The nerve fiber bundles of the optic nerve are separated from one another in the early stages of development by neuroglial septa, derivatives of cells of the stalk of the optic cup. The lamina cribrosa develops later and may not be completely formed until the end of fetal life. Connective tissue elements of the pia mater, sclera, blood vessels, and choroid contribute towards its formation. The septal system of the optic nerve is developed only from pia mater and consequently is fairly delicate, but fundamentally it forms a common system with the lamina cribrosa. The lamina cribrosa lies in a shallow depression in the foremost part of the scleral canal. The depression is termed the nest of the optic disc. The proportion of nervous tissue to connective tissue at the optic disc is 80 to 20 respectively, and at the lamina cribrosa it is 36 to 64. Fixation of the optic nerve in the scleral canal is regarded as one of the most important functions of the lamina cribrosa. A plastic model of the lamina cribrosa was constructed based on enlarged microphotographs of serial sections of the region. Illustrations of this model are given in the paper.