Hartline continued and extended the work initiated by Adrian and Matthews on electrical discharges from the optic nerve. See also his later papers In the same journal, 1940, 130, 690-711. For his work on visual mechanisms he shared the Nobel Prize in 1967 with Granit (No. 1534) and G. Wald (No. 1535). Reprinted with historical introduction by Hartline in F. Ratliff (ed.). Studies on excitation and inhibition in the retina, New York, [1974],