Dr. Pearl offers here an expansion of a lecture given in 1933 at the Army Medical Center. In this statement Dr. Pearl indicates the present point of view of the relationship of constitution to health. He points out that the constitution of the individual may change during life, listing some of the studies that have been made on the relationship of body form to health and disease. His conclusion is rather striking—namely, that a careful statistical examination of rather accurate, if not very extensive, material does not yield evidence of any very marked or striking association between bodily habitus and general health. He points out that we are only at the beginning of any real knowledge in this field and that many vast statistical studies are necessary before any definite conclusions can be drawn.