RAPIDITY GAP EVENTS AND SHADOWING IN DEEP-INELASTIC SCATTERING

We suggest that the ''rapidity gap'' events reported from HERA are ess entially the diffraction dissociation channels corresponding to the sc aling shadowing seen on nuclei. We stress the interest of checking for virtual photons the old ''inelastic optical theorem'' relation connec ting diffraction dissociation of the photon and the total cross sectio n. We explain how it is possible at high q2 to have shadowing, if this relation holds, even though diffractive processes - narrowly defined - become negligible in the total rate.