WHAT EVOLUTION IS 17 



days of Lamarck the chief question 

 was on the modifiabihty of species, 

 and on this first Hne of attack the 

 forces of evolution received for the 

 time being a serious setback. But 

 under Darwin and Huxley a new of- 

 fensive was launched, and after a 

 vigorous campaign both objectives 

 were attained. It is to the credit of 

 Charles Darwin, and his body of able 

 supporters, that the scientific world 

 was finally brought to accept the prin- 

 ciple of descent with modification, 

 and natural selection as the means 

 whereby it was accomplished. 



The evidence that convinced the 

 world in Darwin's day that descent 

 with modification, and not special 

 creation, was the means of peopling 

 the present globe with its variety of 

 living forms was meager in the ex- 

 treme as compared with what might 

 be drawn upon to-day, but it never- 



