Caption

Jacques Loeb (1859-1924), German-US physiologist, in a laboratory. Loeb held several professorships before becoming a member of the Rockefeller Institute for Medical Research in 1910. Loeb researched simple plant and animal reactions (tropisms) towards or away from stimuli, such as light or gravity. He argued that such behaviour could also be applied to higher animals and that even humanity's morals and ethics were due to combinations of tropisms. His experiments at the Woods Hole Marine Biological Laboratory on marine invertebrates achieved artificial parthenogenesis of sea urchin eggs. Photographed in 1907.