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EUROPE 



timber-trees and shrubs which diversify the continental 

 mountains, and generally for the poverty of plant forms. 

 In the lowlands, the Scots pine usually marks the 

 occurrence of dry, poor soils such as gravel and sand, 

 or again moor- lands ; with it generally appears the 

 heather, forming low heaths, which may be taken as 

 connoting infertile soils, either cold and devoid of lime, 

 or sandy and porous. 



FIG. 115. Turf-cutting on an Irish bog. 



The extension of moors in the plains is similarly con- 

 nected with poor glacial soils in Scotland and Ireland. 

 The wet moors, also called high moors or peat bogs, 

 originate in ill-drained areas supplied with pure siliceous 

 water. They are due to the enormous development of 

 several kinds of mosses, chiefly of sphagnum or peat- 

 moss, whose dead remains putrefy under unfavourable 

 conditions, namely, an excess of moisture and lack of 

 air : a similar result is produced by other plants, mainly 



