THE CHICAGO EXPERIMENTS WITH RACCOONS 169 



experiments and my own the raccoons responded to the constant 

 factor. What more could they do, pray ? This seems to me 

 to be an excellent example of the method of agreement. 



But this was the behavior of Jill, the single raccoon which 

 succeeded in discriminating in their experiments. One would 

 suppose that no very weighty conclusions would be drawn from 

 the behavior of the animal which failed. But he is said to have 

 responded to the sounds of the levers. Their "usual sound." 

 (P. 248.) (Why not make the levers noiseless ?). This animal 

 then responded to sound, perhaps partly to lever order and, 

 I have no doubt, to any other element of the situation which was 

 left constant, and which also enabled him to get food. "He 

 seemed to watch the peep hole, although possibly he was merely 

 listening for some sound upon which to base his reactions" 

 (P. 246), so they set a metronome going to drown the noises 

 made by movements of the experimenter! 



I confess I can see nothing in these experiments except a 

 rather determined effort to divert the animal's attention from 

 the cards and to get him to respond to the levers. The following 

 items seem to show this: 



1. Two days preliminary training on levers alone. 



2. The board screen was reduced to "about five inches" in 

 width (p. 244), thus showing apparently two thirds of the 

 length of the levers, if Figures 2 and 4 (pp. 243 and 247) correctly 

 represent the apparatus. 



3. Putting the cards above the raccoon's line of vision, if 

 Figure 4 is correct. 



4. Converting my visual experiment into a tactual one by 

 letting the raccoon touch the levers. 



5. Adding the cue of noises in operating the levers, as well 

 as noises due to the experimenter's movements. 



6. Each of the three strings attached to the levers (Figure 

 4, p. 247) must have changed from slack to taut before the lever 

 appeared, thus further directing the animal's attention to the 

 levers' positions. I am unable to find "controls" against the 

 animals having reacted to the strings. 



7. Feeding the raccoon for having reacted to the levers. . 



8. The colored cards were much smaller than mine. 



9. Finally only one of their animals succeeded in discriminating 

 as compared with four of mine. 



