174 SCIENCE REMAKING THE WORLD 



of increase, the equilibrium of species, variation, and 

 artificial selection, from which natural selection was the 

 inevitable inference. In brief, it claims that nature 

 selects among variations, that the method of selection 

 is competition, that the result is the destruction of the 

 relatively unfit, or as Spencer put it, the "survival of 

 the fittest." In brief, the theory is really an explana- 

 tion of what is called adaptation. 



As facts multiplied, the current explanations of 

 evolution were found to be inadequate to explain some 

 of them. This led to a general misunderstanding of 

 the situation by the uninformed public. For example, 

 more intensive study developed the fact that Darwin's 

 explanation does not always explain. His name is so 

 identified with evolution in public thought, that this 

 criticism of the universal application of his conclusions 

 by certain scientific men was taken to mean that the 

 theory of evolution was being abandoned. The real 

 situation is that every proposed explanation may prove 

 inadequate, and yet the fact of evolution remains to be 

 explained. 



All of the explanations offered are partial explanations 

 which simply means that no one of them applies to all 

 the facts. We need them all and more besides. So far 

 from being abandoned, evolution is the basis of all bio- 

 logical work to-day. 



The method of comparison and inference continued 

 until the beginning of the present century. Then came 

 a new epoch in the history of evolution. 



3. EXPERIMENTATION. This may be called the 

 modern period, in contrast with the mediaeval and 



