To Sea - Reef Madness: Charles Darwin, Alexander Agassiz, and the Meaning of Coral - David Dobbs

Reef Madness: Charles Darwin, Alexander Agassiz, and the Meaning of Coral - David Dobbs (2005)

Part III

Chapter 14. To Sea

I

THE CORAL REEF expeditions Alexander Agassiz took over the rest of his life, together with those he’d already taken to Florida, Cuba, Yucatán, the Bahamas, Bermuda, the Galápagos, and Hawaii, constitute one of the most comprehensive and wide-ranging scientific investigations ever conducted. If to prove his case he had to see more reefs than Darwin and Dana together had seen, he would do so. He would sail to Tahiti, as Darwin had. He would travel to the Fijis and the Ellice and the Marshalls, as Dana had. He would even go to the Maldives, a huge Indian Ocean archipelago that neither Darwin nor Dana had visited but that by the time Alex traveled there, in 1902, remained the only major coral area he had not seen. He spent altogether several years at sea, covering more than 100,000 miles. He passed thousands of days peering onto garishly colorful, fish-filled reefs, sounding the depths of blue offshore banks and apple green lagoons, hammering fossils from cliffs of limestone and basalt, and squinting into microscopes to identify the tiny animals he found imprisoned in island stone.

Few scientists ever covered more water. None saw more coral. As the century turned, it was clear that this insistently empirical investigator intended not only to see more coral than anyone else (for he accomplished that early in his quest) but to see every significant trop icalcoral reef formation on the globe. When he finished, there would be no archipelago of which another could say he knew more. And Alexander would harbor no doubt that Darwin and Dana, having gone before him, had seen poorly and spoken rashly. It was a mistake he would avoid perhaps too well.

2

Compared with his later journeys, Alex’s first trips after the “conspiracy of silence” controversy and the latest editions of Darwin and Dana seem like practice runs. In 1891, following a plan long in the works, he sailed the U.S. Fish Commission’s Albatross out of Panama on a general oceanographic journey to the Galápagos. For his coral reef work, the trip proved valuable mainly for showing him a set of islands sparse in coral despite a seemingly conducive site. The next winter, wanting to finish his Caribbean surveys before heading to the Pacific, he spent almost five months sounding banks off Cuba, the Bahamas, and the long string of islands that swing east-southeast off Florida’s east coast out to the Turks and Caicos. In the winter of 1894-1895 he took what proved an ill-timed look at Australia’s Great Barrier Reef. He wrote Murray that the Australia trip was the biggest bust he’d ever taken part in. The trade winds blew hard virtually every day and because the ship he had leased, the Croyden, handled heavy seas poorly, he spent most of the time anchored in harbors, seldom reaching the reef banks he came to explore. What he did see, however, convinced him (as it did J. Stanley Gardiner soon after) that the 1,250-mile-long Great Barrier Reef rose not from a sinking island but by growing on current-formed banks.

Alexander Agassiz, center, about to examine the catch from a trawl net

His next destinations were obvious: the South Sea Islands, the scattered string of archipelagoes that bends in a seven-thousand-mile-long dogleg across the equator in the western Pacific, roughly halfway between Hawaii and Australia. These beautiful and remote islands, already deeply storied and romanticized by this time (Dana, fifty years before, had with reason feared becoming “long pig”-the local term for roasted European-there, while Gauguin was now there living his famously uninhibited life of “ecstasy, calmness, and art”), were the home ground of the Darwin-Dana theory. It was in Tahiti that Darwin experienced his epiphany, looking down from one island peak to see another framed “like an engraving” by its lagoon and reef. It was in the barrier islands and atolls of Fiji that Dana saw the “abundant evidence of subsidence” that convinced him Darwin was right. Dana found more confirmation in the other Pacific archipelagoes-the Tuamotus, Tonga, the Ellice and Gilbert Islands. Here was the proving ground for Darwin’s argument and, of necessity, for any theory that sought to displace it.

Alex might have chosen any of these island groups for his first South Sea expedition. On the advice of Dana and the British researcher William Wharton, he headed to Fiji. There, both men said (Dana arguing subsidence, Wharton otherwise), he would find numerous examples of every coral reef form. There were fringing reefs that skirted coastlines. There were barrier reefs that left sheltered lagoons between themselves and the shore. There were ring-shaped atolls on which surf broke from all directions around calm lagoons. The consistency with which the Fijis’ several hundred is lands took these three main forms helped persuade Dana that Dar- win’s was “the true theory of Coral Islands,” and ever since then, Dana had cited Fiji as the subsidence theory’s clearest and most complete illustration.

