MAZE STUDIES WITH WHITE RAT 291 



which directly support the first conception of a directive func- 

 tion of vision. 



3. Vision is a detriment to the mastery of the rotated maze 

 when untrained animals are utilized. This fact cannot be ex- 

 plained on the assumption that rotation is detrimental because 

 visual-motor habits are continually being disrupted, because 

 rotation will prevent the development of any such visual habits. 

 Only one possibility remains, — the assumption that these visual 

 alterations operate as distractions. 



4. Vision is an advantage in the mastery of the maze, when 

 the rats have had previous experience on other problems. The 

 paucity of data upon which this conclusion, is based renders its 

 validity questionable. Accepting the fact at its face value, we 

 may assume that the previous experience of the normal animals 

 has operated to render them less dependent upon the extraneous 

 environment; this result will minimize their susceptibility to the 

 distractive influences of the rotation as demanded by the con- 

 clusion of the previous paragraph. The two groups thus approx- 

 imate equality as to susceptibility to the distractions due to 

 rotation, and the visual group is now enabled to master the 

 maze more readily in virtue of its greater learning capacity. 



All comparative data on the mastery of the maze can thus be 

 explained on the assumption that vision possesses both detri- 

 mental and beneficial features in relation to the mastery of a 

 maze problem. Visual stimuli tend to distract the animal and 

 thus retard the development of the kinaesthetic-motor habit. 

 The existence of vision on the other hand increases learning 

 capacity. Two conceptions of the relation between vision and 

 learning capacity receive some factual support. Light exerts a 

 tonic and stimulative effect upon activity, while on the other 

 hand the removal of the eye balls is to be regarded as some 

 sort of a positive disturbing or distracting factor. 



As to the nature of the process of adaptation, certain explan- 

 atory conceptions may be suggested. 1. We may suppose that 

 the alterations disrupt the system of sensori-motor connections 

 involved in running the maze, and that adaptation is to be 

 conceived as a process of reorganization, — -the acquisition of new 

 motor controls. This conception assumes a directive function 

 for the senses involved. Animals with vision have an advantage 

 because they can utilize visual as well as other sensory cues. 



