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’ 
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 cases of imitation in two rhesus 
monkeys which he studied. In one instance in which the 
female pulled out a vlug immediately after seeing a male do 
it the evidence for imitation is not entirely conclusive, since 
the femaie 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. Ina 
few cases, however, the monkeys showed evidence of learn- 