Alex went half hoping to find Dana wrong. But he also half expected to find Dana and Darwin confirmed in Fiji-but only there. He hoped that if the Fijian reefs did prove a perfect illustration of reefs formed through subsidence, it would be an illustration so markedly different from other reef systems that did not seem to con form to subsidence that Fiji would be the exception, as it were, to the many exceptions that Guppy Bourne, Wharton, Gardiner, and others had found to Darwin’s rule. They would be the nonexception that proved the rule wrong.

3

He almost didn’t go. On October 5, 1897, as he was packing to leave the next day, Alex read newspaper reports that an Australian scientist named Edgeworth David, working on a project sponsored by Lon don’s Royal Society, had drilled into the coral of Funafuti (one of the Ellice Islands, one group north of Fiji) and penetrated over six hundred feet of coral without breaking through to anything beneath. “This information,” as Alex put it later, “seemed to settle the coral question.” Continuous coral so thick strongly suggested an island that had thickened as it sank. The only way a nonsubsiding reef could create such a result was if the drill happened to pass through the long-accumulated talus that the reef had shed and then expanded outward upon. The newspaper story that Agassiz read, however, implied that the coral that the drill had passed through was too uniform to have been talus, that it was all one great thickness of continuous reef. Still, he knew better than to put much faith in preliminary reports, especially those in newspapers. He had already chartered a boat and shipped thousands of dollars of supplies to Fiji. So though he was tempted to stay home, “convinced that at any rate, whatever had been my experience in the West Indies, Australia, and the Sandwich Island reefs, yet that in a region of typical atolls in the Pacific the conditions of subsidence suggested by Darwin and Dana might exist,” he decided to go anyway. But the Funafuti results worried him. If the early reports were correct, if the drill had passed through six hundred feet of sunken reef rather than six hundred feet of talus, he might be spending a small fortune and several months simply to prove Darwin right.

It took almost a month to reach Fiji. Alex trained from Boston to Montreal, where he boarded a private railcar he had hired, then rolled over three thousand miles of Canadian Pacific track to Van couver. There he boarded a steamship that took him over the nearly seven thousand miles of sea between Vancouver and Fiji. There was only one stop, in Hawaii, for coal and supplies. It was the longest stretch of water Alex had ever covered, and he was glad to have good weather and moderate seas.

When he arrived in Suva, the Fijian capital, he found waiting the Yaralla, the solid, well-appointed, fully crewed, twin-screw steamer he’d chartered out of Australia. The drilling, dredging, sounding, and collecting equipment he’d shipped months before were in crates on deck. He was received by friendly British officials, including a couple with whom he had steamed from Bombay to Naples a decade before (he had traveled enough to make the world rather small), one of whom was now the British commissioner in charge of relations with natives. Fiji had been made a colony in 1874, bringing a bit of British order after several decades in which European and American traders, whalers, and deserting sailors had disrupted the native tribal network into a chaos unsettling to the Empire’s sensibilities and trade.* The intervening years had granted enough calm that Alex could travel free from dangers posed by other humans, though the subjugation of the native population, particularly its manipulation by missionaries, often depressed him.

The Yaralla, however, was just what he’d hoped for, a great improvement on the Croyden. It was skippered by a Captain Thom son, who had handled the difficult Croyden well off Australia, and piloted by a Captain Cox, who knew every wrinkle of every lagoon. Alex had also brought along a William Eyers of Michigan, the Diamond Drill Company’s best drilling technician; Museum of Com parative Zoology staffers Alfred Mayer and William Woodworth, who looked after the zoological collections and assisted generally; and his son Maximilian, now in his mid-twenties and the expedition photographer. Alexander himself felt as fit as he had in years. His sea legs were nicely under him after the long passage, and he was strong from several weeks of riding in the Mexican highlands earlier that year, checking on mines. He was as tough as the mules he’d ridden there, he wrote Murray, “but I hope not as obstinate.”

