Masson's ammonia ted (reduced) silver nitrate technic (1) has been used in studies of the process of melanization. By this method Zimmermann and Becker (2) demonstrated the existence of premelanin in melanoblasts from 10 week old human fetuses. The term premelanin is defined, on the basis of the staining reaction using this method, as the substance of granules which has “a specific affinity for reduced silver but can not be impregnated with ordinary silver nitrate';. Mature melanin has the property of reducing silver nitrate directly. In the perikaryon of the sole and palm melanocyte Masson (1) had earlier described similar granules which reacted only with reduced silver nitrate but which, during migration into the dendritic processes of the cell, became mature melanin. Recently, Mishima (3) has combined the dopa reaction with Masson's method to reveal the sites of melanization more comprehensively in the weakly reacting nevus cell.