  The small $x$ behaviour of polarized parton distributions is related to
non-leading reggeons in the framework of the high-energy effective action.
Double-logarithmic contributions to the reggeon interaction beyond the ones
included in the GLAP equation are encountered in all polarized parton
distributions. The transversity distributions of quarks and gluons behave
similar at small $x$. Contribution to the spin workshop at DESY-Zeuthen,
September 1997.

High Energy Physics - Phenomenology