After a few days of securing permissions, checking provisions, and unpacking and installing equipment, Alex had Captain Cox steer the Yaralla out of Suva and set off to survey the isles. He had already worked out a plan designed to bring him against reef formations and into lagoons with the sun behind him, shining into the water to illuminate navigational hazards and sea life and give good light for Max’s pictures. Moving efficiently through the scattered archipelago required daily adjustments. Alexander took to rising at 5 a.m., when he would have a coffee and, still in his pajamas, walk the quiet deck and look out over whatever cove or lagoon they had anchored in. Then he would sit down before the charts and plan the day’s run. After breakfast the work began. He, Max, Woodworth, and Mayer might go ashore to examine the island, paying special attention to any exposed limestone, or take a skiff over the reefs, dredging and fishing and peering down into the water, while Cox steamed the Yaralla around the island sounding the bottom con tours. Alex often napped after lunch, resting during the worst of the heat, then worked until a late dinner. The scientists usually ate and did much of their work under a large awning that covered most of the deck; shaded but swept by any breeze, the deck stayed cooler than the cabins below. Alex did not scrimp on food or wine; he took great pleasure in these twilit dinners with his colleagues and son, sur rounded by stars emerging in a sky darkening over volcanic ridges and the waves breaking phosphorescent on the sheltering reef

As they steamed from place to place, they tended to have at least one island in sight, though they sometimes passed through feature less ocean. Mountainous islands would emerge as dark teeth along the horizon. Low atolls would appear as a dark stretch of horizon, initially barely distinguishable from the wavering sea, that slowly firmed into distinctive spires of coconut trees over dark brush and bright sand. As the boat neared, Agassiz and his crew, looking out from beneath the awning, would be able to see the breakers, then the white-sand beach or any strip of island built by the waves-often only a few yards across, rarely more than a half mile-and finally the lagoon’s calico water, the pale yellow-green of its sandy shallows alternating with blue depths spotted by patches of green, plum, and orange coral.

“The corals here are superb,” Alex wrote Murray. “I had no conption from the West Indian reefs of what a reef can be. The gigantic masses of the Astraeans, Meandrina, etc., dwarf the largest masses of the Florida and Bahamas, and all within six to seven fathoms, so that with a water glass one can see the whole reef.” The water glass was a shallow half-barrel with a glass bottom; holding it over the side of a boat with its base in the water gave a lens to all below. Alexander loved using it almost as much as he loved using the big underlit glass bowl in which he examined medusae and other plankton. To use it he had to go to the calm side of an island or atoll on a still day, for reefs to windward, which in the South Seas usually meant east, were generally pounded by waves that made skiff work over the shallows dangerous. The lagoons, however, were calm but in the most violent gales.

Fish streamed all along, through, and around these isles and reefs, and plankton bloomed in patterns sometimes so regular the locals could plan harvests of them. At one point, having heard of a great explosion of bololo, a reef-dwelling sea worm, Alex arranged to be at the right island on the right morning, and with native guides went out to meet the early bloom.

“We left the ship at three o’clock, bound for a spit named Bololo Point,” he wrote.

We had scarcely reached the spot when our guide put his hand in the water and pulled out one of the worms. In a few minutes the water was full of them, canoes put out from the shore, men,

women, and children were wading on the reef exposed by the tide, with nets, and all kinds of utensils to catch Bololo. As the light increased, the Bololo increased, and at one time they were so plentiful that the water surrounding our boat must have been filled with them so thickly as to resemble vermicelli soup. A bucket put overboard seemed to contain nothing else. We made an excellent collection, and preserved a large number by different methods. We found, as we had expected, that their sudden appearance was connected with spawning; there were males and females swimming about full of eggs and of sperm. When in captivity they soon discharged these, the water became milky and masses of dark eggs were left on the bottom of the dish. With the escape of the eggs came the collapse of the worm, and nothing was left by an empty skin scarcely visible. Thus the Bololo seems suddenly to disappear.

Even aside from such sudden fluorescence, the waters were rich. “We constantly passed long windrows of Algae torn from the reefs, extended patches of a yellow Trichodesmium,* and masses of leaves and flowers, and branches of all kinds of trees, floating at the mercy of the winds and currents.” The fish were dense, and to his delight the water held many of the same medusae he’d found in the Caribbean; when he towed at night, he could tell which species were in the water by the color of the phosphorescence they fired as they passed through the net.

4

He found two kinds of islands mixed throughout the Fijis. The majority, composed of lava, had obviously risen into place through eruptions and possibly the sort of upheaval long associated with volcanic activity. Other islands were composed of or partially capped with great thicknesses of fine-grained limestone holding scattered fossils of mollusk and coral. This limestone seemed to have been lifted into place by the elevation that raised the volcanic isles.

Alex could easily distinguish the two types of island or rock even from the boat, for “the gradual slopes of the volcanic peaks,” as his son George put it, “contrasted] strongly with the flat-topped summits and precipitous cliffs of the limestone islands.” Volcanic isles took roughly conical forms cut by deep gorges and ravines; some still had craters clearly visible, and a few had craters that had become lagoons. Limestone isles or sections had more rectangular profiles, with flatter tops shearing off in pale bluffs. Big islands of either sort were usually surrounded by many small islands and islets, sometimes scattered randomly, sometimes threaded like beads along a line of reef. Surf and storm had carved many of these islets into spectacular shapes: anvils, tabletops, spires, and mushrooms.

