Mr. Darwin, in the foregoing sentences, affirms the improbability of Promiscuity in the Sexual Relations of Man during the Animal Stage, and, incidentally, the Unity of the Human Race in its origin. Both theories are contested. The following thesis, however, on the Genesis of Primal Law in Human Marriage, treats of a _conjectural_ series of events in the Ascent of Man, events which involve a state of the inter-sexual relationships amidst our primitive ancestors identical with that portrayed in the _Descent of Man_. My essay includes further, as regards the continued evolution of society, the development of a theory, based on my ‘Primal Law,’ which, if correct, would seem also to confirm Mr. Darwin’s ideas as to Unity of Origin. I am content, for my part, to hope that my hypothesis, however novel some of its conclusions, is in its general tenor in accord with the views of so great a naturalist as Mr. Darwin. His exposition of the probable relations, within the family group, of the male and female prototypes of mankind, and more especially of the antagonistic attitude, inter se, of the older and younger males, is indeed literally prophetic of the Primal Law, whose existence I surmise. This law is the inevitable corollary of Mr. Darwin’s statement, if Man was ever to emerge from the Brute. My theory, in fact, viewed as to its genesis, is simply evolved from a consideration of the potential results of the attitude of such creatures as our ancestors then were, when subjected to the effects of those changes of environment, which alone, to my deeming, could have fixed modifications towards the human type. Mr. Darwin’s premises, indeed, as to the Early Social economy of our Race in the animal stage, inevitably entail, if progress was to be made, the evolution of law in regulation of Marriage relationship, having regard to the fierce sexual jealousy of the males, on the one hand, and on the other to the patent truth that in the peaceful aggregation of our ancestors alone lay the germ of Society.