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 F2(x, Q2) at small values of the scaling variable x. The results are compared with recent measurements of the diffractive structure function F2d (x, Q2, M2).