A fairly homogeneous civilisation had grown up in the Ecuadorian Cordillera during the four hundred years of Cara influence. Bringing with them from their unknown original home a capacity for military and political organisation far superior to that of most American aborigines, the Caras were like a ferment introduced into the heterogeneous and inert tribes of the plateau, which gradually transformed the latter into a vigorous people so well fitted to their surroundings that they survived the Inca conquest, even turning the tables and becoming the dominant element in the empire, and then outlived the decimating tyranny of the Spaniards, so that ninety-five per cent. of the present population is composed of their descendants. That this civilisation was in the main self-developed can hardly be doubted. There is no evidence of any intimate contact with the Incas; with the peoples of Yucatan and Mexico the Caras had no connection, and the conjectures as to communication with the peoples of eastern Asia have no historical or archaeological basis. Their civilising and consolidating mission was aided by exceptionally favourable surroundings. The climate was healthy, agreeable, and conducive to bodily and intellectual vigour; the soil reasonably fertile and well adapted to the production of eminently nourishing food crops, while requiring hard labour in its cultivation. The potato, the quinoa grain, and maize played no insignificant role in the history of the Caras; they might never have risen above the level of Caribs if they had lived in a region where savoury and poorly nourishing esculents grow wild. Not less important was the physical configuration of Ecuador. Dry and open valleys, some of them large enough to sustain two hundred thousand people, and easily penetrable in every part, while surrounded by high mountains and bleak "paramos," shut off from the outer world by the forest-covered declivities of the Cordilleras, were admirably adapted to favour the growth of compact little states, whose inhabitants would retain their individual initiative and local pride even after incorporation in a larger political system.