There continue to be disagreements concerning the embryology of the ventric­ ular septum and the nomenclature of its various parts, as well as on its phylogenetic derivation. It must be obvious that until such time as these uncertainties have been resolved it will not be possible to understand the pathogenesis of ventricular septal defects and other anomalies involving the ventricular septum. In an effort to clarify some of these difficulties a number of individuals, including anatomists, embryologists, pathologists, cardiologists, and sur­ geons, all acknowledged experts in their respective fields of endeavor, were invited to present their views and concepts in sessions devoted to the ventric­ ular septum. In this "Boerhaave Course", detailed descriptions of the normal anatomy, embryology, and phylogeny of the septum were followed by papers on ventricular septal defects, atrioventricular defects, straddling valves, and various forms of univentricular heart. Major contributions were made through clinical accounts of these anomalies. This course again clearly demonstrated the value of and the need for a multidisciplinary approach to the recognition, understanding, diagnosis, and management of congenital cardiac disease. While obviously it could not be ex­ pected that all of the problems and uncertainties concerning the normal and abnormal ventricular septum would be resolved, the lively and frank dis­ cussions among all participants of the course undoubtedly contributed to a better understanding of the still existing difficulties. All ofthe contributors to this monograph should be congratulated for a job superbly well done.