Reprint of 2 works, the 1st is a reprint of the 1963 ed. published by Adriatica editrice, Bari, and the 2nd is a reprint of the fourth chapter of an essay by D. Nörr, first published in Zeitschrift der Savigny-Stiftung für Rechtsgeschichte, vol. 82, Römanistische Abteilung.