  An explicit quark model, based on a mean field description of non-overlapping
nucleon bags bound by the self-consistent exchange of $\sigma$, $\omega$ and
$\rho$ mesons, is used to investigate the properties of both nuclear and
neutron matter. We establish a clear understanding of the relationship between
this model, which incorporates the internal structure of the nucleon, and QHD.
Finally, we use the model to study the density dependence of the quark
condensate in-medium.
