by What Linnaeus Saw- A Scientist's Quest to Name Every Living Thing (retail) (epub)
On March 24, the plant stopped flowering. Still no banana. But at the base of each flower, a lime-green bulge—the flower’s fruit-making ovary—had been swelling and elongating. As the bulges grew longer, they looked like fingers pushing their flowers upward farther and farther away from the stalk.
On June 3, the flower petals began to wither and fall away. Now the green fingers looked like a giant’s hand. The hand began to yellow.
At last, on July 3, there came success—ripe bananas!
“The pulp was very sweet,” said Linnaeus of his first taste, “like glue bubbling with particles of honey.” He compared it with the taste of a fig or roasted apples with sugar and cream. This was a happy man.
He was surprised, however, that the fruit contained no seeds. Fortunately, several months earlier, on the day the first flower appeared, a shoot had pushed up from the soil next to the base of the plant. This, Linnaeus realized, meant that the plant was preparing for the next generation. It did not need seeds to reproduce. It had another way—roots and shoots. In plants like this one, a horizontal underground stem, called a rhizome, sends up shoots to grow a new plant.
Although wild bananas are stuffed with big, inedible seeds, the fruits of the plant that Linnaeus and Nietzel cared for in Clifford’s greenhouse had no visible seeds. Botanists now know that forms with smaller seeds were selected for cultivation by native peoples from banana plants that had varied naturally because of hybridization and mutation in the wild as well as during their cultivation. The seeds had become tiny, infertile specks, while rhizomes perpetuated those varieties.
For eight days, the fruits ripened on the plant. Then black spots began to freckle the skins, and the bananas did what bananas do: rot, rot, rot.
It had been an extraordinary experience for Linnaeus, and he was disappointed when the plant withered and died back.
Linnaeus had built his reputation on his Sápmi journey. His job in Holland launched him on the global stage. And the banana plant, his muse, catapulted him into his future.
6
NATURE’S BLUEPRINT
We count the number of species as the number of different forms that were created in the beginning.
—CARL LINNAEUS, PRINCIPLE NO. 157, PHILOSOPHIA BOTANICA (THE SCIENCE OF BOTANY), 1751
Two months before Linnaeus began work at George Clifford’s estate, a familiar lanky figure in black had surprised him at a tavern one morning in Leiden. It was July 8, 1735. Almost a year had passed since his best friend, Peter Artedi, had left Sweden to study abroad for his medical degree. Now there he stood in the tavern, newly arrived in Holland.
Dutch taverns were popular places. A person could buy a mug of coffee or steaming hot chocolate or a tankard of ale, eat a meal, hear a lecture, read newspapers, debate current events, and even pick up mail. They were also places where old friends could bump into each other.
Artedi had been in London, where he met with British scholars and studied private natural history collections, including those of Sir Hans Sloane, whose collections were so extensive that they later became the foundation for what is today the Natural History Museum. Artedi was eager to talk about his latest observations and his new classification system of fishes. He probably described a “Greenland whale” that he’d seen in London the previous November. It had two blowholes on top of its head in front of its eyes. Linnaeus discussed the project he was working on with a printer there in Leiden—a chart-style overview of nature’s three kingdoms, which as students the two friends had dreamt of mapping.
His money nearly gone, Artedi faced the unhappy prospect of returning home to Sweden without a medical degree. A companion of Linnaeus’s helped out by supplying him with three of his own extra shirts, and Linnaeus told Artedi about an opportunity. For more than thirty-five years, in his apothecary shop by Amsterdam’s busy harbor, the rich pharmacist Albertus Seba had bought medicinal plants in bulk and natural curiosities from returning captains and sailors. Having amassed an impressive curiosity cabinet, he was now assembling a three-volume thesaurus of those and other rare objects. Linnaeus knew the first volume well: it included the notorious seven-headed hydra of Hamburg. But Seba, at seventy, was having trouble mustering the energy to finish the third volume, which was, coincidentally, devoted entirely to fishes. Who better than Artedi to provide help? Linnaeus escorted his friend to Amsterdam, and Seba hired him on the spot.
