VARIATION IN RAY FLOWERS OF ANTHEMIS 
COTULA AND OTHER COMPOSITES. 
BY H. S. FAWCETT. 
The object of this study was to determine the amount of 
variation occurring in the number of ray flowers of the 
Mayweed {Anthemis cotula L.), to compare the variations 
occurring in different localities, and also the variations in 
different plants of the same locality, and Anally to compare 
this variation with that of a few other species of Com- 
posite. 
For this study of Anthemis the plants of each locality 
were picked indiscriminately within a radius of perhaps 
100 feet. The count of the available heads of each plant 
was kept separately' for comparison, as shown in the 
appended tables. 
The counting of the ray flowers was done very carefully, 
and in order to avoid possible error, those heads injured by 
insects or other causes were discarded. One thousand three 
hundred and ninety-four heads of Mayweed were counted 
from seven different localities; four localities in Iowa, 
two, four and forty-five miles apart, and three localities in 
Washington state, Seattle, Bellingham, and Hot Springs. 
It will be seen by the tables that the predominating 
number of ray flowers in each locality was thirteen, with 
the exception of Seattle, where the number counted was 
not sufficient to give any evidence of a real difference. 
Tables and curves are shown for the entire number of 
heads counted, and also for those of each locality. It will 
be noticed that all these curves for the Mayweed are much 
steeper on the side below thirteen ray flowers, than above 
( 55 ) 
