On the occasion of the 450th anniversary of Philipp University, the porphyrin research group of. the Department of Clinical Biochemistry in the Faculty of Medicine organized an international symposium. This was held between June 28 and July 1, 1977, under the joint chairman ship of Professor Samuel Schwartz and the editor. The organizers and chairmen of the symposium wish to thank the Sozialminister of Hessen, Armin Clauss, the President of the German Society for Clinical Chemis try, Professor A. Delbrlick, and the Dean of the Faculty of Medicine of Philipp University, Professor F. Neurath,...