In normal times Tucumán has all the labour it requires, but the harvest always compels it to seek help in other provinces. In May and June the agents, well supplied with money, set out for the Salado, the districts round the Sierra d'Ancasti, etc. The temporary attraction of Tucumán at this season is felt over a considerable distance. At Santa Maria, on the far side of Mount Aconcagua, 600 people—men, women, and children—emigrate for five months, and live on the cane-fields. The merchants of Santa Maria make them advances, in the name of the refiners, to the amount of about sixty piastres per worker. Further north the Tucumán enganchadores come into collision with those from Salta and Campo Santo, and they divide the available labour between them. Some of the temporary immigrants settle down permanently every year, and swell the normal population of the sugar industry.

Outside the Tucumán district an unfortunate attempt was made to plant the sugar industry at Santiago del Estero, and large works were constructed. But the frost is severe there. For some years they tried to keep the Santiago works going with cane brought from Tucumán, but the freight was too heavy, and the works had to be abandoned, or else dismantled and set up elsewhere. The valley of the Rio Grande, from Jujuy to 200 miles north of Tucumán, in the sub-Andean depression between the Sierra de Zenta and the Lumbrera, has, on the other hand, suitable conditions for the cultivation of the cane. Frost is rare. The climate is warmer than at Tucumán, the canes ripen more quickly, and the average return is higher. The water-supply also is good. There have long been plantations in this region. Their first market was the region of the tableland and the valleys, where they chiefly sold brandy: a traffic of long standing, which one always finds round the cold districts of the Andes, from Colombia to the north of Argentina. The modern refineries of Ledesma and San Pedro took the place of the primitive mills as soon as the railway approached Jujuy, and even before it entered the valley of the Rio Grande. They then sent their sugar by waggon in November and December, between the close of the sugar season and the commencement of the rains, which spoil the roads.

The sugar district of Jujuy now has a very different economic and social organization from that of Tucumán. Here there are no farmer-proprietors. Each centre is a large estate, in the midst of the forest, where the workers are lodged and fed by the works that employs them. The contractors who clear the ground for them are obliged by the terms of their contract to import their workers directly from the south, so that they will not take any away from the farming. There is no available labour, no free market, on the spot. Since the completion of the Quebrada de Humahuaca line, however, there has been a good deal of immigration, to settle or temporarily, of the mountaineers of the tableland. The sphere of influence of San Pedro now extends as far as Bolivia. For the harvest, which, like that of Tucumán, requires a good deal of additional manual labour, the works look to the wild Indians of the Chaco. This curious stream of seasonal migration, which the sugar campaign of Jujuy provokes every winter outside the zone of white colonization, is of very old date, going back more than sixty years. Belmar notices it about the middle of the nineteenth century. The recruiting agents of San Pedro and Ledesma set out from Embarcación, where the railway ends, and enter the Chaco, from which each of them brings a troop of some hundreds of natives between March and June. The number of these temporary immigrants seems to be about 6,000. The Chiriguanos of the north leave their families on the Chaco, and the men come alone. The Matacos immigrate in whole tribes. They camp in huts like those of their own villages, under the shelter of the works, and are paid in maize, meat, and cigars. In October, when the algarroba flowers and makes them dream of their own country, they receive the remainder of their pay in money, and spend it in brandy, clothing, knives, and firearms.

The history of Mendoza resembles that of Tucumán in many ways. In the province of Cuyo, as at Tucumán, urban life has been precocious. In the middle of the eighteenth century Mendoza and San Juan exported wines, dried fruit (pasas and orejones), and flour to the coast and to Paraguay. Part of the so-called "Chilean flour" consumed on the Pampa, really came from Jachal and Mendoza. This trade ceased in the nineteenth century, but San Juan and Mendoza found another source of wealth in fattening cattle and sending them to Chile. Belmar, in 1856, estimates the extent of the lucerne farms of Cuyo to have been 150,000 cuadres(440,000 acres). [35] As at Tucumán, the present period is characterized by a rapid expansion of cultivation and a rapid growth of population. But, whereas at Tucumán the neighbouring provinces have provided the whole of the manual labour required, and the actual population is essentially creole, at Mendoza there has been a larger number of foreign immigrants. In 1914, foreigners were 310 per 1,000 of the entire population of Mendoza: a larger proportion than for the whole country. The immigrants going straight to Mendoza from the ports numbered 12,000 in 1911, and 15,000 in 1912; almost as much as for the province of Santa Fé, and more than for the province of Córdoba. Thus Mendoza plays a part of its own in the charm which Argentina has for the imagination of Europe. When we examine a chart of the population of South America, we notice that the oases of Cuyo contain the only important groups of European population at any distance from the coast.

