TRANSFER OF RESPONSE IN THE WHITE RAT 15 



walls of the box close to the partial partitions, excepting 

 the one found on the wall of the food box. These sounders 

 are also joined to the batteries. L, L, etc., are small electric 

 lights of the same size as used in the positive experiments. 

 They are attached to the partial partitions near the sound- 

 ers and are also joined to the batteries. In one box used for 

 these experiments a switch was attached to the side of the box, 

 marked Sw in the figure. This switch was used to turn the 

 current into the right or left sounders or lights as the case 

 demanded. A later box had a slightly different arrangement. 

 Two keys were used on the battery and induction box, one 

 for the right and one for the left. This allowed of more rapid 

 and less noticeable action on the part of the experimenter 

 when giving the stimulus or combination of stimuli required 

 in any particular case. The sounders, lights, and brass plates 

 were so wired as to allow them to be used singly or in com- 

 bination. Thus the lights on any one side could be used 

 alone or in combination with the sounders of that side or in 

 combination with the brass plates for pain stimuli. Also it 

 was arranged at first so that one, two or all three of the 

 sounders might be used at any one time. This was found 

 to be unnecessary, however, and so it was finally arranged 

 that all of the sounders on any one side would come into 

 play by pressing the key controlling the sounders on that 

 side. The sounder found on the wall of the food box was 

 the first one used in attempting to teach the negative response 

 to the sound, but it was found necessary to place the sound- 

 ers along the side of the box as indicated above before the 

 animals would pay sufficient attention to them to learn the 

 response required in any reasonable number of trials. So 

 the sounder in the food box was abandoned and the sound- 

 ers along the side were substituted. Since the wiring re- 

 quired was rather intricate no detailed description of it will 

 be given here. Any electrician can make the proper con- 

 nections to secure the working combinations of sound, light 

 and pain required in the experiments. 



(2) Method of Procedure, — The animal was put through 

 the entrance door (ED) into the main alley (MA) and was 

 required to go up the main alley and back to the food box 

 through either the right or the left return alley (RA or R'A')- 