Alex found a fairly typical collection of such islands in the Exploring Isles, a small archipelago along the Fijis’ eastern edge. The group’s dominating feature was the island of Vanua Mbalavu, a fat, backward Sof lava and limestone surrounded by a low, narrow reef that circled off to the east and back like a tossed loop of string. Most of the reef was under water, detectable only by the surf breaking over it. Here and there rose cays colonized by brush and coconut trees. A few passes allowed entrance through the breakers.

The lagoon inside, miles across, made a superb and picturesque anchorage. At its western end, mountainous Vanua Mbalavu and two flanking islands rose hundreds of feet, the very picture of high, mysterious lava islands, with scores of wildly eroded islets clustered around them. The surf had carved caverns and holes into some of these islets, especially those made of the softer limestone; the tip of Ngillangillah, a limestone island on the lagoon’s south side, “was merely a thin shell covering a huge cavern some 50 feet in diameter and rising to a height of nearly 100 feet, and full of stalactites.”

Alex spent several days working from this lagoon, thoroughly sounding it and its perimeter shores and taking a skiff out to examine the reefs. The more he saw, the more these islands seemed to deny Darwin and Dana. He was a bit stunned, or at least professed to be, for Dana had so often assured him that here in the Fijis subsidence showed itself as plainly and as variously as one could hope. Yet Alex could not line up his impressions with Dana’s. Every single feature of the reef system seemed to contradict Dana’s explanation.

It began with the lagoon in which he anchored. As Darwin and Dana saw it, Vanua Mbalavu was a sinking volcanic mountain, and the barrier reef surrounding it was a ring of coral that had begun as a fringing reef before the island started its slow descent. The enclosed lagoon, by this explanation, must be fairly stagnant if it was not to get too deep-for if a subsiding lagoon was constantly swept clean by currents, its depth would match the extent of the subsidence, presumably hundreds of fathoms. The subsidence theory thus demanded a static view of lagoons.

Alex found just the opposite.

“There is no filling up of that lagoon,” he would write in his report. “It is well scoured, and a strong current is constantly deepening the entrance and outlets at the western end.” He found the same throughout the area. In almost every lagoon he surveyed, he discovered currents and current-formed channels-moving water and a live bottom, as it were, instead of still water and accruing silt. In addition, the lagoons’ bottoms clearly seemed carved by the cur rents. Subsidence not only wasn’t needed to explain these lagoons, it couldn’t explain them. Their genesis and maintenance seemed due to known, well-established forces: erosion, a bit of Murrayesque solution, and the universally recognized tendency of corals to grow faster to seaward, leaving a pool of protected water behind.

As to the islands and reefs themselves, Agassiz found abundant evidence of elevation but none of subsidence. Chief among this evidence were the great beds of limestone. The limestone cliffs, he wrote, “many hundreds of feet in height, plainly attest a great upheaval of the region.” This limestone appeared not to be coralline limestone, as Dana had concluded, but classic marine lime stone, that is, sedimentary rock composed of the remains of zillions of tiny sea animals, mostly microscopic, single-celled foraminifer, that had long ago accumulated and then been calcified on the seafloor before being lifted, with larger shells of mollusks and occasional corals mixed in. Most limestone on land, from the White Cliffs of Dover to the Dolomite Mountains of the Italian Alps to the hill country of Texas, is made up of such material, which is marked by a fine texture inlaid with larger shells and fossils. This seemed the same stuff. True, the faces and sometimes the tops of these cliffs and slabs were thick with coral, suggesting old, upraised reefs. But some drilling or even a bit of hammering always showed this coralline outer layer to be a veneer over what appeared to be more classic marine limestone.

Alex backed up this interpretation by hiring an Australian geologist to drill and blast through the surface on several Fiji islands to examine the underlying limestone. The geologist confirmed that the thickly brecciated, coral-rich limestone surface was a mere cap over a more ordinary-looking marine limestone. Later, back in Cambridge, a mollusk specialist verified that the limestone’s fossil mix was typical of that in very old limestone, and thus probably too old to be part of any coral formed in more recent times. The evidence seemed over whelming. These limestone bluffs and hills were not old coral reefs that had subsided and then been raised; like limestone all over the world, they were upraised sea bottoms of sedimentary marine rock.

