Carr and Watson, Orientation in the White Rat. 37 



of our contention, but we do maintain that they can be more readily 

 explained on the basis of our conception'^ than in terms of a theory 

 which assumes that orientation is secured mainly through some 

 distance sense. 



EXPERIMENT II. 



THE EFFECT OF SHORTENING AND LENGTHENING CERTAIN ALLEYS 



IN THE MAZE. 



I. The Effect of Shortening the Maze. — For the second experi- 

 ment, the maze was divided into three sections by sawing it across 

 at the dotted lines. By removing or replacing the middle sec- 

 tion, the maze could be shortened or brought back to its original 

 length. This change merely alters the length of four alleys with- 

 out altering the relation of the turns leading to or from them. 

 The maze was cut very carefully so that the two end sections would 

 fit quite snugly together after the middle section had been removed. 

 For reasons presently made known the cul-de-sac, B, remained 

 open during Experiment II. 



The trained rats formerly used were employed in this experi- 

 ment with the exception of the second blind one. This animal 

 became somewhat feeble and refused to work consistently from 

 day to day. After the maze had been sawed through but before 

 the middle section was removed, the animals were allowed to run 

 the maze for seven days. Four trials per day were given each 

 rat. All disturbances of their old habits due to the new smell 

 factors introduced by sectioning of the maze, to the opening of 

 cul-de-sac B, and to the tests described above were thus eliminated. 

 After their reactions became thoroughly automatic, the maze 

 was shortened and the behavior of the rats in the new situation 

 was noted. Each rat was given four trials per day for five days. 



As above outlined, our theory assumes that the rats make the 

 correct turns in the maze in response to some internal (kinaes- 

 thetic) impulse. If the assumption is not true, the rounding of the 

 corners must be in response to some extraorganic stimulation 

 received there. That is, the wall at the end of the runways and 

 the opening into the next alley must contribute data through some 

 distance sense. The experiment is designed to test the relative 



' With the exception of the cases of immediate orientation. Since two out of eight animals made 

 eight of the nine unquestioned immediate orientations we are willing to admit the possibility of the 

 use of distance sense data in their cases. 



