8o WHAT EVOLUTION IS 



3. LAMARCKISM CRITICIZED 



Notwithstanding the ease with 

 which Lamarckism appears to pro- 

 vide the necessary machinery for the 

 evolutionary process, this hypothesis 

 is not free from serious defects. Dar- 

 win considered it as a possible factor 

 in evolution but did not lay much 

 stress upon it. It was not until after 

 Darwin's time that Lamarckism came 

 into prominence in consequence of the 

 contrast between it and natural selec- 

 tion. Half a century ago a new 

 school, chiefly paleontological, arose 

 which, under the name of neo-La- 

 marckian, attempted to establish and 

 expand the principles of Lamarck. 

 This school was opposed by the neo- 

 Darwinians who, under the leader- 

 ship of Weismann, made a vigorous 

 onslaught against Lamarckism and 