Alex knew that the question of how this limestone formed was crucial. Much of his reading of the Fijian reefs rested on his interpreation of the limestone, and his interpretation contradicted that of Dana, whom he had long recognized as a more able and experienced geologist. But he thought Dana wrong here. He had Dana’s coral reef book on the boat, and he had read the short chapter explaining how coral limestone was often indistinguishable from ordinary marine limestone. According to Dana, most coral limestone (or reef rock, as Dana liked to call it) formed through calcification not of largely intact coral structures but of the sand into which coral reefs were constantly being beaten. After all, Dana argued, large areas in and around any coral reef structure are sand, so we should expect that when such an area becomes calcified, the resulting limestone should be largely fine-textured like ordinary limestone, with only occasional pockets of preserved coral breccia. Thus reef rock would often be “a fine white limestone, as compact as any secondary marble [which is limestone transformed by heat and pressure], and as homogenous in texture.”

While this made a certain amount of sense, it struck Alex as a justifying afterthought. It was even presented that way, delivered in a brief chapter that followed Dana’s central argument for subsidence, which drew almost wholly on patterns of reef form and distribution rather than the islands’ actual geology. Dana brushed aside, for instance, the sharp contrast between the coral-rich, brecciated lime stone that topped these limestone hills and the finer-grained limestone that lay beneath it. His conclusions seemed to rise not from close observation but from his eagerness to identify a dynamic that would explain all reef forms. They were a search for an idea, not a response to the landscape. Fascinated with the forms of the reefs and how they seemed to express subsidence, he had underplayed and misinterpreted the more direct geological evidence that would describe the origin and history of these islands. He had succumbed to the “danger of leaps” Alex had warned of in the margin of Dana’s 1885 paper. He had deduced, then pushed the facts to fit.

This was, as Alex would say, a very unsound way of working. If you encountered what looked like classic sedimentary marine lime stone, you couldn’t just say that it was really reef limestone because reef limestone would probably look like ordinary limestone; if you wanted to use the limestone to bolster the reef argument, you had to explain why it had to be reef limestone. You couldn’t constantly choose the least likely explanation and add a bunch of them up to support your theory. Yet Darwin’s theory seemed constantly to demand such rationalization. Nothing was as it appeared. Rising land was really falling land. Well-scoured lagoons were really inert, debris-filled basins. Ordinary limestone was really coral limestone. It surprised Alex that a geologist of Dana’s stature should fall for all this. Then again, Dana had been young at the time, only in his twenties and, by his own confession, enthralled with Darwin’s theory.

The more Alex saw, the more certain he felt that Dana had erred. By every appearance this “reef rock” was just ordinary limestone. Indeed, the only reason to doubt that it was common marine lime stone was to accommodate Darwin’s theory. His certainty deepened when, still in Fiji, he received a letter from Edgeworth David saying that closer examination of the Funafuti drill cores showed a sharp distinction between the coral of the first forty feet and the rock beneath it, which might be marine limestone, coral, or coral talus (David wasn’t sure). So in Funafuti too, a limestone bed once deemed all continuous coral now fell into question.

In several more weeks of zigzagging through the Fijis, Alex found more of the same: limestone hills capped with coral rock; vibrant lagoons being actively shaped by currents; abundant signs of elevation and none of subsidence.

He also found everywhere evidence of the force he came to believe played the major role in determining the form of these islands and reefs: erosion. Looking at the Fijis, he realized that just as the role of currents in creating lagoons had gone underrecognized, so erosion had been underestimated as a shaper of coral reefs and islands. The islands’ deep gorges, sharply serrated ridges, and fantastically shaped peaks all declared how actively water and wind had sculpted the Fijis since they’d risen from the ocean two million years before. Significant erosion clearly occurred underwater too, as shown by the way the banks around the islands differed according to their exposure to current. Where currents brought little new material, banks were narrow. Where they brought abundant sand and silt, banks were wide. Their every dimension and contour appeared dictated more by the movement of the water against and around them than by the form of any supposedly subsiding under lying landmass. Eroded elevated banks, not subsiding mountains and isles, had formed the foundation for Fijis’ reefs. Subsidence didn’t figure.

Looking at the craters and loops of reef, Alex could even see how a volcanic crater could become an atoll without subsidence. Vanua Mbalavu, for instance, had only to finish losing its peak to erosion to become an atoll. The extinct, half-submerged crater that was the island of Totoya also illustrated this process. Totoya was but a jagged, circular rim that reached as high as twelve hundred feet and dipped down in one narrow spot, known as the Gullet, that allowed entrance into a lagoon filling the old crater. While Darwin and Dana saw this as an extinct volcano that had sunk below the surface, Alex saw it as a crater with a wall that had been eroded to let in the sea. Allow that possibility, he argued (and who could question the fact of erosion?), and you could see how the present Totoya, with its three peaks rising above the rest of the rim, would eventually be ground to sea level to form a classic atoll with surrounding banks. Here again, the known power of erosion replaced Darwin’s hypothetical subsidence.

