Individual progress implies habit 13 



Before attempting to attack this problem 

 directly there is however still a characteristic 

 of life or experience that we may for a moment 

 consider, which seems to throw some light 

 upon it. Experience I once proposed to 

 define as the process of becoming expert by 

 experiment; and recent elaborate observa- 

 tions^ of the behaviour of the Protozoa shew 

 that these microscopic creatures frequently 

 succeed, as we do, only by way of trial and 

 error. Even plants prove capable to a great 

 extent of accommodating themselves to 

 changes in their environment. All this pre- 

 supposes a certain plasticity, which in turn 

 implies retentiveness : in other words, just 

 as later generations inherit from earlier 

 generations so later phases of the individual 

 inherit, as it were, from earlier phases. In 



^ H. S. Jennings, Contributions to the Study of the Behaviour 

 oj the Lower Organisms, Washington, 1904. 



