Origin of Wild Species 597 



»endently at least thrice, at different periods 

 ,nd in distant localities. 



From all these statements and a good many 

 ithers which can be found in horticultural and 

 >otanical literature, it may be inferred that 

 nutations are not so very rare in nature as is 

 )ften supposed. Moreover we may conclude 

 ;hat it is a general rule that they are neither 

 >receded nor accompanied by intermediate 

 iteps, and that they are ordinarily constant 

 :rom seed from the first. 



Why then are they not met with more often? 

 In my opinion it is the struggle for life which is 

 ;he cause of this apparent rarity ; which is noth- 

 ng else than the premature death of all the in- 

 iividuals that so vary from the common type of 

 ;heir species as to be incapable of development 

 mder prevailing circumstances. It is obvious- 

 y without consequence whether these deviations 

 are of a fluctuating or of a mutating nature. 

 Elence we may conclude that useless mutations 

 will soon die out and will disappear without 

 leaving any progeny. Even if they are pro- 

 duced again and again by the same strain, but 

 ander the same unfavorable conditions, there 

 will be no appreciable result. , 



Thousands of mutations may perhaps take 

 place yearly among the plants of our immediate 

 vicinity without any chance of being discovered. 



