1874 12 p. 2 (1 folded) lithographed pls, disbound (no covers). Plates with minor scattered foxing. Unopened copy. Published in: Sitzungsberichte der Kaiserlichen Akademie der Wissenschaften. Scarce.In March 1876 Sigmund Freud, a promising young scientist, was awarded a travel grant to pursue a between-semesters research project at the university's zoological research station at Trieste, Italy. His task was to identify the testes of the eel (the so-called Syrski organ described in this paper). He dissected and studied under the microscope 400 eels during the spring of 1876, trying to confirm Syrski's suggestion that a certain small-lobed organ found in immature males (no one had ever found a mature male!) was the missing testes. His analysis of the organ 's structure tended to support Syrski's idea, but he was disappointed that his results were not more conclusive. His professors, however, appreciating his cautious and thorough approach, were favorably impressed. They thought the young biologist would go far.