and those of primeval man. But mutual tolerance of the grown males, freedom from jealousy, was the first condition for the formation of such large and permanent groups, within which alone the transformation from beast to man could be accomplished. And indeed, what do we find to be the most ancient and original form of the family, undeniably traceable by history and even found to-day here and there? The group marriage, that form in which whole groups of men and whole groups of women mutually belong to one another, leaving only small scope for jealousy. And furthermore we find at a later stage the exceptional form of polyandry which still more supersedes all sentiments of jealousy and hence is unknown to animals. But all the forms of the group marriage known to us are accompanied by such peculiarly complicated circumstances that they of necessity point to a preceding simpler form of sexual intercourse and, hence, in the last instance to a period of unrestricted sexual intercourse corresponding to a transition from the animal to man. Therefore the references to animal marriages lead us back to precisely that point, from which they were intended to remove us forever. What does the term "unrestricted sexual intercourse" mean? Simply, that the restrictions in force now were not observed formerly. We have already seen the barrier of jealousy falling. If anything is certain, it is that jealousy is developed at a comparatively late stage. The same is true of incest. Not only brother and sister were originally man and wife, but also the sexual intercourse between parents and children is permitted to this day among many nations. Bancroft testifies to the truth of this among the Kaviats of the Behring Strait, the Kadiaks of Alaska, the Tinnehs in the interior of British North America; Letourneau compiled reports of the same fact in regard to the Chippeway Indians, the Coocoos in Chile, the Caribeans, the Carens in Indo-China, not to mention the tales of ancient Greeks and Romans about the Parthians, Persians, Scythians, Huns and so forth. Before incest was invented (and it is an invention, a really valuable one indeed), sexual intercourse between parents and children could not be any more repulsive than between other persons belonging to different generations, which takes place even in our day among the most narrow-minded nations without causing any horror. Even old "maids" of more than sixty years sometimes, if they are rich enough, marry young men of about thirty. Eliminating from the primeval forms of the family known to us those conceptions of incest--conceptions totally different from ours and often enough in direct contradiction with them--we arrive at a form of sexual intercourse that can only be designated as unrestricted. Unrestricted in the sense that the barriers drawn later on by custom did not yet exist. This in no way necessarily implies for practical purposes an injudicious pell-mell intercourse.