Sylvia J. BedfordDepartment of Clinical Studies, School of Medicine and Reproduction, University of Pennsylvania, New Bolton Center, Kennett Square, PA 19348. Present address: Department of Veterinary and Animal Sciences, Paige Laboratory, University of Massachusetts, Amherst, MA 01003.
Sue M. McDonnellDepartment of Clinical Studies, School of Medicine and Reproduction, University of Pennsylvania, New Bolton Center, Kennett Square, PA 19348.