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CLIMATE AND VEGETATION 
49 
dry, is not so in any excessive degree. 1 We see nearly the 
whole of Australia covered by lofty trees, yet that country 
possesses a far more arid climate. Hence we must look to 
some other and unknown cause. 
Confining our view to South America, we should certainly 
be tempted to believe that trees flourished only under a very 
humid climate ; for the limit of the forest-land follows, in a 
most remarkable manner, that of the damp winds. In the 
southern part of the continent, where the western gales, charged 
with moisture from the Pacific, prevail, every island on the 
broken west coast, from lat. 38° to the extreme point of Tierra 
del Fuego, is densely covered by impenetrable forests. On the 
eastern side of the Cordillera, over the same extent of latitude, 
where a blue sky and a fine climate prove that the atmosphere 
has been deprived of its moisture by passing over the mountains, 
the arid plains of Patagonia support a most scanty vegetation. 
In the more northern parts of the continent, within the limits 
of the constant south-eastern trade wind, the eastern side is 
ornamented by magnificent forests ; whilst the western coast, 
from lat. 4 0 S. to lat. 3 2° S., may be described as a desert : on 
this western coast, northward of lat. 4 0 S., where the trade wind 
loses its regularity, and heavy torrents of rain fall periodically, 
the shores of the Pacific, so utterly desert in Peru, assume near 
Cape Blanco the character of luxuriance so celebrated at 
Guayaquil and Panama. Hence in the southern and northern 
parts of the continent, the forest and desert lands occupy 
reversed positions with respect to the Cordillera, and these posi¬ 
tions are apparently determined by the direction of the prevalent 
winds. In the middle of the continent there is a broad 
intermediate band, including central Chile and the provinces of 
La Plata, where the rain-bringing winds have not to pass over 
lofty mountains, and where the land is neither a desert nor 
covered by forests. But even the rule, if confined to South 
America, of trees flourishing only in a climate rendered humid 
by rain-bearing winds, has a strongly-marked exception in the 
case of the Falkland Islands. These islands, situated in the 
same latitude with Tierra del Fuego and only between two and 
three hundred miles distant from it, having a nearly similar 
1 Azara says, “Je crois que la quantite annuelle des pluies est, dans toutes ces 
contrees, plus considerable qu’en Espagne.”—Vol. i. p. 36. 
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