CHAPTER XX 



THE RELATIONS BETWEEN LAMARCKISM AND 

 DARWINISM ; NEOLAMARCKISM 



Since the appearance of Darwin's Origin of 

 Species, and after the great naturalist had converted 

 the world to a belief in the general doctrine of evolu- 

 tion, there has arisen in the minds of many working 

 naturalists a conviction that natural selection, or 

 Darwinism as such, is only one of other evolutionary 

 factors ; while there are some who entirely reject the 

 selective principle. Darwin, moreover, assumed a 

 tendency to fortuitous variation, and did not attempt 

 to explain its cause. Fully persuaded that he had 

 discovered the most efficient and practically sole 

 cause of the origin of species, he carried the doctrine 

 to its extreme limits, and after over twenty years of 

 observation and experiment along this single line, 

 pushing entirely aside the Erasmus-Darwin and La- 

 marckian factors of change of environment, though 

 occasionally acknowledging the value of use and dis- 

 use, he triumphantly broke over all opposition, and 

 lived to see his doctrine generally accepted. He had 

 besides the support of some of the strongest men in 

 science : Wallace in a twin paper advocated the same 

 views ; Spencer, Lyell, Huxley, Hooker, Haeckel, 

 Bates, Semper, Wyman, Gray, Leidy, and other rep- 



