DIS TRIB UTION OF MEM ORY 217 



that we are justified in substituting the term activity 

 of associative memory for the phrase consciousness 

 used by the metaphysicians. 



2. We have spoken of associative memory because 

 the word memory is often applied in quite a different 

 sense scientifically, namely, to signify any after-effect 

 of external circumstances. For instance, the term 

 memory has been used to account for the fact that a 

 plant which had been cultivated in the tropics will 

 often not endure low temperatures so well as a plant 

 of the same species which was raised in the north. It 

 is true in this case that preceding conditions influence 

 the ability of the plant to react, but the process differs 

 from the one which we have called associative memory 

 in the lack of associative processes. No definite stim- 

 ulus produces in a plant, in addition to its own effects, 

 those of another entirely different stimulus which at 

 some former time occurred simultaneously with the 

 given stimulus. It is probable that the tropical plant 

 is somewhat different chemically from the plant raised 

 in the north. This would account for its smaller 

 power of resistance. Further illustrations of a differ- 

 ent use of the word memory can easily be given. 



Many moths sleep during the day and wake in the 

 evening when it becomes dark. If kept for days in 

 a dark room, they will continue at first to do the same 

 thing. The same is true of certain plants. One 

 might also say in this case that the moth or the plant 

 " remembers " the difference between day and night. 

 It is probable, however, that internal changes take 



