They have spread over the north, and are pushing southward in leisurely treks. So far they have not come in contact with any other races; their wars have been with one another. Fifteen hundred years in the north country have made them a tall, tawny-haired, grey-eyed race, vigorous and warlike, and already exhibiting a well-defined artistry and poetism of nature. They still live mostly by the hunt, but the southern tribes have been raising cattle for some centuries. There is one exception in their so far complete isolation from other races: a wanderer into the far north returned with the news that the supposedly deserted ice wastes were inhabited by an extensive tribe of ape-like men, descended, he swore, from the beasts driven out of the more habitable land by the ancestors of the Hyborians. He urged that a large war-party be sent beyond the arctic circle to exterminate these beasts, whom he swore were evolving into true men. He was jeered at; a small band of adventurous young warriors followed him into the north, but none returned. But tribes of the Hyborians were drifting south, and as the population increased this movement became extensive. The following age was an epoch of wandering and conquest. Across the history of the world tribes and drifts of tribes move and shift in an everchanging panorama. Look at the world five hundred years later. Tribes of tawny-haired Hyborians have moved southward and westward, conquering and destroying many of the small unclassified clans. Absorbing the blood of conquered races, already the descendants of the older drifts have begun to show modified racial traits, and these mixed races are attacked fiercely by new, purer-blooded drifts, and swept before them, as a broom sweeps debris impartially, to become even more mixed and mingled in the tangled debris of races and tag-ends of races. As yet the conquerors have not come in contact with the older races. To the southeast the descendants of the Zhemri, given impetus by new blood resulting from admixture with some unclassified tribe, are beginning to seek to revive some faint shadow of their ancient culture. To the west the apish Atlanteans are beginning the long climb upward. They have completed the cycle of existence; they have long forgotten their former existence as men; unaware of any other former state, they are starting the climb unhelped and unhindered by human memories. To the south of them the Picts remain savages, apparently defying the laws of Nature by neither progressing nor retrogressing. Far to the south dreams the ancient mysterious kingdom of Stygia. On its eastern borders wander clans of nomadic savages, already known as the Sons of Shem. Next to the Picts, in the broad valley of Zingg, protected by great mountains, a nameless band of primitives, tentatively classified as akin to the Shemites, has evolved an advanced agricultural system and existence.