The prosperity of Mendoza to-day depends upon the cultivation of the vine, just as that of Tucumán depends upon sugar. The cultivation of the vine is possible in the greater part of Argentina. In the early days of colonization there were vineyards as far as the Paraguay. They still flourish at Concordia on the Uruguay and at San Nicolas on the lower Paraná. But the wet summers of the eastern provinces are not suitable for them. The climate for them improves as one goes westward, and there is less rain. The dry zone of eastern Argentina is the special field of the vine. There it has spread over nearly twenty degrees of latitude, and it depends, like other cultivation, upon irrigation. In the Andean valleys of the north-west it rises to a height of 7,500 feet. South of Mendoza the higher limit of the vine sinks rapidly, and there are no vineyards in the mountainous district itself. On the other hand, its range increases; in the east it spreads as far as the Atlantic coast, in the valley of the Rio Negro.

The former centres of viticulture in the north-west, in the oases of the costas of La Rioja, Catamarca, and Salta, have scarcely been affected by the advance; and, in any case, their extent is very limited. The vine-district of the Rio Negro is only in process of creation, and its output is still small. Thus the area of production on a large scale is limited to the three oases of San Juan, Mendoza, and San Rafaël, which in 1913 yielded 4,750,000 hectolitres, out of the total Argentine production of 5,000,000 hectolitres. These three centres differ from each other to-day rather in their economic development than in their physical conditions. At San Juan, the transformation of the earlier methods of production and the traditional creole industries is only now taking place. At Mendoza it is quite finished. The San Rafaël centre, on the other hand, is of recent origin; it was created on the site of a fortress which guarded the Indian frontier until 1880. Cultivated areas have appeared on virgin soil, in the midst of the desert. These different circumstances account for diversities which, though they will disappear in the course of time, are still obvious to the traveller. The general scene is the same everywhere. Arid and desolate mountains close the horizon in the west; at their feet spreads the immense alluvial deposit on which the vineyards, surrounded by rows of poplars, grow wherever water is to be found.

There are so few gaps in the lower slopes of the Cordillera that the available water is gathered at a small number of points. The Rio San Juan alone drains a belt of the Cordillera at least 140 miles broad. Each of the two oases, Mendoza and San Rafaël, has two streams of water to feed it. The Mendoza and the Tunuyan at Mendoza, and the Diamante and the Atuel at San Rafaël, approach each other, when they leave the mountains, so closely that the estates they water blend into a continuous area. Then, however, instead of uniting, they diverge and are lost, separately, in the plain. These streams have less fall than the thinner torrents of the oases of the north-west, and the average inclination of the dejection-cones which bear the vineyards is slight. The upper slopes of the cone, where thin beds of clay lie upon shingle, give clear wines of excellent aroma. Hence, in the Mendoza district, the vineyards of Lujan and, further down, of Godoy Cruz, Guaymallen, and Maipu produce choice brands. On the plain, to the east of Mendoza, at San Martin and Junin, the harvest is larger, but the wine is rough, and one can often taste the saltpetre of the clayey soil. There is the same difference between the upper and lower district at San Juan and San Rafaël.

The oases of San Juan and San Rafaël spread evenly over the most suitable parts of the alluvial talus, but the oasis of Mendoza has a peculiar shape which can only be explained by historical causes. The cultivated belt is a narrow strip along the Tunuyan, for more than sixty miles, as far as the heart of the plain, out of sight of the Cordillera. It is one instance, out of a thousand, of the influence of traffic on colonization. As a matter of fact, the road from Mendoza to the coast, by which the cattle convoys of San Luis went to the invernadas, passes along the Tunuyan. The estates grew up by the side of it. The villages of Santa Rosa, Las Catitas, and La Paz, which mark the various stages of it, are all of ancient origin. Strangers are rarely found there. One still sees in them very old houses, built before the railway was made, dating from the days of the carril or waggon-road. The importance of this line of water across the desert is clearly seen on the Woodbine Parish map.