288 THE EARTH'S SURFACE AND PLANT LIFE 



accumulating masses of snow and ice, hundreds of feet 

 thick, are formed. The ice then slowly flows down a val- 

 ley till a point is reached where the melting at the end is 

 equal to the forward movement. An ice stream of this 



CORNER GLACIER 

 A typical Alpine glacier. 



kind is called a valley glacier or an Alpine glacier, because 

 first studied in the Alps. 



Although the moving ice conforms to the bed over which 

 it passes, it does not yield itself to the irregularities as 

 easily as does water. When it passes through a narrows 

 or over a steep and rough descent, it is broken into long, 



