  The electromagnetic and weak structure functions of the photon can be studied
in the deep inelastic electron-photon processes e+gamma -> e+X and e+gamma ->
nu+X. While at low energies only virtual photon exchange is operative in the
neutral-current process, additional Z-exchange becomes relevant for high Q2 of
order MZ^2 at e+e- linear colliders. Likewise the charged-current process can
be observed at these high energy colliders. By measuring the electroweak
neutral- and charged-current structure functions, the up- and down-type quark
content of the photon can be determined separately.
