CANADA PORCUPINE 31 



The same thing appeared even more clearly when another 

 locking device was substituted for the lever. The plug gave 

 No. 4 considerable difficulty and it w^as necessary to rub it 

 with a piece of food to give it an odor in order to attract his 

 attention to it. Up to this stage, where appeal was made to 

 the olfactory sense, No. 4 had errors or failures in abundance, 

 but what he needed was a success. Nor are the porcupines 

 peculiar in this respect for other experimenters have experi- 

 enced similar difficulties and have usually resorted to the same 

 plan of solution. The necessity passes after a few trials in the 

 case of most higher animals. After operating the plug five 

 times the effort of porcupine No. 4 was directed toward the 

 plug as a means to an end, without examining to see if it were 

 good to eat. The button, which was the third device used, 

 gave even more definite results. The sixth trial again found 

 the animal with the problem solved. He operated the button 

 by putting one hand on the top of one end and the other hand 

 at the bottom of the other end, giving the button a quick, firm 

 turn till the internal mechanism squeaked. How significant 

 that sound was to No. 4 is only conjectural but he was consider- 

 ably disconcerted on one or two occasions when the sound did 

 not occur although the door of the box fell open as usual. The 

 hook gave No. 4 considerable trouble. It was of iron and he 

 persisted in opening it with his teeth. He also made the mis- 

 take, for some time, of pulling directly outward on it, but later 

 learned to operate it very dextrously. In the case of the hook 

 the third trial was a direct attack although his movements 

 were not properly co-ordinated till much later. Thus an aver- 

 age of 6.25±i.9 trials has enabled porcupine No. 4 to associate 

 these devices with the opening of the box if one may infer from 

 the first direct attack on the de^'ice then in use. This leads to 

 the belief that the mental association of the porcupine, in a 

 vague and general way at least, may often be far in advance of 

 his abihty to profit by experience, or, in other words, intelH- 

 gence may be in advance of dexterity which is usually taken 

 as the measure of intelligence. The same thing may be ex- 

 pressed in a less objectionable way by saying that it is easier 

 to get attention directed to the proper sensory stimuli than it 

 is to get that stimuli to discharge into the appropriate motor 

 responses. 



