This book contains the proceedings of the first meeting on invertebrate immunity ever sponsored as a summer research conference by the Federation of American Societies for Experimental Biology (FASEB). The conference was held in Copper Mountain, CO from July 11-16, 1999. It was a an extension of a New York Academy of Sciences meeting entitled "Primordial Immunity: Foundations for the Vertebrate Immune System" held on May 2-5,1993 at the Marine Biological Laboratories in Woods Hole, MA. The proceedings of that meeting were published in The Annals of the New York Academy of Sciences (volume 712). At that meeting all the attendes agreed that this type of conference (a relatively small focused gathering) allowed for participation by investigators at all levels of their careers. We further agreed that we should search for a forum that would allow this meeting to continue. The FASEB Summer Research Conference was an excellent vehicle for this type of meeting. Furthermore, this year's participants decided to continue this meeting as a regularly scheduled FASEB sponsored event. This was a unique conference in the sense that it focused upon mechanisms of development and defense in protostome and deuterostome invertebrates and lower vertebrates. There was a strong emphasis on evolutionary cell biology, phylogenetic inferences and the evolution of recognition and regulatory systems.

1. New Major Histocompatibility Complex Class IIB Genes from Nurse Shark.- 2. Evolutionary Factors in the Emergence of the Combinatorial Germline Antibody Repertoire.- 4. Molecular Characterization of IL-1-like Molecules from Lower Vertebrates and Invertebrates.- 8. The Discovery and Characterization of an Interleukin 6 Cytokine Family Antagonist Protein from a Marine Sponge, Callyspongia sp.- 9. Phylogeny of Vertebrate Cytokines.- 10. Antimicrobial Proteins in Crustaceans.- 11. Form, Function and Phylogenetic Relationships of Mosquito Immune Peptides.- 12. Reactive Oxygen Species and Antimicrobial Defenses of Invertebrates: A Bivalve Model.- 13. A Role for Protease Inhibitors In Immunity of Long-Lived Animals.- 15. Annelid Humoral Immunity: Cell Lysis in Earthworms.- 16. Horseshoe Crab Hemocyte-Derived Lectin Recognizing Specific 0-Antigens of Lip opolysaccharides.- 19. Hemolytic Capacity, Properties, and Activation Requirements of Cobra Venom Factor-Treated Chicken Serum.- 20. Molecular Studies of the Molluscan Response to Digenean Infection.- 21. Insect Lectins and Innate Immunity.- 22. Collagenous Lectins in Tunicates and the Proteolytic Activation of Complement.- 23. Immunological Properties of Heat Shock Proteins are Phylogenetically Conserved.- 24. Drosophila Cellular Immune System: Dorothy Encodes a UDP Glycosyltransferase.- 25. Eicosanoids in Insect Immune Signal Transduction.- 26. Lectins from Tunicates: Structure-Function Relationships in Innate Immunity.- 27. Control Mechanisms of the Prophenoloxidase Cascade.- 28. Activated Prophenoloxidase Engaged in the Cell Clump/Cell Adhesion of Coleopteran Insect, Ten ebrio molitor Larvae.- 29. Three Kinds of Encapsulation-Relating Factors in Coleopteran Insect, Ten ebrio molitor Larvae.- 33. Cytotoxic Reactions Associated with Insect Immunity.- 35. The Complement System in Sea Urchins.- Contributors.