474 'Journal of Comparative Neurology and Psychology. 



TABLE 9. 

 The results of the experiments of set II, stimulus 375 units. 



TABLE 10. 

 The results of the experiments of set II, stimulus 420 units. 



The results of the second set of experiments contradict those of 

 the first set. What does this mean .? It occurred to us that the 

 apparent contradiction might be due to the fact that discrimination 

 was much easier in the experiments of set II than in those of set I. 

 To test this matter we planned to use in our third sec of experiments 

 a condition of visual discrimination which should be extremely 

 difficult for the mice. The reader will bear in mind that for set 



