THE LOESS OF SOUTHWESTERN IOWA 721 



tion. It remains to be seen whether a general recognition of the com- 

 plexity of the loess is to be followed by a satisfactory explanation 

 of the loessial and interloessial stages. Iowa, which has become 

 classic ground for the glaciologists, will undoubtedly afford much illu- 

 minating material to the students of the loess. 



O. W. WiLLCOX. 



Iowa State College, 

 Ames, Iowa. 



