sentences:  Other important influences to his career were immunologist Paul Ehrlich at the Institute for Experimental Therapy in Frankfurt (1901) and zoologist Richard von Hertwig at the University of Munich.With radiologist Ludwig Halberstädter, he described the inclusion bodies (Halberstädter-Prowazek bodies) of "Chlamydia trachomatis", the agent that is the cause of trachoma.In 1906 he succeeded his late friend, Fritz Schaudinn, as director of the zoological section at the Institut für Schiffs- und Tropenkrankheiten in Hamburg.