Until we arrive at the period of neolithic art, with its perforated hammers, grooved axes, net-sinkers, gouges, adzes, and numerous other ground and polished implements, fashioned of granite, diorite, trap, and other igneous rocks, the forms of implements are few and simple, dependent to a large extent on the natural cleavage of the flint. The commoner examples of neolithic art, recovered in thousands from ancient Scandinavian, Gaulish, and British graves, from the lake-dwellings of Switzerland, the Danish and British shell mounds, the peat mosses of Denmark and Ireland, and from numerous other depositories of prehistoric industrial art, are scarcely distinguishable from the flint knives, scrapers, spears, and arrow heads, or the chisels and axes, manufactured by the American Indians at the present day. The material available in certain localities, such as the claystone of the Haida and Babeen Indians, and the argillite of the old implement-makers of New Jersey, the obsidian of Mexico, or the quartz, jasper, and greenstone of many Canadian centres, give a specific character to the implements of the various regions; but, on the whole, the arts of the Stone period of the most diverse races and eras present striking analogies, scarcely less suggestive of the operation of a tool-making instinct than the work of the nest-builders, or the ingenious art of the beaver. But the massive and extremely rude implements of the river-drift and caves present essentially different types, controlled indeed, like the productions of later artificers, by the natural cleavage and other essential properties of the material in which the flint-worker wrought, but with some characteristic differences, suggestive of habits and conditions of life in which the artificer of the Mammoth or Reindeer period differed from the tool-maker of Europe’s Neolithic age, or the Indian savage of modern centuries.