Scientific exchange: Jacques Loeb (1859-1924) and Emil Godlewski (1875-1944) as representatives of a transatlantic developmental biology

The German-American physiologist Jacques Loeb (1859-1924) and the Polish embryologist Emil Godlewski, jr. (1875-1944) contributed many valuable works to the body of developmental biology. Jacques Loeb was world famous at the beginning of the twentieth century for his development and demonstration of artificial parthenogenesis in 1899 and his experiments on regeneration. He served as a role model for the younger Polish experimenter Emil Godlewski, who began his career as a researcher like Loeb at the Zoological Station in Naples. Following Godlewski's first visit to Naples in 1901 a close relationship between the two scientists developed. Until Loeb's death in 1924 the two exchanged ideas via correspondence that was only interrupted during the First World War. The aim of the paper is to examine the transatlantic transfer of knowledge in the field of biological experimentation that was fostered by these two protagonists. Using a modification of Bruno Latour's model of the 'Circulatory System of Science' as a heuristic tool, different mechanisms of scientific exchange are displayed. With the help of Loeb's and Godlewski's correspondence the role of scientific communities, methods, allies, the public and institutions in the process of knowledge transfer are analysed. Preconditions for success and failure in transferring science are examined.