Charles Darwin, in his work "The Variations of Animals and Plants Under Domestication,"1mentioned a communication from Wedderburn, wherein he described 10 men of a Hindoo family with little hair on the body, early baldness, partial anodontia and excessive dryness of the skin in hot weather. He observed that this anomalous condition did not occur in the female members of the family but was transmitted to males by healthy female conductors. Wedderburn reported this case in 1838. In 1848 Thurman2described 2 similar cases, and in 1883 Guilford3reported another. The total number of cases of hereditary ectodermal dysplasia known is difficult to estimate. Lord and Wolfe4(1938) collected about 40 cases from the literature. De Silva5(1939) mentioned 48 cases, excluding the Hindoo cases of Wedderburn (10) and the cases reported by Thadani6(2) in 1921. Clouston7(1939) dif