This vision of reef formation, in which the Fiji reefs grew on foundations lifted into place by tectonic elevations and then shaped by erosion, was original not in its parts but in the particular combination of forces it envisioned. Though it rejected the subsidence the ory (and completely ignored Murray’s theory of bank construction through planktonic accretion; this was Alex’s theory now), it drew on almost every other reef theorist up to Alexander’s time. The growth of reefs to seaward went back to Eschscholtz. The emphasis on tectonic elevation drew on a long association of uplift with volcanic areas going back through Kiekie, Dana, Darwin, and Lyell to Humboldt. The stress on erosion echoed Lyell and expanded on ideas offered by William Wharton. The lagoon-formation model drew on Eschscholtz, Murray, Bourne, and Guppy The reading of the lime stone expanded on similar views and observations by Semper and Guppy. Alex put these ideas together with a set of emphases that was new but that stressed methods and ideas insistently not new: He pro posed, in essence, that understanding reefs did not require any grand new theory but simply a better, more empirical consideration of how known forces worked together in particular places.

It was just the sort of theory he loved: specific, localized, tied to close observation, and with a grounded truth no global theory could hold. As he examined one atoll after another, the gradual accretion of his theory-the facts and observations slowly piling together into a sort of brecciate explanation-gave him a slower-growing version of the thrill Darwin took from his epiphanies. The more Alex saw in the Fijis, the more excited he became. By the time he returned to Suva the first week of December, he was feeling almost cocky.

“Hurrah!” he wrote Murray, a world away in Scotland.
I have been and gone and done it, as we say in Yankee slang. We have just come in from nearly a month’s trip round the islands of the Fijis, and a more interesting trip I have never made. I have learned more about coral reefs and islands than in all my expeditions put together, and it looks to me as if I had got hold of the problem of deep [lagoons of] atolls, and of the history of the coral reefs of the group. But I’ll not go into details now except to say that I am more than ever satisfied that each district must be judged by itself and that no sweeping theory as that of
Darwin can apply to coral reefs as a whole, or even to atolls. I don’t believe from what I have seen that a single atoll in the Fijis has been formed by subsidence!-Darwin and Dana to the contrary notwithstanding…
… I shall give them a dose they do not expect, and the theory of subsidence will, I think, be dead as a doornail and sub side forever hereafter.

5

After writing Murray, Alex set off for another two weeks of cruising and towing. The hardest of the work was behind him, however, as most of what he found now matched what he had already seen. He worked in the best of moods, almost boisterous in his enjoyment of the weather, the work, and the islands. By mid-December he’d seen all the reefs and islands he felt he needed to. He had Cox steer the Yaralla back into Suva on December 17,1897.

That afternoon he found Max and Woodworth wreathing the main cabin in palm leaves and masses of flowers; it was Alex’s sixty-second birthday, a marker he’d forgotten was coming. “You have no idea how prettily Max and Woodworth decorated the cabin,” he wrote home to his stepmother. “There was not a piece of the wood work to be seen.” Outside it was pouring, a third straight day of torrents, but the blowing sheets of gray did not dampen Alexander’s spirits. As he had enjoyed weeks of good weather, missing only two days to squalls, the arrival of bad weather now, when they were back in port with the work done, only underlined what good luck had followed this expedition. It had been as decisive a trip as he could have hoped for. The bare revelatory power of what he saw-the seeming obviousness of the geology and bottom topography-had over whelmingly validated his suspicion that Darwin and Dana had horribly erred. And for the first time he had his own theory of Pacific reefs, one based on the well-documented forces of elevation and erosion rather than indemonstrable subsidence.

With his confirmation he seemed to cross a line, both in his own confidence and in his attitude toward Darwin and Dana. His long-held respect for Darwin withered. Whatever genius Darwin had shown in his other work-something Alexander never questioned- his reef work was beginning to look like another Glen Roy.

