CANADA PORCUPINE 17 



capable was exercised. Close observation, however, showed that 

 when food was seized with the right hand it was transferred to 

 the left in the act of cramming it into the mouth, leaving the 

 right hand free to reach for the next morsel. Thus the two 

 hands were used alternately when all went regularly; but when 

 the right hand failed to provide food for the left to pass into 

 the mouth, the action of the left hand which habitually fol- 

 lowed that of the right hand had nothing to express itself upon. 

 It was, therefore, the hand which, on the principle of the reflex 

 arc, one would expect the animal to employ in getting his next 

 particle of food. When this hand received the food and carried 

 it to the mouth, it performed the feeding act without transfer to, 

 or assistance from, the right hand. In this way the normal 

 rhythm was restored which was for the right hand to be extended 

 for the food after the left had finished putting the last portion 

 into the mouth. And thus the irregular behavior is explainable 

 as a simple reflex — the perfect working of a well formed habit. 

 No. 4 in the first test was fed from the experimenter's right 

 hand and also developed a righthandedness, after showing con- 

 siderable tendency to be ambidextrous. Soon afterward, this 

 animal became lame in one hind foot and could not stand well, 

 so work was discontinued even before the process had been 

 perfected, but not until there was no doubt of the direction in 

 which he was tending. Two months later, after No. 4 had 

 spent his time on puzzle -box and maze work, with no inter- 

 vening hand training, he was started again. He was believed 

 to be free from any set tendency with his hands due to the few- 

 days' earlier experience. But this time the experimenter pre- 

 sented food with his left hand. The animal showed the same 

 tendency to use both hands but delevoped a lefthandedness, 

 using the right hand alone only once in 600 times. No. 6 was 

 fed from the experimenter's left hand and varied the procedure 

 by becoming righthanded, using the left hand only once in 406 

 trials. No. 9 was fed from the experimenter's left hand. He- 

 began taking the food with the left hand, used the right hand 

 on the 1 8th reaction, and not again till the 79th with only five 

 lefthanded reactions in 700. No. 8 was fed from the experi- 

 menter's right hand and used the left hand only twice in the 

 first 20, twice in the sixth 20, and no more in 625 reactions. 

 No. 7 was fed from the experimenter's left hand and became 



