THE SURFACE OF THE EARTH. 



Not only is the torrid zone by the abundance and luxuriance 

 of its organic forms most rich in powerful impressions, but it pre- 

 sents another and greater advantage, in the uniform regularity 

 which characterises.the succession of its meteorological and organic 

 changes. The well marked lines of elevation which separate the 

 different forms of vegetable life, demonstrate in a striking manner 

 the same play of general and invariable laws, which govern the 

 celestial motions reflected in terrestrial phenomena. Thus, in the 

 burning plains which stretch nearly on the level of the sea in these 

 regions, we behold in profusion the families of bananas, of cyca- 

 dacese, and of palms, of which the number of species included in the 

 Floras * of the tropical regions, has been so wonderfully augmented 

 by modern botanic travellers. To these succeed, on the slopes of 

 the Cordilleras, in the mountain valleys, and in humid and shaded 

 clefts of the rocks, tree-ferns raising their thick cylindrical stems, 

 and expanding their delicate foliage, whose lace-like indentations 

 are seen projected against the deep azure of the firmament. 

 There, too, flourishes the cinchona, whose fever-healing bark is 

 deemed the more salutary, the oftener the trees are bathed and 

 refreshed by the light mists, which form the upper surface of the 

 lowest stratum of clouds. 



Immediately above the region of the forests the ground is 

 covered with white bands of flowering social plants, small aralias, 

 thibaudias, and myrtle-leaved andromedas. The alp-rose of the 

 Andes, the magnificent befaria, forms a purple girdle round the 

 spiry peaks. On reaching the cold and stormy regions of the 

 Paramos, shrubs and herbaceous plants, bearing large and richly- 

 coloured blossoms, gradually disappear, and are succeeded by a 

 uniform mantle of monocotyledonous plants. This is the grassy 

 zone, where vast savannahs clothe the high tablelands and the 

 wide slopes of the Cordilleras, whence they reflect a yellow hue, 

 savannahs, on which graze llamas and cattle descended from those 

 formerly brought from the Old World. Trachytic rocks next 

 appear forcing the turf and rising high into those strata of the 

 atmosphere containing a less proportion of carbonic acid, and 

 supporting only plants of inferior organisation, such as the lichens, 

 the lecideas, and the many-coloured dust of the lepreria, which 

 forms small round patches on the surface of the stone. 



Scattered patches of fresh fallen snow arrest the last feeble 

 traces of vegetation, and are succeeded by the region of perpetual 

 snow, of which the lower limit is distinctly marked, and undergoes 

 but little change. 



* The collection of vegetable productions natural to a country is called 

 its flora, and that of the animals indigenous to it its fauna. 

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