242 THE INTELLIGENCE OF MAMMALS 



events is too great. But if (A) can be associated with (B) 

 over an interval of ten seconds why can it not be directly 

 associated with the impulse (C) over an interval but slightly 

 greater? Ten seconds after (A) the cat sees (B), eleven 

 seconds after she performs (C). That the cat had pre- 

 viously associated (B) and (C) does not necessarily play 

 any part in the process. The experiment proves only that 

 some sort of a neurosis persists from (A) during ten or more 

 seconds of time; but it fails to afford any proof of the r6le of 

 the idea (B) in the process. It shows the persistence of 

 impressions, not the association of ideas. Indirectly it 

 may support the theory of association. If the neurosis of 

 (A) persists and is accompanied by consciousness in the 

 form of an idea of (A), ideas of (B) probably occur also, and 

 if ideas occur why may they not become associated as well 

 as impressions and impulses? Such ideas may be more like 

 after-images in ourselves, but no sharp line can be drawn 

 between the latter and ideas properly so called. While 

 such an experiment as the one described may not prove the 

 association of ideas it may serve to make association more 

 probable by showing the persistence of impressions. 



The experiments of L. W. Cole on the raccoon yielded 

 better evidence of the existence of ideas than the investiga- 

 tions of Thorndike, owing perhaps to the greater degree of 

 intelligence of the animals employed. Raccoons learned to 

 get out of a box with seven fastenings consisting of two 

 buttons, two loops, a thumb latch, a treadle and a hook. 

 They were first put into boxes with one or two of these 

 devices, and when these were learned others were added until 

 the above combination was reached, which seemed to be 

 about the limit of a raccoon's learning capacity. The rac- 

 coons in attacking the fastenings did not take them up in 

 any constant order in successive trials, but they showed a 



