Does it accord with geographical probability to derive our large dark area of present Jewish aggregation entirely from the small secondary one about Frankfort, which, as we have just said, is the relic of a mediæval center of gravity? The question is a crucial one for the alleged purity of the Russian Jew; for the longer his migrations over the face of the map, the greater his chance of ethnic intermixture. A moot point among Jewish scholars is, as to the extent of this exodus from Germany into Poland. Bershadski has done much to show its real proportions in history. Talko-Hryncewicz[6] and Weissenberg,[7] among anthropologists, seem to be inclined to derive this great body of Polish Jews from Palestine by way of the Rhone-Rhine-Frankfort route. They are, no doubt, partially in the right; but the mere geographer would rather be inclined to side with Jacques.[8] He doubts whether entirely artificial causes, even mediæval persecutions, would be quite competent for so large a contract. There is certainly some truth in Harkavy's theory, so ably championed by Ikof (1884), that a goodly proportion of these Jews came into Poland by a direct route from the East. Most Jewish scholars had placed their first appearance in southern and eastern Russia, coming around the Black Sea, as early as the eighth century. Ikof, however, finds them in the Caucasus and Armenia one or two centuries before Christ. Then he follows them around, reaching Ruthenia in the tenth and eleventh centuries, arriving in Poland from the twelfth to the fourteenth. The only difficulty with this theory is, of course, that it leaves the language of the Polish Jews out of consideration. This is, in both Poland and Galicia, a corrupted form of German, which in itself would seem to indicate a western origin. On the other hand, the probabilities, judging from our graphic representation, would certainly emphasize the theory of a more general eastern immigration directly from Palestine north of the Black and Caspian Seas. The only remaining mode of accounting for the large center of gravity in Russia is to trace it to widespread conversions, as the historic one of the Khozars. Whichever one of these theories be correct--and there is probability of an equal division of truth among them all--enough has been said to lead us geographically to suspect the alleged purity of descent of the Ashkenazim Jew. Let us apply the tests of physical anthropology.