GROUND-WATER 



47 



Fig. 32. A column of earthy matter weathered out. It was once a part of 

 the cliff. Its cap of rock keeps it from crumbling. 



Fig. 33. A tree growing in a crack 

 in the rock. The growth of the 

 tree widens the crack. Sierra 

 Nevada Mountains. California. 



Fig. 34. Masses of rock in the 

 roots of an upturned tree. 

 Yosemite Valley, California. 

 (From photo, by Fairbanks.) 



