The trapping means also preferably includes a biasing means, such as an interference fit between the pushers 118 and the bottom portion of the staple housing 112 forming the slot 121, for biasing the pushers 118 vertically away (downward in FIG. 22) from the tissue to be stapled and for biasing the hook surface 79 of the pusher 118 into engagement with the trap surface 78 of the staple housing 112