The attempt to simplify for the student the vast complexity of modern medicine by the monographic method receives a notable addition in Dr. Williams' book on streptococci. For years a thorough student of bacteriologic problems and always on the firing line in the battle against disease, she assembles here a great storehouse of knowledge on all matters pertaining to this ubiquitous and treacherous group of micro-organisms. In matters dealing primarily with the biologic aspects of the problem, Dr. Williams writes with authority and confidence; her personal interpretations are both stimulating and convincing. But the sections dealing with clinical relations — applied bacteriology, if you will — lack, perhaps, a little of the spontaneity of the earlier chapters. The author has achieved the purpose, to be sure, of assembling all the important information, but here there is more the atmosphere of a compendium. The important questions (to the clinician) of focal