The periods and succession of the races whose annals make up the history of what we now call Mexico, prior to the coming of the Spaniards, are confused and debatable. Whether under the name of Chichimecs we are to understand a distinct people, or a varied and conglomerate mass of people, which, in a generic way, we might call barbarians, is a question open to discussion.[805] There is no lack of names[806] to be applied to the tribes and bands which, according to all accounts, occupied the Mexican territory previous to the sixth century. Some of them were very likely Nahua forerunners[807] of the subsequent great influx of that race, like the Olmecs and Xicalancas, and may have been the people, “from the direction of Florida,” of whom mention has been made. Others, as some say, were eddies of those populous waves which, coming by the north from Asia, overflowed the Rocky Mountains, and became the builders of mounds and the later peoples of the Mississippi Valley,[808] passed down the trend of the Rocky Mountains, and built cliff-houses and pueblos, or streamed into the table-land of Mexico. This is all conjecture, perhaps delusion, but may be as good a supposition as any, if we agree to the northern theory, as Nadaillac[809] does, but not so tenable, if, with the contrary Bancroft,[810] we hold rather that they came from the south. We can turn from one to the other of these theorists and agree with both, as they cite their evidences. On the whole, a double compliance is better than dogmatism. It is one thing to lose one’s way in this labyrinth of belief, and another to lose one’s head. It was the Olmecs who found the Quinames, or giants, near Puebla and Cholula, and in the end overcame them. The Olmecs built, according to one story, the great pyramid of Cholula,[811] and it was they who received the great Quetzalcoatl from across the sea, a white-bearded man, as the legends went, who was benign enough, in the stories told of him, to make the later Spaniards think, when they heard them, that he was no other than the Christian St. Thomas on his missions. When the Spaniards finally induced the inheritors of the Olmecs’ power to worship Quetzalcoatl as a beneficent god, his temple soon topped the mound at Cholula.[812] We have seen that the great Nahua occupation of the Mexican plateau, at a period somewhere from the fourth to the seventh century,[813] was preceded by some scattered tribal organizations of the same stock, which had at an early date mingled with the primitive peoples of this region. We have seen that there is a diversity of opinion as to the country from which they came, whether from the north or south. A consideration of this question involves the whole question of the migration of races in these pre-Columbian days, since it is the coming and going of peoples that form the basis of all its history.