Among the various researches of geologists, there are perhaps none of a more general interest than those which relate to the antiquity of the human race. We would gladly know whether those strata and caves which contain so many relics of the past afford us also some insight into the primitive condition of man—some indication of the times when he first appeared upon the stage of life. Within the last years many discoveries have been made which have thrown light upon the subject, and proved that, though man, geologically speaking, is of recent origin, and probably the youngest born of creation, his ancestry still stretches back at least as far as that remote period when the huge Mammoth ranged over the north, when the cavern bear and the cavern hyena tenanted the excavations of our limestone hills, and the uncouth form of the rhinoceros brushed through the dense primeval forests of our land. In the following pages I intend briefly to point out some of the most interesting of these discoveries. The peat-mosses of Denmark, varying in depth from ten to thirty feet, show their enormous antiquity by the changes which have taken place in the vegetation of the land since the first periods of their growth. At their lowest levels lie thick prostrate trunks of the Scotch fir, which must once have grown on their margin, but which is not now, nor has ever been in historical times, a native of the Danish isles. At higher levels the pines disappear, and are supplanted by the sessile variety of the common oak, while still higher occurs the pedunculated variety of the same oak, now in its turn almost superseded by the common beech. It is impossible to calculate the number of ages needed to bring about these vast changes in the forest scenery of Denmark—a very moderate estimate carries them back seven thousand years—but at every depth in the peat, and under all these various trees, implements and other articles of human workmanship have been found, which show that, since the appearance of man, the fir and the oak have successively flourished and disappeared. In addition to the peat-mosses, the Danish ‘shell-mounds’ throw some light on the prehistoric ages of that northern land. These mounds, or ‘refuse-heaps,’ consisting chiefly of thousands of cast-away shells of the oyster, cockle, and other molluscs of existing species, may be seen at certain points along the shores of nearly all the Danish islands. The shells are plentifully mixed up with the bones of various quadrupeds, birds, and fishes, which served as the food of the savages by whom the mounds were accumulated, while scattered all through them are rude implements of stone, horn, wood, and bone, with fragments of coarse pottery, mixed with charcoal and cinders, but never any implements of bronze or of iron. Similar refuse-heaps are found near the huts of many wild nations of the present day, as, for instance, near the miserable wigwams of the Fuegians, who live chiefly upon limpets.