282 



FOOT-NOTES TO EVOLUTION. 



organism " must break down sooner or later, man not 

 less than others. Senility brings even to the best some 



form of nerve decay. The wisest man 

 Degeneration of mugt cQme to second childhood g enil . 



senility. f 



ity may come prematurely as a result of 



influences adverse to mental and 

 physical activity. These influences 

 are manifold and the enumeration 



FIG. 25. Sacculina attached 

 to the crab. 



FIG. 26. Sacculina with 

 limbs absorbed. 



of causes and results of the weakness of old age need 

 not be attempted here. 



Race degeneration, or continuous decline from gen- 

 eration to generation, may be distinguished from the 

 wearing out of the individual. The for- 

 mer results from the continuous preser- 

 vation of the unfit. As the destruction 

 of the unadapted is the chief element of race progress, 

 so is their survival the chief element in race decay. De- 

 generation occurs when weakness mates with weakness ; 



Race 

 degeneration. 



