180 



very fair specimen of Peruvian barrenness, of which it is 

 hardly possible to form an idea without witnessing it. I have 

 already alluded to the desert appearance of the coast, where 

 you may travel whole days, over pure sand, without any trace 

 of vegetation ; oi', if the road lies occasionally near a range 

 of mountains, the scene is only varied by masses of bare 

 rock, of which the fragments that cover the road are as fresh 

 and unsoiled as if they had fallen but yesterday from the 

 hammer of a mason. Of the latter description is Rio Seco, 

 except in a few spots, where nature, as if to vindicate her 

 power even in a desert, has scattered some patches of Til- 

 laiidsice, and these exiles from the vegetable world flourish 

 in spite of the arid atmosphere and burning sun. One 

 species, the T. purpurea, was in full flower when we passed. 

 As the day advanced, we found the heat excessive, having 

 now exchanged the hazy atmosphere of the coast for the 

 clear deep blue sky of a tropical mountain region. At the 

 head of the Rio Seco, the road winds up a steep hill, from the 

 summit of which, the green valley is seen at a distance of 

 two leagues, tantalizing the thirstv traveller during the two 

 hours that his mule takes to crawl over the rough stony 

 bottom of the ravine that leads to it. The TillandsicB are 

 here replaced by a few Melocacti, and one or two solitary 

 plants of Cactus tetragonus. 



We regained the main valley about three o'clock, at a 

 place called Yangas, consisting only of half a dozen houses, 

 immediately beyond which is the village of Alcocota, five 

 leagues from Cavallero, by the road we came; by the valley 

 it is six leagues and a half The valley, where we turned off, 

 is nearly a league in breadth, but here it had contracted to 

 about a mile, and the hills that bound it are high and steep, 

 especially on the north side, where the rock forms a perpen- 

 dicular wall. Greenstone is the prevailing rock all the way 

 from Lima to this place ; between the city and Arnipuquio, it is 

 partially covered with stratified limestone and slate-clay, and 

 in the ravine leading to Alcocota, by coarse argillaceous 

 limestone. 



Alcocota is considered the boundary of the rainy district, 



