In Brazil such shell-heaps are called _sambaquis_, and they are of frequent occurrence along the bays and inlets of the coast. Some of them are of extraordinary dimensions, rising occasionally to more than a hundred feet in height. The lower layers have been consolidated into a firm, stony breccia of shells and bones, while the surface stratum, from six to ten feet thick, is composed of sand and vegetable loam supporting a growth of the largest trees. Yet even the lowest layers of this breccia, or shell-conglomerate, yield tokens of human industry, as stone axes, flint arrow-heads, chisels, and fragments of very rude pottery, as well as human bones, sometimes split to extract the marrow. The shells are by no means all of modern type. Many are of species now wholly extinct, or extinct in the locality. This fact alone carries us back to an antiquity which probably should be counted by thousands of years before our era. At that remote period not only did a fishing and hunting race dwell along the Brazilian coast, but this race was fairly advanced on the path to culture; it was acquainted with pottery, with compound implements, and with the polishing of stone. We further know that this race was not that which occupied the land when the whites discovered it; for the human skulls disinterred from the sambaquis are, craniologically, almost diametrically opposite those of the Botocudos and the Tupis. Yet if we can trust the researches of Dr. Lund in the caverns of Brazil, the oldest skulls in these deposits, found in immediate connection with the bones of extinct mammalia, belonged to the ancestors of these tribes. Markedly dolichocephalic, they present an entire contrast to the brachycephalic type from the sambaquis.[15] This class of monuments, therefore, supply us data which prove man’s existence in America in what some call the “diluvial,” others the “quaternary,” and others again the “pleistocene” epoch—that characterized by the presence of some extinct species. _Industrial._ Let us now turn to the industrial activity of the American race, and see whether it will furnish us other data concerning the pre-historic life of the New World. We may reasonably look in this direction for aid, since it is now universally conceded that at no time did man spring into being fully armed and equipped for the struggle for existence, but everywhere followed the same path of painful effort from absolute ignorance and utter feebleness to knowledge and power. At first, his only weapons or tools were such as he possessed in common with the anthropoid apes: to wit, an unshapen stone and a broken stick. Little by little, he learned to fit his stone to his hand and to chip it to an edge, and with this he could sharpen the end of his stick, thus providing himself with a spear and an axe.