238 matured Miracles 



for the arctic plants to seek refuge on these 

 isolated elevations, such as the continental 

 mountains furnish. 



Thus it will be seen that the progression and 

 recession of the ice have not only formed great 

 lakes, changed river beds, and covered a mil- 

 lion square miles of area with glacial drift 

 averaging fifty feet in depth, making many 

 waterfalls and giving variety to the surface of 

 the earth, besides producing the finest agri- 

 cultural region in the world, but have also 

 given variety to our forests and plants wher- 

 ever this ice sheet has extended. 



