4'2 THE PRESENT. 



the waters? Next in order come the Acrogens the mosses, 

 equisetums, and ferns -the lovers of the swamp and shade, 

 and the colonists of emerging and new-formed lands. Of 

 rapid and widespread growth, they have ever contributed 

 to the consolidation of alluvial soils, and their remains 

 mingle largely with the coals and shales of the past, as they 



Gymnoftenous Aspect of Vegetation 



do now with the peat-bogs and mud-silts of the present 

 day. Less cosmopolitan than the amphigens, they still have 



