288 THE FITNESS OF THE ENVIRONMENT 



effects of vitalistic control of its evolution, 

 just as we perceive in a house not only the 

 material structure, but the idea of the archi- 

 tect. Further, the origin of life itself remains 

 shrouded in mystery. Meanwhile, for most 

 men physiology has become merely biophys- 

 ics and biochemistry, and mechanism is un- 

 doubtedly firmly established throughout every 

 department of the science. 



Such limitations of the vitalistic hypothesis, 

 damaging though they may be, do not de- 

 stroy its claim to consideration as a controlling 

 factor of the processes of evolution, embry- 

 ology, repair, etc., in spite of the fact that 

 even here it has suffered serious though less 

 complete reverses. In 1859 Darwin's natural 

 selection offered itself as a possible substi- 

 tute for vitalism in a part or the whole of this 

 field, and soon gained very general accept- 

 ance. The survival of the fittest has now 

 become in the judgment of all biologists an 

 unquestioned force in the molding of life. 

 Therefore, at best, but a restricted scope 

 within its restricted field remains to vital- 

 ism. 



From the earliest days of the new hypothesis 

 it has been widely recognized that to accept 

 the survival of the fittest as one factor in the 

 adaptation of life to its environment is quite 



