Foreword; K. Jeon. Preface; J. Seckbach. Acknowledgements; J. Seckbach. I: General Aspects. Prioritizing Symbiosis to Sustain Biodiversity: Are Symbionts Keystone Species D.P. Zook. Morphological aspects; P. Nardon, H. Charles. Symbiosis and Their Consequences for Community and Applied Ecology D. Secord. II: Origin & Evolution. What's in a Tree? Does Horizontal Gene Transfer Determine Microbial Taxonomy; L. Olendzenski, et al. The Commonality of Cyanobacterial Endosymbioses Does Not Support the Endosymbiotic Theory for Origin of Eukaryotic Organelles; T.E. Jensen. Non Symbiotic Origin of Locomotory Organelles; M. Rizzotti. The Cyanelle (Muroplast) of Cyano paradoxa: A Paradigm for Endosymbiotic Organelle Evolution; W. Loffelhardt, H.J. Bohnert. The Syntrophy Hypothesis for the Origin of Eukaryotes; P. Lopez-Garcia, D. Moreira. Thermodynamic Ecology of Hydrogen-based Syntrophy; D.L. Valentine. Nutritional Syntrophies and Consortia as Models for the Origin of Mitochondria; D.G. Searcy. Reversion of Endosymbiosis? The Case of Bleaching in Euglana; J. Krajcovic et al. Symbiosomes; R. Hinde, D.A. Trautman. The Abscence of Nitrogen-Fixing Organelles Due to Timing of the Nitrogen Crisis; Ch.P. McKay, R. Navarro-Gonzalez. Nucleus Symbiosis Hypothesis: Formation of Eukaryotic Cell Nuclei by the Symbiosis of Archaea in Bacteria; T. Shinozawa, et al. III: Bacteria, Cyanobacteria & Algae. Phototrophic Consortia: A Tight Cooperation Between Non-Related Eubacteria; J. Overmann. Structure and Phylogeny Cyanophora species; P. Kugrens. The Microenvironment and Photosynthetic Performance of Prochloron sp. in Symbiosis with Didemnid Ascidians; M. Kuhl, A.W.D. Larkum. IV: Fungi Symbiosis. Survival Strategies in Arbuscular Mycorrhizal Symbionts; M. Giovannetti. Three Part Harmony -- Ascophyllum and its Symbionts; D.J. Garbary, R.J. Reckert. Arbuscular Mycorrhizae Fungi and Their Endobacteria; P. Bonfante, et al. V: Lichens. Origin and Evolution of Green Lichen Algae; T. Friedl, D. Bhattacharya. Lichenization of the Trentepohliales; R.L. Chapman, D.A. Waters. Trebouxia: Reflections on a Perplexing and Controversial Lichen Photobiont; V. Ahmadjian. VI: Symbiosis in Plants. Algae Living on Trees and in Other Strange Places; W. Reisser. Cycad Coralloid Roots Housing Cyanobacteria; M. Grilli Caiola. Evolution of Epicholoe/Neotyphodium Endophytes and Other Clavicipitalean; J.F. White, et al. The Effect of Endophytic Fungi on Host Plant Morphogenesis; S. Scannerini, et al. VII: Association with Protozoa. Anaerobic Ciliates and Their Methanogenic Endosymbionts; J.H.P. Hackstein, et al. Endosymbiosis of Beta-Proteobacteria in trypanosomatid Protozoa; M.C.M. Motta, et al. Ectosymbiosis in Ciliated Protozoa; G. Rosati. Living Sands: Symbiosis Between Foraminifera and Algae; J.J. Lee. Protistan-Prokaryotic Symbiosis in Deep-Sea Sulfidic Sediments; K.R. Buck, J.M. Bernhard. VIII: Symbiosis in Insects and Higher Animals. Sponge/ Algal Symbiosis: A Diversity of Associations; D.A. Trautman, R. Hinde. The Taxonomy and Evolution of the Zooxanthellae-Coral Symbiosis; S.Karako, et al. Algal Symbiosis in Flatworms; A.M. McCoy, I. Balzer. Trichomycetes: Fungi in Relationship with Insect and Other Arthropods; R.W. Lichtwardt. Evolution of Ascomycete-Arthropoda Symbioses; J.W. Spatafora. The Laboulbeniales - An Enigmatic Group of Arthropod-Associated Fungi; A. Weir. Wolbachia-Induced Cytoplasmic Incompatibility; S. Charlat, et al. How Do Wolbachia Symbionts Increase the Proportion of Females in Their Hosts; B. Pintureau et al. Genome of Buchnera sp. Aps, An Intracelluar Symbiotic Bacterium of the Pea Aphid, Acyrthosiphon pisum; H. Ishikawa. The Functions of Symbiotic Mirco-Organisms in Insects. A Perspective from Studies on Aposymbiotic Aphids; A.E. Douglas. Ants, Agriculture and Antibiotics. A Quadripartite Symbiosis; C.R. Currie. Termite Hindgut Symbiont; B.D. Dyer. Symbiosis in the Termite gut; M. Ohkuma. Cultivation of Symbiotic Fungi by Termites of the Subfamily Mactrotermitianae; C. Rouland- Lefevre, D.E. Bignell. Co-speciation Between Host and Symbionts: The Sepiolid Squid-Vibrio Mutualism; M.K. Nishiguchi.