mountain belt in which cereals are grown; that is up to eleva- tions of 11,000 to 12,000 feet. The surface of the high Central Andean plateau may be seen at its best between Lake Titicaca and La Paz. Barley, wheat, and millet are raised; and the small native potato grows above the zone of irrigation up to very high levels, only a thousand feet below the snow line. Naturally the location of settlements as well as the houses of individual farmers is determined by access to water for irriga- tion. This is true for the terraces and valley floors of deep- sunk canyons like those of the Cotahuasi and the Apurimac in central Peru and the great plantations around Abancay. In all the deeper basins and valleys there is dependence for cereals, fruit orchards, and corn and cane fields upon an as- sured source of water.
Least dependent upon the water supply are the small settle- ments and individual farms which rely upon flocks and herds for a livelihood and supplement such resources by growing potatoes in favorable sites. Such communities and individuals depend for part of their livelihood, as a rule, upon services to plantation owners. Even the lands they occupy are normally rented from the large hacendados upon the valley floor where the main settlements and the distillation works for producing brandy are located. The rent is paid in labor in such instances, sometimes supplemented by a very small money payment.
The very existence of the system of land tenure that prevails in these two countries and that brings into vital relation the dweller in the high mountain valleys and the owner of the valley floor and the town upon it is an indication of the thor- ough usefulness of the land in the Central Andes north of the Puna de Atacama throughout the entire belt from deep-cut ranyon up over terraces and intermediate slopes, high basins, and still higher pastures, to the snow line. There may be bouldery tracts here and there, expanses of bare rock, arenales or local sandy wastes, poorly drained, brackish or saline swamps, steep canyon borders, and coarse, stony land waste at the head of an alluvial fan where both soil and a convenient water supply are lacking—but these are all local exceptions. The amount of land that is necessary to support a community
