VII] PLANT POPULATION 119 



question is the origin of those variations. Variants 

 from the type are classified as (a) Mutations, and 

 (b) Fhictuating Variations, and it is commonly held by 

 those who are engaged with enquiry into such matters 

 that the Mutations bring considerable divergence 

 from the type and are transmitted to the oiFspring, 

 while Fluctuating Variations involve as a rule minor 

 divergence from the type and are not transmissible to 

 the offspring. More especially has it been insisted 

 upon that characters acquired during the individual 

 life of the parent are not transmitted to the offspring. 

 It has been shown, it is true, that certain considerable 

 variations which are held as spontaneous Mutations 

 are transmissible, and that certain minor variations 

 rightly held as fluctuating variations are not trans- 

 mitted. But what is not yet proved to the satisfaction 

 of all is that no acquired characters are in whole or 

 in part transmissible : nor is it clear that there is 

 necessarily a distinction between minor mutations 

 and fluctuating variations. The precise statement of 

 the distinction between these two categories, and the 

 assumption on the basis of a limited experience that 

 the one is inherited by the offspring and the other 

 not, has placed an obstacle in the way of understanding 

 how direct adaptation to environment can possibly 

 proceed. It is hard indeed to believe that all the 

 wonderful aitconunodations of organisms to their sur- 

 roundings are the product of blind chance. If there 



