Plate XVII. 
CM 
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.jMOjLl LjJOd UO g^D9LI 'OU 
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VJ 
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1 ^ 
^ t 
w 
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V 
- 
>0 
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nS 
Fig. 2. Variability curves for .4 wiTiewis coiMia. Fig. 1. Figures at the top iadicate the number of rays, those at the left the 
number of heads. Anthemis cotula. Two miles north of Ames. 
