In process of time, so Mr Atkinson suggests, with the lengthening childhood conditioned by the progress of the race, maternal love of a more enduring kind developed, than is found among the non-human species of the present day.  This led eventually to the presence of a young male, perhaps the youngest born of a given mother, being permitted to remain, on conditions, in the herd after he had attained maturity.  The original lord and master of the herd retained, Mr Atkinson supposes, his full sovereignty over the females born in the herd as well as over those whom his prowess had perhaps added to it from time to time.  The young male on the other hand was not condemned to a life of celibacy as a condition of his non-enforcement of the traditional decree of banishment.  He was permitted to find a mate, but she must be a mate not born in the herd, nor one of the harem of his sire; he had, if he wished to wed, to capture a spouse for himself from another herd.  For the detailed working out of this ingenious theory we must refer our readers to Mr Atkinson’s work, Primal Law.  Here it suffices to state the primal law which resulted from the process sketched above.  This primal law was “thou shalt not marry within the group.”  This law, at first enforced by the superior strength of the sire, came in the process of time to be a traditional rule of conduct, almost an instinct.  And with this we reach the theory put forward in Social Origins by Mr Andrew Lang, according to which local groups received animal names, perhaps from their neighbours.  These local groups being exogamous for the reason just given, and the group name being eventually[108] given, not only to the actual members of the group, but also to the women, captured or otherwise, who became the mates of the men of the adjoining groups, it necessarily resulted that the men of a group, so long as the mother’s group name did not descend to her children, were of one name, while their wives were of another, or more probably of many other names.  The group became definitely heterogeneous when the maternal group name descended to the children born in the alien group, and in process of time these maternal group names became totem names.

Meanwhile the original group names had been retained and applied, along with the totem or quasi-totem names, to the members of the group; the name being probably, in the first place, that of the group in which they were born, but, with the rise of the matrilineal descent, which has been discussed above, eventually taken from the group to which the mother belonged.

During these processes the custom had sprung up to select a wife, not at random from any of the probably more or less hostile surrounding groups, but from one particular group with which the group of the candidate for matrimony had in the course of time come to be on friendly terms.