Although her work was greatly respected by scholars from both psychology and biology, such as Wolfgang Köhler, Max Wertheimer, and Karl von Frisch, the life and work of the German sensory physiologist and comparative psychologist Mathilde Hearz (1891-1975) have remained relatively obscure until recently. Her research represented a combination of biological principles fused with a psychological-phenomenological perspective. After a prolific career within a short time span, Hertz's career came to an abrupt end in 1933, despite the intervention efforts of Max Planck. Hertz's personal and professional fates are in many ways representative of the field of comparative psychology in Germany prior to the middle of the 20th century, both of its history and its demise.