THE WHITE RAT AND THE MAZE PROBLEM 



II. THE INTRODUCTION OF AN 

 OLFACTORY CONTROL* 



STELLA B. VINCENT 



Chicago Normal College 



What part has olfaction in the life of a rat ? The answer to 

 this query would have to be based upon what we know of brain 

 structure and from our casual observation of rat behavior, since, 

 there has been very little direct experimentation published 

 that has as its main concern this form of sensitivity. 



The rat has well defined olfactory lobes and tracts. But 

 these parts are relatively smaller than those of some other rodents 

 and decidedly smaller than those of some other mammals. The 

 olfactory paths in the brain of the rat have not had much study 

 and we are thrown back, therefore, upon what we know of the 

 life and habits of the animal for the answer to our question. 



It might be thought, from watching the reactions of the rats 

 in the maze, that smell was a very important sense. The frequent 

 sight of a rat lifting itself on its hind feet and sniffing vigorously, 

 the constant use which it makes of its nose on the floor and 

 sides of the maze, would lend credence to such a supposition. 

 Yet it has been shown that anosmic animals are under no serious 

 disadvantage in learning the maze and that much of this sniffing 

 and apparent smelling has an important tactual function. What 

 the world of odor is to a rat we have little power of conceiving 

 but how it affects the behavior we may somewhat discover. 



The odors which are vital in the animal world are, presumably, 

 food odors, sex odors and body odors. By the term body odor 

 is meant those olfactory qualities which perhaps are peculiar to 

 individual animals but which certainly characterize the animals 

 of a single cage or group. By differentiation from this familiar 



1 This work was done in the Psychological Laboratory of the University of Chicago. 

 I am greatly indebted to the department for the opportunity to do it and to pro- 

 fessor Carr for suggestive help and criticism of both experimentation and paper. 



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