SEMON, RICHARD WOLFGANG

(b Berlin, Germany, 22 August 1859; d. Munich, Germany, 27 December 1918)

Zoology, anatomy

Semon’s father, Simon Joseph Semon, a banker and stockbroker, and his mother, Henrietta Aschenheim, came from well-to-do Jewish families. His older brother Felix was a leading laryngologist in England, becoming physician in ordinary to King Edward VII and receiving a knighthood.

After reading the works of Charles Darin and Erns Haeckle, Semon became interested in biology while still at the Gymnasium. In 1879 he began to study zoology at Jena under Haeckle, whose views on natural philosophy had a lasting influence on Semon. He later stated that Haeckel’s school was characterized by “the feeling for the connection of all branches of human knowledge [and] monism as a method of thinking and research.” Beginning in 1881, Semon stuided medicine at Heidelberg and at the same time prepared under Otto Bütschli’s supervision a dissertation on “Das Nervensystem der Holothurien,” He obtained the Ph.D. with this work at Jena in 1883, and a year later he passed the state medical examination at Heidelberg.

In 1885 Semon served as physician on an expedition to Africa led by Robert Flegel, but he had to withdraw from the expedition because of malaria. He then worked at the zoology station in Naples (1885–1886) before becoming an assistant at the Jena anatomical institute in 1886. After receiving his medical degree that same year, Semon qualified as a university lecturer at Jena in 1887 with a work “Die indifferente Anlage der Keimdrüsen beim Hüchen und ihre Differenzierung zum Hoden” (“The Undifferentiated Rudiments of the Genital Glands of the Chick and Their Differentiation Into Testicles”). In 1891 Semon was named extraordinary professor at Jena.

From 1891 to 1893 Semon supervised an expedition to Australia. He published the results with the assistance of a number of co-workers.

In 1897 Semon gave up his teaching activities at Jena for personal reasons and began working as a private scholar in Munich. Two years later he married Maria Krehl (born Geibel), who became widely known for her translations of the works of Auguste-Henri Forel, L. Morgan, and the young Charles Darwin.

Semon based his Zoological works on comparative anatomical and embryological studies of echinoderms, snails, fish, and birds. In Australia he was concerned mainly with the habitats, sexual reproduction, and development of the lungfish Ceratodus forsteri, as well as with the monotremata. His travel accounts contain remarks on animal geography, paleontology, and geology, as well as ethnographic and anthropological observations, and vivid descriptions of landscapes.

After 1900 Semon devoted himself primarily to an attempt to bring together into a unified concept “all those phenomena in the organic world that involve reproduction of any kind.” Out of this attempt emerged his hypothesis of “the mneme as the enduring principle in changes occurring in organic life.” Semon used the concept of the mneme (cell memory) to designate a particular property of organic substance, pursuing ideas first put forth in 1870 by Ewald Hering, who saw in memory “a universal function of organic matter.” According to Semon, not only can a stimulus influence irritable organic substance temporarily, but it can also effect a persisting, latent change. In this case, the stimulus inscribes itself by means of an engram. These engrams can, he thought, be eliminated by certain influences, or ecphoria. The mneme consists of the sum of the engrams that an organism has individually acquired in the course of its life or that have been produced within it by heredity. In Semon’s view, under favorable circumstances the individually acquired adaptations can be passed on to offspring (somatogenic inheritance).

Semon’s Lamarckian concepts were rejected by, among others. August Weismann and Wilhelm Ludvig Johannsen, but were welcomed by Forel and his student Eugen Bleuler (the founder of Mnemismus). According to Jürgen Schatzmann, modern research on memory and on heredity provides partial justification for Semon’s ideas. since “in both processes entirely similar chemical structures are involved.” Nevertheless, the idea of an identity of the two processes is no more acceptable today than it was when Semon proposed it.

BIBLIOGRAPHY

I. Original Works. A complete list of Semon’s publications can be found in Otto Lubarsch, ed., Bewustseinsvorgang im Gehirnprozess. Eine Studie von R. Semon (Wiesbaden, 1920), xiv-xiviii.

Semon’s principal works are Zoologische Forschungsreisen in Australien und dem Malayischen Archipel-Denkschriften der medizinisch naturwissenschaftlichen Gesellschaft Jena4–8 (Jena, 1893–1913)— this contains all Semon’s works on the Ceratodus as well as on the monotremata and Marsupialia; Im australischen Busch und an den Küsten des Korallenmeeres (Leipzig, 1896); Die Mneme als erhaltendes Prinzip im wechsel des organischen Geschehens (Leipzig, 1904; 3rd ed. 1911); Das Problem der Vererbung ’erworbener Eigenschaften’(Leipzig, 1912): and “Aus Haeckels Schule,” in H. Schmidt, ed., Was wir Ernst Haeckel verdanken (Leipzig, 1914).

Semon’s letters for Forel can be found in the archives of the Medizinhistorische Institut of the University of Zurich. Semon’s letters to Haeckel are held at the Ernst-Haeckel-Haus of the Friedrich-Schiller-Universität in Jena; Haeckel’s letters to Semon are held at the Bavarian State Library in Munich.

II. Secondary Literature. See the article by Lubarsch in the book he edited under the title Bewustseinsvorgang und Gehirnprozess von Richard Semon (Wiesbaden, 1920). See also Auguste-Henri Forel, “Richard Semons Mneme als erhaltendes Prinzip im Wechsel des organischen Geschehens,” in Archiv für Rassen-und Gesellschaftsbiologie, 2 , no. 2 (1905), and “Richard Semon,” in Journal für Psychologie und Neurologie, 25 (1919); O. Lubarsch, “Richard Wolfgang Semon,” in Münchener medizinische Wochenschrift, 66 . no. 11 (1919); August Weismann, “Semons ’Mneme’ und die Vererbung erworbener Eigenschaften,” in Archiv für Rassen-und Gesellschaftsbiologie, 3 , no. 1 (1906); George Uschmann, in Geschichte der Zoologies und der Zoologischen Anstalten in Jena (Jena, 1959); and Jürgen Schatzmann, “Richard Semon (1859–1918) und seine Mnemetheorie,” in Zürcher medizingeschichtliche Abhandlungen n.s. no. 58 (1968).

Georg Uschmann