The present volume contains the edited proceedings of the Vth Symposium of the Gesellschaft fiir Nephrologie held in Lausanne, Switzerland, from September 21 to September 23, 1967. The manuscripts were arranged according to their contents rather than to their titles. An attempt was made to divide the allotted space between different contributors according to the apparent importance or originality of the contributions. Most of the papers submitted were written in either German or a rather inarticulate English, and subsequently, have been translated into English by the editors and their collaborators. The editors are indebted to Mr. R. Darling, student of medicine of the Faculte de Medicine de l'Universite de Lausanne, for reviewing the English translation. Editing was limited to requirements based on form rather than on content. In a few instances, manuscripts which were inadequate in form were accepted because their contents appeared interesting or important. A very few manuscripts were either not submitted or could not be included in the present proceedings, because they did not satisfy the editorial standards. Some papers are published in the present proceedings in abstract form because they have been submitted elsewhere for full publication. The editors’ responsibility does not extend to the factual content of the manuscripts. The editors wish to apologize for the long delay in publishing these proceedings, a delay which may be attributed to difficulties in communication and cooperation with various authors.