by What Linnaeus Saw- A Scientist's Quest to Name Every Living Thing (retail) (epub)
Tournefort insisted the flower’s internal structures were organs that excreted waste, and that the “dust” that fell off flowers was a waste product. This mysterious and hotly debated substance was termed pollen, a Latin word which at the time referred to any powder or fine grain. Vaillant disagreed with his teacher. He argued that the parts inside the flower—the stamens and pistils—did not excrete waste. They were reproductive parts. Plants, he said, reproduced sexually. The stamens were male, the pistils were female, and pollen was not waste. It was a “volatile spirit,” the “breath” of life that enabled a plant to produce offspring.
That plants might reproduce sexually was not an idea that originated with Vaillant. In 1682, British physician Nehemiah Grew had suggested it. His countryman, botanist John Ray, wrote in support of the theory, citing date palms and spinach as examples. Finally, in 1691, Rudolph Camerarius, a German physician, proved it in an experiment using a plant called dog’s mercury (Mercurialis), repeating it with spinach and hemp. When Camerarius isolated flowers without “dust” from those with it, the seeds either failed to develop or were infertile.
Sébastien Vaillant scandalized Parisians with his lecture on plant reproduction.
Many botanists in Europe had come to accept the theory, but not Tournefort. News of Camerarius’s important experiment ran in an obscure German publication and never “made headlines.” Other than a handful of botanists, few Parisians had heard of it when Vaillant delivered his memorable “X-rated” lecture at 6 a.m. on June 10, 1717, in the King’s Garden in Paris to a crowd of six hundred. In his speech, Vaillant used human reproduction as a colorful metaphor for plant reproduction, referring to the dust grains as “embryos with powdery feet,” dust sacs as “testicles,” seeds as “true eggs,” and the bud as the “nuptial bed.”
Some professors were outraged by what they considered a disrespectful attack on their deceased colleague. Tournefort had been killed in an accident in 1708, crushed against a wall by a speeding carriage. Others were shocked by Vaillant’s terminology. Such talk was considered crude in polite Parisian society. Better that this sort of discussion be dry as a desert and explained in the dullest possible way. On the other hand, two hundred members of the audience that morning—young medical students—applauded enthusiastically.
At his school in Sweden, Carl pored over Dr. Rothman’s handwritten summary, engrossed.
Even if Carl sensed, after reading Vaillant’s speech, that this was a big idea, he didn’t yet know what to do with this new understanding. What questions he pondered, at nineteen, are lost to history. Did he make a connection with the evidence he’d seen himself, the pumpkin plant in his father’s garden that failed to produce pumpkins? Did he realize then that this theory explained the mystery, since the male flowers—the ones with pollen—had been snapped off before the pollen could reach the female flowers to fertilize the pumpkins? Did he wonder which trait would be most essential for a plant—that its flowers were yellow, white, or blue; or that its flowers were shaped like a bell, a funnel, or a cup; or that its leaves were oblong, triangular, or lobed, or . . . the way in which it made more plants?
Whatever his questions were then, one answer would become clear to Carl Linnaeus over time: in the natural world, the most important trait was a plant’s ability to sustain life by making more plants. This key understanding would eventually guide all of his life’s work.
For now, Carl put Vaillant’s idea aside and went back to his immediate task—organizing his unruly plant collection. But this seed of an idea germinated and grew. Flowers, he was beginning to see, were all about sex.
2
EVERY GROWING THING
Minerals grow; Plants grow and live; Animals grow, live, and have feeling.
—CARL LINNAEUS, SYSTEMA NATURAE (THE SYSTEM OF NATURE), 1735
Grain fields and marshes fringed the slow-moving water outside the city walls. Inside, the ribbon of river bisected the small city of Uppsala, Sweden. On one bank sat shops and houses; on the other, the medieval red brick cathedral towered over the university. Here, as in the famous Latin Quarter along the river Seine in Paris, neighbors and passersby could overhear students speaking in Latin, the universal language of scholars. Among those young scholars was twenty-one-year-old Carl Linnaeus, from the low rolling hills of southern Sweden. After graduating from Växjö, at age twenty, and spending a year at Lund University, he transferred to Uppsala in the fall of 1728 with one purpose: to learn all he could about the natural world.
