1. Nissl: Allg. Ztschr. f. Psychiat., 1891–1892, xlviii, p. 197.
2. James: Arch. Ophth., 1933, ix, p. 338.
3. Ranvier: Quoted by Ramon y Cajal, Degeneration and regeneration of the nervous system (translated by R. M. May). London: Oxford University Press; 1928, i, p. 6.
4. Bielschowsky: Bumke and Foerster, Handbuch der Neurologie. Berlin: Julius Springer; 1935, i, p. 155.
5. Leinfelder PJ. Retrograde degeneration in the optic nerves and retinal ganglion cells. Trans Am Ophthalmol Soc. 1938;36:307–15.