“When I came here,” Alexander wrote his old friend Wolcott Gibbs,
I took it for granted that Dana’s and Darwin’s premises about the coral regions of the Central Pacific were correct and that this group of islands (Fijis) was in an area of subsidence. You may judge of my surprise when I found that Fiji is an area of elevation. … I cannot understand how Dana ever made such a mistake, for he was in the group quite a while, but Darwin’s observations were all theoretical and based upon cartographic study in his house, a very poor way of doing, and that’s the way all his coral reef work has been done. He never was more than ten days in a region of reefs and thought out [beforehand] everything he has written. I never could see how his theory had got such a hold with so little holding ground.

They stayed another three weeks in Suva, taking over a wing of a hotel and using one end of the piazza as a laboratory and work space. Max, Woodworth, and Mayer packed specimens and developed photos. Alex, in no hurry to get back to Cambridge and happy with weather “hot enough even for me,” worked up his notes, helped classify the more obscure specimens, and on calm days some times took a motor launch out onto the flat around Suva to do some extra collecting.

On January 13 they departed for the States. On the way there, during a stop in Hawaii, Alexander came upon one last piece of good luck, taking a short outing that gave his new thesis the sort of confirmation he might only have dreamed about. It occurred when he went out with a Mr. McCandless, one of Hawaii’s more experienced drillers. Both Alex and Dana had queried McCandless extensively over the years about what his drills passed through in their hunt for artesian wells. Agassiz had interviewed McCandless thoroughly when he’d been in Hawaii thirteen years before, as had Dana twenty years before that, and both had put much faith in his accounts. McCandless had told them that he often punched through beds of coralline limestone several hundred feet thick, sometimes several hundred feet under the ground. Coral beds this deep and thick would seem to indicate subsidence, and that’s how Dana interpreted them. But Agassiz, noting that the well drillers also sometimes struck pieces of old trees several hundred feet down, concluded that these buried reefs were just that-reefs that had been buried by eruptions from Hawaii’s still-active volcanoes. The thicker reef beds were accumulated talus.

The active nature of Hawaii’s volcanoes thus explained the buried coral limestones McCandless had described. Alexander had never doubted they existed. But when he went out now with McCandless, he found he should have. Working from a surface just above sea level, the drillers went through eighty feet of recent coral rock and then hit a different limestone with “but few corals,” as Agassiz wrote later, and “composed almost entirely of the shells of mollusks”-a particularly shell-heavy sedimentary rock, seemingly formed on a shallow but noncoralline sea bottom, and quite different from the coral reef the drill had passed through first. When Alexander remarked on it, McCandless said it was always like this, and when Alex pressed him further, McCandless assured him that this lower limestone was identical to the limestones he had long described to both him and Dana as being reef rock. Alex was stunned and elated. Like a lucky gumshoe in a detective novel, he had stumbled across the true meaning of a misread clue.

“What [McCandless] calls an old reef,” he wrote a friend that week, “is nothing but a mass of shells. This practically knocks out all the evidence there was in favor of subsidence derived from the [previous] boring holes… All that was limestone they have called coral, so that both Dana and I were fooled, he in one way and I in another.”

6

While his Blake report had taken seven years to publish and his Hawaii report three, Alex wrote and published the Fiji monograph in just fourteen months. The result-144 pages of text and several score photos, maps, and graphs occupying a full volume of the Bulletin of the Museum of Comparative Zoology- was unprecedentedly frank. Amid extensive descriptions and interpretation he made his conclusions uncharacteristically clear and emphatic. And in an impassioned voice familiar to his correspondents but rare in his publications, he gave vent to the pique he felt with Dana and Darwin.

The facts, of course, stood foremost. “These atolls and islands,” he concluded, “have not been built (as is claimed by Dana and Dar win) by the subsidence of the islands they enclose. They are not situated in an area of subsidence, but on the contrary in an area of elevation. The theory of Darwin and Dana is therefore not applicable to the Fiji Islands.”

Rather, he said, the reef forms come from “causes which have acted during a period preceding our own. The islands of the whole group have been elevated and … exposed to a great and prolonged process of denudation and of aerial and submarine erosion.” This erosion had created the submarine platforms upon which the reefs had grown. Lagoons were formed by the faster growth of seaward-facing coral and then further scoured and sculpted by currents.

This is the report’s barest, plainest statement of both his negation of Darwin and Dana’s theory and his own elevation-erosion model of how the Fijian reefs formed. It appears about three-quarters of the way through the monograph, a suitable place for a succinct state ment of conclusions. He summarizes again at the end, reiterating his theory and insisting that “my observations in Fiji only emphasize what has been said so often, that there is no general theory of the formation of coral reefs … applicable to all districts, and that each district must be examined by itself.”

