The marriage ceremony had already supplied a precedent for introducing members into a house who were not born in it. It was very natural, then, that this principle should be extended to the introduction of males when there was any danger of the male line becoming extinct. This was done by the ceremony of adoption, which was in many respects similar to that of marriage, being a formal renunciation of the person adopted by the patriarch of his original family, in case he was a member of one, and a formal acceptance and admission into the new family of his adoption, of which he was thenceforward regarded as a regular member. This ceremony exhibits in a very marked manner the leading peculiarity of the patriarchal household. We see how completely isolated, in theory, such a group was from the rest of the world; having its own distinct worship, in which no one but its own members were permitted to share, reverencing its own ancestors only, who might receive worship from none but their descendants. So jealously was this separation of families guarded, that it was impossible for a man or woman at the same time to worship at two family shrines. While displaying its isolation in the strongest light, adoption is nevertheless a mark of decay in the patriarchal family. It is an artificial grafting on the original simple stock; and however carefully men may have shut their eyes at first to its artificial nature, it must have had a gradual tendency to undermine the reverence paid to the principle of blood relationship.
Before we consider, however, the causes of decay of this form of society, which we shall do in the next chapter, there are some other indications of their manner of livelihood which will help us to understand the social condition of these Aryan patriarchal families. We have seen that, with the introduction of bronze into Europe, various changes took place in the manner of men’s lives. One of these is the regular domestication of animals. It is true that domestic animals were by no means unknown before the bronze age in Europe: but until that time this custom had not attained any great extension. In remains of settlements whose age is supposed to be before the introduction of bronze, by far the larger number of animals’ bones found are those belonging to wild species, while those belonging to tame species are comparatively rare. This shows that the principal part of the food of those people who lived before the bronze age was obtained by hunting. After the introduction of bronze, however, exactly the reverse is the case. In these later remains the bones of domestic animals become much more common, while those of wild animals are comparatively rare, which shows what an important revolution had taken place in men’s habits.