414 IOWA ACADEMY OF SCIENCE Vol. XXV, 1;;18 



The accompanying- table shows the date for each of the four 

 years on which the first flower of a number of representative 

 plants was collected. xV comparison of the four springs in terms 

 of plant development may more readily be had from the graph. 

 It is interesting that while the spring of 1918 did not start off 

 as early as the spring of 1917, it soon became earlier and was 

 the earliest of the four years studied until about the middle of 

 April when the few weeks cold weather caused it to be<x>rae rela- 

 tively later. 



If opportunity is afforded, the writer hopes to continue the 

 record for several years, which will make possible a more com- 

 plete and more accurate study. 



