Among Japnaese the high rate of 9603% show the-Mongolian-Fleck This fleck has been. considered as-characteristic solely of the Mongolian race, and it has-therefore been calle M ngolian Fieck Upon furhur study it has been found among other races. Now it isc onsidered not as characteristic to any one race, but as appearing in all races to a larger or smaller percent. The authors having been delegated to investigate the Mongolian Fleck among Ainu, by the Nihon Gakujitsu Shinko. Kai, (Japan Society for the Encouragement of Science) went in July, Showa. 9 c1934) and 10 (1935), to Hidaka, Iburi and Tokachi and examined 257 nursing infants for the presence, form and other features of the Mongolian Fleck. The results of the investigation are as follows - I. Presence of fleck in pure blood Ainu 46.24%. A-nong mixed blood 14.64%. II. The numler of flecks per individual, found in mixel blood infants is greater than in pure plood Ainu. III. That the fleck or flecks occurs in flaces other than the back re ion more frequently among mixed blood than among pure blood Aiuu.