Somehow or other, by this route or that, the migrants from Asia drifted across to the Americas, down the two continents, and out to their uttermost limits. Of the many possible tests of man’s age in the New World—some good, some not so good—one of the least accurate is a guess at how long it would take men and women, encumbered with children, to walk—and to eat their way—from Bering Strait to Cape Horn. It has been estimated that they might have covered the 4,000 miles from Harbin, Manchuria, to Vancouver Island in from 20 to 1,000 years; the time involved really depends on how fast and in what direction those wild animals moved upon which early man depended for food. As the country widened out, then narrowed in Central America, and widened out once more, there is no knowing how long the trip to Cape Horn may have taken. Our migrants would have had to camp and hunt as they went, and at first they would have moved only as the pursuit of game spurred them on. There would have had to be time, too, for increase in numbers—among themselves as well as among later invaders—to create pressure of population, and force the earlier men to the peripheries of northeastern America, Florida, and Lower California, and push them across jungled Panama and Amazonia and toward the bleaker and less desirable parts of South America. The various invaders multiplied as they moved, and it is anybody’s guess how many people were crowded into America by 1492; one authority says 8,400,000, another 50,000,000 to 75,000,000.[1] It took much time, of course—many millenniums—to breed so many men and cover so wide a space. [Illustration: THE TREKS OF EARLY MAN _This map shows how far man would have had to walk from southern Africa to a spot just east of the Caspian Sea, where it used to be supposed that man originated, and it also shows the distance from that area to England, Australia, and Tierra del Fuego. The journey of early man from Bering Strait to the tip of Cape Horn was a matter of 10,000 miles._]