  The general evolution kernels of the twist 2 light-ray operators for
unpolarized and polarized deep inelastic scattering are calculated in ${\cal
O}(\alpha_s)$. From these evolution kernels a series of special evolution
equations can be derived, among them the Altarelli-Parisi equations and the
evolution equation for the meson wave function. In the case of twist 3 the
results of Balitzki and Braun are confirmed.
