  The diffraction dissociation of virtual photons is considered in the
framework of conventional Regge theory. It is shown that the recent HERA data
on large rapidity gap events can be successfully described in terms of the
Pomeron structure function. Using Regge factorization, the latter can be
related to the deuteron structure function. The parameters which relate these
two structure functions are determined from soft hadronic diffraction data. The
size of the shadowing corrections at low x and large Q**2 is also obtained.
