  Chiral loop corrections for hadronic properties are considered in a
constituent quark model. It is emphasized that the correct implementation of
such corrections requires a sum over intermediate hadronic states. The leading
non-analytic corrections are very important for baryon magnetic moments and
explain the failure of the sum rule
$(\mu_{\Sigma^{+}}+2\mu_{\Sigma^{-}})/\mu_{\Lambda}=-1$ predicted by the
constituent quark model.
