An attempt to describe the ultrastructure and ultrahistochemistry of ciliary processes in mammals.

The aim of the present paper was to reexamine fine structural characteristics and glycogen topochemistry of ciliary processes in small laboratory mammals (hamsters, guinea-pigs and mice). A two-layered epithelium continuously covered all ciliary processes. The epithelium consisted of inner nonpigmented and outer pigmented cells whose apices faced each other. They were linked by desmosomes and tight junctions. Basal cell aspects showed extensively interdigitating processes adjacent to the inner (rarely also outer) basal lamina. The ciliary process core was made up of reticular fibers, few fibrocytes, and capillaries with or without fenestrations. No glycogen particles were found in the ciliary epithelium using the PA-TSC-SP procedure.