Abstract: The magnetic brush arrangement provides for the formation of a brush-like mass made up of a pulverulent mix of carrier particles and toner particles supplied in measured amounts. Measured amounts of developer particles are picked up in the flutes provided on the surface of a rotating drum which is partially immersed in the granular mass. The flutes are axially parallel to the axis of rotation of the drum and it is the volume capacity of the flutes that determines the quantity of developer mix picked up and conveyed to a developing station. At the developing station there is provided a series of cylinders having disposed within magnetic flux generating means so as to attract the granular mass of particles from the flutes and pass it along the series of cylinders in the form of a moving carpet of developer mix.