tip first into two adjoining body tissues. As this occurs, the heads 615 of the fasteners are carried inside the body tissues by the front tip of the tool, while the portions of filament 610 that extend through slots 730 and 736 are bent through interaction with the surrounding tissue so as to lie nearly flat against sheath 705. Referring now to FIG. 17, the fastener is thereafter set into the tissue by pressing plunger 710 forward until the fastener head 615A closest to front tip 715 is propelled out of the sheath and into the tissue. Tool 700 typically retreats slightly under this action, leaving an opening in the tissue to accomodate the fastener's head. The resilient nature of the fastener thereupon urges the fastener to straightenon itself, whereby the sharply pointed ends of head 615A will dig into the surrounding tissue as the head attempts to return to its normal position substantially perpendicular to the adjoining length of filament. Due to the fact that the hole formed in the tissue by the retreating tool 700 is significantly smaller in diameter than the length of the fastener's head, and due also to the fact that the hole will tend to close inwardly somewhat under the pressure of the surrounding resilient tissue, head 615A will typically be able to return only a fraction of the way back to its original perpendicular position; however, the sharply pointed ends of head 615A will allow the fastener to penetrate sufficiently into the walls of the tissue so that