224 journal of Cofnparativf Neurology and Psychology. 



each fastening perceptible to the animal. It might at least be 

 arranged that each act should bring the animal nearer to the food. 

 Until this has been done we cannot confidently assert that an 

 animal cannot learn to perform a series of acts in a fixed order. 



In Box 21, which had three hitherto untried fastenings and in 

 which the plug was extremely difficult to draw, all the raccoons 

 failed in their first and second attempts. The average time 

 required for their first success was 132 seconds, for the second, 85 

 and for the third, 37. Some failures followed the third trial in the 

 records of all except No. 3. The records in this box serve to show 

 the rate of learning ot raccoons compared with the more slowly 

 formed associations of cats. 



All the raccoons showed a tendency to abbreviate their acts. 

 They would merely turn toward a loop without clawing it or make 

 a slight motion toward it without touching it. 



Only rarely did one of the raccoons press down two buttons 

 simultaneously. In Box 12, liowever, raccoon No. 3 was observed 

 to try to pull a loop while standing on the platform whose depres- 

 sion raised another bolt. The next day he succeeded several 

 times and finally settled down to doing both these acts at the same 

 moment. A few days later No. 4 had also combined these two 

 acts, and thereafter she did both simultaneously in about one-half 

 the trials. The other two raccoons never combmed these acts. 

 Often the thumb-latch and one button would be worked simul- 

 taneously; but this, we believe, was a mere physical convenience, 

 since the animal could press on the latch with one forepaw^ and 

 depress the button with the other without changing the position 

 of its body. 



Variability. — I have shown that in a series of acts no routine 

 order was established. Was there variation in the method of per- 

 forming the act ? Box 14 was fastened with a horizontal hook 

 which could not be raised with the paw and was therefore very 

 difficult for the animals to learn. All except No. 2 lifted it with 

 the nose; he did the act with his teeth for thirty trials and only 

 twice the first half-day with his nose, and six times the second half- 

 day, up to the twentieth trial. That time he raised the hook with 

 his nose and continued to do so thereafter. He was escaping by 

 means of the mouth reaction in the average time of two and one- 

 half seconds, so he had fully mastered the mechanism before 

 changing thus abruptly to the muzzle reaction. All of the rac- 



