The electroretinogram of the sheep

The electroretinogram of the sheep was quantitatively and qualitatively investigated to determine the range of amplitudesand implicit times of the major components for the normal animal. The stimulus variables were intensity, duration, frequency and wave-length. The normal ERG responses to the above stimulus conditions were established for light- and dark-adapted sheep. The results indicate that the sheep ERG responds predictably to changes in the stimulus arrangement. The form of the recorded response is basically similar to the ERGs recorded from other mammals with mixed receptor retinae. However, the scotopic fusion frequency found for the sheep (34 fps) is higher than the fusion frequency reported for other species.