Аннотация:Crosa and Boynton’s empirical model of discrete mass transfer in Her X-1 has been advanced. The large life time (\equiv20 - 30 h) of the cold (\ap3\times10$^4$K) blob and the deep X-ray flickering (τ = 150 - 500 s) in dips are suggested to be a result of spraying of accreting matter by Rayleigh-Taylor instability developed in the blobs at the outer rim of the accretion disk surrounded by a corona with T$_k$ \ap 3\times10$^6$K and n$_k$ \ap3\times10$^11$cm$^-3$. The thermal equilibrium in the corona and in the blobs is supported by the X-ray flux. Various observational data are interpreted in the frame of the model.