OBSERVATIONS OF PIGMENT ACCUMULATION IN THE EPITHELIUM OF THE SHELL GLAND AND SUPERFICIAL PIGMENTATION ON THE EGG-SHELL IN JAPANESE-QUAIL

The pigment accumulation in the shell grand through an ovulation cycle and the pigmentation onto the surface of egg shell were observed in J apanese quail. The pigment granules and PAS-positive material in the a pical cells of the epithelium of the shell gland increased progressive ly as time elapsed after ovulation and decreased suddenly 2-3 hrs befo re the expected oviposition as the pigmentation onto the egg shell occ urred. The pigment granules and PAS-positive material secreted from th e cells gathered to form pigment masses between folds of mucous membra ne. The pigment masses were deposited on the surface of egg shell. Aft er the pigmentation, only the PAS-positive material was seemed to be d eposited on the surface to complete the cuticle.