PARAGUAY AND LOWER PARANA MARSHES 155 



the banks of streams only are inhabited, while the 

 hinterland is impassable. The islands of really firm 

 ground, above the level of the floods, and yet irrigated 

 by them, may also become centres of forest growth. 

 Tropical in the north, the forest belts and islands 

 assume a decidedly subtropical, and even temperate, 

 character in the south. As might be expected, the chief 

 industry of the region is cattle and horse breeding. 



Western Argentine Wastes. West of the latitude of 

 San Luis, the landscape, though retaining the name of 

 pampa, slowly changes for the worse. The rainfall is 

 well below 20 inches yearly, and there is a prolonged 

 dry period ; the variations of temperature are therefore 

 very wide. The ground also becomes somewhat rougher 

 and more varied. Immense levels and hollow tracts of 

 marshy or salt deserts — the ' travesias'— are broken by 

 sandy dunes — the ' medanos ' — some of which are shifting. 

 An outlier of the Andes, the Sierra de Cordoba, is thrown 

 athwart the track to the Cordilleras, and more or less 

 encloses the desolate land on the east. Isolated hills or 

 hillocks here and there break the rolling or level surface. 



The vast plains at the foot of the Andes, under these 

 latitudes, gradually pass from the grassy pampa into 

 a vast dreary thorn shrubland. The grass grows sparser 

 and sparser westward, where low compact bushes, 

 with small, hard, divided leaves and formidable spines, 

 are spread like cushions here and there on the naked 

 ground. They belong to the typical bush of West 

 Argentina, the chanor, somewhat like an acacia, 

 which is everywhere conspicuous. Shrubs of hard-leaf, 

 prickly verbena and of retama, tufts of dwarf jprickly 

 palms, stand solitary, whilst more forbidding leafless 

 cacti, cerei, and opuntias stretch the ungainly shapes of 

 their bristling limbs. 



