  We present exact inhomogeneous and anisotropic cosmological solutions of
low-energy string theory containing dilaton and axion fields. The spacetime
metric possesses cylindrical symmetry. The solutions describe ever-expanding
universes with an initial curvature singularity and contain known homogeneous
solutions as subcases. The asymptotic form of the solution near the initial
singularity has a spatially-varying Kasner-like form. The inhomogeneous axion
and dilaton fields are found to evolve quasi-homogeneously on scales larger
than the particle horizon. When the inhomogeneities enter the horizon they
oscillate as non-linear waves and the inhomogeneities attentuate. When the
inhomogeneities are small they behave like small perturbations of homogeneous
universes. The manifestation of duality and the asymptotic behaviour of the
solutions are investigated.
