MENTAL LIFE OF MONKEYS AND APES 71 



(d) June 29, movement to box at right end of group, hesita- 

 tion before it, and turning through a complete circle so that the 

 second box from the right was faced. This, the correct box, was 

 often promptly entered. This method, if persisted in, would 

 obviously have yielded solution of the problem. 



(e) July 5, approach to and pretense to enter the box next 

 to the right end (right one), and then choice of some other box. 

 This feint is pecuharly interesting, and its origin and persistence 

 are difficult to account for. 



(f) In connection with the tendency to pretend that he was 

 going to enter the second box from the right end, Julius developed 

 also the tendency to turn around in front of the box at the right 

 end, starting sometimes to back into it, and then to enter, in- 

 stead, the box second from the end. 



(g) July 6 and 7, a fairly definite tendency to take the one 

 next in order or, instead, to go directly to the right box. 



(h) July 10, direct first choices without approach to other 

 boxes appeared for the first time on this date. 



For this problem, it proved impossible to establish and main- 

 tain uniform conditions of experimentation. Instead, because 

 of the failure of the animal to improve and the tendency to 

 discouragement, both punishment and reward had to be altered 

 from time to time, and other and more radical changes were 

 occasionally made in the experimental procedure. Below for 

 the sake of condensed and consecutive presentation, the most 

 important conditions from day to day are arranged in tabular 

 form: 



Conditions of Experiment from Day to Day for Problem 2 



Date Punishment Reward 



May 17 20 sec. confinement Food in right box for each 



(Aid after 10 trials) trial 



" 18 to 21 30 sec. confinement Food (banana) in right box 



for each trial 



" 22 to June 2.. Illness, no experiments , 



June 3 15 sec. confinement Food (banana) in right box 



for each trial 



" 4 30 " " Food (banana) in right box 



for each trial 



" 5-10 60 " " Beet, carrot and loquat, in 



addition to banana 



" 11 10 to 30 sec. confinement Beet, carrot and loquat, in 



addition to banana 



" 12 to 15 60 sec. confinement Beet, carrot and loquat, in 



addition to banana 

 " 16 60 " " Banana and sweet com — for- 



mer preferred 



