More than this: some writers, especially zoologists, have maintained that there is not merely dualism but _antagonism_. When the feelings of domestic life are strong, social solidarity is lax or non-existent. When social solidarity is close and rigorous, the family tendencies are transitory, effaced, or _nil_—_e.g._, in ants and bees. The case of the Australian birds shows us this antagonism in an alternating form, the domestic and the social tendency predominating by turns. No doubt this antagonism is not irremediable and is compatible with various modifications and compromises; but there is, in fact, a dualism not to be explained away. I shall return later on to this question, only remarking in anticipation that the dualist view seems to me the only admissible one. IV. The higher societies are those in which the animal world has attained its loftiest degree of social development. In them we find division of labour, solidarity, stability, and continuity through several generations. Such are bees, wasps, ants, termites, beavers, etc. It is not part of our subject to study them, since our only aim is to follow the social tendencies to their highest point; but the problem already suggested again arises: On what foundation do these higher societies rest? Espinas, who admits the view of the family as the source of social life, classes them among societies having reproduction for their purpose. For my own part, I refer them to the gregarious state, in which they mark the stage of the highest perfection. Let me take this opportunity of pointing out the inconveniences of a false position and the factitious difficulties arising from it. The author draws out (pp. 370 _et seq._) a detailed comparison between the societies of bees and those of ants; he demonstrates the superiority of the latter, who, according to circumstances, dig, carve, build, hunt, store up food, reap harvests, keep slaves and cattle, and when they carry on war against the wasps (the warlike representatives of the bees) gain the victory. He also clearly shows that this superiority is due to their terrestrial habits, in which every contact, every march, leaves them a precise indication of the nature of their surroundings. But he finds something perplexing in this superiority. As a matter of fact, a hive is a perfect domestic society, since the queen-bee—_i.e._, the common mother—is the visible soul of social life among the bees. An ant-heap is imperfect, “inferior” as a domestic society, as containing several females. The apparent contradiction disappears, if we consider that in both cases, especially in the second, the essential element is the solidarity among the members, the mutual attraction between similar beings, and that, consequently, we must refer them to the gregarious, and not to the domestic type. For the rest, in neither case does the family, in the true sense of the word, exist: it is needless to demonstrate this at length, it is