The central Andean region, which was the home of the imperial race of Incas, extends from the water-parting between the sources of the Ucayali and the basin of Lake Titicaca to the river Apurimac. It includes wild mountain fastnesses, wide expanses of upland, grassy slopes, lofty valleys such as that in which the city of Cuzco is built, and fertile ravines, with the most lovely scenery. The inhabitants composed four tribes: that of the Incas in the valley of the Vilcamayu, of the Quichuas in the secluded ravines of the Apurimac tributaries, and those of the Canas and Cauchis in the mountains bordering on the Titicaca basin. These people average a height of 5 ft. 4 in., and are strongly built. The nose is invariably aquiline, the mouth rather large; the eyes black or deep brown, bright, and generally deep set, with long fine lashes. The hair is abundant and long, fine, and of a deep black-brown. The men have no beards. The skin is very smooth and soft, and of a light coppery-brown color, the neck thick, and the shoulders broad, with great depth of chest. The legs are well formed, feet and hands very small. The Incas have the build and physique of mountaineers. To the south of this cradle of the Inca race extended the region of the Collas[1166] and allied tribes, including the whole basin of Lake Titicaca, which is 12,000 feet above the level of the sea. The Collas dwelt in stone huts, tended their flocks of llamas, and raised crops of ocas, quinoas, and potatoes. They were divided into several tribes, and were engaged in constant feuds, their arms being slings and _ayllos_, or bolas. The Collas are remarkable for great length of body compared with the thigh and leg, and they are the only people whose thighs are shorter than their legs. Their build fits them for excellence in mountain climbing and pedestrianism, and for the exercise of extraordinary endurance.[1167] The homes of the Collas were around the seat of ancient civilization at Tiahuanacu. A remarkable race, apart from the Incas and Collas, of darker complexion and more savage habits, dwelt and still dwell among the vast beds of reeds in the southwestern angle of Lake Titicaca. They are called Urus, and are probably descendants of an aboriginal people who occupied the Titicaca basin before the arrival of the Hatun-runas from the south. The Urus spoke a distinct language, called _Puquina_, specimens of which have been preserved by Bishop Oré.[1168] The ancestors of the Urus may have been the cromlech builders, driven into the fastnesses of the lake when their country was occupied by the more powerful invaders, who erected the imperishable monuments at Tiahuanacu. These Urus are now lake-dwellers. Their homes consist of large canoes, made of the tough reeds which cover the shallow parts of the lake, and they live on fish, and on quinua and potatoes, which they obtain by barter.