THE PIvANT WORLD 133 



rocks that compose most of the surface, and pile this light sand into 

 more or less crescent-shaped hills up to perhaps six or eight feet in 

 height and fifty feet or more in length ; these advance slowly with the 

 wind as it blows the sand on the exposed side over the crest to the 

 sheltered side. These hills, moreover, not only stand out clearly defined 

 over the darker surface, but they are covered all over the windward side 

 by the most delicate tracery of little waves, closely imitating those pro- 

 duced on water b}^ a slight breeze, and they are so numerous that at a 

 little distance the outline of one hill becomes merged into that of its 

 neighbors on either side. 



As one rises and approaches Arequipa vegetation gradually appears 

 again to some extent. Various tall, more or less branching cacti are 

 conspicuous, shrubby composites are common, and various small bushes 

 and grasses appear on the gravelly hillsides and ravines. Even a few 

 ferns and mosses are found, but everywhere the country is too dry for 

 any extensive cultivation without artificial irrigation, and this is carried 

 on quite extensively, both in Arequipa and neighboring valleys. The 

 railway on leaving Arequipa rises rapidly, winding in and out among 

 the bare hills till near the summit of the continental divide, when the 

 grade becomes more gradual and one scarcely realizes that he is at the 

 highest point at a station called Crucero Alto, 14,666 feet above the sea. 

 Let one attempt the slightest exertion, however, and at once the great 

 difference in the air is perceptible by the difficulty of breathing, often 

 accompanied by headache and even nausea. Vegetation is not uncom- 

 mon at this altitude, some of the best and most abundant grasses thriving 

 at from 12,000 to 14,000 feet ; various cacti also occur, although what may 

 be termed the cactus belt is somewhat lower, from about 6,000 to 10,000 

 feet. Rather above the grasses and near the summit of the divide a 

 resinous composite a foot or two high is abundant, large quantities of 

 which are pulled out by the roots, made into bales and sold for fuel. At 

 about the same height also are several odd cespitose plants. One is 

 perhaps umbelliferous. It grows in hard, dense masses, that when dug 

 out are nearly the size of a bushel basket and furnish an excellent fuel. 

 Another species forms more or less complete yellow-brown rings over 

 the surface of the ground. This last evidently continues to grow about 

 the outside of the dense tuft it first forms. Finally the center, composed 

 of the older branches, dies away and becomes replaced by sand, 

 thus leaving a very perfect ring, often several feet across and of a pecu- 

 liar yellowish color, in strong contrast with the dark sand around and 

 within it. 



As one approaches Lake Titicaca the low flats bordering the lake are 

 observed to be extensively cultivated. The principal crop raised is 

 barley, next perhaps comes kenoa, then potatoes. The barley is mostly 



