CHAPTER XIII 
NORTHERN STATES OF SOUTH AMERICA 
The great continent of South America (Pig. 18), with its 
roughly triangular shape, is not much smaller than its 
northern relative. The basis of the triangle facing northward 
is bounded by the Caribbean Sea, and the two other sides 
by the Atlantic and Pacific Oceans respectively. There is 
a very general impression that the west coast of South 
America is mountainous, the remainder being a vast plain. 
This is not quite correct. A northern continuation of 
the long chain of the Andes skirts also the southern shores 
of the Caribbean Sea, while to the south-east of it lies the 
highland of Guiana and further south the Brazilian highland. 
The two eastern highlands—that of Guiana and Brazil—are 
broken into two parts by the Amazon valley. The space 
between these eastern highlands and the Andes is occupied 
by the central lowlands. We might say, therefore, that the 
three great natural regions of South America are the eastern 
highlands, the central lowlands and the western Cordillera. 
The Amazon, Orinoco and La Plata—the three great streams 
—all drain eastward. 
The main part of the continent has a tropical climate. 
Sub-tropical and temperate conditions prevail in the south. 
The climate of the Brazilian region is exceptionally favour¬ 
able for a luxuriant development of the fauna and flora, 
whereas certain parts of what Dr. Wallace called “ the Chilean 
sub-region ” are arid, and inimical to expansion and specific 
differentiation of animals and plants. 
Although our acquaintance with the fauna, flora and 
geology of this vast continent is naturally much less complete 
than that of North America or Europe, we possess unmis¬ 
takable evidences of the fact that South America has under¬ 
gone considerable alterations in the distribution of land and 
