The Mental Life of the Monkeys 211 
is a different question. Such may be present and function 
as the excitants of acts. 
It is likely that this question could have been definitely 
solved if it had been possible for me to work with a larger 
number of animals. With enough subjects one could use 
the method mentioned on page 105 of Chapter II, of 
giving the animals tuition in acts which they would 
eventually do themselves without it, and then leaving them 
to their efforts, noting any differences in the way they 
learned from that in which other subjects who had no tui- 
tion learned the same acts. The chief of such differences to 
note would be differences in the time of their first trial, in the 
slope of the time-curve and in the number of useless acts. 
It would also be possible to extend experiments of the 
type of the (on chair) experiment, where a subject is given 
first a certain time (calculated by the experimenter to be 
somewhat less than would be needed for the animal to hit 
upon the act) and if he does fail is then given certain tuition 
and then a second trial. The influence of the tuition is esti- 
mated by the presence or absence of cases where after tuition 
the act is done within the time. 
There is nothing necessarily insoluble in the problem. 
Given ten or twenty monkeys that can be handled without 
any difficulty and it could be settled in a month. 
With this general preface we may turn to the more special 
questions connected with the experiments on imitation of 
human acts and of the acts of other monkeys and on the for- 
mation of associations apart from the selection of impulses. 
IMITATION OF HuMAN BEINGS 
It has been a common opinion that monkeys learned 
to do things from seeing them done by human beings. 
