Constitutional schemata have been of continuing interest in medicine and psychology ever since the time of Hippocrates. With the work of Sheldon, Stevens and Tucker (5, 6), biotypology has been placed on a new basis. The reader who wishes to orient himself quickly and without too much detail, to the subject matter of typology, will find an interesting and substantial review by Anastasi (1). Wertheimer and Hesketh (7) have produced a comprehensive, but brief, historical and analytic treatment of the constitutional approach in their rather short monograph on the subject. Hempel and Oppenehim (2) have examined the concept of psychological type in a novel fashion from the standpoint of modern logic and positivist philosophy. Typology has been of more interest to continental writers than to American writers. Numerous medical school dissertations at European universities attest to this fact. Medical and psychological literature on the subject is also more frequently of European or Latin American origin, than of United States origin, as a cursory glance at the Index Medicus (4) or the Surgeon General's Catalogue (3) will quickly reveal. The work of Sheldon has raised fresh theoretical considerations which we propose to outline to some extent in this paper and the above sources, we feel certain, will furnish sufficient orientation to those readers who come to this subject with little or no previous acquaintance with it. Before going any further the reader is urged to read Chapter V of the “Varieties of Human Physique” (5).