TRANSFER OF RESPONSE IN THE WHITE RAT 11 



light and the electric shock substituted, (c) where the 

 response was first learned to the sound and the light sub- 

 stituted, (d) where the response was first learned to the sound 

 and the electric shock substituted, (e) where the response 

 was first learned to the electric shock and the light substi- 

 tuted, (f) where the response was first learned to the electric 

 shock and the sound substituted. 



C. Positive 



(1) Apparatus. — The apparatus consisted of a wooden 

 box whose plan is shown in figure I. The base LMNO 

 upon which the box rested was approximately two feet by 

 three. The food box (F) was 13 inches wide and 13 inches 

 long on one side but longer on the other because of the 

 entrance of the two return alleys as shown in the figure. 

 ED is a door which leads from the food box to the main 

 part of the box (B) through the entrance alley (EA). This 

 entrance alley was four inches in length. X and X' are the 

 entrances to the return alleys (RA and R'A'). RD and 

 R'D' are doors from return alleys to foodbox. 



S and S' are sounders hung just outside of the box close 

 to three-quarter inch holes through the side of the box into 

 the heads of the return alleys. Lt and Lt' are two small 

 electric light bulbs just inside the wall of the box and just 

 above the holes mentioned above. K and K' are two keys 

 which control the left and right sounders and the left and 

 right lights respectively. Sw and Sw' are two switches 

 which allow the use of the same keys (K and K') for both 

 the sounders and the lights, either singly or simultaneously. 

 Thus the key (K) could be used to work the sounder 

 (S) or the light(Lt) or both the sounder (S) and the light 

 (Lt) simultaneously. The sounders were small electric 

 buzzers so fixed that with one pressure of the key but one 

 click was produced, instead of the rapid succession of clicks 

 ordinarily produced by such an instrument. The lights 

 were small electric bulbs of approximately one and one 

 half candle power. The current necessary was produced 

 by a cell of dry batteries indicated in the figure by the letters 

 DB. The box and all partitions were six inches deep. 

 The alleys were five inches wide. All the alleys were 



