Development of the prenatal rat retina.

The present observation has demonstrated the developmental order of the rat retina as follows: the pigment epithelium differentiates earlier than the retina cells; Midler's cells and ganglion cells differentiate from the basal portion of the retina within a few days after the optic cup formation; the ganglion cells form a layer on the fourteenth to fifteenth day; the nerve fiber layer is formed on the fifteenth to sixteenth day; the rest of the retina cells differentiate gradually in the postnatal period. The inner limiting membrane is formed at the earliest stage of development. However, the completion of the outer limiting membrane in the adult form is at a much later stage—postnatal tenth day. Development of the nervous processes originates by vesicle formation at the marginal zone of the cytoplasm.