The instinctive desires of woman are monogamous. The progress of civilization is continually extending her rights, and the more refined sentiments of sympathy among civilized people are less and less compatible with polygamy. As regards polyandry, Westermark shows that it has always been an exception and that it has only been established among phlegmatic races, having a certain degree of civilization and being unacquainted with jealousy. Spencer believes that monogamy will prevail in the future, while Lubbock inclines to polygamy. Westermark thinks that if the progress of civilization continues as hitherto to become more altruistic, and that if love tends to become more refined, the conjoints having more and more regard for each other, monogamy will always become more strict. For my part, I think it idle to prophesy. If mental culture ever succeeds in overcoming brutality and barbarism, and if it continues to make real progress, I do not think that any of the old systems of marriage will persist in their primary form. Primitive monogamy adapted to an unsocial savage condition, is incompatible with the social requirements which become more and more imposed upon humanity. Marriage by purchase and Islamite polygamy, which regard woman as merchandise and place her entirely under the dependence of man, are barbarous customs of semi-civilized people, which have already fallen into disuse. Polyandry is contrary to human nature and to the requirements of reproduction, and its implantation is everywhere a sign of decadence. Our present religious monogamy, completed by the shameful promiscuity of prostitution, is both hypocritical and unhealthy. Till the contrary is proved, I consider the most advantageous form of marriage for the future a kind of free monogamy (eventually polygamy), accompanied by obligations relative to the procreation of children and to the children procreated. Polyandry should only have an accessory right to existence in certain pathological or exceptional cases. We shall return to this point later. DURATION OF MARRIAGE Among birds, marriage is generally concluded for life; among mammals rarely for more than a year, with the exception of the anthropoid apes and man. The duration of marriage varies enormously in man. Among the Andamanese, the Weddas, certain Papous, marriage can only cease with death. Among the North American Indians, on the contrary, it is only concluded for a limited period. Among the Wyandottes the custom exists of trial marriages for several days. In Greenland, divorce often takes place at the end of six months. Among the Creeks marriage does not last more than a year. In this way is constituted a kind of polygamy by succession or limited monogamy, which results in the father not knowing his children.