1. A gear hobbing machine comprising a hob head, a hob carried by the hob head, a table for supporting a workpiece to be hobbed, a template mounted on the hob head, a stylus, means for effecting relative axial movement of the hob and workpiece to perform first and second cuts and to traverse said template past said stylus during said cuts, a push rod mounted on the table in alignment with the stylus and initially out of contact with the stylus, means for advancing the table to approach the workpiece to the hob head and thereby to cause said push rod to engage the stylus and move it into contact with the template, means controlled by the stylus for effecting relative radial movement between the hob and the workpiece and thereby modify the tooth form cut on the workpiece in accordance with variations in contour of the template, and means for automatically reducing the effective length of the push rod after the hob has made a first cut and prior to commencement of a second cut by the hob.