Early in 1963 WHO convened a Scientific Group to report on the present state of knowledge of the biology of human reproduction, to indicate gaps in that knowledge, and to make recommendations. Professor Parkes acted as consultant and the Group met in Geneva in April 1963 under the Chairmanship of Professor G. W. Harris of Oxford, with Dr R. O. Greep of Boston and Professor Caldeyro-Barcia of Montevideo as rapporteurs. Russia, India and Japan were also represented.After nearly a week of almost continuous work the Group reported and among its many recommendations was one urging that WHO should convene a series of more specialist Scientific Groups to consider and report on specific aspects of the subject. Since that time, ten Scientific Groups have met in Geneva, the latest one in WHO's magnificent new building near the Palais des Nations. The earlier groups all dealt with matters of basic biology bearing on human reproduction, but later ones dealt progressively with more applied matters ; the last three Groups dealt with the three main methods of fertility control involving matters of biological principle.