272 MENTAL LIFE OF APES AND MONKEYS 



forms Watson's monkeys occasionally performed acts which 

 were " suggestive of a low order of imitation." One of them 

 found a hole in a window frame. "This one would 'peek 7 

 and then another one would push him aside and 'peek ' in turn. 

 This was observed several times." Hirschlaff in his account 

 of the chimpanzee Consul describes a number of cases in 

 which he considers that imitation was unmistakably shown, 

 but his observations are not described in sufficient detail to 

 enable one to judge of the correctness of the interpretation. 

 Kinnaman reports a few case,s of imitation in two rhesus 

 monkeys which he studied. In one instance in which the 

 female pulled out a ulug immediately after seeing a male do 

 it the evidence for imitation is not entirely conclusive, since 

 the female had pulled out the plug on previous occasions. 

 The second case is a more satisfactory one and is described 

 as follows: " Recalling that she had failed to work the bear- 

 down lever for opening the box. ... I placed it before 

 her. She rushed up, but missing the plug she sat down. 

 The male passed her, pushed the lever down and procured 

 the food. When the box was set again she worked the lever 

 and took the food in the same way that he had done. She 

 manipulated this apparatus several times immediately 

 and 250 times later as a part of a combination lock. Besides 

 these, once when the male peeped under the bottom of one 

 of the trees the female came and peeped in the same manner." 



Mr. Witmer states that the chimpanzee, Peter, twice copied 

 a W which was written on a blackboard, and learned to repeat 

 the word "mama." It is unfortunate that more extended 

 and thorough experiments were not carried out with so prom- 

 ising a subject. 



The experiments of Shepherd on imitation in rhesus 

 monkeys yielded for the most part negative results. In a 

 few cases, however, the monkeys showed evidence of learn- 



