Two research centers joined to study the development of numerous malformations of the vertebral column in 30 mutants of the laboratory mouse: the Department of Anatomy of the University of Zurich, that has long been a center of research in vertebral anatomy and pathology, and the Jackson Laboratory in Bar Harbor, Maine, the largest center of research in mouse genetics. This volume describes the normal and abnormal morphogenesis of vertebrae and summarizes the data presently available in order to give better insight into the developmental mechanics of the vertebral column.