INDEX. 



ABYSSINIA, elevation of the mountains of, 



116, 118. 



Acaciae, various species of, in South Ame- 

 rica, 307 ; of Australia, 313. 



Accaouais, tribe of the, 184. 



Achaguas, savage tribe of, 197. 



Acicular, or needle-leaved trees, natural 

 history of, and their extensive geogra- 

 phical diffusion, 314, et seq.; varieties 

 of, 325, 328. 



Aconcagua, elevation of the volcano of, 

 205. 



Actinea, the, 252. 



Adansonia, a colossal species of dragon- 

 tree (known as the Baobab or monkey- 

 bread tree), 270, 271, 273. 



Aerial Ocean, the influence of its pres- 

 sure on plants, 292, 295, 296. 



Africa, extensive barren plains in the 

 interior of, 2 ; deserts of, uninhabitable 

 by man, 3 ; Oasis of, 2 ; deserts of de- 

 scribed by Herodotus, 9; causes of 

 excessive heat, 9; mountains of, 9; 

 Northern Africa one connected sea of 

 sand, 9, 110; character of its vegeta- 

 tion, 10; two races of men separated 

 by the great north desert, 19, 140; 

 nomadic tribes of, 50. 



Agouti, the antelope of South America, 

 12. 



Aguas Calientes, elevation of, 208. 



Ahuahuetes, a colossal species of tree, 274. 



Air, currents of, on the vertical ascent of, 

 266 ; influence of its pressure on plants, 

 292, 295, 296. 



Alders, 23J . 



Allco, a Peruvian dog, 218. 



Alleghanys, temperature of the, 102, 103. 



Almond tree, the Bertholletia excelsa, 

 158, 179. 



Aloes, one of the vegetable forms by 

 which the aspect of Nature is princi- 

 pally determined, 228, 332; various 

 species of, 334. 



Alpine regions; elevation and temperature 

 of, 84. 



Altai, mountain plateau of, 53 ; the moun- 

 tain-chain of, 63, 64. 



Aluates, the plaintive cry of the, 199. 



Amazon, plain of the, 6 ; the wild luxu- 

 riance of its regions, 19; called the 

 "Great River" by the natives, 155; its 

 extent, 157; boundless wooded plain 

 of the, 161. 



, Upper, plains of, 390; breadth of, 



at Tomependa, 401. 



Amentacese, 194, 285. 



America, migrations to, through Northern 

 Asia, 11, 131; absence of cereal food 

 in, 12; pastoral life unknown to the 

 aborigines, 12; on the cosmological 

 origin of, 105 ; the southern hemisphere 

 cooler than the northern, 107. 



, North, inclination of the eastern 



shore, 29; natural leatures and con- 

 figuration of, 31-40 ; no pastoral tribes 

 discovered among the aborigines, 42; 

 on the climate and distribution of heat 

 in, 102 et seq. 



, South, the vast Steppes of, 6, 8, 85 ; 



physical causes of the diminution of 

 heat, 7, 96 et seq.; presents a remark- 

 able similarity to the south-western 

 continent of the old world, 8, 105; cha- 

 racter of its vegetation, 10; aborigines 

 of, 11 ; cattle of, 1 1 ; quadrupeds of, 12, 

 133; the regions by which the Steppes 

 of, are bounded, 19; the wild luxuri- 

 ance of nature, 19; various races of 

 man, 20; mountain systems of, 30, 31; 

 forests of, 98; general disquisition on 

 the climate of, 96-109; vast savannahs 

 of, 98; early civilization of, 130, 131; 

 limits of European civilization in, 140; 

 carved rocks found in, 147-151 ; the 

 great rivers of, 155 et seq.; different 

 routes proposed in the unknown por- 

 tions of, 177; Schomburgk's journey 

 across the continent of, 176, 177; 

 the early maps of, 181 ; their uncer- 

 tainty, 182; immense extent of the 

 woody region between the plains of 

 2 G 



