Volumes 30 and 31 of this series, dealing with "~1any Degrees of Freedom," contain the proceedings of the 1976 International Summer Institute of Theoretical Physics, held at the University of Bielefeld from August 23 to September 4, 1976. This Institute was the eighth in a series of summer schools devoted to particle physics and organized by universities and research institutes in the Federal Republic of Germany. Many degrees of freedom and collective phenomena playa critical role in the description and understanding of elementary particles. The lectures in this volume were intended to show how a combination of theoretical prejudices and experimental results can lead to the crys tallization of models and theories. Topics ranged from quark, parton, and bag model~ to du~l unitarization, from cluster pictures to hadron-nucleus collisions and to astrophysical implications. The Institute took place at the Center for Inter disciplinary Research of the University of Bielefeld. On behalf of all participants, it is a pleasure to thank the officials and the administration of the Center for their cooperation and help before and during the Institute. Special thanks go to V.C. Fulland, M. Kamper, and A. Kpt tenkamp for their rapid and competent preparation of the manuscripts.

Inhalt
Reggeon Field Theory with ?(0) gt 1.- Some Remarks on Implementing Hadrons as Extended Objects with Applications to Dual Models.- High Density Matter in the Universe.- Dual Unitarisation A New Approach to Hadronic Interactions.- Collective Effects in High Energy Interactions with Nuclei.- Unified Interactions of Leptons and Quarks.- The M.I.T. Bag, 1976 Edition.- Charmed Particles and Drell-Yan Photons as Sources of Direct Leptons.- Three Lectures on Lattice Gauge Theory.- Clustering and Clusters.- Quark Partons.- Lectures on Hadron-Nucleus Collisions at High Energies.- Heavy Clusters at High Energy.- Inclusive Correlations in the Central Region.- Recent Developments in Dual String Models.- Who Needs Clusters in the Dual Bootstrap?.- List of Participants.