THE WHITE RAT AND THE MAZE PROBLEM 181 



a vital part in the solution of the problem. In the end the rats 

 ran this maze with as much boldness and confidence as the 

 other, with heads up, almost leaping corners, etc. The one 

 exception was the group of blind rats without vibrissae. 



Let us compare the results of the two mazes as to accuracy 

 and speed. We find that the time of learning was the same but 

 in the Y maze the errors were less by one-half in the first trial 

 and one-third in the first five trials, and the total number of 

 errors was decreased about one-third although the final accuracy 

 of the two mazes was practically the same. The beginning 

 time was shorter because of the fewer errors but the average 

 time of the first five trials was about the same in both. The 

 final speed in the Y maze was slightly better. The most notice- 

 able difference, then, was the decrease in errors. The open maze, 

 from the beginning, favored accuracy and it should be noted 

 that this accuracy was not attained at the expense of speed. 



In a maze, where the paths are enclosed by restraining walls, 

 there is little need of fine bodily adjustments. The turns in the 

 H.C. maze and in this maze are always 90 degrees but the place 

 of the turn in the H.C. maze is always marked by some corner 

 or projecting wall against which the body of the rat brushes 

 or his vibrissae drag as he runs. A railway engineer does not 

 have to keep his train on a straight course by the fraction of 

 an inch, he has only to develop speed, his track is laid for 

 him. The analogy is not perfect but in the enclosed maze the 

 rat is comparatively ' safe." He does not have to control, 

 as on the open maze, the finer postural and positional adjust- 

 ments and as a result of this looseness of running he makes 

 more errors. On the open maze the control of these finer adjust- 

 ments is necessary in order to avoid slips and falls and hence 

 there is greater initial and final accuracy. 



The nose, feet and vibrissae were constantly used at the 

 different places of turning. The direction of the turn seemed 

 a much easier thing to conquer than the exact place. The 

 operated animals were at a great disadvantage. Vision aided 

 these finer adjustments but the nose and feet and vibrissae 

 seemed to be of greater help to the rat than sight. However, 

 either sight or the touch of nose or vibrissae seemed to be a 

 vital necessity to the learning. The animals could not well 

 dispense with both in such a problem as was here presented. 



