Opening Session.- Hemerythrins.- Structure and Function of Invertebrate Hemoglobins.- Structure of Arthropodan Hemocyanins.- Subunit Structure of Molluscan Hemocyanins.- Evolution of Hemocyanins.- Physiological Role and Modulation of Hemocyanin Function.- Allosteric Interaction - Theories and Experiments.- The Active Site of Hemocyanins.- Hemoglobins and Hemocyanins: Studies at the Levels of DNA and RNA, and Biosynthesis.- Concluding Remarks.- Author Index.