MAZE STUDIES WITH WHITE RAT 301 



normal animals. This adaptive capacity was in evidence in 

 the experiments in which the environment was rotated in refer- 

 ence to the maze, or the maze was rotated in relation to the 

 environment. The records of these anosmic animals thus con- 

 firm our previous conclusion as to the sensitive and corrective 

 values of vision. 



The function of smell may be determined from several sources. 

 1. Since no other senses than smell and vision are concerned in 

 these tests, the records of the blind rats must be due exclusively 

 to the olfactory factor. 2. The differential sensitivity of the 

 blinds as compared with those blind and partially anosmic must 

 be interpreted in terms of smell. 3. The records of the normals 

 as compared with those of the anosmic group must likewise be 

 explained in terms of smell. 



Smell possesses a sensitive function; by this statement we 

 mean that these alterations do affect in some way the animal's 

 behavior through the medium of olfaction. All three sets of 

 facts support this conclusion. The blind and partially anosmic 

 group suffered less disturbance than the blind rats in every ex- 

 periment in which comparisons are poss ; ble. The anosmics on 

 the whole manifested a lesser degree of sensitivity than did the 

 normal animals; their sensitivity was much less for those experi- 

 ments, e.g., cleanliness test, in which the olfactory element 

 predominated. The blind animals, possessing only smell, ex- 

 hibited the maximum amount of disturbance in those experi- 

 ments in which the anosmic animals were the least sensitive. 

 In the cleanliness test, those animals with smell intact, — blind 

 and normal groups, suffered a pronounced disturbance, while 

 but little effect was manifested by those groups in which olfac- 

 tion was partly or completely eliminated. 



In the previous paper, we noted that blind rats were sensitive 

 to alterations of the environment, and concluded that these 

 alterations operated as distractive stimuli rather than as motor 

 controls. The results of this paper prove that smell is the main 

 mediating sense involved in the detection of these changes by 

 blind rats. No additional facts were developed necessitating a 

 revision of the conclusion as to the distractive character of these 

 olfactory stimuli. 



Several significant features are contributed by the experi- 

 ments concerning the functions of smell and vision in the mastery 



