THE WHITE RAT AND THE MAZE PROBLEM 19 



BRIGHTNESS 



But it may be argued that although the reactions of the rats 

 in the black-white maze differ from those made in the normal 

 maze in respect to speed and accuracy, the contributing cause 

 may not have been the brightness of the runways. In reply it 

 can only be said that no other difference can be seen in the 

 experimental conditions. The maze was the same in every 

 experiment and it stood in the same place. The animals were 

 from the same breeding cages, were given the same care and 

 were used by the same person throughout. Tests to prove that 

 it was the brightness factor, however, were introduced. 



The blind animals furnished the best means of control. These 

 animals were of the same original stock as the others and during 

 the entire period of experimentation were kept in the cage with 

 the others. They ran the maze daily with the other rats. They 

 were put through the box problem but could not learn this as 

 the rats with vision did. When taken over to the maze they 

 behaved just as the blind rats in the normal maze behave. The 

 learning curve for these rats has been plotted and may be seen 

 in Fig. 8. Compare this curve with that made for the rats in 

 the normal maze, Fig. 2, and see how nearly identical they are. 

 Neither resembles at all the curve for the black-white maze, Fig. 

 3. These blind rats were in good physical condition, active 

 and strong, and the only observable difference from their com- 

 panions was in their lack of vision. Is not the conclusion fair 

 that the contrast in behavior and the different numerical results 

 of the two groups of animals used in this part of the experiment 

 were due to the visual situation in the maze ? 



The second control was the use of the problem box. Rats 

 taken from the box over to the normal maze showed no favor- 

 able effect of general training. The training if anything resulted 

 unfavorably. The reasons have already been given. Rats 

 trained on the box when taken to the black-white maze exhib- 

 ited no unfavorable effects of training but gave some slight 

 indications that the brightness experience had been an aid. 

 The slightness of this effect was probably due to the differences 

 in the essential nature of the two problems and the briefness 

 of the time in which the animals were in the box. 



From the black-white maze to the box, however, the effect 

 was different. The experience certainly did carry over. The 



