SEMON, RICHARD WOLFGANG

SEMON, RICHARD WOLFGANG (1859–1918), German zoologist. Born in Berlin, he was educated at Jena, where in 1891 he was appointed professor extraordinary. In that year Semon undertook an extensive voyage of exploration to Australia and the Malay Archipelago to study the primitive reptile-like mammals and the Australian lungfish, both of which had great interest for students of evolution. The results of this expedition appeared in an extensive series of scientific publications, including Semon's classic monographs on the embryology of the lungfish. Semon wrote an account of his travels in a book Im australischen Busch (1896; In the Australian Bush, 1899). In 1897 Semon left his professorship at Jena and went to Munich. He then devoted himself to the theoretical problems of evolution. Semon's theory, set forth in Die Mneme (1904; The Mneme, 1921), was an attempt to describe a mechanism for the inheritance of acquired characteristics. His thesis was that the organism is permanently affected by its reactions to external stimuli. These reactions produce impressions or "engramms," which modify the development of the progeny through "somatic inductions" that affect the germ cells. The power of the organism thus to accumulate a record or "memory" of past reactions to the environment Semon termed the "mneme." This theory, which was found mystical and lacking in a convincing experimental basis, was rather coldly received by most biologists, and is today of historical interest only. -BIBLIOGRAPHY: W. Gutmann, Psychomechanik: Freud und Semon (1922). (Mordecai L. Gabriel)