shells and fossil sea creatures in the rocks, sometimes hundreds of miles inland and sometimes on the tops of snow-capped mountains. He found oyster beds, like those deep under the waters of the Firth of Forth, on the sides of mountains. On 4 February 1835 he rode inland in southern Chile to see an oyster bed, out of which large forest trees were growing, at an elevation of 350 feet. Now he knew how such raised beaches had been created. He had seen it happen.

  In moments, violent earthquakes could create rai
sed beaches, erupting volcanoes, mountains. The formation of the Earth’s crust could be dramatic and instantaneous, or infinitesimally subtle and gradual. Off the coast of Australia Darwin studied architects of the land so small that they had to be studied with a microscope, but so powerful that over millions of years they had created reef barriers that could resist the batterings of the fiercest storm waves: corals – island architects.

  These low, insignificant coral islets stand and are victorious: for here another power, as antagonist to the former, takes part in the contest. The organic forces separate the atoms of carbonate of lime one by one from the foaming breakers, and unite them into a symmetrical structure. Let the hurricane tear up its thousand huge fragments; yet what will this tell against the accumulated labour of myriads of architects at work night and day, month after month? Thus do we see the soft and gelatinous body of a polypus, through the agency of vital laws, conquering the great mechanical power of the waves of an ocean, which neither the art of man, nor the inanimate works of nature could successfully resist.50

  These tiny animals en masse could light up the sea or make islands or conquer the sea. Accumulated labour and immense time. With the corals Darwin’s zoological and geological puzzles merged into one beautiful, branched, ancient enigma. Corals were animals, but they were also islands. They were individuals living in colonies, working together, independent and interdependent. They were animals that looked like plants – plants that worked like animals. He wrote to his sister Catherine from Chile in July 1834: ‘Amongst Animals, on principle, I have lately determined to work chiefly amongst the zoophytes or Coralls; it is an enormous branch of the organized world, very little known or arranged, and abounding with most curious yet simple forms of structures.’51