" USE" INCLUDES USEFULNESS. 93 



The inevitable simulation of use-inheritance may 

 be entirely deceptive. 



Darwin thinks that " there can be no doubt that 

 use in our domestic animals has strengthened and 

 enlarged certain parts, and disuse diminished 

 them ; and that such modifications are inherited." 

 Undoubtedly " such " or similar modifications have 

 often been inherited, but how can Darwin possibly 

 tell that they are not due to the simulation of use- 

 inheritance by natural or artificial selection acting 

 upon general variability ? Of the inevitability of 

 selection and of its generally adaptive tendencies 

 " there can be no doubt," and panmixia would tend 

 to reduce disused parts ; so that there must always 

 remain grave doubts of the alleged inheritance of 

 the similar effects of use and disuse, unless we can 

 accomplish the extremely difficult feat of excluding 

 both natural and artificial selection as causes 

 of enlargement, and panmixia and selection as 

 causes of dwindling. 



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