Alex, of course, was prominent among those who had been saying this so often, and his frustration that these continual efforts had not yet toppled Darwin’s theory shows in the rest of the Fiji report, which, while mostly matter-of-fact and dispassionate, is peppered with jabs, plaints, indignant outbursts, and repetitions. He repeats his main assertions, for instance, close to a dozen times, as if he wants to make trebly and quadruply and quintuply sure, in this report that generally sticks so close to the facts, that not just his own reading of Fiji but his rebuttal of Darwin will finally get through to a group of peers that prefers a theory with, as he had written Gibbs, “so little holding ground.” He seems to fear, given the past, that merely presenting evidence might not be enough, and that he must bludgeon the stubborn. Some of the reiterations are concise. Others are ponderous.

The most labored reads like the closing statement from a courtroom lawyer determined to summarize every bit of evidence favoring his client.* At times his disgust comes through vividly. “It is playing with words,” he writes at one point,

… to speak of the localities to which Darwin’s theory … does not apply as exceptions to the rule. These exceptions now cover a good deal of ground. They include nearly all the coral reefs which have been examined by recent investigators,-from Semper in the Pelew Islands, Rein in the Bermudas, Murray in Tahiti and elsewhere, of Forbes, and of Bourne, of Guppy in the Solomon Islands, Kramer in Samoa, and others,-down to my own in Florida, the Yucatan bank, Cuba, Bermuda, the Bahamas, and West India Islands, as well as the Galapagos and Sandwich Islands, besides the exploration of the Great Barrier Reef of Australia, and of the Fiji Islands. Surely the list of investigators and localities is long enough. The negative evidence is now becoming overwhelming… The Darwinian theory [has not] been proved to exist in a single location, either by a careful examination of the locality or by borings.

What on earth, you can hear him growl, will it take to displace this poppycock?

Despite this exasperation (or in its cause), he refused to apply his Fijian findings globally or even to the rest of the Pacific. He would not offer one overstretched theory to replace another. While his letters and the Fiji report reveal that he now believed that most other Pacific reefs had also formed on eroded, elevated sea bottoms, the closest he would come to saying so in the Fiji report was to gently (and just once) assert this probability: “It is well known that many of the [Pacific] islands are composed of elevated coralliferous lime stones, and that is probably the composition of the substratum of many of the atolls of the Paumotos, Ellice, Gilbert, Tonga, and Fiji groups.” His caution expressed both his longtime assertion that each reef area was different and his conviction that “sweeping generalizations” were bad for science. He would not expose himself to the danger of leaps.

If he wanted to make global statements, he would have to see more of the globe. He hadn’t yet seen even the entire Pacific.

*The expedition on which Dana had been naturalist, the seven-ship U.S. Exploring Expedition of 1838-1842, had done a good part of this disrupting. Its commander, Lieutenant Wilkes, took it upon himself to levy harsh punishment on the Fijians for both hostility shown his own party and reported previous acts of cannibalism on two Europeans. (The Fijian’s traditions of ritual cannibalism, in which they sometimes ate members of villages they conquered, had in some tribes loosened and expanded with the opportunities afforded by newly acquired firearms.) Wilkes carried out several cannon and rifle attacks against the allegedly offending villages, killing dozens of Fijians and sharpening hostilities for some time to come. When he was later brought before a court-martial for these excesses, he argued that however unfortunate the result of his authority’s application, he had not clearly exceeded it, for along with being charged with trying at all times to create goodwill among the people he would visit, he had also been given broad authority to protect his crew and the interests of his country (which included the whaling industry that used the Fijisfor trade), which he felt himself to be doing. His peers acquitted him.

*Trichodesmium is a planktonic cyanobacteria that gathers in large brownish or yellowish “blooms” in the South Pacific. In the 1770s Captain James Cook at first mistook them for sandbanks.

*Two pages after his most succinct offering, Alex produces this recapitulation: “From this evidence I am inclined to think that the corals of today have actually played no part in the shaping of the circular or irregular atolls scattered among the Fiji Islands, that they have had nothing to do in our time with the building up of the substructure of the barrier reef encircling either wholly or in part some of the islands, that their modifying influence has been entirely limited in the present epoch to the formation of fringing reefs, and that the recent corals living upon the outer margin of the reefs, either of the atolls or of the barriers, form only a crust of very moderate thickness upon the underlying base. This base may be either the edge of a submarine flat, or of an eroded elevated limestone, or of a similar substructure composed of volcanic rocks, the nature of that base depending absolutely upon its character when elevated in a former period to a greater height than it now has; denudation and erosion acting of course more rapidly upon the elevated coralliferous limestones than upon those of a volcanic character.”