  Chiral perturbation theory is the low energy effective theory of the strong
interactions for the light pseudoscalar degrees of freedom. This program is
based on effective Lagrangian techniques and is an expansion in the powers of
the momenta and the powers of the quark masses, which correct the soft-pion
theorems. After briefly reviewing these features and some results, we address
the implications of this program to $\pi-N$ scattering, the $\pi-N$ sigma term
and some recent investigations of the implications of chiral symmetry to
nucleon-nucleon forces. We finally look at the implications of chiral
perturbation theory to hadron mass relations.
