ledge, often a great help, he would have to leave a large fraction of the whole in an unclassed heap, confessing that he did not know within thousands of miles or thousands of years, where and when they were made.
How, then, is this remarkable uniformity to be explained? The principle that man does the same thing under the same circumstances will account for much, but it is very doubtful whether it can be stretched far enough to account for even the greater proportion of the facts in question. The other side of the argument is, of course, that resemblance is due to connexion, and the truth is made up of the two, though in what proportions we do not know. It may be that, though the problem is too obscure to be worked out alone, the uniformity of development in different regions of the Stone Age may some day be successfully brought in with other lines of argument, based on deep-lying agreements in culture, which tend to centralize the early history of races of very unlike appearance, and living in widely distant ages and countries.
To turn to an easier branch of the subject, I have brought together here, as a contribution to the history of the Stone Age, a body of evidence which shows that it has prevailed in ancient or up to modern times, in every great district of the inhabited world. By the aid of this, it may be possible to sketch at least some rude outline of the history of its gradual decline and fall, which followed on the introduction of metal in later periods, up to our own times, when the universal use of iron has left nothing of the ancient state of things, except a few remnants, of interest to ethnologists and antiquaries, but of no practical importance to the world at large.
In the first place, there are parts of the world whose inhabitants, when they were discovered in modern times by more advanced races, were found not possessed of metals, but using stone, shell, bone, split canes, and so forth, for purposes in making tools and weapons to which we apply metals. Now as we have no evidence that the inhabitants of Australia, the South Sea Islands, and a considerable part of North and South America, had ever been possessed of metals, it seems reasonable to consider these districts as countries where original Stone Age conditions
