USE OF THE HANDS IN THE RHESUS MONKEY 179 



the immediate environment upon the reactions. An attempt 

 was then made to alter the proportionate use of the hands. 

 As the animals were to be used in other experiments the time 

 available for this work was limited and it was not possible to 

 undertake a permanent modification of their activity: a success- 

 ful suppression of such an instinct would perhaps require a year 

 or more. Since the complete alteration of an instinctive prefer- 

 ence would necessitate the production of an altered predomi- 

 nance in the use of the hands under conditions in which train- 

 ing had not been given, a question of primary importance for 

 the problem is the possibility of transfer of training from one 

 situation to another, and the time available was sufficient for 

 a limited study of this. The observations upon the animals' 

 behavior in different situations formed a basis for a test of such 

 transfer, requiring that the training be carried out in only a 

 part of the situations. 



The observations were made upon the animals, in part while 

 they were in the cages described earlier by Franz ('13), in part 

 while they were fastened by a strap one meter in length to a 

 swivel snap in the floor of the room where the monkeys were 

 kept. In the tests upon the use of the hands in taking food 

 the following seven conditions were used. 



Animal fastened to the floor with the strap. — 



1. Picking up food from the floor. The food was dropped 

 as nearly as possible in front of the animals and within easy 

 reaching distance. 



2. Taking food from the experimenter's right hand. The 

 food was held directly in front of the animal and about 10 inches 

 from him, so that he could reach it equally well with either hand. 



3. Taking food from the experimenter's left hand. The con- 

 ditions were otherwise as in situation 2. 



Animal in the cage. — 



4. Picking up food from the floor of the cage. 



5. Taking food from the experimenter's right hand. His 

 fingers, holding the food, were thrust through the coarse wire 

 netting of the front of the cage so that the monkeys did not 

 need to reach out of the cage to get the food. 



6. Taking food from the experimenter's left hand. Condi- 

 tions were otherwise as in 5, 



