[Endocytosis at the lower pole of the retinal pigment epithelium]

Intracardially injected horseradish peroxidase was endocytosed by coated vesicles at the base of the RPE. The fate of these labelled vesicles was observed; they were seen to fuse either together or with cisternae of the smooth endoplasmic reticulum in the basal one-third of the RPE. Peroxidase-negative vesicles, suggesting a double population, were also observed.