25 

 and "before learning was complete. A few more trials 



were necessary when trials were given every other day 



and every day, ] circular dot indicates where the 



first rat completed learning. 



lZE. 



Though the maze was the last problem taken up, it 

 is convenient to treat it at this point, for it is the 

 only other problem taken alone. 'The plan of the maze 

 has already been given and it differs in one important 

 respect from the square maze in that it has no corners 

 and only short turns from one path to another. For 

 this reason it may be said to be an easier problem to 

 learn. This plan of ;e had another advantage; 

 towards the end of learning, the movements of the rats 

 are confined to a quadrant of the maze and the observer 

 could easily detect errors without changing his position. 



As with the latch box the rats were divided into 

 groups which were given one, three and five trials. The 



