134 DEVELOPMENT AND HEREDITY. 



unicellular organisms (and I can conceive no other 

 reasonable interpretation of the facts), then the same 

 must be admitted for multicellular organisms. For, 

 in neither case, is it a process dependent on the 

 malleability or plasticity of the body or soma of the 

 organism ; but it is a process of acquiring new ner- 

 vous co-ordinations, — just as it is a chiefly nervous 

 difference which we observe to exist between the 

 amoeba, with its slow pseudopoda, and the infusorian, 

 with its quivering cilia. 



