148 SOUTH AMERICA 



hard -leaved shrubs, while grassy glades occupy the 

 intervening lower and moister ground. The almost 

 imperceptibly swelling surface is thus distributed be- 

 tween the meadow-like, somewhat marshy shallows and 

 the 'dry quebracho woods, which then appear like 

 islands or ' islas ' on the flats. Thin forests of waxy 

 palms grace the grass-lands and belt the forest: the 

 swamps which are strewn over the surface disappear 

 under tall wavy reeds and sedges. The northern Chaco 

 is said to contain patches of moist tropical forests, and 

 gradually merges into the Bolivian llanos. The great 

 park plain is interrupted by the vast and impassable 

 swamps of the Pilcomayo and the Bermejo. 



As the land rises towards the Andes very gently, and 

 with increasingly dry climate and soil, the quebracho 

 forest gradually thins out, becoming lower and sometimes 

 passing into a thorny scrub-land of various small-leaf, 

 prickly bushes, such as prosopis, acacia, mimosa, cassia, 

 chanar, &c. Even this thins out in places, and leaves 

 desolate stony wastes dotted with single scraggy shrubs 

 of acacia, atrlplex, and scattered cereus and cactus. 



In Tucuman and farther north along the Andes, the 

 upper plains are more fertile, owing perhaps to increasing 

 altitude and, consequently, to a somewhat more liberal 

 rainfall. Dry forests of quebracho reappear with in- 

 creased vigour, and other forests are known here which 

 are almost entirely composed of cebil acacias, alternating 

 with a dry kind of narrow-leaf grass-land, and making 

 the park landscape known as ' parque.' This links 

 the plains with the luxuriant forests of the sierra. 

 Quebracho forests are now being developed for their 

 hard timber and bark, whilst the grass-lands are used 

 for grazing. 



Horse and cattle breeding have so far been fittingly 



