In 1822, E. Metchnikoff discovered phagocytosis while he was studying starfish larvae. The following year, while carrying out experiments on Daphnia (Crustacea), the same author demonstrated the scale of the phe nomen in the defence of the organism. Finally, between 1891 and 1910, L. Cuenot was the first to reveal lymphoid organs, in crustaceans and in sects; some of these organs playa role in both phagocytosis and inhaema topoieses. With rare exceptions, research into defence reactions in invertebrates was meagre in quantity and sometimes meagre in quality from then until the mid-1960's. The renewal of interest in the subject over the past few years is now well established, and invertebrates are no longer the poor re lation of immunity research. Three of the many reasons which have been found to account for this renewal of interest can be stressed. One concerns the preoccupations of fundamental research and the other two are associated with applied re search. Firstly, there is hope of fmding defence mechanisms in inverte brates that are new (or not yet known) or of using phylogenesis to fmd explanations for phenomena in vertebrates which are still unaccounted for.

Inhalt
Section 1 The Immunocompetent Cells in Invertebrates.- 1 Insect Haemocyte Separation An Essential Prerequisite to Progress in Understanding Insect Cellular Immunity.- 2 Surface Membrane Components of Circulating Invertebrate Blood Cells and Their Role in Internal Defense.- 3 Structure and Functions of Oyster Hemocytes.- 4 Insect Haemocytes: A New Classification to Rule out the Controversy.- 5 Haemogram and Its Endocrine Control in Insects.- Section 2 The Molecules of Immunity and the Immunorecognition Process.- 6 Antibacterial Immune Proteins in Insects A Review of Some Current Perspectives.- 7 Antibacterial Molecules in Annelids.- 8 Invertebrate Lectins Biochemical Heterogeneity as a Possible Key to Their Biological Function.- 9 Immunorecognition in Invertebrates with Special Reference to Molluscs.- 10 Transplantation Immunity in Arthropods: Is Immunorecognition Merely Wound-Healing?.- 11 Evolution of Histocompatibility.- Section 3 The Defense Reactions.- 12 Encapsulation in Arthropods.- 13 Cellular Immune Response and Their Genetic Aspects in Drosophila.- 14 Hemolymph Clotting in Insects.- 15 The Prophenoloxidase System: The Biochemistry of Its Activation and Role in Arthropod Cellular Immunity with Special References to Crustaceans.