Introduction Improved techniques of fixation and ultrathin sectioning in electron microscopy now permit the study of biological tissue on a nearly molecular level and in its natural milieu; as a result, a great amount of new information is available to cytologists. The lens epithelium was selected for the present investigation because of its important role in the biology of both the normal and the pathological lens. A variety of functions is combined within this monolayered structure, as can be presumed from the morphological differentiation into a "resting" (central) zone and a "germinative" (equatorial) zone. Another interesting aspect is that the mature lens, although devoid of any nervous and vascular supply, constitutes an organelle with continuous cytokinetic activity. Previous electron microscopic studies on the lens have been primarily concerned with the capsule (Bahr,1Bairati and Grignolo,2and Grignolo3), zonular fibers (Böke and Lindner4), and lens fibers (François,