The incidence of syphilis in various communities has been the subject of some study and much speculation. Groups of individuals have been examined by different observers, and the incidence of the disease in these groups has been assumed to indicate its prevalence in the community. It is evident, however, to all who examine such group studies that the groups observed are not truly representative of the entire community and that any estimates based on them are consequently open to criticism. As recently as December, 1920, the All-America Conference on Venereal Disease concluded that "no reliable statistics are available at the present time"; this applies equally to the hereditary as well as the acquired form of the disease. Several estimates have been made of the incidence of hereditary syphilis based on group studies,1 but none is based on observations that render it applicable to the general population. To illustrate some