152 STELLA B. VINCENT 



box. This box had three runways, leading from a common 

 entrance, and they terminated in a food-box. The paper trail, 

 some of the original paper from the runways, could be laid along 

 these runways, changed in irregular order, and the rats tested 

 here. Before taking them to the box, however, after the con- 

 clusion of Experiment 1, the paper was entirely removed from 

 the maze and the rats given one trial each on the maze itself. 

 They made perfect runs showing no hesitation whatever. They 

 did not seem to miss the paper at all and even incorporated 

 in the runs a slight "slowing up," as had always been the case 

 at the places where the trail changed from beef extract to cheese. 

 Evidently the control had become kinaesthetic. The question 

 we had to face now was this: Had the olfactory experience 

 persisted notwithstanding the change of control. 



The rats were now taken over to the box. The first trials 

 here gave entirely negative evidence. The olfactory trail might 

 as well have been absent for all the attention which the rats 

 gave to it. The path with the trail was only taken on an average 

 of six times out of twenty trials. The next morning the animals 

 were tried again and then it was seen what they were doing. 

 No matter where the trail was laid, they were always making 

 a straight run to the left and down the runway on the left side. 

 Now this was just their first run in the maze. Clearly kinaesthesis 

 was at the helm and olfaction had retired from the engagement. 

 It was necessary, therefore, to arrange conditions such that 

 the opportunity to make this run to the right or to the left 

 should be done away with — a condition in which position so far 

 as possible should be eliminated. 



A long rose box, about three feet in length was procured from 

 a florist and in its end were inserted long, heavy, pasteboard 

 mailing tubes. These tubes just filled one end of the box. They 

 were lined with paper taken from the maze and one tube contained 

 paper on which was the trail. In the experiment the tubes 

 were alternated according to an irregular schedule. For the 

 next few days the rats were tried out in this box. When they 

 were put in at the end farthest from the tubes they immediately 

 ran down to these exits. The two openings were side by side, 

 there was no chance to turn, and in fifty trials they made 90% 

 correct choices: i. e., they followed the trail nine-tenths of the 

 time. While sitting in front of the tubes the rats could smell 



