I am prepared to predict that this monograph by Dr. Ernest Beutler will long serve as a model for monographs dealing with topics in medical science. I make this bold statement because we encounter in this work a degree of accuracy and authoritativeness well beyond that found in much of the medical literature. Too often, a monograph is simply a review of past reviews. The preparation of an exhaustive and completely accurate study such as the present one is a very laborious task; consequently, many authors make extensive use of the reviews of earlier writers assum­ ing that the latter have checked and evaluated each previously published report. Unfortunately, however, this assumption of validity has not al­ ways been correct. Dr. Beutler, who is a world authority on the subject about which he writes, was determined to make this book as correct and complete as possible, and, to this end, has checked all the original sources. Nowhere else will such an exhaustive bibliography be found. Moreover, he has also undertaken to reevaluate in the light of current knowledge material pub­ lished in earlier days. This he is eminently able to do, and in some in­ stances his investigations have resulted in new interpretations. The result is a volume that will be recognized as truly the last word on this important subject.