Electroretinal Demonstration of a Purkinje Shift in the Chicken Eye

¹ From the Army Medical Service Graduate School, Walter Reed Army Medical Center, Washington, D. C.

Spectral sensitivity of the chicken electroretinogram was determined for the photopic and scotopic condition. Physiological procedures were adopted which permitted the examination of the same three experimental animals upon repeated experimental occasions. It was found that this ERG exhibits components which are typical of the eyes of other animals, and a Purkinje shift could be demonstrated. Photopic ERG sensitivity agreed with the absorption spectrum of iodopsin. The form of the scotopic sensitivity curve suggested a mixed response in which the visual purple of the rods dominated, but in which a small contribution was made by the photopic iodopsin system.