This revision of Dr. Wintrobe's excellent treatise brings the subject of hematology fully up to date. However, the greatest feature of the book is its really comprehensive handling of the subject. The introductory chapters on the blood and the blood cells are obviously from the pen of an authority who has done original work in the field. The discussions of disease are satisfying and deal in a critical way with the many intriguing problems of pathogenesis. There are innumerable excellent drawings and charts, and each chapter is followed by a really full bibliography. It is a comparable work from the standpoint of thoroughness and scholarship.