between a first position fig3 and a second position fig5 with the driver 18 more closely adjacent the anvil 12 in its second position also included is a staple engaging member 19 comprising a plurality of spaced lugs 20 adapted to engage staples 13 along the track 14 the staple engaging member 19 is mounted by means for causing movement thereof from an initial position fig3 with its lugs 20 spaced from staples 13 along the track 14 toward the track 14 to an engage position fig4 with the lugs 20 aligned with and between the staples 13 along the track 14 during a first position of movement of the driver 18 from its first toward its second position for causing movement of the staple engaging member 19 with the driver 18 to engage and move staples 13 along the track 14 and to close the leading staple 13 along the track 14 around the anvil 12 during a second portion of the movement of the driver toward its second position fig5 and 12 for causing movement of the lugs 20 away from the track 14 and out of engagement with the staples 13 along the track 14 during a first position of movement of the driver 18 from its second position fig5 back toward its first position and to move the staple engaging member 19 with the driver 18 back to its initial position fig3 during a second portion of movement of the driver 18 back toward its first position the driver 18 comprises an elongate driving portion 22 which has a semi cylindrical bearing surface 23 fig6 and 7 and a longitudinally extending u shaped slot 24 along its side opposite its bearing surface 23 so that the driving portion 22 is generally c shaped.