86 EVOLUTION, SOCIAL AND ORGANIC 



while in the mutation it remains on a new 

 base. 



Everybody has heard something of the fa- 

 mous evening primrose which gave DeVries 

 his first and most conclusive evidence of mu- 

 tation. At Hilversum near Amsterdam, he 

 discovered a large number af the plants of the 

 evening primrose, named Lamarckiana after 

 Lamarck. It is an American plant imported 

 to Europe. It often escapes from cultivation 

 and in this case DeVries says it had escaped 

 from a park. It had run wild ten years. A 

 year after first noticing them DeVries ob- 

 served two new forms which he at once rec- 

 ognized as two new elementary species. 



In the test conditions of his own garden, in 

 an experiment covering thirteen years, he 

 observed over fifty thousand of the Lamarcki- 

 ana spread over eight generations and of these 

 eight hundred were mutations divided among 

 seven new elementary species. These muta- 

 tions, when self-fertilized, or fertilized from 

 plants like themselves, bred true to them- 

 selves, thus answering the test of a real spe- 

 cies. DeVries also watched the field from 

 which his original forms were taken, and saw 

 that similar mutations occurred there so that 

 they were not in any way due to cultivation. 



Thus has the modest mutating primrose 



