MODERN FAUNA AND FLORA. 



607 



and even Man himself appear to have been driven away, yet 

 observations made on the vitality of seeds preclude the inference 

 that many Plants were exterminated, for even in modern railway- 

 cuttings numerous forms unknown to a district, or previously 



destroyed, spring up from the newly-exposed subsoils. Be this 

 as it may, when the Glacial conditions were passing away, and 

 before vegetation had again covered the land, denuding forces 

 must have acted with greater facility than is now possible. So 



