Ludwig Jost

 Ludwig Jost ForMemRS (born November 13, 1865 in Karlsruhe – February 22, 1947 in Heidelberg) was a German botanist, and university professor.
Life and work.
After attending the gymnasium in Karlsruhe, Jost studied natural sciences at the University of Heidelberg, then from 1885, was a student at Kaiser Wilhelm University in Strasbourg. In 1887 he obtained his PhD as a student of Anton de Bary, and later on, worked as an assistant to Karl von Goebel at the University of Marburg. Afterwards, he returned to Strasbourg, where in 1891, he received his habilitation under the sponsorship of Hermann zu Solms-Laubach. In 1894 he became an associate professor, and from 1919 to 1934, he held the chair of botany at the University of Heidelberg.
He earlier research largely dealt with morphological and histological issues — later on, his main field of study involved the physiology of plants; working with subjects such as: growth rhythm, nyctinasty, geotropism, leaf positioning, electrical potential differences on cell walls, et al.