In Mr. Daniel Wilson's "Pre-historic Annals of Scotland," we have the best _data_ for the next portion of the question, viz., the extent to which geological changes have occurred since the first occupancy of our islands. In the valley of the Forth,[1] alterations in the relations of the land and sea to the amount of twenty-five feet have occurred since the art of making deers' horns into harpoons was known in Scotland. Such at least is the inference from the discovery, in the Carse lands about Blair Drummond Moss, of the skeleton of a whale, with a harpoon beside it, twenty-five feet above the present tides of the Forth. As much as can be told by any single fact is told by this; its valuation being wholly in the hands of the geologists. Then, the bone of an Irish elk, according to one view (but _not_ according to another), gives us a second fact. A rib, with an oval opening, where oval openings should not be, and with an irregular effusion of callus around it, is found under eleven feet of peat. Dr. Hart attributes this to a sharp-pointed instrument, wielded by a human hand, which without penetrating deep enough to cause death, effected a breach on the continuity of the bone, and caused inflammation to be set up. But Professor Owen thinks that a weapon of the kind in question, if left in, to be worked out by the _vix medicatrix_ of Nature, would be fatal, and consequently he prefers the notion of the wound having been inflicted by a weapon which was quickly withdrawn, _e.g._, the horn of some combative rival of its own kind, rather than the human. Now if it be a difficult matter to say what will, and what will not kill a man in the year '52, much more so is it to speak chirurgically about Irish elks of the Pleiocene period. Hence the evidence of man having been cotemporary with the Megaceros Hibernicus is unsatisfactory. That a certain amount, then, of change of level between the land and sea, in a certain part of Scotland, has taken place since Scotchmen first hunted whales is the chief fact, relative to the date of our introduction, that we get from geology. From archæology we learn something more. Those sepulchral monuments which have the clearest and most satisfactory signs of antiquity, contain numerous implements of stone and bone, _but none of metal_. When metal is found, the concomitant characters of the tomb in which it occurs, indicate a later period. If so, it is a fair inference for the ethnological archæologist to conclude, that although the earliest colonists reached Britain late enough to avail themselves of boats, their migration was earlier than the diffusion of the arts of metallurgy. And this has induced the best investigators to designate the earliest stage in British ethnology by the name of the STONE PERIOD, a technical and convenient term.