Byron H. Waksman, M.D., teaches at New York University Medical Center and is a part-time volunteer teacher at the Salk School of Science. After successive stints as an academic microbiologist and immunologist at Harvard and Yale and as director of research and medical programs of the National Multiple Sclerosis Society, he developed laboratory-education programs for science journalists. Address: Department of Pathology, NYU Medical Center, New York, NY 10016. Internet: bhw1@is2.nyu.edu..nyu.edu.