In 1932 there appeared the work of SCHMORL and JUNGHANNS, Die gesunde und kranke Wirbelsiiule im Rontgenbild, which laid the foundations of diagnostic radiology of the spine. Since that time the discipline has been extended and refined in a systematic manner and our knowledge has been greatly enriched by the large number of monographs in which leading experts have assembled additional data. An encyclopedic treatment of all that is currently known requires not only that reference be made to all work published since 1932 in order to reveal the problems that remain but also that a serious attempt be made to contribute to the solution of such problems. For this reason, Professor TONDURY and Professor THEILER of Zurich, who know more than anyone else about the ontogeny of the spine, have been invited to display their erudition in this field. Should contra dictions or divergent opinions on certain points be revealed through this confrontation with radiologically obtained findings, so much the better; the effect of this could only be to spur workers in both disciplines on to more advanced research. We have only to recall how in Goethe's time the premaxilla was still the subject of controversy, yet this great man pursuing his studies in comparative anatomy and anthropology was able to prove its existence beyond all doubt. Mainz, May 1974 L. DIETHELM Inhaltsverzeichnis - Contents A. Die normale Wirbelsliule . . . . . . . . . . . . . . . . . . . . 1 1 I. Phylogenetische Entwicklung des Achsenskelets. Von K. THEILER 1 1. Die Bogenelemente. . . . . . . . . . . . . . . 2. Die Chorda dorsalis . . . . . . . . . . . . . ."