Abstract: An attachment for an open fronted harvesting machine to assist movement of cut heads to the harvester conveyor system has a flexible skirt extending rearwardly of the cutter blades. The skirt is supported along its forward edge by a relatively rigid support member which is reciprocated to impart reciprocal movement to the skirt. The support member can be connected to the reciprocating cutter blades of the harvester or can be moved independently thereof.