Hemoglobin and the red cell have continued to set a dizzying pace as the objects of research in the two and one-half year interval since the First International Conference on Red Cell Metabolism and Function. Most exciting perhaps, is a beginning molecular attack on sickle cell disease. The story of the inter­ action of red cell metabolism and oxygen transport has continued to unfold, and we can now infer that patients with hypoxia usually utilize red cell metabolic adjustments to improve oxygenation. This puts the red cell squarely in the center of medical practice, since much of medicine-heart, pulmonary, and blood disease- deals with inadequate oxygenation. On April 27th through the 29th, 1972, crystallographers, chemists, biochemists, physiologists, geneticists, and physi­ cians from many medical disciplines met in the Towsley Center for Continuing Medical Education at the University of Michigan, Ann Arbor to present new data, to review recent developments, and to try to piece together additional features of the red cell puzzle. The meeting was dedicated to Dr. Francis John Worsley Roughton, Professor Emeritus of Colloid Science, University of Cambridge, England, in recognition of his numerous excellent contributions to the understanding of hemoglobin and red cell function. The program got off to a good start with a paper from M. F. Perutz, Nobel Laureate, on the structure of hemoglobin. Dr.