86 



Plant-Breeding 



previous type. The whole plant departed absolutely 

 from the old type of its progenitors." 



What is true of the toad-flax is also true of the snap- 

 dragon and other unsymmetrical flowers the production 

 of peloric flowers by mutation. 



FIG. 26. Chrysanthemum segetum plenum. One of the six inflorescences 

 which in 1899 first exhibited true " doubling." The figure represents 

 the parent plant of the " double " variety. 



Experiments in the production of double flowers (Figs. 26- 

 29) . De Vries performed a series of experiments with the 

 corn marigold (Chrysanthemum segetum) with the object 

 of the production of double flowers. This plant has never 

 been known to produce double flowers. The cultivated 

 variety (grandiflorum) was found to be more stable and 

 was used as a basis of the experiments. This cultivated 



