Libraries at University of Nebraska-Lincoln


Date of this Version

June 1975


Published in Vision Research 15:6 (June 1975), pp. 733–736. Copyright © 1975 Pergamon Press/Elsevier. Used by permission.


Critical flicker frequency (CFF) was investigated in a free swimming harp seal using behavioral techniques. The resulting CFF vs intensity curve indicates a definite rod/cone break, suggesting a duplex photoreceptor population, whose presence had not been observed in previous morphological reports.