On the role of oil drops in colour vision.
D000818:Animals; D001717:Birds; D003118:Color Perception / Q000502:physiology*; D008055:Lipids / Q000502:physiology*; D010786:Photoreceptor Cells / Q000502:physiology; D012104:Reptiles; D012168:Retinal Pigments / Q000502:physiology*; D013053:Spectrophotometry
D008055:Lipids; D012168:Retinal Pigments