The organization of heart societies has stimulated greatly the effort toward a more thorough understanding of the heart and its diseases. Many important facts have been revealed and a mass of interesting statistics have been recorded. Much of this new knowledge, together with previously existing facts, has been scattered through the literature and has been badly in need of correlation and systematic presentation. It is this need that the author has undertaken to fill. His object, as he states it is: "... a summary of studies which have occupied over twenty years, both for the help of those who would like to know how the matter stands at the present day, and also perhaps for the guidance of some who would like to investigate all the as yet unexplored areas of this field of medicine." In general, the aim of the author is adequately accomplished.
The book is well organized and