The study of individuals and families that may show various manifestations of mental and nervous degeneracy not infrequently discloses the existence of constitutional disorders that are direct or indirect causes of these.
These constitutional disorders appear sometimes as peculiar defects or abnormalities of body structures that tend to be transmitted through the family. Numerous instances of these are recorded in the literature dealing with problems of heredity. These are in most instances treated rather more from the point of view of being specific unit qualities that are transmitted than as the results of a more general inherent deficiency of organs whose healthy functioning is essential for determining normal development and successful adaptation to the requirements of life.
Recently we have had the opportunity of studying a family that for generations had shown among its members peculiar trophic disorders of the nails and hair, and various abnormalities of a mental or