This extraordinarily interesting volume on blood transfusion is the work of an authority in this field. As he says, "Within the past twelve years the sum total of new knowledge which has been derived from the practice of blood transfusion has been remarkable. In the United States the discoveries of Landsteiner, Levine, and Wiener laid the foundations for a swift and astonishing expansion of the subject of blood groups." Dr. Mollison has been responsible for many of the recent developments. He has contributed much to both the testing of new preservative solutions and the fundamental research dealing with the storage of red blood cells. The author, since the end of the war, has been director of the Blood Transfusion Research Unit set up by the British Medical Research Council. There are 13 chapters, covering all aspects of blood transfusion. The bibliography is excellent, and the index is satisfactory. Because of