ILLUSTRATED AMONG PROTOZOA. 119 



and redivides, it adds continually new co-ordinations 

 to those already acquired ; the process of growth 

 and development comes by repetition to have the 

 character of reflex action, — becomes more rapid. 

 As the same forces act on each generation, and form 

 a series of stimuli which are similar for each gener- 

 ation, so each generation repeats in its life the 

 course of development followed by all its ancestors ; 

 or, more concisely, the continuity of the protoplasm 

 repeats in each generation the same series of re- 

 actions to stimuli that it has repeated, with addi- 

 tions, in each previous generation since it began 

 its existence. We have here the explanation of 

 growth, development, and inheritance. The illus- 

 tration just given shows how fundamentally the 

 three are related in their nature, being in reality 

 only different phases of one process. 



