Descriptive anatomies have been the source of the misinformation that a theoretically normal body exists in which a definite type and relationship of organs are found and deviations from which have been described in footnotes as anomalies or abnormalities. Until comparatively recent years, students have attempted to find in the living the same topographic relationships as were found in the cadaver. The bodies used as the basis for descriptive anatomic studies were usually well developed, muscular ones which, in a measure, fitted in with the types previously described. Professors of anatomy require clear-cut anatomic material to serve best for their lectures and illustrations.
The necessity for recognition of various normal types of the genus Homo, each differing from the other in certain major features, is now quite apparent.
The use of the x-rays in studying the skeleton, body cavities, viscera, positions and organic relationships has revealed many marked deviations from