In this work Dr. Bruce embodies the results of his researches on the pons and medulla, their various nuclei and tracts of fibres. The method employed was that of Weigert, or some of its modifications, and was applied to structures obtained from the human fótus from the fifth month up to the full time. It is well known that this method has already yielded most valuable information regarding the origin and course of many tracts in the cord and other parts of the nervous system, and in Dr. Bruce's hands, besides affording the material on which the illustrations are traced, it has been the means of his adding still further to our knowledge of these structures.