Preface. Introduction. Photophysical Reactions in Cells; G. Renger. Weak Light Emission from Bacteria and Their Interaction with Culture Media; R. Vogel, R. Sumuth. Biophotons and Defense Response in Plants; M. Hiramatsu. Experimental Examination on the Possible Optical Interaction Between Two Separate Cell Populations; L. Bei, et al. Luminometry in Cellular Stress Research; J.E.M. Souren, R. van Wijk. UV-Induced DNA Damage and Repair: A Powerful Light Trapping System in DNA in Order to Convert Light Energy Into Biochemical Signals; H.J. Niggli. The Photon Count Statistic Study on the Photon Emission from Biological Systems Using a New Coincidence Counting System; F.A. Popp, X. Shen. Weak Photon Emission of Non-Linear Chemical Reactions of Amino Acids and Sugars in Aqueous Solutions; V.L. Voeikov, V.I. Naletov. Coherence and Biophoton Emission as Investigated on Acetabularia Acetabulum; F. Musumeci, et al. Biophoton Emission from Developing Eggs and Embryos: Non- Linearity, Holistic Properties and Indications of Energy Transfer; L.V. Beloussov, N.N. Louchinskaia. Measuring Weak Light Signals not Far from the Noise Level; W. Heering. Measurement of Low-Level Emission Under Lab Conditions; D. Gall, et al. Whole-Body Counting of Biophotons and its Relation to Biological Rhythms; S. Cohen, F.A. Popp. Fluorescence Imaging Technique for Detection of Human Melanoma; B.W. Chwirot, et al. Electro-Luminescence and Its Application; J.J. Chang, F.A. Popp. Biological Organization: A Possible Mechanism Based on the Coherence of Biophotons; J.J. Chang, F.A. Popp. Do We Always Need to Know the Molecular Origin of Light Emitted by Living Systems? B.W. Chwirot. The Physical Background and the Informational Character of Biophoton Emission; F.A. Popp, J.J.Chang. Photon Emission of Cereal Seeds, `Biophotons' as a Measure of Germinative Ability and Vigour; B.F. Zeiger. Biophotons and Nonclassical Light; Q. Gu. Coherent Nature of Biophotons: Experimental Evidence and Phenomenological Model; R.P. Bajpai. Quantum Coherence and the Understanding of Life; G.J. Hyland. The Concepts of Coherence and `Binding Problem' as Applied to Life and Consciousness Realms; M. Lipkind. Holism and Field Theories in Biology; M. Bischof. Coherence in Art and in the Physical Basis of Consciousness; F. Frohlich. Author Index. Subject Index.