no The Dancing Mouse 



tion, for the boxes themselves were interchanged in posi- 

 tion, and, as was proved by additional tests, the animals were 

 utterly unable to tell one from the other, the mouse was re- 

 quired to choose the box on its right. Only one of the five 

 animals went to the box on the left after once experiencing the 

 electric shock. The results of the series are given in Table n. 



TABLE ii 

 CHOICE BY POSITION 



This conclusively proves that the habit of turning in a 

 certain direction or of choosing by position can be formed 

 more readily than a habit which depends upon visual dis- 

 crimination. A rough comparison justifies the statement 

 that it takes from six to ten times as long for the dancer to 

 learn to choose the white box as it does to learn to choose 

 the box on the right. Since this is true, it is exceedingly im- 

 portant that the possibility of choice by position or direction 

 of movement be excluded in the case of tests of brightness 

 discrimination. To indicate how this was effectively ac- 

 complished in the experiments, the changes in the position of 

 the cardboards made in the case of a standard set of white- 

 black series are shown in Table 12. The number of the 

 series, beginning at the top of the table with the two lettered 

 preference series, is given in the first column at the left, the 

 number of the tests at the top of the table, and the posi- 

 tion of the white cardboard, left or right, is indicated below 

 by the letters / (left) and r (right). 



