688 Mutations 



ods for bringing additional instances to light. 

 These methods may direct effort toward two dif- 

 ferent modes of investigation. We may search 

 for mutable plants in nature, or we may hope 

 to induce species to become mutable by artificial 

 methods. The first promises to yield results 

 most quickly, but the scope of the second is 

 much greater and it may yield results of far 

 more importance. Indeed, if it should once be- 

 come possible to bring plants to mutate at our 

 will and perhaps even in arbitrarily chosen di- 

 rections, there is no limit to the power we may 

 finally hope to gain over nature. 



What is to guide us in this new line of work? 

 Is it the minute inspection of the features of the 

 process in the case of the evening-primroses! 

 Or are we to base our hopes and our methods on 

 broader conceptions of nature 's laws? Is it the 

 systematic study of species and varieties, and 

 the biologic inquiry into their real hereditary 

 units? Or is the theory of descent to be our 

 starting-point ? Are we to rest our conceptions 

 on the experience of the breeder, or is perhaps 

 the geologic pedigree of all organic life to open 

 to us better prospects of success ? 



The answer to all such questions is a very 

 simple one. All possibilities must be considered, 

 and no line of investigation ignored. For my- 

 self I have based my field-researches and my 



