RONALD RAINGER is an assistant professor of history at Texas Tech University. He has published a number of articles on the history of anthropology and paleontology and is the author of An Agenda for Antiquity: Henry Fairfield Osborn and Vertebrate Paleontology at the American Museum of Natural History, 1890–1935. KEITH R. BENSON is an associate professor of medical history and ethics at the University of Washington. He has published papers on biology at Johns Hopkins University, the American natural history tradition, and the history of marine biology. JANE MAIENSCHEIN is a professor of philosophy and zoology at Arizona State University. She is the editor of Defining Biology: Lectures from the 1890's and has recently completed Transforming Traditions in American Biology, 1880–1915.