Whatever its point of departure, the traffic in stock always passed through the _valles_. Transport of cattle was particularly difficult in the Argentine Andes. The chief obstacles were not the elevation of the passes or the steepness of the roads, but the scarcity of water and the extent of the _travesias_, which were equally poor in pasturage and water, and had to be crossed rapidly by doubling the stages. The difficulties of the journey were very profitable to the oases that lay along the route. The cattle-driver could not dispense with the hospitality of the _vallista_ or dispute the price he cared to charge. [Illustration: MAP II.--IRRIGATION IN THE WEST AND NORTH-WEST OF ARGENTINA. _Extent of the irrigations in the north (zone of the great summer rains), and the south (glacier zone) The historic industry of fattening cattle in the invernadas and the export of cattle to the Andean regions only survive in part. On the other hand large modern industries have developed at Tucuman, Jujuy (sugar-cane), Mendoza, and San Juan (vines), and they supply the Buenos Aires market._ To face p. 52.] The length of the journey and the difficulty of keeping the animals in good condition in the poor pastures of the breeding districts made it advisable to stay longer in the oases. There thus arose lucerne-farms--the _invernadas_--to receive and fatten the cattle which passed through. Lucerne is the characteristic and most profitable produce of the _valles_. It is grown wherever there is an assured supply of water, and is invariably found in the upper section of the system of irrigation-channels; the cereals are sown lower down, and are the first to suffer from drought. In the _quebradas_, where space is more limited, the lucerne-fields cover the entire oasis. Every cattle track has a corresponding line of _invernadas_, which is often completed on the opposite slope by a last group of lucerne-farms where the beasts recover from the journey before they are sold and dispersed. 1910 1911 1912 1913 1914 Export of Cattle: To Bolivia 3,600 6,600 6,200 6,300 4,800 To Chile 61,200 87,500 68,400 58,000 28,300 Export of Mules: To Bolivia 2,700 4,600 7,900 8,300 2,500 To Chile 2,300 3,200 5,000 2,600 3,500 Export of Asses: To Bolivia 9,000 10,500 15,000 15,600 14,400[27]