JOURNAL OF ANIMAL BEHAVIOR 



Vol. 7 SEPTEMBER-OCTOBER No. 5 



MAZE STUDIES WITH THE WHITE RAT 



II. Blind Animals 



HARVEY CARR 



University of Chicago 



In the previous paper there was formulated the proposition 

 that the maze habit is dependent to some degree upon the sta- 

 bility of various environmental conditions. The present paper 

 concerns the function vision in sensing these alterations and 

 becoming adapted to them. The method consists of comparing 

 the records of blind rats with those of animals with intact sense 

 organs. The possibility of vision was eliminated by the usual 

 method of extirpation of the bulb. Three of the rats were 

 subjected to an autopsy and a microscopical examination by 

 Professor C. J. Herriek, who reports that all three were prob- 

 ably blind. Comparisons will be facilitated by certain classi- 

 fications of the experiments. 



1. The first group contains all those experiments in which no 

 blind animals were tested, and hence comparisons are impossible. 

 This group consists of the following experiments. Covering cage, 

 covering maze, increase of illumination, decrease of illumination, 

 rotation of a uniform environment, the second phase of uncov- 

 ering the maze, and the 3rd, 4th, and 5th tests on rotating 

 the maze. 



2. The second group contains those experiments in which both 

 seeing and blind animals were utilized but in which no rats 

 were disturbed by the alterations. Obviously these experiments 

 can furnish no data as to the function of vision. Nine blinds 



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