Experimental Pedigree-Cultures 561 



same species growing in distant localities, and 

 it would be improbable they should be affected 

 in the same way. Hence we should conclude 

 that when a species is converted into a new type 

 in one locality it is only to be considered as one 

 of numerous possible ones, and its alteration 

 would not in the least change the aspect of the 

 remainder of the species. 



But even with this restriction the general be- 

 lief is not supported by the evidence of the even- 

 ing-primroses. There is neither a slow nor a 

 sudden change of all the individuals. On the 

 contrary, the vast majority reinain unchanged; 

 thousands are seen exactly repeating the orig- 

 inal prototype yearly, both in the native field 

 and in my garden. There is no danger that 

 Lamarckiana might die out from the act of mu- 

 tating, nor that the mutating strain itself would 

 be exposed to ultimate destruction from this 

 cause. 



In older swarms, such as Draba or Helianthe- 

 mum, no such center, around which the various 

 forms are grouped, is known. Are we to con- 

 clude therefore that the main strain has died 

 out? Or is it perhaps concealed among the 

 throng, being distinguished by no peculiar char- 

 acter ? If our gig as and ruhrinervis were grow- 

 ing in equal numbers with the Lamarckiana in 

 the native field, would it be possible to decide 



