Further Observations on the Blood Factor Di^a

Abstract

IN a previous communication¹ we remarked that the blood factor Di^a promised to be of great anthropological interest: it might prove to be a Mongoloid characteristic. Since then we have, on one hand, found it in a second northern Indian tribe—the Crees of northern Manitoba—three Di(a +) out of thirty-five, and on the other hand in none of thirty-five American Negroes, while Dr. Layrisse tells us that he has tested a number of Nigerians without finding any positive. It looked, indeed, as if Di^a were a Mongoloid ‘marker’, so it came as a surprise when we found no Di(a+) among 156 Eskimos.