COLOR BLINDNESS OF CATS 129 



Thus far we have shown that, the colors, yellow, green, violet, 

 blue, and red have each been confused with a colorless paper 

 (or cambric) by the cats. 



Each confusion was found to be identical for two cats. 



In each case inability to discriminate was shown by six hundred 

 trials, during which there was no increase in the proportion of 

 right choices. (This is not shown in the above tables but it is 

 shown clearly in our records by series of trials). 



F.E.. 



T&A.oJiyS, 



The confusions were made in each case after the cat had 

 discriminated its food-color from a number of other grays. 



The colors, blue, red, violet, and green were each confused 

 with a gray which is much darker than the gray which represents 

 the brightness value of that color for the human eye. 



The yellow was confused with a gray of identical flicker 

 equivalent. 



Conclusions: It seems probable that cats cannot distinguish 

 any one color from all the shades of gray, under light adaptation. 

 It is possible that the animal may be totally color-blind by 

 daylight. 



Our results in the case of red seem to agree with those of other 



