GLACIAL PERIOD 



383 



enjoys a temperate climate. The greatest ice invasion 

 during this period extended from northern Canada across 

 New England into the sea, across the basins of the Great 



ARKA COVERED BY THE ICE OF THE GLACIAL PERIOD. 



Lakes and the upper Mississippi valley and across a part 

 of the Missouri valley. It wrapped in its icy mantle al- 

 most the entire region between the Ohio and Missouri 

 rivers and the Atlantic Ocean. 



Another great ice invasion spread out from the high- 

 lands of Scandinavia. As in later days the Norsemen, so 



