  The quark-meson coupling (QMC) model for nuclear matter, which describes
nuclear matter as non-overlapping MIT bags bound by the self-consistent
exchange of scalar and vector mesons is modified by the introduction of a
density dependent bag constant. The density dependence of the bag constant is
related to that of the in-medium effective nucleon mass through a scaling
ansatz suggested by partial chiral symmetry restoration in nuclear matter. This
modification overcomes drawbacks of the QMC model and leads to the recovery of
the essential features of relativistic nuclear phenomenology. This suggests
that the modification of the bag constant in the nuclear medium may play an
important role in low- and medium-energy nuclear physics.
