  After a brief history of two known types of neutrino mixing and oscillations,
including neutrino spin and spin-flavour oscillations in the transversal
magnetic field, we perform systematic study of a new phenomenon of neutrino
spin and spin-flavour oscillations engendered by the transversal matter
currents on the bases of the developed quantum treatment of the phenomenon.
Possibilities for the resonance amplification of these new types of
oscillations by the longitudinal matter currents and longitudinal magnetic
fields are analyzed. We also consider modifications of the oscillation
probabilities due to possible arbitrary orientation of the magnetic field
vector ${\bf B}$ and the matter velocity ${\bf v}$.
