136 J. C. DeVOSS AND ROSE GANSON 



that orange is confused with yellow. The per cent of right 

 choices of orange was but 66.2, of VRT2 by Cat 4, only 60.7. 



There were six cases of difficult discrimination with blue, four 

 with red none with green. 



It remains to present the colors which, in experiments with 

 yellow as a stimulus color, were promptly discriminated from it 

 and yet were of nearly the same flicker value as the yellow. It 

 will be interesting to set down in parallel series the colors confused 

 with yellow, those discriminated from it with difficulty, and those 

 easily discriminated from it but of similar flicker value, and 

 underneath each color the number denoting its flicker equivalent. 



Stimulus Color, Yellow. F.E.— 1-2 



1. Confused 



GYT1, GYT2, YT1, YT2, OY, OYT1, OYT2, YO, YOT1, YOT2, OT1, OT2 

 2 1-2 1-2 1-2 2 2 1-2421-23 2 



2. Discriminated with Difficulty 



G, GT1, GT2, YG, OYS1, O, ROS1, RO, VRT2 

 6 3 1-2 3 5 6 15 9 5 



3. Discriminated Easily 



RVT2, VT2, BT2, GBT2, BGT1, BGT2, YGT1, YGT2, GY, ROT2, ORT2, 

 2 332 3 2 3 1-2 32 3 



The first two series of flicker-equivalents show that flicker 

 values were a factor in producing confusions and in causing 

 difficulty of discrimination. In the second series the presence of 

 orange, which we have already seen to be almost as bright as 

 yellow for the cat, is a factor which produces difficulty in four 

 cases. In the case of GT2 the extreme brightness of the tint is 

 overcome by the darkening effect of the green, though they come 

 near balancing each other. 



In the third series of flicker values the effect of red, violet, 

 blue, green, and orange in darkening the tints for the cat is very 

 evident. This would indicate that those colors have great dark- 

 ening effect and that fact confirms to a great degree the brightness 

 position we have given them in Figure 2, which is drawn from the 

 results of grays. 



If further evidence of 'the opposite effects of antagonistic 

 factors is needed, we may take the case of GY. Though the 



