1. Department of Obstetrics and Gynecology (A.-R.F.), Cornell University Medical College, New York, New York 10021
2. Département d’Ontogénie et Reproduction, Centre de Reserche du Centre Hospitalier de l’Université Laval, Centre de Recherche en Biologie de la Reproduction (P.D., M.A.F.), Ste Foy, Quebec, Canada
3. Institute for Hormone and Fertility Research (M.B.), Hamburg, Germany
4. Animal Science Department, University of Florida (M.J.F.), Gainesville, Florida 32611