Interaction between Light and Matter.- Receptor Pigments in Light-Induced Behavior of Microorganisms.- Sensitization of the Visual Pigment in a Photoreceptor.- In Vitro Regeneration of Visual Pigment in Isolated Vertebrate Photoreceptors.- Retinal Binding Protein in the Honeybee Retina.- Early Steps in the activation of Photoreceptor Enzymes by Light: Interaction between Disk Membrane Proteins Triggered by Light and Regulated by G.T.P.- Intracellular Changes of H+ and Ca2+ in Balanus Photoreceptors.- Light-Induced Voltage Fluctuations in Barnacle Photoreceptors.- The Early Receptor Potential: its Mode of Generation, Application to Study of Photoreceptors, and Functional Significance.- Some Basic Information about the Light Response of Frog Rods.- Recovery from Light-Desensitization in Toad Rods.- Ionic Currents Activated by Voltage and by Intracellular Calcium: A Voltage Clamps Study in Solitary Vertebrate Photoreceptors.- Regenerative Photoresponses in Toad Rods.- Synaptic Responses of Retinal Photoreceptors.- Microtubules in Vertebrate Photoreceptors.- A Quantitative Study on Synaptic Ribbons in the Photoreceptors of Turtle and Frog.- A Note on the Synaptic Events in Hyperpolarizing Bipolar Cells of the Turtle's Retina.- Quantitative Morphology of Amacrine Cells in Teleost Retina.- Chromatic Organization and Sexual Dimorphism of the Fly Retinal Mosaic.- Visual Control of Flight in the Fly.- Contributors.