Quantitative morphological study of the outer nuclear layer in the turtle retina.

Types and densities of retinal cells with somata located in the outer nuclear layer of the turtle retina were studied with combined light and electron microscopic observations of serial sections. One third of the somata in the outer nuclear layer were found to be those of displaced bipolar cells, while the rest were of those of photoreceptors. Somata were 8-10 micrometers in horizontal diameter for both types of retinal cells.