The Sense of Sight: Color Vision 139 



papers, 1 6 by 3 cm., were placed on the floor at the entrances 

 to the electric-boxes, instead of on the walls of the boxes. 

 Mouse No. 2 was given five series of ten tests each with a 

 yellow card to indicate the right box and a red card at the 

 entrance to the wrong box. At first he chose the red almost 

 uniformly, and at no time during these fifty tests did he ex- 

 hibit ability to choose the right box by color discrimination. 

 I present the results of these series in Table 16, because they 

 indicate a fact to which I shall have to refer repeatedly later, 

 namely, that the brightness values of different portions of 

 the spectrum are not the same for the dancer as for us. Pre- 

 vious to this yellow-red training, No. 2, as a result of ten days 

 of white-black training (two tests per day), had partially 

 learned to go to the brighter of the two electric-boxes. It is 

 possible therefore that the choice of the box in the case of 

 these color experiments was in reality the choice of what 

 appeared to the mouse to be the brighter box. If this were 

 not true, how are the results of Table 1 6 to be accounted for? 



TABLE 1 6 

 YELLOW -RED TESTS 



In Color Discrimination Box with 6 by 3 cm. Pieces of Hering 

 Papers at Entrances to Boxes 



No. 2 



1 These were the only Hering papers used in my experiments. 



