Many of the studies discussed in this book were addition to discussions of a variety of hormonal, presented at the First Pan American Congress of biochemical, immunological, physical, and me- Andrology, which was held in Caracas, Venezuela, chanical approaches. It is our hope that the efforts in March 1979. An international group of in- of the contributors will help to intensify research vestigators have contributed reviews designed to and development of improved methods for safely be informative to medical, graduate, and post- regulating male fertility. graduate students, as well as...