The Fine Structure of Retina Studied With Electron Microscope

The retina of frog, Rana pipiens, is studied with electron microscope. The observations are summarized as follows :1. The lamellar body in the rod outer segments divides into several columnal lobules. Each lobule shows a characteristic pile of the flat sacs, so called rod sacs.2. The connection between the segments is a short narrow stalk and represents a ciliary nature.3. The ciliary filaments extend a certain distance into the outer segment, but no direct connection is observed between the filaments and rod sacs.4. The numerous mitochondria accumulate in the distal portion of the inner segment and arrange in such a way as showing an orientation toward the basal body of connecting cilium.5. The endoplasmic reticulum of the characteristic arrangement and the Golgi bodies are recognized in the inner segment.6. The synapses between visual and bipolar cells, and between bipolar and ganglion cells are described.7. The nervefiber layer is composed of bundles of numerous unmyelinated nerve fibers and of glial element of large quantity which embeds the nerve fibers.8. The glial element is recognized in all layers of retina and the local modifications and some fine structure of the element are demonstrated.9. Some physiological points of these structures are discussed.