1859 studies of science (especially physiology and chemistry) at Heidelberg; 1862 doctorate; move from natural sciences to medicine and studies in Paris with Claude Bernard and Charles-Adolphe Wurtz, later in Berlin, Vienna and Bonn; 1865 qualification as a lecturer in zoophysics and zoochemistry in the Faculty of Philosophy in Bonn; 1866 medical degree at Bonn; in 1867 qualification as a teacher of physiology at the Faculty of Medicine of the University of Jena; 1869 professor of physiology at Jena in succession to Johann Nepomuk Czermak and appointment as director of the Physiology Institute; 1888 retirement and for the rest of his life private scholar in Wiesbaden.