Scenarios: Why?.- General Ecology of Primitive Fishes.- Facts and Thoughts on Piscine Phylogeny.- Reconstructing the Life Cycle and the Feeding of Ancestral Vertebrates.- Habitat, Phylogeny and the Evolution of Osmoregulatory Strategies in Primitive Fishes.- The Brain and Sense Organs of the Earliest Vertebrates: Reconstruction of a Morphotype.- The Lateral Line System of Cyclostomes.- Freshwater Parasitic Lamprey on Vancouver Island and a Theory of the Evolution of the Freshwater Parasitic and Nonparasitic Life History Types.- Organ Development and Specialization in Lamprey Species.- Early Development of Oral, Olfactory and Adenohypophyseal Structures of Agnathans and Its Evolutionary Implications.- Immunologic Relations Among Fish Groups.- Evolution of Temperature Regulation and of Constancy of Function (Homeokinesis) at Different Temperatures.- Respiration in Phyletically Ancient Fishes.- Regulation of Blood and Body Fluids in Primitive Fish Groups.- Evolution of the Renin-Angiotensin System and Its Role in Control of Cardiovascular Function in Fishes.- Evolutionary Aspects of Reproduction in Cyclostomes and Cartilaginous Fishes.- On Urea Formation in Primitive Fishes.- Some Aspects of Hormonal Regulation of Metabolism in Agnathans.- Hagfish Insulin: Evolution of Insulin.- Evolution of Gastro-Entero-Pancreatic Endocrine Systems in Lower Vertebrates.- Functional Evolution of Gastrointestinal Hormones.- Hormonal Peptide Evolution.- Tissue Distribution of Hormonal Peptides in Primitive Fishes.- Group Photo.- Contributors and Participants.