Plants of Past Ages. 



357 



and Asia, but were able to find a congenial home in Ore- 

 gon and California. 



In all probability the northern flora in its southern migra- 

 tion attempted to disseminate itself throughout the breadth 

 of the continent, but some forms found themselves more 

 readily adaptable to the Atlantic slopes, some to the Mis- 

 sissippi valley, and others to the Rocky Mountains and 

 the regions west, so that now we find more or less distinct 



Fig. 193. 



Base of the giant Sequoia " General Grant." Photograph by SQUIRES. 



floras in these different regions. Along the eastern coast 

 of Asia, including the Japan islands, the physical condi- 

 tions approximated those of our Atlantic slopes, and we 

 find that in these regions, remote from each other, very 

 similar floras have been evolved from the common stock 

 which came to them during the migration in the glacial 

 period. 



229. Migration Northward. — When, for some reason, 



