THE DIFFERENCES IN ELECTRICAL RESPONSE OF THE RETINA OF THE FROG AND HORNED TOAD ACCORDING TO THE POSITION OF THE ELECTRODES

Abstract

The electrical responses from the horned toad''s retina are either positive or negative, depending upon the position of the grid electrode. The negative responses are obtained when the grid electrode makes contact with the retina in a band which extends across the eye just above the pecten and blind spot. The negative responses are similar to the positive responses inverted except that the flat region between "on" and "off" effects is always negative. Responses, part positive and part negative, can be obtained on the borders between regions. Oscillations are present on the "on" effects from the positive regions but are less marked than in the responses from the frog''s retina, probably because they are more rapid and less easily resolved.