The Sense of Sight : Color Vision 165 



152 revealed three facts: that the mice depend chiefly upon 

 brightness differences in visual discrimination; that they 

 probably have something which corresponds to our red-green 

 vision, although their color experience may be totally unlike 

 ours ; and that the red end of the spectrum seems much darker 

 to them than to us, or, in other words, that the least refrangi- 

 ble rays are of lower stimulating value for them than for us. 

 So many of the results of my color experiments have 



June i, 1906 



TABLE 25 

 GREEN-RED TESTS 



No. 151 



