CHAPTER II 



STAGES IN HUMAN EVOLUTION 



WHEN we look at a great mountain, we 

 notice first its height and shape. We 

 observe its cliffs and great rock 

 masses, its summit in the clouds. As we approach 

 nearer we see that its slopes are covered with 

 pastures and forests abounding in life. We know 

 something about the mountain. The geologist 

 tells us that it is composed of material which 

 was slowly accumulated at the bottom of some 

 primeval sea. Age after age contributed to its 

 bulk. Its strata bear witness to the life of the 

 different periods of its formation. Gradually it 

 was raised to the surface, and then lifted or 

 crowded to more than its present height. It has 

 been hardened by pressure, plowed and scored 

 by glaciers, broken by frost, and polished by 

 wind and rain. Very gradually it has gained its 

 present form and height from a very humble ori- 

 gin. Now we begin to understand the mountain. 



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