MENTAL LIFE OF APES AND MONKEYS 273 
ing by imitating the experimenter’s movements. In one 
such case a piece of banana was suspended by a string a 
little beyond the monkey’s reach, and a pole was so ar- 
ranged that when it was swung under the banana the 
monkey could get upon it and reach the fruit. A monkey 
which had proven himself incapable of solving the problem 

Fic. 18.—Peter’s efforts at copying letters on a blackboard. a. Two 
superimposed letters drawn by Mr. Witmer; a‘, Peter’s copy after the sec- 
ond tracing; a*, Peter’s second effort when told to make a W again. (By 
permisson of the Psychological Clinic.) 
alone was shown how to manipulate the pole. After wit- 
nessing the experimenter push the pole under the banana 
the monkey gradually learned to perform the act, although 
it was some time before he manipulated the apparatus with 
accuracy and dispatch. 
The most extensive study of imitation in monkeys has 
been made by Mr. Haggerty. While many of the experi- 
18 