The two friends were so busy working during the next weeks that they rarely saw each other. Linnaeus observed that Artedi was living “a lonely life, went to the tavern from 3 to 9, was at work from 9 to 3 in the night, and slept from 3 till noon.”
When they met again in early August, Linnaeus showed Artedi a newly finished manuscript, Fundamenta Botanica (The foundations of botany). In it, he distilled the science of botany to a list of 365 concise principles, or aphorisms, organized into twelve chapters like the months of a year.
1. All things that are found on the earth go by the names of elements or natural [bodies].
2. The NATURAL [bodies] are divided into the three kingdoms of nature: mineral, vegetable [meaning plant], and animal.
3. MINERALS have growth. VEGETABLES have growth and life. ANIMALS have growth, life, and feeling.
Each principle built logically on the one before it.
During their meeting, Artedi, whose work for Seba was nearly finished, insisted on reading aloud another entire manuscript. It was a meticulous classification of fishes that included a description of a fish, Anableps, with remarkable two-part eyes that could see above and below the surface of the water at the same time. As the two had done in Uppsala, they scrutinized each point and debated their differing opinions.
When this went on for hours, Linnaeus grew too tired to continue, which he remembered later with regret. “He kept me long, too long, unendurably long (which was unlike our usual practice), but had I known that it was to be our last talk together I would have wished it even longer.” On the night of September 27, two weeks after Linnaeus moved to Clifford’s estate to reorganize those gardens and tend the banana plant, Peter Artedi dined at Seba’s house. It was late when the party broke up and he walked back to his rented room. The next day the police determined that the young man from Sweden, still unfamiliar with the streets along Amsterdam’s canals, had lost his way in the dark, fallen into a canal, and drowned.
Devastated, Linnaeus traveled to Amsterdam to identify his friend’s body. He arranged a modest burial and, with a loan from the generous George Clifford, negotiated the return of Artedi’s manuscript from the hard-bargaining landlord. He needed to keep his promise to his closest friend.
Linnaeus continued their work alone.
Working day and night, Linnaeus wrote, revised, and polished several manuscripts at once. Nulla dies sine linea: Never a day without lines. The quotation, attributed to an ancient Greek artist, was Linnaeus’s favorite adage. In addition to his own work, he published Peter Artedi’s 532-page book on fishes, a stellar work that one day would earn Artedi the title of “father of ichthyology” (the study of fishes).
By studying nature’s exquisite diversity, Linnaeus hoped to identify its underlying scheme and use that scheme to develop a classification system that could be used by every scientist everywhere. To do this required two strategies: first, a way to sort all natural things into groups of similar objects, and second, a consistent way to name them.
How was Linnaeus certain that he could find every one of the species in the first place? This Lutheran pastor’s son, like most Europeans then, believed that all species had originated at one point in time—during the Creation as described in the Bible. To him, this meant that no new kinds of animals or plants could ever emerge and that the original species would always remain fixed and unchanging.
Since he thought the number of species could never increase, Linnaeus was convinced that it was possible to inventory nature. Later, in 1749, he wrote:
If according to gross calculation we reckon in the world 20,000
species of vegetables [meaning plants], 3,000 of worms, 12,000 of insects, 200 of amphibious animals, 2,600 of fishes, 2,000 of birds, 200 of quadrupeds; the whole sum of the species of living creatures will amount to 40,000.
Researchers now describe about 15,000 new species every year. Scientists calculate that there are 8.7 million species in the world today, of which only 1.9 million have been named so far. They also know that some go extinct and others emerge. Therefore, the number of different species changes, and so do the species themselves.
However, having grown up in his little corner of Sweden in the early 1700s, Linnaeus began his career with a limited worldview. Without access to herbaria from other countries or knowledge of the world’s diverse natural habitats, he had no idea of the enormity of the project he set for himself.
