We have to remember that human races can all interbreed freely and that they separate, mingle and reunite as clouds do. Human races do not branch out like trees with branches that never come together again. It is a thing we need to bear constantly in mind, this remingling of races at any opportunity. It will save us from many cruel delusions and prejudices if we do so. People will use such a word as race in the loosest manner, and base the most preposterous generalizations upon it. They will speak of a “British” race or of a “European” race. But nearly all the European nations are confused mixtures of brownish, dark-white, white and Mongolian elements. A MAYA STELE A MAYA STELE Showing a worshipper and a Serpent God. Note the grotesque faces in the writing _Brit. Mus._ It was at the Neolithic phase of human development that peoples of the Mongolian breed first made their way into America. Apparently they came by way of Behring Straits and spread southward. They found caribou, the American reindeer, in the north and great herds of bison in the south. When they reached South America there were still living the Glyptodon, a gigantic armadillo, and the Megatherium, a monstrous clumsy sloth as high as an elephant. They probably exterminated the latter beast, which was as helpless as it was big. The greater portion of these American tribes never rose above a hunting nomadic Neolithic life. They never discovered the use of iron, and their chief metal possessions were native gold and copper. But in Mexico, Yucatan and Peru conditions existed favourable to settled cultivation, and here about 1000 B.C. or so arose very interesting civilizations of a parallel but different type from the old-world civilization. Like the much earlier primitive civilizations of the old world these communities displayed a great development of human sacrifice about the processes of seed time and harvest; but while in the old world, as we shall see, these primary ideas were ultimately mitigated, complicated and overlaid by others, in America they developed and were elaborated, to a very high degree of intensity. These American civilized countries were essentially priest-ruled countries; their war chiefs and rulers were under a rigorous rule of law and omen.