  The conventional approach to perturbative evolution is illegal because the
expansion in powers of $\alpha_s$ of the the DGLAP splitting matrix ${\bf
P(z,\alpha_s)}$ breaks down at small $z$. The small-$x$ data for the proton
structure function $F_2(x,Q^2)$ and its charm component $F^c_2(x,Q^2)$ show
that a hard pomeron, with intercept close to 1.4, must be added to the familar
soft pomeron. Conventional perturbative evolution may be applied to the
hard-pomeron component and provides a striking test of perturbative QCD.
