title: Photoperiod, pineal, melatonin and reproduction in hamsters.
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D006224:Cricetinae / Q000502:physiology*; D008027:Light; D008297:Male; D008550:Melatonin / Q000502:physiology*; D009929:Organ Size; D010870:Pineal Gland / Q000502:physiology*; D012098:Reproduction; D012621:Seasons; D013737:Testis / Q000033:anatomy & histology / Q000502:physiology; D013997:Time Factors
chemical_list: D008550:Melatonin