Wilhelm Friedrich Philipp Pfeffer (9 March 1845 – 31 January 1920) was a German botanist and plant physiologist born in Grebenstein.
He studied chemistry and pharmacy at the University of Göttingen, [1] where his instructors included Friedrich Wöhler (1800-1882), William Eduard Weber (1804-1891) and Wilhelm Rudolph Fittig (1835-1910). Afterwards, he furthered his education at the universities of Marburg and Berlin. At Berlin, he studied under Alexander Braun (1805-1877) and was an assistant to Nathanael Pringsheim (1823-1894). Later on, he served as an assistant to Julius von Sachs (1832-1897) at Würzburg,
In 1873 he was appointed professor of pharmacology and botany at the University of Bonn, followed by professorships at the Universities of Basel (from 1877) and Tübingen (from 1878), where he also served as director of the Botanischer Garten der Universität Tübingen. In 1887 he became a professor at the University of Leipzig and director of its botanical garden.
He was elected a member of the Royal Swedish Academy of Sciences and an International Honorary Member of the American Academy of Arts and Sciences in 1897, an International Member of the United States National Academy of Sciences in 1903, and the American Philosophical Society in 1909. [2] [3] [4]
Pfeffer was a pioneer of modern plant physiology. His scientific interests included the thermonastic and photonastic movements of flowers, the nyctinastic movements of leaves, protoplastic physics and photosynthesis. In 1877, while researching plant metabolism, Pfeffer developed a semi-porous membrane to study the phenomena of osmosis. The eponymous "Pfeffer cell" is named for the osmometric device he constructed for determining the osmotic pressure of a solution. [5]
During his tenure at Leipzig, Pfeffer published an article on the use of photography to study plant growth. He wanted to extend the chronophotographic experiments of Étienne-Jules Marey (1830-1904) by producing a short film involving the stages of plant growth. This "movie" would be filmed over a period of weeks by frame-at-a-time exposure taken at regular spaced intervals. Later, time-lapse photography would become a commonplace procedure. [6]
Carl Wilhelm von Nägeli was a Swiss botanist. He studied cell division and pollination but became known as the man who discouraged Gregor Mendel from further work on genetics. He rejected natural selection as a mechanism of evolution, favouring orthogenesis driven by a supposed "inner perfecting principle".
Otto Renner was a German plant geneticist. Following the work of Erwin Baur, Renner established the theory of maternal plastid inheritance as a widely accepted genetic theory.
Georg Albrecht Klebs was a German botanist from Neidenburg (Nidzica), Prussia. His brother was the historian Elimar Klebs.
Hermann Friedrich Stannius was a German anatomist, physiologist and entomologist. He specialised in the insect order Diptera especially the family Dolichopodidae.
Hartmut Erbse was a German classical philologist.
Wilhelm Friedrich Benedikt Hofmeister was a German biologist and botanist. He "stands as one of the true giants in the history of biology and belongs in the same pantheon as Darwin and Mendel." Largely self-taught he was the first to study and establish alternation of generations and the details of sexual reproduction in the bryophytes.
Alexander Carl Heinrich Braun was a German botanist from Regensburg, Bavaria. His research centered on the morphology of plants.
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Karl Johannes Kniep was a German botanist who was a native of Jena.
Heinrich Nissen was a German professor of ancient history.
Friedrich (Fritz) Wilhelm Ludwig Kränzlin was a botanist associated with the Natural History Museum (BM).
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Dr. Julius Ritter von Wiesner was a professor of botany at the University of Vienna, a specialist in the physiology and anatomy of plants.
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Hermann Vöchting was a German botanist.
Bernhard Schweitzer was a German classical archeologist.
Johannes (Hans) Theodor Gustav Ernst Fitting was a German plant physiologist. He was the son of law professor Heinrich Hermann Fitting.
Friedrich Wilhelm Hagen was a German psychiatrist. His father, also named Friedrich Wilhelm Hagen (1767–1837), was a noted clergyman.
Hermann Gerhard Weyland was a German chemist and botanist. In collaboration with Richard Kräusel, he carried out significant paleobotanical investigations of Devonian flora.
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