Scaling and Diffraction in Deep Inelastic Scattering

We pursue the hypothesis that the events with a large rapidity gap, observed at HERA, reflect the scattering of electrons off lumps of wee partons inside the proton. A simple scaling behaviour is predicted for the diffractive structure functions, which are related to the inclusive structure function $F_2(x,Q^2)$ at small values of the scaling variable $x$. The results are compared with recent measurements of the diffractive structure function $F_2^D(x,Q^2,M^2)$.