PROCEEDINGS 
Q 
11 
I5X 
NH 
OF THE 
Iowa Academy of Science 
FOR 1920 
VOLUME XXVII 
THIRTY-FOURTH ANNUAL SESSION, HELD AT 
IOWA CITY, APRIL 23 AND 24, 1920 
^ ^ »9 3A' 
PUBLISHED BY 
THE STATE OF IOWA 
DES MOINES 
