Reconquest of the Water 



No doubt at every flood the '' white " water deposits 

 a minute film of sediment all over Hylaea, and in pro- 

 cess of time this may perhaps become a rich and fertile 

 pampas like that of the Argentine. 



It is this last great country which is perhaps the most 

 striking example of the geological importance of the 

 plant world. From Buenos Ayres on the Atlantic, the 

 express train which starts for the Pacific Coast passes 

 over one flat, illimitable, scarcely undulating plain, until 

 at Mendoza, some 1047 kilometres (655 miles) away, it 

 reaches the Andine foot-hills. 



The flatness and monotony of this Pampas is only 

 perhaps really interesting at sunrise or sunset, to which 

 the enormous horizon gives spaciousness and dignity. 

 But even the most casual traveller is struck by its 

 fertility. Vigorous alfalfa, rich crops of wheat and 

 Indian corn luxuriate in a soil which is for the most 

 part rich alluvial silt, mixed with the lime and other salts 

 brought down from the Cordillera of the Andes. 



The whole country was once the Pampean sea, whose 

 waters extended to the eastern slopes of the Andes. 

 Then it became a land of lagoons and morasses with 

 sluggish silt-laden and winding rivers, and now it is the 

 Argentine Pampas. Unfortunately there is not enough 

 rain from the Atlantic to sufficiently supply more than 

 the eastern edges of the Argentine, but there can be no 

 doubt that it is all the work of plants, especially of 

 reed-thickets and brakes of trees, such as have been 

 described in this chapter. 



The importance of this process of valley-land forma- 

 tion has not yet been appreciated either by geographers, 

 geologists, or men of business. Still less have any 

 practical steps been taken to assist or stimulate this im- 

 portant work. On the contrary, it is in most places 

 delayed as much as possible by the pernicious habit of 



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