PLATE 33 



The degree of fluctuation in corolla diameter of flowers on plants 

 of variety I, variety III and of flowers on plants of the cross 111$ X Ic?, 

 on each of sixteen different days between September 15 and November 6. 

 The heights of the columns represent the relative number of flowers 

 measured, of the various diameters noted as occurring in the flowers of 

 the two varieties and the cross between them. 



[166] 



