This is an unusual book in both concept and presentation. The first half presents the problem of autoimmune hemolytic anemias in a clinical perspective. Material from the vast literature is interwoven with a very substantial personal clinical experience, more than 200 cases, that the author observed during an eight-year period. With this material he tries to formulate a number of the still-unresolved problems presented by this disease: those of classification, relationship to other so-called autoimmune processes and to other underlying diseases, and, most importantly, the fundamental mechanisms of autoimmunization itself. The clinical material, some presented in summaries but much of it in selected illustrative brief case reports, is of real interest to students of this problem. These data add convincingly to the growing conviction that autoimmune hemolytic anemia is not a homogeneous clinical entity, a view which the author of this book has long advocated. In the second portion of