It would be interesting to trace, if we could, what share the several domesticated animals have had in the development of the human races; but this task is not to be done. We can, however, discern that the Arab without the camel and the horse would not have found the place in history which he has filled, and that our own race could not have attained its place save for the aid which the horned cattle, sheep, and a host of other helpers which we have pressed into service, have afforded. These economic gains have to be judged in mass, they cannot be reckoned in detail. When we have made the best account of them we can, there remains another class of influences, the value of which, though evidently great, is yet harder to reckon; these arise from the education which has been attained through the care of these adopted creatures. Among savages the great need is a training in forethoughtfulness; all primitive peoples are like children, they live in the interests of the day; the cares of the seasons to come, or even of the morrow, are not for them. The possession of domesticated animals certainly did much to break up this old brutal way of life; it led to a higher sense of responsibility to the care of the household; it brought about systematic agriculture; it developed the art of war; it laid the foundations of wealth and commerce, and so set men well upon their upward way. Moreover, the use of domesticated animals of the better sort enabled the more vigorous and care-taking races to gain the strength which led to their advancement in power to a point where they were able to displace the lower and feebler tribes. In other words, the system of domestication has provided a method by which those peoples who were fitted to develop the qualities which make for civilization could advance; it has provided the opportunity for selection.