There is even a certain scientific interest about investigations into Jewish phenomena. Thus the question about the purity of the Jewish race, on which so much has been written of recent years, has a direct bearing on the opposition noticed by the late Sir Francis Galton, between the nature and the nurture of men. In other words, does birth or training deter mine human characteristics? The Jews throw light upon this subject whether they are a distinctive race or not. If they are, their common Characteristics shown in such different parts of the world is evidence of the in?uence of breed or nature. If they are not, the same characteristics prove the in?uence of nurture, education or environment. Jewish characteristics have even been made the subject of discussion in the struggle now going on between the Mendelians and the Biometricians. The former assert, the latter deny, that Jewish features are hereditable in mixed marriages, according to the Mendelian Law.