What is even more admirable than the ingenuity of the _vallista_ in utilizing the natural resources is the minute detail of the water-rights. It seems as if the _vallista_ is even more cunning in protecting himself from his neighbour than in dealing with nature. The water-customs of these Andean valleys are worth an extensive study. The water does not belong to the State, and is not used by concession from the State. It is private property. The owner uses or abuses it as he pleases on the lands which he has selected. A man may be poor in land and rich in water, which he accordingly sells. There are frequent business deals in regard to water-rights, just as in regard to the soil and its produce. Appropriation of water often precedes appropriation of the soil. Many oases are communities where the non-irrigated lands are common to the whole population, and the irrigated fields alone are divided. A primary group of customs regulates the relations to each other of communities higher up and lower down the same stream. At Catamarca the water of a certain stream is shared by Piedra Blanca and Valle Viejo. Piedra Blanca, in the upper part, absorbs the whole of the water for a week, but it must then suspend its irrigation during the following week and permit the stream to flow down the valley. The same evening, or the next morning, according to the season, the water reaches Valle Viejo. It is a custom known as the _quiebras_ in the southern valleys of the desert side of Peru, where it allows different stages of cultivation to proceed simultaneously. In the same way, above Santa Maria, where several communities (S. Jose, Loro Huasi, etc.) receive the water brought by a channel from the Rio Santa Maria, each of them has a right to the full output of the channel for three days. At the end of that time the sluices are closed, and the water passes to the next community. There is grave trouble for any oasis that has its rights infringed or does not compel the communities higher up to respect them. Amongst individuals the water-right is generally defined by a measurement of time, a certain number of days or hours--during which the owner controls the entire flow of the spring or stream. It is only when the water is more abundant that we find another method of fixing the right of water, defining it by bulk. The water is then said to be _demarcada_, as the unit is customarily the _marco_, or the volume which passes through an opening about twenty-one centimetres in width and eight in height. The _marco_ has infinite divisions, and each subdivision has its own name--the _naranja_, the _bombilla_, the _paja_, and so on.