The "Leyes de Indias,"[2] faithful reflections of the purposes of Spanish colonization in America, show how extraordinary was the importance of the native races, how relatively few were the Spanish conquerors and how closely the two races became mingled, through the régime of the _encomiendas_[3] the _mitas_[4] and the _yanaconazgos_.[5] The Spanish colonies were founded and developed in the midst of a mass of people, who, because of their enormous superiority in point of numbers, necessarily reacted in turn upon the small number of the invaders, either by interbreeding with the latter, or by the contact of daily life, or by their superior adaptability to their natural environment. The conquerors themselves presented different traits, according to the region of Spain from which they came, and naturally they sought to group and to settle themselves in obedience to the ethnic affinities of their origin. Biscayans, Basques, Castillians, Aragonese, Andalusians, etc., gave typical characteristics to every American region where they established themselves. They transplanted their social prejudices, their spirit of communal independence, their concentrated energy and their buoyant temperament. From this it resulted that in whatever corner of America a particular Spanish strain of blood was found, there were reflected the traits of the corresponding district of Spain. As the native races varied according to the region, from those of a peaceful and civilized character to those of an untamable and warlike nature, and even to ferocious savages, the Spanish settlements existed without any common plan. They made a republic with the tribes, and they were the beginning of a creole type which was quite distinct in each locality. In the viceroyship of Buenos Ayres the ethnic geography of the aborigines shows a kaleidoscopic variety of races. In the north and in the regions which formerly had been subject to the rule of the Incas, the population--both servient and dominant classes--was peaceful, attached to the soil, resigned and passive.