Carl Linnaeus and the Linnaean Legacy
The father of modern plant and animal classification
Linnaeus was born in 1707, the son of a Lutheran clergyman, at Rashult in Sweden. He began to study medicine at the University of Lund in 1727, transferring to the University of Uppsala the following year. Linnaeus headed an expedition to Lapland in 1732, travelling 4,600 miles and crossing the Scandinavian Peninsula by foot to the Arctic Ocean. On the journey he discovered a hundred botanical species. In 1734, he mounted another expedition to central Sweden.
He undertook his medical degree in 1735 at the University of Harderwijk in Gelre, the Netherlands (which no longer exists), thence going to the University of Leiden for further studies. Also in 1735, he published Systema Naturae, his classification of plants based on their sexual parts. His method of binomial nomenclature using genus and species names was further expounded when he published Fundamenta Botanica (1736) and Classes Plantarum (1738). This system used the flower and the number and arrangements of its sexual organs of stamens and pistils to group plants into twenty-four classes which in turn are divided into orders, genera and species.
A Binomial Naming System
In his publications, Linnaeus provided a concise, usable survey of all the world's plants and animals as then known, about 7,700 species of plants and 4,400 species of animals. These works helped to establish and standardize the consistent binomial nomenclature for species which he introduced on a world scale for plants in 1753, and for animals in 1758, and which is used today. His Systema Naturae 10th edition, volume 1(1758), has accordingly been accepted by international agreement as the official starting point for zoological nomenclature. Scientific names published before then have no validity unless adopted by Linnaeus or by later authors. This confers a high scientific importance on the specimens used by Linnaeus for their preparation, many of which are in his personal collections now treasured by the Linnean Society.
In 1738, he went to Stockholm to practice medicine and lecture, and became a professor at Uppsala University in 1741, attracting students from many countries to his often crowded lectures. Twenty-three of Linnaeus' students themselves became professors and this spread his methods widely, as did his extensive correspondence with leading naturalists all over Europe. He was granted nobility in 1761, becoming Carl von Linné. He continued his work of classification and as a physician, and remained Rector of the University until 1772. In that decade, he suffered from strokes, ill health, and memory loss until his death in 1778.
The Linnaean binomial system consists essentially of giving a one-word name such as Rhododendron or Equus to a genus and a two-word name such as Rhododendron ponticum or Equus caballus to an individual species within the genus.
The Linnaean Binominal System
Linnaeus did not invent binomial nomenclature. The use of such two-word names for species or for kinds within a group occurs in many languages and goes back to remote times. It is indeed the common practice in vernacular nomenclature. Linnaeus gave classification consistency and precision. He linked each of the specific names for everyday use with a descriptive name, which helped to identify the species concerned and limited the application of its two-word name to that one species.
The general adoption by botanists and zoologists of this consistent two-word nomenclature for species during the second-half of the 18th century came about because Linnaeus introduced it in comprehensive works which naturalists soon found indispensable.