married only for a part of each week. Of these genera and species of families, those varieties which are found in advanced societies are the most coherent, most definite, most complex. Not to dwell on intermediate types, we see, on contrasting with the primitive kind of family group that highest kind of family group which civilized peoples present, how relatively high is its degree of evolution. The marital relation has become perfectly definite; it has become extremely coherent—commonly lasting for life; in its initial form of parents and children it has grown larger—the number of children reared by savages being comparatively small; in its derived form, comprehending grandchildren, great-grandchildren, etc., all so connected as to form a definable cluster, it has grown relatively large; and this large cluster consists of members whose relationships are very heterogeneous.
Again, the developing human family fulfills, in increasing degrees, those traits which we saw at the outset are traits of the successively higher forms of reproductive arrangements throughout the animal kingdom. Maintenance of species being the end to which maintenance of individual lives is necessarily subordinated, we find, as we ascend in the scale of being, a diminishing sacrifice of individual lives in the achievement of this end; and, as we ascend through the successive grades of societies with their successive grades of family, we find a further progress in the same direction. Human races of the lower types, as compared with those of the higher, show us a greater sacrifice of the adult individual to the species; alike in the brevity of that stage which precedes reproduction, in the relatively heavy tax entailed by the rearing of children under the conditions of savage life, and in the abridgment of the period that follows: women especially, early bearing children and exhausted by the toils of maternity, having a premature old age soon cut short. In superior family types there is also less sacrifice of juvenile life: infanticide, which in the poverty-stricken groups of primitive men is dictated by the necessities of social self-preservation, becomes rarer; and juvenile mortality otherwise caused decreases at the same time. Further, along with the diminishing sacrifice of adult life, there goes an increasing compensation for the sacrifice that has to be made: more prolonged and higher pleasures are taken in rearing progeny. Instead of states in which children are early left to provide for themselves, or in which, as among Bushmen, fathers and sons quarreling try to kill one another, or in which, as Burton says of the East Africans, "when childhood is past, the father and son become natural enemies, after the manner of wild beasts," there comes a state in which keen interest in the welfare of children extends throughout parental life. And then to this pleasurable care of offspring, increasing in duration as the family develops, has to be added an entirely new factor—the reciprocal pleasurable care of parents by offspring: a factor which,
