not blindly, preserved, if the future of the race is to be guarded.
Inbreeding, which is frequently confused with incest, is a radically different matter, although in particular cases the two conditions may overlap. The union of cousins is inbreeding, and may be incest, but the reasons for prohibiting it as incest have nothing to do with the biological results of the inbreeding. The popular notion that the incest-convention has grown up as a result of observation of the evil effects of inbreeding, or through an “unconscious” knowledge of such evil effects is entirely fallacious. The justification, moreover, of an outworn incest-convention of this sort, through an appeal to the supposed evil effects of inbreeding, is without proper foundation.
It is now well known that inbreeding has in itself no evil effects. Stocks do not deteriorate through consanguineous marriages, but strong points as well as points of weakness are accentuated. Feeble-mindedness furnishes a good illustration of the results of breeding. Some of the progeny of the union of a sound and a feeble-minded parent, will be sound: but they carry in their germ-cells the “determinant” of feeble-mindedness, and transmit it to a certain proportion of their own progeny. If two persons, both of whom carry this determinant, mate, the charac-
