LUTHER BURBANK 



aware that all species of plants as well as animals 

 have been evolved in past ages by a development 

 from earlier forms, but you very probably sup- 

 posed that this creative process has now come 

 to a standstill. Let me assure you, then, that this 

 process is going on to-day very actively, in all 

 probability quite as actively as at any time in 

 the past. 



"Species of plants in a state of nature are 

 constantly hybridizing, and new species are 

 being developed under our eyes. 



"There is nothing anomalous about the case 

 of the tarweeds, although they afford a very 

 interesting illustration of the development of 

 which I speak. The same thing may be observed 

 in the case of certain genera of the mint family. 

 Here in some cases the hybrids thrive almost to 

 the entire exclusion of the parent species. In 

 other cases they gradually disappear, being too 

 unstaple to establish themselves by seed. 



"Everything, of course, depends upon the 

 qualities of the hybrid. If it is well adapted to 

 the environment it survives. If better adapted 

 than its parents, it probably runs them out alto- 

 gether. But, on the other hand, if the hybrid 

 is less well adapted than the parent forms to 

 make its way in the world, it is of course weeded 

 out by natural selection." 



[34] 



