  We study four-dimensional simplicial gravity through numerical simulation
with special attention to the existence of singular vertices, in the strong
coupling phase, that are shared by abnormally large numbers of four-simplices.
  We attempt to cure this disease by adding a term to the action which
suppresses such singular vertices. For a sufficiently large coefficient of the
additional term, however, the phase transition disappears and the system is
observed to be always in the branched polymer phase for any gravitational
constant.
