The human race is setting itself some formidable problems by both increasing at an unprecedented rate and raising its living standards at an even faster rate. Have we the resources to feed, house, clothe, let alone provide leisure and culture, for all? What, for example, are the untapped food resources of the sea, of rivers and lakes, of wildlife? Nobody knows. The task of the International Biological Programme is to find the answers. Dr. Worthington, deputy director of the Nature Conservancy, and scientific director designate of the IBP, explains the task, and outlines the methods.