Those who prepared the "flyers" for this book on blood diseases did not exaggerate when they described it as a "complete, yet concise and practical guide. . . ." They might also have claimed it to be a "must" for the library of every physician caring for mothers, infants and children; for such physicians must know what the normal state of the blood of the patient should be, before they can consider the abnormal, and sooner or later they will encounter one or another of the diseases or pathologic states discussed in this book.