THE WHITE RAT AND THE MAZE PROBLEM 143 



90 days old. They were fed in the -maze and handled for a week 

 preceding the beginning of the real work. During the experi- 

 mentation they ran the maze three times a day under the stimulus 

 of hunger and were amply fed at the conclusion of each day's 

 work. The first experiment was one in which the trail was laid 

 in the true path in the maze and not in the cul de sacs. 



EXPERIMENT I. Olfactory Trail in True Path 

 1. Behavior 



The behavior in this experiment will be described somewhat in 

 detail since it is significant. There was none of the wild running 

 seen in the usual maze reaction. When put in the box the rats 

 were at once attracted by the odor. Their little noses went 

 down to the trail and they began to follow it immediately. They 

 moved along in a jerky fashion stopping occasionally to smell 

 and to lap the trail with their tongues. This manner of running 

 made their progress an exceedingly slow one. Both the cheese 

 and the beef extract which were used were diluted with water 

 so that there was but a very slight trace of the food on the paper. 

 Still the animals may have obtained some satisfaction in lapping, 

 but such gratification must have been very limited. In general 

 the rats lingered longer over the cheese than over the beef extract 

 trail. The odor was probably stronger. They often hesitated 

 at the places where the trail changed from one substance to 

 another and sometimes struck the "back" or "home trail" here. 

 These returns only now and then resulted in an entrance into a 

 blind alley. They usually ended where the trail changed again. 

 The maze is so constructed that the food box is in the center. 

 When in use, there is always food in this box which the animals 

 are encouraged to smell before the beginning of the experiment 

 and which furnishes their reward when they reach the box at 

 the end of their run. The true path passes directly by the side 

 of this box. (See "Vision in the Maze," Fig. 1.) In the normal 

 maze the early runs are always broken at the food box which 

 the animals have to pass in the center of the maze. The food 

 odor is stronger here and they bite and claw and scratch in a 

 futile endeavor to end the quest at this spot. But notwith- 

 standing the marked early influence of the odor of the food box 

 this behavior, in the normal maze, is very quickly abandoned. 



