536 



STRUCTURE AND LIFE HISTORIES 



tion. The great contribution of de Vries is that he demon- 

 strated that evolution may be studied by the method of 

 experimentation. The next step for him to take after 

 discovering the two forms that he supposed to be mutants, 

 was to breed them in carefully guarded, pedigreed cultures 



FIG. 402. Giant evening-primrose (Enothera gigas, a mutant from 

 (Enothera Lamarckiana, originated in 1895. (Cf. Fig. 401.) (After de 

 Vries.) 



in his garden, and also to breed the parent form, (Enothera 

 Lamarckiana, and see if he could observe the two forms 

 above mentioned, or other mutants, arise from seed pro- 

 duced without crossing with any other species. 



The entire story of this classical series of experiments 

 is too long to be told here. Suffice it to say that de Vries 

 did observe numerous other aberrant forms arise, and also 



