  A self-consistent system of interacting nonlinear spinor and scalar fields
within the scope of a Bianchi type-I cosmological model filled with perfect
fluid is considered. Exact self-consistent solutions to the corresponding field
equations are obtained. The role of spinor field in the evolution of the
Universe is studied. It is shown that the spinor field gives rise to an
accelerated mode of expansion of the Universe. At the early stage of evolution
the spinor field nonlinearity generates the acceleration while at the later
stage it is done by the nonzero spinor mass.
