Structure and mechanism of vertebrate visual pigments (W.J. DeGrip, K.J. Rothschild). The primary photoreaction of Rhodopsin (R.A. Mathies, J. Lugtenberg). Late photoproducts and signaling states of bovine Rhodopsin (K.P. Hofmann). Ion channels of vertebrate photoreceptors (R.S. Molday, U.B. Kaupp). Phototransduction in vertebrate rods and cones: molecular mechanisms of amplification, recovery and light adaptation (E.N. Pugh Jr., T.D. Lamb). Comparative molecular biology of visual pigments (S.Yokoyama, R. Yokoyama). Invertebrate visual pigments (W. Gartner). Phototransduction mechanisms in microvillar and ciliary photoreceptors of invertebrates (E. Nasi, M. del Pilar Gomez, R. Payne). Genetic dissection of Drosophila phototransduction (B. Minke, R.C. Hardie). Modeling primary visual process in insect photoreceptors (D.G. Stavenga, J. Oberwinkler, M. Postma). Subject Index.