Much later, with more experience and information, he realized that he had been wrong and that his calculations were way off. His increasing knowledge would eventually inspire him to take a fresh look at the so-called unchanging “fixity of species” and then to question that traditional view. In the meantime, he and his contemporaries still operated under the old notion that no new species could ever come into existence. As he laid out his charts and systems in Holland, Linnaeus felt confident that he could catalog all the world’s plants, minerals, and animals.
It may have been a good thing that he started with the limited plants of his childhood home. If he’d also seen all the tropical plants early on, he might have been overwhelmed. That could have kept him from seeing the simple patterns that he needed to create his system.
Scientists disagreed with one another on how best to order the natural world. They organized their specimens differently. They used different definitions for scientific terms. Occasionally, when duplicate specimens of a species reached scientists at the same time, each scientist gave that species a different name. Only a shared scientific language could eliminate this confusion. One system. One set of rules. One set of names.
Linnaeus believed that he could revolutionize the worldwide study of plants, animals, and minerals by creating a stable base for scientists to work from. But he still had a problem: the established scientists. Could he, a newcomer in his twenties, convince older scientists to follow his plan? How would he ever be able to talk them all into abandoning their own ways of doing things?
For this task, it turns out, he was perfectly suited. Enthusiastic. Passionate. Persistent. A clear communicator. Obsessive about tiny details, yet capable of seeing the big picture. Confident— though, some said, to the point of being egotistical and arrogant. A workaholic. Plus, there was no denying that he possessed one trait especially helpful in bringing people around: charisma.
Along with his friendly charm and boundless energy, Linnaeus had brought to Holland the rough drafts of several manuscripts he had begun as a student in Sweden. Some he had even carried through Sápmi in his pack so that he could work on them while he traveled. These manuscripts were all cogs in a wheel that would move science into the future. He cranked them out, publishing thirteen works—a total of 2,550 pages—during his three years in Holland, all while he was tending to George Clifford’s gardens and banana plant.
In these books, the young upstart got rid of the old, conflicting systems. He dumped many names coined by other scientists. No one’s work was immune, not even that of his mentors and friends. He tossed out old rules. In their place, Linnaeus developed clear new rules for sorting organisms into groups and rules for coining consistent scientific names. He proposed new rules for describing species so that each description followed the same format. This way someone who was trying to identify a specimen would know exactly where in the description to find the leaf shape, flower structure, roots, or habitat. He wrote clear definitions of botanical terms, listed 935 genus names for plants, and created three charts showing the structure of the animal, plant, and mineral kingdoms. His methodical, practical, list-loving mind felt right at home in the wild flurry of details.
Linnaeus’s way of organizing the natural world so inspired two new friends, Jan Frederik Gronovius, a physician from Leiden, and Isaac Lawson, a Scottish physician working in Holland, that they insisted on paying for printing the three enormous charts.
The charts were published in one slim book, Systema Naturae (The system of nature), in 1735. It ran only eleven pages but measured 24 inches tall by 18 inches wide. The book’s big, complex tables were a typesetter’s nightmare. Even though the typesetting began on June 30, the printing was not finished until December 13.
This book would provide the platform for all of Linnaeus’s future work. Over the next thirty years, he would revise it a dozen times to keep up with newly discovered species sent to him by colonial traders, ocean-going travelers, and eventually his own students. As he and his colleagues learned more about various species, he used future editions to rearrange the groups. After thirty years of additions and changes, the book’s original eleven pages had mushroomed to more than two thousand! It is one of the most important books on biology ever written.
His charts divided each of the three kingdoms—animals, plants, and minerals—into ever smaller groups. Like a box within a box within a box, each chart narrowed from kingdom to class to order to genus to species. This hierarchy, which Linnaeus saw as governing nature, neatly paralleled a country’s government of kingdom, province, territory, parish, and village. Linnaeus arbitrarily chose the first three categories—kingdom, class, and order—simply because they were easy to sort. But he intended the last two—genus and species—to reflect natural groups as said to be created by God.