Uppsala University, founded in 1477, was Scandinavia’s first university and the alma mater of Linnaeus’s teacher. Dr. Rothman assumed the school was still as he’d experienced twenty years earlier and had convinced the young man that he would find botany courses there.
A 1702 map of the walled city of Uppsala and the river that ran through it. Included are the king’s palace (a), the cathedral (b), the university hospital (c) and anatomical theater (d), Dean Celsius’s house (e), Dr. Rudbeck’s home (f), and the medical gardens (g).
What Linnaeus found, however, were just two talented but disheartened medical professors, Olof Rudbeck the Younger and Lars Roberg. Nearing seventy, Dr. Rudbeck the Younger, professor of anatomy, botany, zoology, and pharmacology, was no longer young. In a massive fire that had ravaged the city in 1702, he had lost most of his unpublished twelve-volume work about his expedition into Lapland (today called Sápmi), as well as thousands of illustrations prepared for another lengthy book. Since the fire, he had spent most of his time in pursuit of a new interest—comparing the Sami and Hebrew languages. He spent little time teaching. The anatomical theater, which had been built in 1662 by his father, Olof Rudbeck the Elder, was rarely used now.
The other professor, Dr. Roberg, taught theoretical and practical medicine, surgery, physiology, and chemistry. He’d fought to keep open his poorly funded teaching hospital (Sweden’s first), even renting out one room as a tavern. When the hospital was forced to close, Dr. Roberg turned to tutoring private students and seldom gave public lectures. It was no wonder that of the five hundred students at the university, only ten were studying medicine.
With just one hundred silver coins—all his parents could spare—Linnaeus enrolled in school, paid rent, and bought food. To afford a few of Roberg’s costly private lectures on Aristotle and his course on medicine, he skipped meals. In January, four months after he arrived in Uppsala, the last of his money went to a month-long stay in Stockholm to attend an autopsy with six lectures at a professional physicians’ organization. Four hundred miles from home and in debt, he had to borrow money for food and line his worn-out shoes with layers of paper to keep out the snow. These hungry winter months imprinted on him a lifelong anxiety over money.
Learning alone, self-directed and without regular classes, Linnaeus worked hard on projects of his own, occasionally asking Rudbeck and Roberg for advice. He frequented the university’s library where he savored a century-old work—sheets holding three thousand dried European plant specimens bound into twenty-five large books. He joined his “student nation,” one of the regional groups of students similar to today’s fraternities. Yet nowhere among his fellow students could he find a like mind to spur him on.
Classmates told him that the university’s most brilliant medical student had gone home to care for his dying father. When the student, Peter Artedi, returned to campus in March, Linnaeus rushed to meet him.
“We immediately started talking about stones, plants, and animals,” Linnaeus recalled. He was amazed both by his new friend’s knowledge and his willingness to share it.
Two years older, tall and thin with long black hair, Artedi reminded Linnaeus of a picture he’d seen of the English botanist John Ray. In contrast, Linnaeus was short and sturdy with reddish brown hair. Linnaeus described his friend as determined and modest, a man of integrity and honor, someone who took his time forming opinions, while he described himself as spontaneous, passionate, and intense, someone who made friends easily and did everythin
g in a hurry.
They couldn’t have been more different. Or more the same.
As Linnaeus’s parents had, Artedi’s parents pushed their son to become a clergyman like his father and grandfather. Their son, too, disappointed them by choosing medicine. In their schools, both boys had learned Aristotle’s ideas from the same texts that boys in ancient Rome might have read. Artedi had already made a list of the plants in his home province. Another of his interests was alchemy, chemistry’s medieval forerunner, which held that matter could be transformed. Alchemists experimented, for example, to find ways to turn common metals, such as lead, into precious metals, such as gold. Artedi lived quietly on the outskirts of Uppsala where he tutored a potter’s children and used the potter’s kiln for alchemical experiments.
