which was then removed and rapped against the wood beyond 

 the right doorway. The left doorway was locked. After 

 the first trial, rapping to indicate the position of the food 

 was left off. The carrot was shifted back and forth and 

 the time taken by the pig to follow through the respective 

 doors was recorded. This measurement began when the 

 pig had just finished chewing one mouthful and was reach- 

 ing for another, the carrot being removed at that time. The 

 measurement ended when the animal had passed through the 

 door and it had fallen shut behind him. Thus there were 

 two series of measurements; one of the time taken to enter 

 the maze and one of the time taken to leave it. These are 

 expressed in the following table. The trials in each series 

 were taken consecutively, a period of several hours elapsing 

 between the series. 



Into Maze No.TrialsAv. of All A. D. Av. Firsts. A.D. 1st Trial 



Series 1 11 168.9 222.6 553. 324.7 1040. 



Series 2 



Series 3 



Series 4 



Out of Maze 



Series 1 



Series 2 



Series 3 



Series 4 



Series 5 



Series G 



The measurements in all the tables are given in seconds. 



Antagonistic Habit Formation and Cross Training. 



After an interval of one hundred and three hours, the 

 Guinea pig was returned to the maze. This time the right 

 door was locked and the left door was unlocked. There 

 was no difference in appearance, that would be noticeable 

 to the pig, between the maze now and before, because the 

 means of locking the door was a wire nail, driven into the 

 wood at the side of the door and bent to an angle of ninety 

 degrees, which could be turned so as to prevent the door 

 from swinging and was visible only from the outside. A 

 turn in the direction opposite to that which the Guinea pig 

 had learned had now to be made before he could leave the 

 maze. The carrot was concealed until the Guinea pig had 

 left the maze and was then given him as a reward. 



FIFTEEN] 



