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. [Sidenote: Introduction of the pastoral life.] It must also be remembered that many remains supposed to belong to the later stone age may, in fact, belong to societies that existed during the bronze age, but who had not yet adopted the use of bronze, or else from their situation were unable to obtain any. As yet so little is known of how this metal was obtained at that time, that it is impossible to say what situations would be least favourable for obtaining it; but considering that tin, of which bronze is partly composed, is only found in a very few places, the wonder is rather that bronze weapons are so frequent amongst the different remains scattered over Europe, than that they should be absent from some of them. Moreover, the races that inhabited Europe before the Aryans came there would afterwards remain collected together in settlements, surrounded by the invading population, for a considerable length of time before they had either been exterminated or absorbed by the more civilized race. These aborigines would adopt such of the arts and customs of the Aryans as were most within their reach. The increased population and the greater cultivation of the land which followed the Aryan invasion would make it more difficult to obtain food from hunting, and the aborigines would therefore be compelled to adopt domestication of animals as a means of support, which they would have little difficulty in doing, as they would be able to obtain a stock to start from, either by raids on their neighbours’ herds or, perhaps, by barter. But the manufacture of bronze weapons, being a much more complicated affair than the rearing of cattle, would take a much longer time to acquire. This perhaps may