Figure 7. Histogram of reported UV cone and violet cone cone pigment λmax values.
Blue bars on right represent violet cone pigments from human, macaque monkey, marmoset, squirrel monkey, cow, chicken and frog. Magenta bars on the left represent UV cone pigments from house mouse, rat, golden hamster, parakeet, canary, zebra finch, tiger salamander, chameleon and goldfish. The gray bar from 393 to 409 nm represents the violet cone pigment from domestic pigeon which has been reported to have variable λmax in this range. Similarly, for the other pigments where a range of λmax values were reported, bars of reduced height occur at the corresponding wavelengths.