Driesch-Morgan Collection


Date: 1893-1933 | Size: 1 reel(s)


An innovative embryologist and confirmed vitalist, Hans Driesch worked successively at the International Zoological Station in Naples, Italy, and at the Universities of Heidelberg, Cologne, and Leipzig, before being forcibly retired by the Nazis in 1933. The Driesch-Morgan Collection consists of letters written by Thomas Hunt Morgan to Driesch between 1893 and 1915, with one letter from 1933, relating to their work on the embryology of sea urchins and theories of development. The microfilm is based on originals held at the Universitätsbibliothek, Leipzig.

Background note

The developmental biologist and ardent vitalist Hans Driesch was born on October 28, 1867, in Bad Kreuznach, Germany. After studying zoology at Freiburg and Munich, he received his doctorate at Jena in 1889 for work under Ernst Haeckel on coelenterates. Through a series of major monographs including Die Biologie als Selbständige Grundwissenschaft (1893), Analytische Theorie der Organischen Entwicklung (1894), Die Seele als Elementare Naturfaktor (1903), and History and Theory of Vitalism (1905), Driesch developed a unqiue "biotheoretical" approach to organismal study, incorporating mathematical analysis of organismal structures in a strongly teleological vitalist framework that he called entelechy. He remained an antimaterialist throughout his career.

Between 1891 and 1900, Driesch worked at the International Zoological Station in Naples, Italy, where he met performed a renowned series of experiments on sea urchin embryos that conclusively demonstrated that the fate of a cell is not determined in the early developmental stages and, in 1896, he became the first to demonstrate embryonic induction. At Naples he also met Thomas Hunt Morgan, the young American embryologist and soon to be geneticist, with whom he maintained a long correspondence. After serving as the Gifford lecturer at Aberdeen in 1907-1908, Driesch was appointed professor of philosophy at Heidelberg (1911-20), and subsequently at Cologne and Leipzig. His pacifism and philosophical beliefs made him anathema to the Nazi regime, however, and he was forced to retire in 1933. He died in Leipzig on April 16, 1941.

Scope and content

The Driesch-Morgan Collection consists almost exclusively of letters written by Thomas Hunt Morgan to Hans Driesch before the First World War. Concentrated in the period 1893-1905, the letters offer insight into the course of Morgan's and Driesch's highly amicable, but increasingly disparate thinking on embryology. The one post-war letter, written at the time of Driesch's forced resignation from Leipzig in 1933, relates to Driesch's attempts to locate an academic appointment in the United States.

Collection Information

Physical description

1 reel

1 reel


Restrictions on Use:

None. Permission to duplicate must be obtained from the the Universitätsbibliothek, Leipzig.


Gift of Garland Allen, 1973. From originals in the Universitätsbibliothek, Leipzig.

Preferred citation

Cite as: Driesch-Morgan Collection, American Philosophical Society.

Processing information

Catalogued by rsc, 2003.

Related material

Additional Driesch letters at the APS appear in the papers of Charles B. Davenport, Simon Flexner, H. S. Jennings, Wolfgang Kohler, and Raymond Pearl.

Indexing Terms


  • Embryology -- Germany