Photoreception.- Biochemistry of Visual Pigments in Relation to Visual Excitation.- The Role of Protons in the Metarhodopsin I–II Transition.- Aktivitäten von ATPasen im Fliegen-Auge.- Thermal and Photic Regeneration of Rhodopsin in Perfused Frog Retina.- Experiments on the Isomerization of 11-cis-Retinal.- Cephalopod Retinochrome.- Vergleichende Aspekte der Photorezeption von Retinal-Proteinkomplexen.- On the Ionic Mechanisms Responsible for the Generation of the Electrical Response of Light Sensitive Cells.- Chemoreception.- Chemotaxis in Bacteria.- The Chemotactic Response in Bacteria.- Functions of Bacteriorhodopsin.- The Role of the Escherichia Coli Galactose-Binding Protein in Galactose Transport and Chemotaxis.- ?-Glucosidases as Sugar Receptor Proteins in Flies.- Thaumation and Monellin, the Intensely Sweet-Tasting Proteins from Tropical African Fruits.- Sensory Transduction in Insect Olfactory Receptors.- A Formalism on Selective Molecular Interactions.- Cell Communication and Cyclic-AMP Regulation during Aggregation of the Slime Mold, Dictyostelium discoideum.- Conjugation of the Ciliate Blepharisma: A Possible Model System for Biochemistry of Sensory Mechanisms.- Chemical Signal Transmission by Gamete Attractants in Brown Algae.- Energy Transfer and Signal Conversion.- On the Significance of Two-Dimensional Super-Structures in Biomembranes for Energy-Transfer and Signal Conversion.- On the Topography of Photoreceptor Membranes.- Carrier and Pore Mechanisms in Lipid Membranes.- Drugs to Explore the Ionic Channels in the Axon Membrane.- Mechanisms of Electrical Membrane Responses in Sensory Receptors, Illustrated by Mechanoreceptors.- Cell Cultures as Model Systems for Studying the Biochemistry of Differentiated Functions of Nerve Cells.- ImmunogeneticStudies on Cell Surface Components of the Mammalian Nervous System.- Neurotransmission.- zu den Vorträgen Nachmansohn und Neumann.- Biochemical Foundation of an Integral Model of Nerve Excitability.- Towards a Molecular Model of Nerve Excitability.- Aspects of the Biochemistry of Cholinergic Transmission in Torpedo and Loligo.- An Experimental Model for Exocytosis of Chromaffin Granules.- Characterization of an Acetylcholine Receptor.- Biochemistry of Serotonin and Synaptic Membranes in Neurotransmission.- Purification of Serotonin- and LSD-binding Proteins from Synaptic Membranes.- Biochemistry of Learning Processes.- Biochemical Concomitants of the Storage of Behavioral Information.- Besseres Lernen und Behalten in Schwerem Wasser bei Fischen.- Versuche zur chemischen Übertragbarkeit erworbener Informationen.- Epilogue.