Table of Contents

Introductory remarks.- Coelenterata.- The nervous systems of Cnidarians.- Platyhelminthes.- The flatworm nervous system: Pattern and phylogeny.- Nematoda.- Repeating patterns of motoneurons in nematodes: The origin of segmentation?.- Annelida.- Genesis of segmental identity in the leech nervous system.- Mollusca.- Comparative aspects of gastropod neurobiology.- The cephalopod nervous system: What evolution has made of the molluscan design.- Onychophora.- Common and special features of the nervous system of Onychophora: A comparison with Arthropoda, Annelida and some other invertebrates.- Arthropoda Chelicerata.- Comparative aspects of the chelicerate nervous systems.- Mandibulata Embryogenesis.- Conservation versus change in early axonogenesis in arthropod embryos: A comparison between myriapods, crustaceans and insects.- Motoneurones.- Homologous structures, exemplified by motoneurones of Mandibulata.- Sensory neurones.- Developmental mechanisms, homology and evolution of the insect peripheral nervous system.- Interneurones.- Lineage analysis as an analytical tool in the insect central nervous system: Bringing order to interneurons.- Peptidergic neurones.- Comparative aspects of peptidergic signaling pathways in the nervous systems of arthropods.- The arthropod brain.- Ground plans, evolutionary changes and homologies in decapod crustacean brains.- The arthropod mushroom body: Its functional roles, evolutionary enigmas and mistaken identities.- Is the evolution of arthropod brains convergent?.- Echinodermata.- The nervous systems of Echinodermata: Recent results and new approaches.- Methodological comment.- The homology concept—still alive.- Coda.- Are the main grades of brains different principally in numbers of connections or also in quality?.