Abstract
Four cats were trained on an intensity and color discrimination. Manipulations of stimulus size and viewing distance exerted a strong influence on the cats' color discrimination but had no effect on their discrimination of intensity. Variation of stimulus shape and orientation had no effect upon the cats' color discrimination beyond the influence of overall stimulus size. The finding that stimuli must subtend a large visual angle for the cat to perform well on a color discrimination accounts for much of the past discrepancy in behavioral studies.