After all, I must insist that it is to history one must go to determine a question of this sort. Jews have shown such marked individuality throughout their career for the last two thousand years among the nations--they have been so much in the world's eye throughout that time--that any appreciable degree of intermarriage would not have escaped notice, both by themselves and by their enemies. Now there is practically no evidence of this kind during the Christian era. Religious antipathy has been so strong throughout that period as to form an almost insurmountable barrier to intermarriage and the consequent proselytism to Judaism which is necessary for a valid Jewish marriage. Sporadic cases doubtless occur, but their very infrequency drew attention to them, and all that historical research can discover is under one hundred cases throughout the middle ages, scattered through Europe. Jewish nomenclature has special formulæ to name the proselyte, and yet, though we have hundreds of the mediæval lists of Jewish communities and martyrologies, it is the rarest thing in the world to find one of these names referred to as "sons (or daughters) of Abraham our father." In earlier days, doctors of the Talmud, when discussing hypothetical cases, dismissed that of the proselyte as being so rare.[12] In my Memoir in the Journal of the Anthropological Institute for 1885 I have taken the marriage statistics of modern Algeria as most nearly representing the most favorable conditions that one could imagine at any time during the middle ages, and have found that during nearly half a century (1830-'77) there were only thirty mixed marriages out of an average population of twenty-five thousand Jews--not one a year. The only instances of proselytism on a large scale are those of the Chozars in southern Russia, converted to Judaism in the eighth century, and the Falashas of Abyssinia, about the same time. Yet these are an indirect proof, by the method of difference, of the comparatively pure descent of the rest of the Jews, for neither the Karaites, who are the descendants of the Chozars, nor the Falashas show any of the characteristic Jewish features or expression. [Footnote 12: Babylonian Talmud, Gittin, 85a.]