Rod outer segments elongate in constant light: darkness is required for normal shedding.
D000818:Animals; D001001:Anura; D001699:Biometry; D003624:Darkness; D008027:Light; D009900:Optic Nerve / Q000502:physiology; D010587:Phagocytosis; D010786:Photoreceptor Cells / Q000166:cytology*; D010870:Pineal Gland / Q000502:physiology; D010902:Pituitary Gland / Q000502:physiology; D011894:Rana pipiens; D013997:Time Factors