184 THE STUDY OF ANIMAL LIFE CHAP. 



into any inanimate material system is attended by effects 

 retardative to the transfer and conducive to dissipation." 

 But the young leaf growing in the sunlight utilises the 

 solar energy acceleratively ; the more it gets, the more 

 it grows, and the more it can take. " The transfer of 

 energy into any animate material system is attended by 

 effects conducive to the transfer and retardative of 

 dissipation." On what this peculiar power depends, 

 Prof. Joly does not tell us that would be the secret of 

 life ; but it is interesting to get from a physicist a clear 

 statement of the dynamic contrast between animate and 

 inanimate material systems. The animate system is 

 aggressive on the energy available to it, spends it with 

 economy and invests it with interest, till death finally 

 deprives it of all." 



3. Effective Behaviour, Registration of Experience, 

 and Variability. The common note in this triad of 

 qualities is agency, self-expressicn, creativeness. (a) Life 

 is a kind of activity that comes to its own in effec- 

 tive behaviour, that is to say, in an organically deter- 

 mined correlated series of acts which converge towards 

 a definite result. Even an Amoeba goes on the hunt and 

 shows effective concatenation of activities. 



(b) The effectiveness which is so characteristic of the 

 behaviour of animals appears to depend on profiting by 

 experience in the individual life-time ; or on the entailed 

 results of ancestral experiments (chiefly, perhaps, in the 

 form of germinal variations) ; or, usually, on both. As 

 W. K. Clifford said : "It is the peculiarity of living 

 things not merely that they change under the influence 

 of surrounding circumstances, but that any change 

 which takes place in them is not lost, but retained, and 

 as it were built into the organism to serve as the founda- 

 tion for future actions." As Bergson puts it: ; Its past, 

 in its entirety, is prolonged into its present, and abides 

 there, actual and acting." As Jennings says : "We know 

 as solidly as we know anything in physiology that the 

 history of an organism does modify it and its actions- 

 in ways not yet thoroughly understood, doubtless, yet 

 none the less real." 



