The stereo-observation of biological materials can effectively achieved by the high voltage electron microscope utilizing the high penetration power of electrons at high accelerating voltage which enables the observation of thick specimens, and the large depth of forcus resulted by the small angular aperture used in the electron microscope (Hama, 1972). The high voltage electron microscope was applied to the study of the neuroglial cell processes in the cerebellar cortex of monkey and rat by Chang-Palayand Palay (1972). We investigated further the three dimensional organization of the neuroglial cell processes in the cerebellum and retina of rat by means of high voltage electron microscope stereoscopy.The Golgi preparations of cerebellar cortex and retina of rat were prepared by the methods described previously (Stell and Lightfoot, 1975; Colonnier, 1964). Plastic sections 100 μm thick were used for the light microscope observation.