Each chart worked as a spreadsheet. Any recently discovered species could be easily popped into its proper place. Always searching nature for patterns and parallels, he applied the same hierarchy to plants, to animals, and to minerals.
With his charts, Linnaeus was cleaning up the cluttered desktop of science. Scientists finally would be able to know exactly what they had in front of them. No more different names for the same thing, less confusion, fewer cases of mistaken identity.
When it came to animals, in this first edition in 1735, he divided them into six classes:
— four-footed animals (Quadrupedia), based on characteristics of their teeth;
— birds by their beaks;
— amphibians, which included snakes, by their cold body and generally naked skin;
— insects by their antennae and wings;
— fish, using Artedi’s carefully-described genera, by the shape of their fins; and
— worms, which included a variety of animals such as earthworms, mollusks, crustaceans, sea cucumbers and sea stars.
Linnaeus’s chart of the animal kingdom, as he understood it in 1735. The original chart is 24 inches tall by 18 inches wide.
Plus, he tacked on a catch-all group of ten organisms, the Paradoxa, whose very existence he doubted.
Even though people in the early eighteenth century knew that humans were animals, they always studied them separately from the “beasts.” Many were shocked when Linnaeus listed humans in the same kingdom as the beasts in his 1735 book.
As for the mineral kingdom, Linnaeus divided it into three classes. The first contained rocks. The second included minerals and ores. The third was made up of fossils and sedimentary rocks called aggregates.
He taught his students that, although none of these was alive, they “grew”—not from eggs or seeds, as animals and plants did, but from different types of loose materials, such as sand or clay. He believed this “growth” could happen in one of two ways. Soils could combine with salts and transform chemically, or they could clump together and harden.
“It is beyond controversy,” he wrote, that rocks “derive from soils, such as schists from vegetable boggy soil, whetstone from sand, marble from clay.”
While Linnaeus believed rocks were simple elements and minerals were complex, today’s geologists view them the other way around: minerals are the building blocks of rocks.
; Linnaeus’s classifications in this kingdom are no longer used, but he did get some things right. For instance, he correctly understood that corals were generated by animals and that their skeletal remains had once been part of living organisms. Also, he recognized an important point: that minerals are a necessary part of living things, but they themselves are not alive. Today we also know that when minerals in the soil undergo chemical weathering from rain and snow, they release many nutrients essential for plant growth. Plants absorb these nutrients, which then continue to move through the ecosystem as those plants are eaten by animals, and those animals are eaten by other animals higher in the food chain.
Linnaeus made several trips to Sweden’s mining district, northwest of Uppsala. This was the place where his fiancée, Sara Lisa, had grown up and where her father was the community’s sole doctor. Linnaeus visited smelting operations, a silver mine, and the Falun mine, which for years had been one of Europe’s most productive copper mines.
While learning from Falun’s mining experts, Linnaeus, whose chief interest still lay in botany and medicine, couldn’t help but see the mine’s effects on the local environment. The “poisonous, stinging, sulphurous smoke” rising from the mine in Great Copper Mountain was so corrosive that no plants grew in the area. He talked with miners and, to get a closer look at their working conditions, he descended into the 870-foot-deep mine.
As he climbed down the long twenty-step wooden ladders, fastened together end to end, they swayed and swung about. Below, twelve hundred miners crouched or crawled on hands and knees through low tunnels “filled with steam, dust and heat. . . . The drifts [passageways] are dark with soot,” he wrote, “the floor of slippery stone, the passages narrow as if burrowed by moles, on all sides incrusted with vitriol, and the roof drips corrosive vitriolic water.” The miners, despite wearing wool respirators over their mouths, suffered lung diseases from breathing stone dust, according to Linnaeus’s diagnosis.
