Fig. 17. Coronal section through a valley of the pars plicata shows superficial blending of zonular fibers and bundles (Z) into the multilaminar, already thickened basement membrane of the ciliary epithelium in a 19-year-old patient (TEM, × 26,200). Inset. Large zonular bundles (Z) are embedded in the even thicker basement membrane of the older eye (50-year-old patient). A dark cap cell (CAP) lies on the surface (TEM, × 5,000).