In nonrelativistic models of nuclei, the underlying mass scales of low-ener
gy quantum chromodynamics (QCD) are largely hidden. In contrast, the covari
ant formulations used in relativistic phenomenology manifest the QCD scales
in nuclei through large Lorentz scalar and four-vector nucleon self-energi
es. The abundant and varied evidence in support of this connection and the
consequences are reviewed. (C) 2000 Published by Elsevier Science B.V. All
rights reserved.