  By introducing auxiliary fields, which by their quantum numbers vanish in
perturbation theory, we relate the dynamical perturbation theory of Pagels and
Stokar and a successful gauged nonlocal constituent quark model to $U(N)$ gauge
theory and to QCD. This sheds light on the duality between quark models and
resonance models. We then derive the effective action in the loop expansion
without dropping cubic and quartic gluon couplings.
