[Richard Semon (1859-1918): expeditions, engrams and epigenetics].

Richard Semon (1859-1918) was a student of Ernst Haeckel and began his career as a zoologist with work on sea urchins, starfish, chicken and lung fish, which he collected at the Mediterranean Sea and in Australia. After his return to Germany he was forced to leave Jena and the university due to private reasons, and settled in Munich, where Semon devoted most of his time to the more philosophical aspects of biology, developed the theory of "mneme" (1904), which he extended towards the inheritance of acquired characteristics (1912). Semon's concept of memory reached far beyond the brain and the individual person. In 1918 he took his life, despondent because of a surmised lack of scientific appreciation, the death of his beloved wife, the political turmoil at the end of WWI, and his-the memory researcher's-suspected loss of memory. Eight years later, the experimental biologist Paul Kammerer (1880-1926) from Vienna, Semon's must trusted source for the inheritance of acquired characteristics, also shot himself. Serious doubts increasingly overshadowed his work on salamanders and midwife toads. Epigenetics, the nature of memory, the fear of cognitive impairment, depression, the impact of private and political matters on scientific work, suspected scientific errors, fraud and a scientists' suicides are condensed in Semon's life and death.