In this volume outstanding specialists review the state of the art in nervous system research for all main invertebrate groups. They provide a comprehensive up-to-date analysis important for everyone working on neuronal aspects of single groups, as well as taking into account the phylogenesis of invertebrates. The articles report on recently gained knowledge about diversification in the invertebrate nervous systems, and demonstrate the analytical power of a comparative approach. Novel techniques in molecular and developmental biology are creating new perspectives that point toward a theoretical foundation for a modern organismic biology. The comparative approach, as documented here, will engage the interest of anyone challenged by the problem of structural diversification in biology.

The originality of this volume is to reveal to the reader the fascination of some unfamiliar sensory organs that are sometimes ignored and often misunderstood. These receptors have only recently been identified and their functional specificity is in some cases still a matter for discussion. The four classes of sensory organs considered here differ widely from one another in many respects. One might even say that the only thing they have in common is that they belong to cold-blooded vertebrates. These classes are: 1. the directionally sensitive lateral-line mechanoreceptors of fishes and amphi bians (Chapter 7); 2. the pseudobranchial organs of some teleosts, equipped with pressoreceptors and at least three other types of receptors (osmo- and chemoreceptors) (Chapter 8); 3. the infrared-sensitive pit organs of some snake families (Chapter 9); 4. the various kinds of electroreceptors found in several marine and freshwater fish families (Chapters 2 to 6). The first three classes of receptors mentioned above thus rate only one chapter each, whereas five chapters are devoted to the electroreceptors. Electroreception has aroused enormous interest among physiologists in specialties ranging from molecular biology to animal behavior. The resulting quantity of research and discussion fully justifies this disproportion. However, it cannot be denied that the contents of the volume must appear unbalanced and heterogeneous, yet it should not be perceived as a mere juxtaposition of particular and unrelated cases."

In this volume outstanding specialists review the state of the art in nervous system research for all main invertebrate groups. They provide a comprehensive up-to-date analysis important for everyone working on neuronal aspects of single groups, as well as taking into account the phylogenesis of invertebrates. The articles report on recently gained knowledge about diversification in the invertebrate nervous systems, and demonstrate the analytical power of a comparative approach. Novel techniques in molecular and developmental biology are creating new perspectives that point toward a theoretical foundation for a modern organismic biology. The comparative approach, as documented here, will engage the interest of anyone challenged by the problem of structural diversification in biology.