  In this note we address the issue of measurability of the hadronic
cross-sections at a future photon collider as well as for the two-photon
processes at a future high energy linear $e^+e^-$ collider. We extend, to
higher energy, our previous estimates of the accuracy with which the \gamgam\
cross-section needs to be measured, in order to distinguish between different
theoretical models of energy dependence of the total cross-sections. We show
that the necessary precision to discriminate among these models is indeed
possible at future linear colliders in the Photon Collider option. Further we
note that even in the $e^+e^-$ option a measurement of the hadron production
cross-section via \gamgam processes, with an accuracy necessary to allow
discrimination between different theoretical models, should be possible. We
also comment briefly on the implications of these predictions for hadronic
backgrounds at the future TeV energy $e^+e^-$ collider CLIC.
