The distribution of these animals is not however constant throughout the whole area, but many of them are confined to the warmer countries. Little more need be said, for the purposes of this book, of the physical nature of the country, save that the rainfall is not excessive, being heaviest upon the Atlantic slope; and that, while the land appears to be rising gradually on the Pacific side, much has been lost to the Atlantic on the east. With these few words of introduction an attempt will now be made to describe the inhabitants of the country and the culture which they built up before they came in contact with the Old World at the beginning of the sixteenth century.[1] CHAPTER I--MEXICO: TRIBAL HISTORY At the time of the conquest by the Spaniards of the province of Mexico, the dominant people was the Aztec population of Tenochtitlan (Mexico city), inhabiting a town built on an island in the lake of Tezcoco, or rather that portion of it known as the lake of Mexico. The Aztec were confessedly immigrants, who had wandered south less than five hundred years before the conquest; by their superiority as fighting-men they had won the hegemony over the kindred tribes which they found settled in the valley of Mexico, and had extended their power to both oceans and as far at least as the isthmus of Tehuantepec. Both they and their immediate predecessors spoke the same language, called Nahua (strictly, _Nahuatl_), and they appear to be a branch of the great Shoshonean family which reaches as far north as the state of Montana. Beyond this, their ethnography and language would seem to connect them rather with the coastal tribes of the far north-west than with those to the east of the Rockies, but on this point little can be said at present. Immediately to the north and north-west of the settled peoples of the valley, the steppe country was inhabited by tribes who lived mainly by hunting, called Chichimec and Otomi, the former being almost purely nomadic, the latter to some extent settled. The Chichimec spoke for the most part a language which was essentially Nahua, but the name itself possessed for the Mexicans rather a cultural than a linguistic significance, and meant little more than “nomadic hunters.” The Otomi tongue was different, and extended down to the valley of Toluca, through the people known as Mazaua to the Matlatzinca. South of the last, among the Tlalhuica around Cuernavaca, Nahua again prevailed. In the hilly volcanic country around lakes Pazcuaro and Chapala, a third speech was found, the Tarascan, of which the exact affinities are still doubtful. The Rio de las Balsas appears to be about the southern limit of the Tarascan tongue, but its northern is less certain; it extends into Jalisco, and may at one time have reached up into Zacatecas where remains in Tarascan style have been discovered (at La Quemada). Roughly south of the Rio de las Balsas and a line drawn thence to Teotitlan is