is no sound evidence in favor of primitive promiscuity, and that at the present day there are few, if any, savage peoples living in genuine unrestricted sexual promiscuity.  This theory of a primitive promiscuity seems to have been suggested, as J.A.  Godfrey has pointed out (Science of Sex, p. 112), by the existence in civilized societies of promiscuous prostitution, though this kind of promiscuity was really the result, rather than the origin, of marriage.  On the other hand, it can scarcely be said that there is any convincing evidence of primitive strict monogamy beyond the assumption that early man continued the sexual habits of the anthropoid apes.  It would seem probable, however, that the great forward step involved in passing from ape to man was associated with a change in sexual habits involving the temporary adoption of a more complex system than monogamy.  It is difficult to see in what other social field than that of sex primitive man could find exercise for the developing intellectual and moral aptitudes, the subtle distinctions and moral restraints, which the strict monogamy practiced by animals could afford no scope for.  It is also equally difficult to see on what basis other than that of a more closely associated sexual system the combined and harmonious efforts needed for social progress could have developed.  It is probable that at least one of the motives for exogamy, or marriage outside the group, is (as was probably first pointed out by St. Augustine in his De Civitate Dei) the need of creating a larger social circle, and so facilitating social activities and progress.  Exactly the same end is effected by a complex marriage system binding a large number of people together by common interests.  The strictly small and confined monogamic family, however excellently it subserved the interests of the offspring, contained no promise of a wider social progress.  We see this among both ants and bees, who of all animals, have attained the highest social organization; their progress was only possible through a profound modification of the systems of sexual relationship.  As Espinas said many years ago (in his suggestive work, Des Societes Animales):  “The cohesion of the family and the probabilities for the birth of societies are inverse.”  Or, as Schurtz more recently pointed out, although individual marriage has prevailed more or less from the first, early social institutions, early ideas and early religion involved sexual customs which modified a strict monogamy.

The most primitive form of complex human marriage which has yet been demonstrated as still in existence is what is called group-marriage, in which all the women of one class are regarded as the actual, or at all events potential, wives of all the men in another class.  This has been observed among some central Australian tribes, a people as primitive and as secluded from external influence as could well be found, and there is evidence to