io8 



The Dancing Mouse 



TABLE 9 



WHITE -BLACK TESTS 



tests to be described later exclude the possibility of other 

 forms of discrimination that the dancer is able to tell white 

 from black ; that it is somewhat easier, as the preference 

 tests might lead us to expect, for it to learn to go to the black 

 than to the white, and that the male forms the habit of choos- 

 ing on the basis of brightness discrimination more quickly 

 than the female. 



It is now necessary to justify the interpretation of these 

 results as evidence of brightness discrimination by proving 

 that all other conditions for choice except brightness dif- 

 ference may be excluded without interfering with the ani- 

 mal's ability to select the right box. We shall consider in 



