94 ARE THE EFFECTS OF USE INHERITED? 



WEAKNESS OF USE-INHERITANCE. 



Use-inheritance is normally so weak that it 

 appears to be quite helpless when opposed to any 

 other factor of evolution. Natural selection evolves 

 and maintains the instincts of ants and termites 

 in spite of use-inheritance to a more wonderful 

 degree than it evolves the instincts of almost any 

 other animal with the fullest help of use-inherit- 

 ance. It develops seldom-used horns or natural 

 armour just as readily as constantly-used hoofs or 

 teeth. Sexual selection evolves elaborate structures 

 like the peacock's tail in spite of disuse and natural 

 selection combined. Artificial selection appears to 

 enlarge or diminish used parts or disused parts with 

 equal facility. The assistance of use-inheritance 

 seems to be as unnecessary as its opposition is 

 ineffective. 



The alleged inheritance of the effects of use 

 and disuse in our domestic animals must be very 



