Deviations from pure Hubble flow - A review

The possible origins of deviations from the Hubble flow in various scenarios is discussed, with emphasis on the gravitational perturbation picture of the growth of structure. The relevant observations are reviewed and the methodology considered in the light of possible effects of the initial conditions during galaxy formation. The agreement, which is marginal at best, between the velocity data and the mass distribution models inferred from the IRAS galaxy catalogues is considered, and finally the confrontation with theory briefly discussed. 37 refs