Changes in Geography and Climate. 47 



country, at the close of the Glacial Epoch, it was far 

 easier for animals and plants to cross from the Continent 

 than it is now. 



The reader will probably rise from the perusal of this 

 chapter with a confused idea of many small changes in 

 the limits of sea and land; which, however, were of no 

 very great importance as bearing on the past history of 

 our flora. This impression is, I believe, the correct one; 

 for, after twenty years' work at deposits belonging to the 

 periods here dealt with, I am greatly impressed with the 

 smallness and multitude of the changes, and with the 

 gradual way in which they occurred, as is demonstrated 

 wherever we can discover continuous records. The 

 climatic changes, on the other hand, though perhaps 

 equally gradual, were most thorough and sweeping ; 

 inevitably they must have been accompanied by corre- 

 sponding changes in the flora. 



