360 SOUTH AMEEICA— THE ANDES EEGIONS. 



^arts, the cctbcceras de mile, the "valley heads," and the valiez, the "valleys" 

 themselves, expressions which in Bolivia have the special sense of temperate 

 uplands, and hot lands respectively. 



The latter zone, comprising all the valleys merging in the plains, takes the 

 general name of Yungas, formerly Yuncas, a term applied to all the hot regions 

 and their inhabitants. In Peru the Yuncas were the coastlanders, whereas in 

 Bolivia the word was applied to both the lands and peoples of the eastern 

 slopes of the Cordilleras with the valleys and woodlands at their base. At present 

 it is restricted to the lower margin of the Andes traversed by the affluents of the 

 Amazons, and abounding in tropical products. 



Lastly, the fourth region comprises the saddle-back extending as far as the 

 Guapore and the Paraguay, with its forests and savannas, its rivers and marshes, 

 and its fertile lands, vast enough to supply bread-stuffs for many hundred thousand 

 people. 



IIL 



Lakes and Rivers of Bolivia. 



Since the loss of its western (Pacific) slopes Bolivia drains partly to the 

 Atlantic through the Amazons and Plate rivers, partly to the closed basin of the 

 plateau, which has, at present, no seaward outflow. But within a probably recent 

 geological epoch this upland basin also communicated with the Atlantic, being 

 flooded by a lake much larger than the great lacustrine basins of North America 

 and Central Africa. At that time the climate appears to have been much more 

 humid than at present, and the whole depression was filled by an inland sea at a 

 much higher level than Lake Titicaca, as shown by the mountains skirting the 

 Oruro plain, where the overhanging whitish cliffs, apparently deposited in water, 

 stretch 200 miles away to the north. 



This vast mediterranean discharged its overflow through the breach where now 

 stands the city of La Paz, and where rises one of the main head streams of the 

 Beni affluent of the Amazons. Thus at that epoch the largest river was fed by 

 the largest lake in the world, while the gorges of the emissary skirted the foot of 

 one of the loftiest summits in America. According to Minchin's measurements 

 the present divide between the lake and the river stands at an altitude of 13,390 

 feet, that is to say, 515 above Titicaca and 1,450 above La Paz. 



Lakes Titicaca and Pampa-Al:llagas. 



Titicaca, " Tin Stone," called also Lake of Puno, and formerly Lake of 

 Chucuito from a Peruvian city on its west bank, is the largest fragment left by 

 the ancient inland sea. From its north-west extremity near the Peruvian town of 

 Lampa, to the south-easternmost Bolivian inlet near Tiahuanuco, it has a total 

 length of 98 miles, with a mean breadth estimated at 36 miles. The southern 



