152 PATAGONIA AND SHEEP-REARING 



the basin of the Caiilaufquen from Nahuel Huapi, 

 the water of which flows northward toward the Limay 

 and southward toward the Chubut : successive eruptions 

 have covered the surface with lava and ash, which at 

 Afiecon rise to a height of 6,700 feet. The granite 

 platform which emerges in the north, at the Cerro 

 Aspero and the Quadradito, rises to a height of 4,400 

 and 4,700 feet, and in some places presents a bold and 

 rejuvenated aspect. The whole has been cut up in 

 all directions by erosion, and it affords comparatively 

 easy means of getting about, which the Indian tracks 

 have followed. Below the higher slopes the valleys 

 deepen into gorges, and these broaden out in the soft 

 tufa and are lost at the cross-streams of lava or the 

 outcrops of the granite. In so varied a land, with 

 such marked differences of altitude, the winter and 

 summer pastures are always close together. Precip- 

 itation is more plentiful than at a distance from the 

 Cordillera ; the pasturage is richer, and the size of the 

 flock rises to 1,600 sheep to the league. The sheep 

 pass the winter on the lower slopes, where they are 

 sheltered from the winds and the snow. They descend 

 to the mallin when the dry season sets in and makes 

 the soil firm. In summer they go on to the 

 tablelands, where the pastures extend to a height of 

 5,000 feet. 



Bailey Willis, studying the improvements that might 

 be made in the pastoral processes, concluded that the 

 essential point was to use each pasturage in its best 

 season, and establish a carefully considered rotation on 

 the various lands. This system, which alone would 

 enable them to nurse the natural resources of the 

 scrub in the way of plants for fodder, is used to-day in 

 only a small number of districts — in the east, where 

 the flocks winter on the coastal plain and spend the 

 summer on the Somuncura tableland, and in the west, 

 round the Afiecon, where the summer and winter 

 pastures are not far from each other. The custom 