Peter Artedi also investigated zoology, especially fish. This fascination began at age eleven when his family moved to a northern area on the Gulf of Bothnia, whose tributaries were known for salmon-spawning runs.
The two met daily. When one made a thrilling discovery—a new mushroom, a new bird, a new idea—he’d try to keep it to himself. After a few days, though, he would be bursting to share his news with his best friend. Each was the other’s sounding board. The friendly rivals worked independently but also compared notes. Fierce competition energized their ideas.
Across the river from the university, behind the botany professor’s official residence, a small swampy garden backed up to a creek. Neglected since the great fire, the once lush medical garden was now a sorry tangle of weeds. Where 1,500 species had grown, only a few rare plants poked through the couple hundred surviving species.
One April day as Linnaeus rummaged through the weeds, a clergyman strolling in the garden asked about some plants. He rattled off the names he’d learned from Tournefort’s book. On further questioning, he retrieved his herbarium—a book he’d created of more than six hundred native wildflowers he’d collected, pressed, glued onto paper, and bound together. The clergyman, it turned out, was Olof Celsius, theology professor, dean of the cathedral, amateur botanist, and the owner of a well-known garden that Linnaeus had been longing to see.
While professors occasionally took in students as paid boarders, Dean Celsius was so impressed with this raggedly dressed student that, soon after, he offered meals at his table, a rent-free room, and access to his private library.
Months later, Linnaeus had a chance to thank him formally. It was tradition at New Year’s for Uppsala students to write flattering poems for their favorite professors. Instead, Linnaeus wrote an essay, “Prelude on the Wedding of Plants,” for his benefactor, Professor Celsius:
I am no poet, but something, however, of a botanist; I therefore offer to you this fruit from the little crop that God has granted me. . . . In these few pages I treat of the great analogy which is to be found between plants and animals, in that they both increase their families in the same way. I beg you graciously to accept this humble gift . . .
Linnaeus’s essay elaborated on the main points of Sébastien Vaillant’s Paris lecture and borrowed the Frenchman’s colorful, provocative style to describe how a flowering plant reproduces through pollination. In an eyebrow-raising comparison with human sexual reproduction, he wrote that pollination is the plant’s sexual act, comparing pollen to sperm, seeds to eggs.
Linnaeus gave this handwritten essay to his benefactor, Professor Celsius, as a New Year’s gift in 1729. The drawings show pollen transfers between dog’s mercury plants of different genders (left) and pumpkin flowers of two genders with pollen floating between them (lower right). He wrote the title in Latin, “Preliminaries on the marriage of plants in which the physiology of them is explained, sex shown, method of generation disclosed, and the true analogy of plants with animals, concluded.”
Despite the startling metaphor, the ideas in the essay intrigued Celsius. He shared it with his colleague Dr. Rudbeck, the botany professor. When Linnaeus applied for a job working in the university’s medical garden that spring, Dr. Rudbeck rejected his application. Instead, he offered him a far more important position: that of botanical demonstrator—showing students how to identify particular plants and use them in treating patients’ symptoms. This job was normally performed by the professor himself or a senior-level student, but on May 4, 1730, Linnaeus, a second-year, largely self-taught student, delivered his first garden demonstration. Not once had he heard a lecture on botany at Uppsala—his reason for attending the university. Yet his knowledge was clear and his passion for plants was contagious. From then on, instead of the usual seventy or eighty attending such demonstrations, as many as four hundred students packed into the garden.
When his mother learned that Linnaeus was giving lectures for a professor, she was relieved. At long last her son was redeemed in her eyes. He might have a future after all.
To boost his small income, Linnaeus also began giving private lectures on botany. Many of his students were older than he was, and many were sons of wealthy families and nobility. Some paid cash: twenty-four copper dalers per class. But most paid him in old books and much-needed cast-offs, such as used shoes, shirts, hats, stockings, gloves, buttons, even a toothpick to clean his teeth.
