134 THE AMERICAN NATURALIST. 
[VoL. XXXVI. 











































































































































u 3 
Fic. 18. — Aster prenanthoides Muhl. Disk curve of 658 heads. 
7 
4i 

5 

[7 
€ 
n 


lasses doubled. Mean = 
C 
50.297872 + .165889 ; modes 48-49, 52-53 ; € = 6.310315  .117301. 
