Fig. 32. Elastic fiber system. A. Bundles of elastic microfibrils (oxytalan) in zonule, showing 12-nm microperiodicity (arrow). (X 51,900) B. Developing elastic fiber with cords of amorphous electron-lucent elastin being laid down on the microfibrillar template. Orbit of 14-month-old child. Note same 12-nm microperiodicity (arrow). (X 51,700) C. Large mature elastic fiber (Bruch's elastica, tangential cut) at site of two branches (arrowheads). Scanty attachment microfibrils peripherally. Gold-labeled with elastin antibody. (X 51,700) D. Predominantly microfibrillar (arrows) elastic fibers (elaunin type) in trabeculum. Elastin-antibody binding to central white elastin cords (arrowhead) in 2-month-old infant. (X 51,700)