Meanwhile, Dr. Rudbeck, having been married three times and the father of twenty-six children, needed a tutor for his three youngest sons. He asked Linnaeus to move in to tutor them and teach medicine to their older stepbrother.
Living in the Rudbeck household gave Linnaeus priceless access every day to Rudbeck’s knowledge and guidance, as well as time to examine the professor’s extensive botanical library, collections, and exquisite bird paintings. He was also able to make improvements to the university gardens outside the professor’s house.
Uppsala university student, of about the year 1700, elegantly dressed in fancy wig, embroidered waistcoat, cravat, tricornered hat, ceremonial saber, and shoes with heels.
The short-eared owl (Asio flammeus) painted by Olof Rudbeck the Younger around 1710.
Perhaps best of all were evenings when the professor would tell stories of his travels as a young man into the wilds of Sápmi in northern Sweden. Thirty years earlier, Rudbeck had accompanied astronomers on an expedition to the Arctic Circle. His tales inspired in Linnaeus a longing to see the rare northern plants and animals for himself.
About a year before moving in with the Rudbecks, Linnaeus had begun to puzzle out a new way to organize his dried plant collection. He decided to produce a small catalog of the rare plants he’d found, to test the three most popular systems against one another:
In France, Tournefort had organized plants by flower shape;
In Germany, Augustus Rivinus used the petals;
In England, John Ray used the fruits, flowers, seeds and roots.
Linnaeus compared them as he classified specimens from his collection and showed his results in a handwritten paper, “Spolia Botanica.” Always fond of military metaphors, he called these results spolia, meaning “spoils,” as if he’d plundered them from the war between those feuding systems. Like the reuse of old building stone for new construction, he was drawing on the three existing systems to see if something new and better could result.
He concluded that the Englishman Ray’s organizing system, which compared the flowers, seeds, fruit, and roots of different plants to determine relationships among them, was the most natural. A natural classification system, the ideal as Linnaeus saw it, was one based on relationships between plants as God had made them. However, Ray’s method had so many criteria to evaluate that it was hard to use. When confronted with an unknown plant, beginning plant-hunters, like Linnaeus’s students, would be swamped by the number of details they had to find, such as the number of tiny developing leaves inside the seed.
Tournefort, on the other hand, went to the opposite extreme—from too many to too few. His system had only one simple criterion—the shape of the flower. That made it easy to use but produced many strange and unnatural groupings. Like any system based on an arbitrary selection
of criteria, such as flower color or, in Tournefort’s case, flower shape, Linnaeus considered it artificial because it was a human choice. It was like grouping people into families by their eye color or height instead of by their relationships. In addition, he disliked that Tournefort separated trees from other plants.
He also ruled out Rivinus’s system. Even though it classified trees and other plants together, the scheme was based on the number and similarity of petals. Since not every type of plant had petals, he judged this system to be artificial as well.
Linnaeus believed that the most natural system for grouping plants would center on the reproductive parts (the fruit and seeds), instead of the vegetative parts (the leaves, stem, and roots) which support and protect the fruit and seeds. In a truly natural group, he believed, related plants might have similar properties. Such a system would be more than merely a means for scientists to identify and describe plants. It might also help in finding substitutes for expensive foreign imports such as tea, coffee, spices or medicines—plants with similar properties that could be grown locally. Science needed one consistent, universal system that everyone could use.
Meanwhile, in the university’s garden, Linnaeus’s students struggled to take notes during his information-packed demonstrations. They asked for help. To eliminate “the great inconvenience of copying all names with pen flying, in the Garden under the open sky, which after all seldom can be done without errors,” he listed all the plants around Uppsala in a handwritten guide. In it, he tried out his new organizing system for the first time.
Peter Artedi also was frustrated with the existing systems, especially when it came to umbellate plants, such as Queen Anne’s lace, parsnip, parsley, fennel, dill, and water hemlock. Like umbrellas, they held up their many tiny flowers on stalks of nearly equal length. They fascinated him. Artedi began plotting out a new way to classify these plants.
