TACTUAL SENSATION IN THE RAT 



127 



As indicated in figure i, the alleys were constructed with re- 

 movable doors at i, 2, 3, 4, 5 and 6. In maze I, doors 3 and 6 

 were open while doors i, 2, 4 and 5 were closed. 



The first set of rats used in this series of experiments were 

 normal animals, two males and three females. They were about 

 three months old, and had never been used in experimentation. 

 They were fed daily in the food-box of the maze until they 

 became thoroughly tame. Their vibrissae were cut oft' two 

 days before our experiments began. At the end of that time 

 all emotional disturbances had disappeared and the rats acted 

 in a perfectly normal way. This was done in order to facilitate 



Fig. 2 



Figures 2 and 3 



the observation of actual head and nose contact in turning the 

 corners of the pathway. No attempt was made in this experi- 

 ment to keep a record of contacts except at the corners. In 

 general, it was very noticeable, however, that the animals at 

 first kept in close contact with the sides of the pathway. 



Reference to figures 2 and 3 will show what we mean by 

 " corners." In figure 2, if a rat touched the corner a at any 

 point between b and c or at d, he was checked up with one 

 corner touched. In no case was a rat checked up with more 

 than one contact for a corner. Likewise, in figure 3, if a rat 

 touched the corner a between c and e or at d he was checked 

 up with one contact ; and if he also touched the side of the path- 

 way again between e and f he w^as checked up with another 



