Annals of the History and Philosophy of Biology, Vol. 13 (2008): 4-52 Das autobiographische Manuskript des Entwicklungsbiologen Julius Schaxel (1887-1943) vom 24. Juli 1938 – Versuch einer Kontextualisierung 1 Christian Reiß, Uwe Hoßfeld, Lennart Olsson, Georgy S. Levit & Oliver Lemuth Abstract. Personal notes, such as laboratory notebooks or, as in this case, an autobiography, are among the most seductive sources for the historian of science. Seductive, as they promise insights only rarely granted in the course of historiographical research and, at the same time, pose severe problems, when it comes to critical assessment of the sources. Autobiographies acuminate both sides in an especially drastic way. Whereas one can on the one hand hope for a look into the author’s mind, on the other hand autobiographies are always written in retrospect and with a specific motivation concerning their content. Keeping this in mind, Schaxel’s autobiography gives fascinating insights into an important but almost forgotten figure in the history of early 20 th century biology. Schaxel was a highly ambivalent figure, in whose biography central themes of early 20 th century science and culture meet. In contrast to older accounts, the autobiography is supposed to switch perspective and to let the author tell his story himself. That way, the picture given includes both Schaxel’s life and the interpretation Schaxel choose for telling the story. Additionally, an important and almost lost and forgotten source for the history of 1 Der Beitrag entstand im Rahmen eines von der DFG geförderten Forschungsprojektes zur Entwicklungsbiologie (Ho 2143/9-1). Unser besonderer Dank gilt den Mitarbeitern des Universitätsarchivs Jena, des Archivs der Universitätsbibliothek Leipzig sowie des Carl Zeiss Archivs für Ihre Unterstützung bei den Recherchen.