Mutations 



63 



De Vries divided the new types of plants into five groups, 

 classified as follows : 



1. Retrograde varieties with 'negative attributes, 

 (E. Icevifolia, (E. brevistylis, and (E. nanella (Figs. 17 

 and 19). 



FIG. 19. (Enothera lata (left), (Enothera Lamarkiana (middle), 

 (Enothera nanella (right). 



2. Progressive elementary species possessing new 

 characters, and appearing as vigorous as the parent plant, 

 (E. gigas and (E. rubrinervis. 



