The Gribov-Lipatov relation in QCD

We analyse and calculate the structure functions of both deep inelastic leptoproduction ande ⁺ e ^? annihilation in QCD and in the parton model in a way which brings out the similarities and differences between the two situations. In particular we give a probability interpretation of the Gribov-Lipatov relation for quarks in QCD. The relation does not hold for hadronic structure functions but we determine its modified consequences for this case. A generalised Drell-Yan conjecture is also discussed and verified to lowest order in QCD.