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Linnaeus: The Name Giver
JUNE 2007
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Linnaeus: The Name Giver
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By David Quammen
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Photographs by Helene Schmitz
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Linnaeus wasn't the first naturalist to try to roster and systematize nature. His predecessors included Aristotle (who had classified animals as "bloodless" and "blooded"), Leonhart Fuchs in the 16th century (who described 500 genera of plants, listing them in alphabetical order), the Englishman John Ray (whose Historia Plantarum, published in 1686, helped define the species concept), and the French botanist Joseph Pitton de Tournefort, contemporary with Ray, who sorted the plant world into roughly 700 genera, based on the appearance of their flowers, their fruit, and their other anatomical parts.
Linnaeus emerged from this tradition and went beyond it. His Systema Naturae, as published in 1735, was a unique and peculiar thing: a folio volume of barely more than a dozen pages, in which he outlined a classification system for all members of what he considered the three kingdoms of nature—plants, animals, and minerals. Notwithstanding the inclusion of minerals, what really mattered were his views on the kingdoms of life.
His treatment of animals, presented on one double-page spread, was organized into six major columns, each topped with a name for one of his classes: Quadrupedia, Aves, Amphibia, Pisces, Insecta, Vermes. Quadrupedia was divided into several four-limbed orders, including Anthropomorpha (mainly primates), Ferae (such as canids, felids, bears), and others. His Amphibia encompassed reptiles as well as amphibians, and his Vermes was a catchall group, containing not just worms and leeches and flukes but also slugs, sea cucumbers, starfish, barnacles, and other sea animals. He divided each order further, into genera (some with recognizable names such as Leo, Ursus, Hippopotamus, and Homo), and each genus into species. Apart from the six classes, Linnaeus also gave half a column to what he called Paradoxa, a wild-card group of chimerical or simply befuddling creatures such as the unicorn, the phoenix, the dragon, the satyr, and a certain giant tadpole (now known as Pseudis paradoxa) that, weirdly, shrinks during metamorphosis into a much smaller frog. Across the top of the chart ran large letters: CAROLI LINNAEI REGNUM ANIMALE. It was a provisional effort, grand in scope, integrated, but not especially original, to make sense of faunal diversity based on what was known and believed at the time. Then again, animals weren't his specialty.
Plants were. His classification of the vegetable kingdom was more innovative, more comprehensive, and more orderly. It became known as the "sexual system" because he recognized that flowers are sexual structures, and he used their male and female organs—their stamens and pistils—to characterize his groups. He defined 23 classes, into which he placed all the flowering plants (with a 24th class for cryptogams, those that don't flower), based on the number, size, and arrangement of their stamens. Then he broke each class into orders, based on their pistils. To the classes, he gave names such as Monandria, Diandria, Triandria (meaning: one husband, two husbands, three husbands) and, within each, ordinal names such as Monogynia, Digynia, Trigynia, thereby evoking all sorts of scandalous ménages (a plant of the Monogynia order within the Tetrandria class: one wife with four husbands) that caused lewd smirks and disapproving scowls among some of his contemporaries. Linnaeus himself seems to have enjoyed the sexy subtext. And it didn't prevent his botanical schema from becoming the accepted system of plant classification throughout Europe.
The artist Georg Ehret helped popularize Linnaeus's ideas by producing a handsome tabella, a poster, illustrating the diagnostic features for Linnaeus's 24 classes. The tabella sold well and earned Ehret some guldens. Linnaeus himself, always stingy about sharing credit, included Ehret's drawing without acknowledgement in one of his later books. But he wouldn't forget his old pal, and evidence left after his death—we'll come to it—suggests that he valued Ehret's botanical vision as he valued few aside from his own.
After returning to Sweden, becoming a husband and father and a professor at Uppsala University, Linnaeus continued to churn out books. He published revised and expanded editions of Systema Naturae, as well as strictly botanical volumes such as Flora Suecica (Swedish Flora) in 1745, Philosophia Botanica (1751), and Species Plantarum (1753). Philosophia Botanica is a compendium of terse, numbered postulates in which he lays out his botanical philosophy. For instance: "The foundation of botany is two-fold, arrangement and nomenclature." Arrangement of plants into rational categories and subcategories is crucial for three reasons: Because there are so many kinds (and more every year, during the great age of discovery in which Linnaeus lived), because much is known about many of those kinds, and because classification makes that knowledge accessible. Alphabetical listing may have worked well enough with 500 plant genera, but as the count rose into many thousands of species, it didn't serve.
There was also a deeper purpose, for Linnaeus, to this enterprise. Find the "natural method" of arranging plants into groups, and you would have discovered God's own secret logic of biological creation, just as Isaac Newton had discovered God's physical mathematics. Linnaeus knew that he hadn't achieved that, not even with his 24-class sexual system, which was convenient but artificial. He couldn't see, couldn't imagine, that the most natural classification of species reflects their degree of relatedness based on evolutionary descent. But his passion for order—for seeking a natural order—did move taxonomy toward the insights later delivered by Charles Darwin.
As for nomenclature, it contributes to the same purpose. "If you do not know the names of things, the knowledge of them is lost too," he wrote in Philosophia Botanica. Naming species, like arranging them, became increasingly problematic as more and more were discovered; the old-fashioned method, linking long chains of adjectives and references into fully descriptive labels, grew unwieldy. In Species Plantarum, he established the Latin binomial system for naming plants, and then in the tenth edition of Systema Naturae, published in 1758-59 as two fat volumes, he extended it to all species, both plant and animal. A pondweed clumsily known as Potamogeton caule compresso, folio Graminis canini, et cetera, became Potamogeton compressum. We became Homo sapiens.
His life back in Uppsala entailed more than authorship. He was a wonderful teacher, with a vivid speaking style, clear and witty, and a terrific memory for facts. His lectures often packed the hall, his private tutoring earned him extra money, and he made botany both empirical and fun by leading big festive field trips into the countryside on summer Saturdays, complete with picnic lunches, banners and kettledrums, and a bugle sounding whenever someone found a rare plant. He had the instincts of an impresario. But he was also quietly effective in mentoring the most talented and serious of his students, of whom more than a dozen went off on adventuresome natural history explorations around the world, faithfully sending data and specimens back to the old man. With his typically sublime absence of modesty, he called those travelers the "apostles." In 1761, the government ennobled him, whereupon he upgraded his linden-tree name to von Linné. By then he was the most famous naturalist in Europe.
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