  We analyse the consequences of t-channel unitarity for the photon hadronic
cross sections. We show that gamma(*)p and gamma(*) gamma(*) elastic amplitudes
must include the complex-j plane singularities associated with hadronic elastic
amplitudes, and give the characteristics of possible new singularities. We also
show that several different models of hadronic total cross sections can be used
to predict the LEP data from the HERA measurements.
