THE TREND OF EVOLUTION 179 



most potent factor in directing evolution though it is extremely 

 slow in its action and excessively wasteful. There is reason to 

 hope that in the near future intelligent human selection may 

 cooperate with natural selection, thus rendering progress more 

 rapid and more merciful. Certainly eugenical education should 

 begin to bear fruit, that is, more children of the better sort 

 and fewer of the worse variety, within the next generation. 

 Unless it does we may be sure that the time will come when in 

 a crowded globe natural selection will reassert itself and there 

 will be a return to "nature's simple plan" of promoting fitness 

 by the ruthless elimination of the unfit. 



THE IMMEDIATE AND THE DISTANT FUTURE 



The Immediate Future. In the midst of all these condi- 

 tions and tendencies of the human race, the decreasing in- 

 fluence of natural selection, the retrogressive selection of 

 civilization, the decreasing birth-rate of the more intelligent 

 classes, the increasing amalgamation of races, the rapid ap- 

 proach of the time when the earth will be fully populated and 

 its natural resources exhausted or greatly diminished, in the 

 whirl of all these changes it does not seem probable that human 

 evolution will long remain stationary. On the whole, it must 

 be admitted that these tendencies do not point to racial prog- 

 ress, and some of them presage retrogression, degeneration, 

 and decay unless they can be overcome. 



There is much in the modern world that reminds one of the 

 period of decline of former civilizations, and especially of 

 Greece and Rome, and many persons have wondered whether 

 our civilization is not traveling the downward road to a similar 

 end. In both Greece and Rome the decline was preceded by 

 a large amount of race mixture, and a decreasing birth-rate 

 among the higher classes, while it remained relatively un- 

 changed elsewhere. Momsen says that the decay of Rome 

 was due mainly to "the difference between the fertility of the 



