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ORIGINAL ARTICLES AND CLINICAL CASES 



rotate still appears in many situations. When the animal is placed on 

 the floor he turns around several times before taking a direct course. 

 The necessity for avoiding an obstacle frequently results in several 

 complete rotations. The tendency to rotate becomes more pronounced 

 in narrow quarters and in the problem box the animals have a good deal 



Fig. 14. — Tracings of paths followed by No. 21 in the discrimination box. The animal 

 was unable to turn to the left but compensated for this motor difficulty by rotation to the 

 right, as shown. The discrimination was in each case correct. The path varies with the 

 alley illuminated and with the initial orientation. 



of difficulty in making the necessary turns. Fig. 14 shows tracings of 

 the path of animal No. '21 at a time when she was making no errors of 

 discrimination. .She was able to walk in a fairly straight line, but any 

 need for change of direction resulted in rotation toward the right. 

 (Only the right caudate nucleus was injured in this animal.) Her path 



