Caves of Chou-k'ou-tien in relation to the old city of Peking and the West Hills

~Evidence for human existence is so far confined to the Pleistocene period, the latest and shortest of the geological periods, which began some two or three million years ago. Toward the end of the period, at about twelve thousand years before the present humans began to produce their food by cultivating plants and domesticating animals, initiating a new stage of...