Background

Jacob Theodor Klein was born on August 15, 1685, in Konigsberg, Duchy of Prussia (now Kaliningrad, Russia). Nothing is known of his early life.

Education

Klein studied law, natural history and history at the University of Konigsberg.

Career

Between 1706 and 1712, Klein traveled through England, Germany, Holland, and Austria in an educational journey, before returning to Konigsberg. He moved to Danzig after the death of his father, where he was elected city secretary in 1713. Between 1714 and 1716 he served as the city’s representative in Dresden and then Warsaw.

He developed a botanical garden in Danzig, founded and directed a naturalist’s society there, made extensive collections, and published about two dozen monographs, including studies of birds, fishes, reptiles, and invertebrates other than the sea urchins, particularly the mollusks. Fossils are dealt with in various publications, and Klein edited the Sciagraphia lithologica curiosa, seu lapidum nomenclátor (1740) of J. J. Scheuchzer, which was published after Scheuchzer’s death.

Achievements

• Jacob Theodor Klein is described as one of the most important natural philosophers of his century. One of his best-known works, Naturalis dispositio Echinodermatum, was one of the earliest monographic treatments of the sea urchins. Although altered and enlarged, this work was a major source of information on the Echinoidea for zoologists and paleontologists through-out the eighteenth century and remained a point of departure in discussions by such early nineteenth-century authors as James Parkinson. He is also known for establishing one of the largest botanical gardens in Germany.
  
  The name of the genus Kleinia was given to the plant family of Compositae (Asteraceae) by Linnaeus in honor of Klein's works.

Works

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  • Historie Piscium Naturalis 1744
  • Mantissa ichtyologica de sono et auditu piscium, sive, Disquitio rationum quibus autor epistolæ in 1746
  • Naturalis Dispositio Echinodermatum 1734
  • Alterior Lucubratio Subterranea 1760
  • Historiae Avium Prodromus Cum Praefatione De Ordine Animalium In Genere 1750
  • Summa Dubiorum Circa Classes Quadrupedum Et Amphibiorum In Celebris Domini Carli Linnaei Systemate Naturae 1743
  • Doutes Ou Observations De M. Klein Sur La Revue Des Animaux Faite Par Le Premier Homme, Sur Quelques Animaux Des Classes Des Quadrupèdes Et Sur Les Animaux 1754
  • Dubia Circa Plantarum Marinarum Fabricam Vermiculosam. Millius Enucleata Observatio Microscopia 1760
  • Tentamen methodi ostracologicae 1753
  • Quadrupedum dispositio brevisque historia naturalis 1751
  • Descriptiones Tvbvlorvm Marinorvm in Qvorvm Censvm Relati Lapides Cavdae Cancri Gesneri 1731
  • Naturgeschichte der Seeigel 1778
  • Tentamen Herpetologiae 1755

Views

Klein’s taxonomic method was based entirely on external characteristics, such as the number and position of limbs and the mouth; and he vigorously opposed any method, including the Linnaean system, based on characters not visible externally.

The 1760 edition of the Philosophical Transactions of the Royal Society of London published a letter by 18th Century botanist and Fellow of the Royal Society, Peter Collinson, criticizing Klein for his belief that swallows (sand martins) are not migratory birds, and instead "retire underwater" during winters.

Membership

Klein was awarded the membership of several scientific societies, including the Royal Society in London, the St. Petersburg Academy, and the Danzig Research Society.

Personality

Although well respected by his colleagues, Klein was nonetheless accused by some contemporaries of being unscientific, alleging that he based his beliefs on the hearsay and the claims of "credulous" people.

Connections

Klein was married to Anna Katharina Reyger. One of his daughters, Dorothea Juliane Klein, married physicist Darniel Gralath, who would become mayor of Danzig.

Spouse:

Anna Katharina Reyger

References

• Dictionary of Scientific Biography, Volume 7
  1973