148 PATAGONIA AND SHEEP-REARING 



San Antonio on the Atlantic, and goes westward to 

 Lake Nahuel Huapi. It has (1914) reached 

 Maquinchao, on the tableland, mid-way across the 

 Andes. The other starts from Bahia Blanca. At 

 Choele Choel it enters the valley of the Rio Negro, 

 and ascends it as far as the confluence of the Neuquen. 

 Then it goes 130 miles westward as far as Zapala, at 

 the foot of the first sub-Andean chains. Each of 

 these lines is ambitious to attract the trans-Andeans. 

 At all events, they are in a hurry to reach the humid 

 zone at the foot of the Andes, which could maintain a 

 busier traffic than the desolate tableland. 



The railway from San Antonio, and the road which 

 is a continuation of it west of Maquinchao, cover a 

 distance of 320 miles from the Atlantic to the Andes, 

 and cross five distinct regions. The first is the coastal 

 plain, composed of horizontal marine Tertiary sedimen- 

 tary rocks, both of sand and clay. The plain rises slowly 

 toward the west, and it attains a height of 650 feet 

 at a distance of seventy miles from the coast. This 

 coastal platform divides, on the north-west, the enclosed 

 hollow of the Bajo del Gualicho from the Gulf of San 

 Antonio. Its surface is very even. The gravel on 

 it has formed a sort of conglomerate, and in spite of 

 appearances, this gravelly soil is not bad for vegetation. 

 It quickly absorbs the rain-water, which thus escapes 

 evaporation. The vegetation is comparatively rich. 

 There are no springs, but the autumn rains sustain 

 manantiales in the marly surface, and these do not 

 dry up until the spring. During the summer the 

 plain is deserted, and there is no water. But the flocks 

 return in the winter and remain there until spring. There 

 is very little snow, as the temperature is moderate. 

 In spite of the density of the pastoral population in 

 winter, the pasturage is not injured. The grass grows 

 plentifully amongst the thickets. This is because the 

 flocks leave the district before the season when the grasses 

 flower and reproduce, so the next generation is secured. 



