Affiliations Courses Research 1924[position unknown]Columbia University1925Assistant In ZoologyColumbia University1926Assistant In ZoologyColumbia University1927National Research FellowColumbia University1928[position unknown]Columbia University1929National Research FellowColumbia University1930Research AssistantCarnegie Institution Of Washington1931InvestigatorCarnegie Institution Of Washington 1924Protozoology 1924Student 1925Zoology[role unknown]1926Zoology[role unknown]1927[subject unknown][role unknown]1928[subject unknown][role unknown]1929[subject unknown][role unknown]1930[subject unknown][role unknown]1931[subject unknown]Independent