routes pass north and south through the succession of mountain valleys, connecting with the coast at Guayaquil, by railroad from Chimbo, or northward down the Cauca and Magdalena. The most frequented eastward route crosses the Eastern Cordillera between Saraurcu and Antisana, and reaches navigable water in the Napo at Puerto Napo. In Peru the plateau within the ranges is connected with the coast by two railways, which are marvels of engineering. The Oroya Railway connects Lima and Callao with Oroya and Concepcion, crossing the Western Cor- dillera at an altitude of 15,665 feet, in a distance of 106 miles from Lima. The second railway connects Mollendo on the coast with Lake Titicaca. It crosses the Western Cordillera at an altitude of 14,666 feet, and terminates at the little town of Puno, on the shore of Lake Titicaca, 12,540 feet high. Several other short lines run from the coast to the foot of the mountains and even some distance into them, following the stream valleys; among them is the line up the Rio Santa to Huaraz.
The somewhat broken character of the ranges in Peru and Bolivia has made the plateau easier of access than it is farther north, and there are many roads and trails from the coast to the summit; but routes of communication to the east, to the country about the upper waters of the Madeira and Plata, are almost entirely lacking. From Antofagasta in northern Chile, on the coast, a railway has been constructed to Oruro, on the plateau, north of Lake Poopo. This road has a total length of 560 miles, making it much the longest of the Andean lines. In central Chile and Argentina a transcontinental railway has long been in course of construction, which is to cross the Andes at Uspallata or Cumbre Pass, not far from Santiago, at an altitude of 12,340 feet. This is the most frequented pass in Chile, as almost all the transcontinental travel goes over it.
Flora. In plant life the Andes is the richest of any mountain system in the world. Not only do these mountains sustain at their bases the flora of all climates, from the equatorial zone at the north to the cold zone at the south, but they possess these zones in altitude as well; and moreover, certain species of plant life are peculiar to this special region. Plant life is especially prolific in the rainy regions of Venezuela, Colombia, Chile, and Bolivia. In Colombia the palms and their associated tropical flora extend upward on the Andean slopes to an altitude of about 4500 feet, while above this is a mixed sub-tropical belt, extending to an altitude of nearly 10,000 feet, in which grow the cinchona, tree fern, and wax palm, and still higher up, at an altitude of 10,000 to 12,000 feet, the higher Andean bush growth, including the Andean rose; a species of bamboo also grows at these high altitudes.
Farther to the south, in the region of less rainfall, the flora on the east and west sides of the Andes is quite different. On the west side, in lower Ecuador and Peru, the plant life is poor, and is that peculiar to a semi-desert region; but it extends up to high altitudes, lichens being found at 18,500 feet altitude; while on the moister Bolivian and Brazilian side the various altitudinal zones occur, beginning with the rich flora of western tropical Brazil and extending up to the true Andean flora. In northern Chile and western Argentina, where there is a rather light rainfall on both sides of the Andes, there is a continuation of the sparser vegetation of the relatively dry region, and the flora of the two sides of the Andes differs less than elsewhere. In the Chile-Argentina region there is a great contrast between the rich vegetation on the moist Chilean side and the thin vegetation on the dry slopes of Argentina. In the southern part of this Andean region great forests of stunted beech and firs occur in the lowlands and extend part way up the mountain slopes. Southward along the Andean chain the altitudinal zones diminish in width in about the same ratio as the decrease in altitude of the snow-line, so that in the south, by making an ascent of less than a vertical mile, one can pass through as many vegetation zones as would be encountered in an ascent of three miles under the equator. The upper limit of tree growth, or the timber line, is a far more definite line than the snow line, yet in many places it is not easy to define. It ranges in the Andes from an average of 11,500 feet under the equator, down to about 3000 feet near Cape Horn. It is higher, for apparent reasons, on the moist, than on the dry, side of the range; thus, in Ecuador it ranges nearly 1000 feet higher upon the east side than upon the west.
Fauna. In the northern Andes of Venezuela and Colombia, where the tropical and sub-tropical forests extend up to an altitude of 10,000 feet, we find the fauna of tropical America existing up to similar high altitudes. The jaguar, puma, bear, ocelot, monkey, tapir, ant-eater, and capibara are found in these forests. Bird life is abundant, and the bat family is well represented. Snakes, saurians, and turtles are met in great numbers at lower altitudes. Above 6000 feet in altitude there is a great diminution of animal life. In Ecuador there occur certain representative species of the southern Andes, such as the llama and the condor. Insect life also continues very abundant, and fish are found up to an altitude of 14,500 feet. In the Peruvian and Bolivian Andes on the Pacific side, the fauna, like the flora, is limited, but on the eastern or Brazilian slope is exceedingly rich. The vicuña, guanaco, and alpaca are still found in the wild state, and with them are found the chinchilla and viscacha. On the Bolivian slopes the fauna is much more abundant than in Peru. Further south on the Andean chain the fauna is less rich, and especially there is to be noticed the disappearance of the larger animals of the northern Andes. Herds of guanacos are numerous, and birds are present in great variety and large numbers, but the reptiles show a decided change of form. At the extreme south the land fauna is but poorly represented.
Bibliography. Orton, The Andes and the Amazon (New York, 1870); Crawford, Across the Pampas and Andes (London, 1884); Güssfeldt, Reise in den Andes (Berlin, 1888); Whymper, Travels Among the Great Andes of the Equator (London, 1892); Fitzgerald, The Hiqhest Andes (New York, 1899); Conway, The Bolivian Andes (New York, 1901); Reclus, Physical Geography, translated and edited by Keane and Ravenstein (London, 1890-95).
AN'DESITE. A volcanic effusive rock of porphyritic texture composed essentially of lime-soda feldspar (andesinc) with bhick mica (biotite) . hornblende, or augite imbedded in a ground mass of smaller crystals or rock glass. The structure may he, but is not necessarily, porous;
