70 THE IGE AGE IN NORTH AMERICA, 



Phleum alpinum, L August 26, 1,600 A. T, 



Elymus mollis August 6. 



Hordeuiu, sp. (?) August 6. 



Fie. 30.— Blocks of stone supported on ice-pillars, showing how they fall toward the sun- 

 See above, page 49. United States Geological Survey (Russell). 



