Abstract: Packaging is effected in a machine where correct filter-tipping and filling of the ends of the single cigarettes occupying the channels of a feed chute is monitored by a plurality of plungers, one to each channel, that are reciprocated axially toward and away from the ends of respective single cigarettes during the course of the work cycle. Each plunger carries a radial appendage, offered to a transducer by which a control signal will be produced in the event that the appendage assumes a given position on arrival of the plunger in contact with the end of the cigarette lying in its path.