170 Dynamic Evolution 



from the more slowly moving generations. 

 There are more recent investigations by 

 others of degenerate families, but, unfortu- 

 nately, the published reports do not give 

 information in regard to either of the factors 

 of energy, or the directions in which energy 

 was expended. 



It is evident from the preceding examina- 

 tion that muscular strength and mental 

 strength stand on the same basis. Each is a 

 special form of the same energy we know in 

 the inorganic world, and each may be in- 

 creased in amount by using it to do work. 

 By an increasing amount of mental work, 

 performed generation after generation, the 

 mental power of human beings may be 

 raised by successive stages to an indefinite 

 extent. The same examination also shows us 

 that if we decrease the amount of mental 

 work performed between generations, each 

 such decrease will result in a step downward 

 in intelligence, and that several steps in 

 succession produce criminals, paupers, and 

 prostitutes. 



