A considerable amount of new and significant data concerning bacillary dysentery has accumulated during the last fifteen years. The need for a review of these accretions is clearly indicated by the fact that relatively little of it has been put to use for the furtherance of the medical and public health aspects of dysentery. A report like this one can obviously not be a substitute for an up-to-date and comprehensive presentation of the whole subject—a presentation that would be highly desirable to possess. The outstanding monograph by Manson-Bahr (1) is written with emphasis on the peculiarities of dysentery in tropical countries. The compilations in the (English) “System of Bacteriology” (2) and in the “Handbuch der pathogenen Mikrorganismen” (3) are obviously not any more up-to-date. Many aspects of our subject are covered in the monographs by Bojlen (4) and by Waaler (5), but neither of these is easily accessible.