Contemporary research in evolutionary developmental biology has been predominantly devoted to interpreting basic features of animal architecture in molecular genetics terms. Considerably less time has been spent on the exploitation of the wealth of facts and concepts from traditional disciplines, such as comparative morphology. This book integrates traditional morphological and contemporary molecular genetic approaches and deals with postembryonic development as well. It offers unconventional views on the basic features of animal organization, such as body axes, symmetry, segments, body regions, appendages and related concepts. This book is of particular interest to graduate students and researchers in evolutionary and developmental biology, cell biology, genetics, and zoology.