Impending famine and a terrifying rate of consumption of natural resources are vital issues which have focussed public interest in the ecologic, social and political problems of ever increasing overpopulation in many countries of the world. As well as the vast material and intellectual expenditure lavished on family planning and birth control, the past decade has seen an immense research effort in the elaboration of improved methods of fertility control, both for men and for women. During the same period, however, research into the causes of male fertility disorders has proceeded with equal...