674 



NATURALIST'S GUIDE TO THE AMERICAS 



"Atlas Geografico del Ecuador" (1907) 

 which will be found extremely useful 

 by all who plan to travel in the republic. 

 It can be obtained in second-hand book 

 stores of Guayaquil and Quito. The 

 Flemming map, based upon Villavi- 

 cencio, Wolf and other sources, is also 

 useful. Large areas of the republic 

 have never been surveyed, hence an 

 altogether satisfactory map is not yet 

 obtainable. 



Students interested in the Quichua 

 language, which is spoken by the Indians 

 of the Ecuadorian highlands, will find 

 the subject well set forth in Juan M. 

 Grimm's "La Lengua Quichua," pub- 

 lished at Freiburg in 1896. This con- 

 tains the essentials of Quichua grammar 

 and a vocabulary of words used in 

 Ecuador. It can be obtained in Quito 

 and Guayaquil. 



5. THE AMAZON VALLEY 



By Orland E. White 



i. general conditions 



1. Topography 



The Amazon valley includes north- 

 eastern Bolivia, eastern Peru, eastern 

 Ecuador, southeastern Colombia, por- 

 tions of southern Venezuela and most of 

 northern Brazil. This huge area, over 

 2,000,000 sq. mi. in extent, lies wholly 

 within the tropical zone and consists 

 for the most part of an alluvial gently 

 sloping dished plain, broken in the 

 east by a series of hills and ridges less 

 than a thousand feet in height, which 

 are extensions of the Guiana moun- 

 tains. This plain with its mountainous 

 borders on the north, south, and west, 

 may be likened in form roughly to a 

 grocer's sugar scoop, lying in an east 

 and west direction parallel to the equa- 

 tor, with its back on the flanks of the 

 Eastern Cordillera and its mouth on 

 the shores of the Atlantic Ocean. The 

 mountainous borders of this basin in 

 the west consist of the wall-like range of 

 the Eastern Cordillera of the Andes, 

 with numerous snow-capped peaks rising 



to over 20,000 ft. and with breaks in 

 the wall through passes often over 

 15,000 ft. high. On the north are the 

 broken ranges of the Orinoco water- 

 shed, not so high as the Andes, but in 

 some respects even more difficult of 

 access. Here the greatest break is that 

 through which the Casiquiare river 

 unites the Orinoco and Aniazonian 

 waterways. The southern side of the 

 Amazonian "scoop" is largely the high 

 table land of central Brazil with low 

 ranges of mountains, the western ex- 

 tension of which causes the series of 

 rapids known as the Falls of the Madeira. 

 Outlying spurs indicate the proximity 

 of the main ranges, which in the west 

 come very abruptly, for practically 

 the whole area lying in Brazilian ter- 

 ritory and comprising the major part 

 of the basin is much less than 1000 ft. 

 in altitude. The head of the Madeira 

 river is less than 500 ft. and the Amazon 

 river on entering Brazil is about 266 

 ft. altitude. 



The central axis of this area is the 

 Amazon river originating in the small 

 streamlet Lauricocha in the Peruvian 

 Andes, about 100 mi. northeast of Lima 

 and at an altitude of about 17,875 ft. 

 For a few hundred mi., under various 

 nam.es, its course is north alm.ost to the 

 northern boundary of Peru, where it 

 changes to east, entering and continu- 

 ing through Brazilian territory as the 

 Solimoens until it unites near Manaos 

 with the Rio Negro, its principal north- 

 ern affluent, where its course becon:es 

 northeast and under its general nan.e of 

 "Amazon," it reaches the Atlantic 

 Ocean, near Para (Belem), after a 

 journey of between 3000 and 4000 mi. 

 Its principal southern tributaries are 

 the Madeira, Tapajos, Xingu and To- 

 cantins. High lands, sometimes rol- 

 ling, som.etimes flat lie betw^een the 

 principal tributaries on both sides of 

 the main river and these are referred to 

 as "canpos." The principal northern 

 one lies north of Obydos — the Campos 

 Geraes. At the head waters of the Rio 

 Branco is another such area, while 

 the southern side is plentifully supplied 



