This volume is a report of the proceedings of the Third International Nephro-Lrological Course held in the Ettore Majorana Centre for Scientific Culture, Erice, Sicily, from 12th to 18th May 1980. Contributions were accepted on the understanding that the editors could make certain changes leading towards a uniformity of style but accepting as a Driority the importance of early publi cation, if necessary at the expense of stylistic perfection. The meeting, directed by A. Vercellone (Torino), R. Maiorca (Brescia) and M. Pavone-Macaluso (Palermo), was sponsored by: the Italian Associations of Nephrology, Immunology and Urology; the Ministries of Scientific Research and Public Education of the Republic of Italy; the Sicilian Regional Government; the National Research Council and the University of Palermo. Immunologic problems in renal disease Rnd metabolic and medical aspects of urolithiasis were the two subjects of the Congress, which was attended by numerous invi~ed speakers and participants. The first part was introduced by A. Vercellone (Torino), who discussed the major steps in the development and the present per spectives of nephrology, a relatively newly born science, recognized as such only in 1960. He called attention to the great significance of our present knowledge of the immunologic mechanisms (circulating immune complexes or in situ mounting, cellular immunity, activation of complement) which are involved in the pathogenesis of glomerulo nephritis.