Microcanonical Thermodynamics, ``Fragmentation Phase Transition'',and   the Topology of the N-body Phase Space
  Microcanonical thermodynamics (MT) is analysed for phase transitions of first and second order in finite systems. The transiton temperature, the latent heat and the surface tension of first order transitions can easily be determined by MT from the caloric equation of state T(E). The outstandig problem of the physical meaning of its backbending is clarified for the Potts-model. The fragmentation phase transition for nuclear multifragmentation is examined in detail. Further experimental signals of the fragmentation transition in hot nuclei are discussed. 
D.H.E.Gross (Hahn-Meitner Institut Berlin, Germany)