  We use SPH/N-body simulations to study the ram-pressure stripping of the gas
of dwarf galaxies orbiting in a disc galaxy. The effects of the gaseous disc
and halo on the satellites are analysed and the results are compared with the
observations of the dwarf spheroidals (and dwarf irregulars) in the Local
Group. The stripped gas is compared with the High Velocity Clouds. Finally, a
model of evolution of the dwarfs is proposed.
