He studied medicine and natural sciences in Berlin, where one of his instructors was Heinrich Wilhelm Waldeyer (1835–1921).
In 1898–1900 he participated in the Nyassa- und Kingagebirgs Expedition to the southern part of the colony, where he conducted anthropological and ethnographic research.
In 1930 he succeeded Bernhard Nocht (1857–1945) as director of the Hamburg Institute for Marine and Tropical Diseases, a position he maintained until his death in 1933.
During his career he took several tropical medical study trips to India, East Asia, the West Indies, etc.
[1] While working with dogs in Hamburg, he described "autoinfection" and discovered the migratory route taken by the parasite Strongyloides stercoralis prior to ending up in the intestine.