156 STELLA B. VINCENT 



If we now attempt to explain the slowness of the reactions 

 of the rats in the maze in Experiment 1 , there are several possible 

 interpretations: First, the slowness may be due to the fact 

 that the odor of the food box which served to initiate the reaction 

 is swamped, overpowered, by the nearer, more potent odor of 

 the trail; or, second, that attention is divided between the two 

 and hence we have the characteristic behavior; third, it may 

 be that the pleasurable feeling set up by the odor of the trail 

 is in itself a deterrent and results in loitering; or fourth, it may 

 be that the nearness and strength of this stimulus does initiate 

 the preliminary instinctive food-taking reactions which of them- 

 selves end or modify the distance reactions of running. 



As one observed the behavior in the initial trial, there did not 

 seem to be any emotional excitement which would suggest the 

 inhibition of running through conflicting motor tendencies and 

 hence the second explanation is discredited. That the trail odor 

 was the predominating one in the first trial seems probable 

 and that it was also pleasurable. The satisfaction of hunger 

 at the end of this trial, however, must, in all succeeding trials, 

 have played a large part and made the original trail a different 

 more intense, more stimulating trail, a somewhat else, viz., a 

 trail which ended with this satisfaction. Yet still there was 

 the loitering and slow movement through all of the early trials 

 which would lead us to think that the fourth supposition may 

 be a reasonable one. Why, then, did this behavior alter in the 

 later trials ? Because of the organization of the whole response 

 into an habitual motor series which only required the odor for 

 the initiation and possible reinforcement of the act. The more 

 rapid final speed, which exceeded the normal, may have been 

 caused by the reinforcement of the kinaesthetic control, now 

 established, by the olfaction of the trail. 



Miss Richardson says, 11 "Olfaction may accelerate or retard 

 the learning process; accelerate when the odor is a part of the 

 stimulus connected with the problem — otherwise be disadvan- 

 tageous." It is easy to conceive that it may have the same 

 effect upon the actual rate of running — that it may result here 

 in a genuine acceleration of speed. 



While the main purpose of this work was to establish and to 



11 Richardson, F. R. A study of sensory control in the rat. Psych. Rev. Mon. 

 Sup., 12, no. 1, p. 68. 



