first condition is more or less vaguely recognized, though the voluntary present is commuted into, or replaced by, a negotiated value exacted by the girl’s family, when the mother-descent is commonly vestigial; and in the next stage, which is abundantly exemplified, wife-purchase prevails, and the clan is replaced by the gens. In this succession the development of wife-purchase and the decadence of mother-descent maybe traced, and it is significant that there is a tendency first toward partial enslavement of the wife and later toward the multiplication of wives to the limit of the husband’s means, and toward transforming all, or all but one, of the wives into menials. Thus the lines of development under militant and civil conditions are essentially parallel. It is possible to project these lines some distance backward into the unknown, of the exceedingly primitive, when they, are found to define small discrete bodies—just such as are indicated by the institutional and linguistic lines—probably family groups, which must have been essentially, and were perhaps strictly, monogamous. It would appear that in these groups mating was either between distant members (under a law of attraction toward the remote and repulsion from the near, which is shared by mankind and the higher animals), or the result of accidental meeting between nubile members of different groups; that in the second case and sometimes in the first the conjugation produced a new monogamic family; and that sometimes in the first case (and possibly in the second) the new group retained a more or less definite connection with the parent group—this connection constituting the germ of the clan. In passing, it may be noted merely that this inferential origin of the lines of institutional development is in accord with the habits of certain higher and incipiently organized animals. From this hypothetic beginning, primitive marriage may be traced through the various observed stages of monogamy and polygamy and concubinage and wife-subordination, through savagery and barbarism and into civilization, with its curious combination of exoteric monogamy and esoteric promiscuity. Fortunately the burden of the proof of this evolution does not now rest wholly on the evidence obtained among the American aborigines; for Westermarck has recently reviewed the records of observation among the primitive peoples of many lands, and has found traces of the same sequence in all.(58) Thus the evolution of marriage, like that of other human institutions, is from the simple and definite to the complex and variable; i.e., from approximate or complete monogamy through polygamy to a mixed status of undetermined signification; or from the mechanical to the spontaneous; or from the involuntary to the voluntary; or from the provincial to the cosmopolitan.