Filter rod sections are transported sideways from a magazine containing a pile of parallel sections toward positions of alignment with the inlet of a pneumatic conveyor and are propelled into the conveyor at a transfer station where they continue to move sideways. In order to avoid damage to sections during propulsion into the conveyor, the duration of complete transfer of successive sections into the inlet is monitored in order to generate signals denoting the intervals of axial advancement of successive sections all the way into the conveyor. Such signals are compared with signals denoting those intervals of sidewise movement of sections past the transfer station during which the sections can move axially without being damaged by the stationary inlet of the conveyor. The evaluating circuit which compares the signals generates defect signals when the transfer of sections in unsatisfactory, and such defect signals are used to reestablish the possibility to advance undamaged sections into the conveyor or to expel the fragments of destroyed or partially destroyed sections from the conveyor and/or from those parts of the apparatus which supply articles to the transfer station.