Cotton fibers were broken under a variety of conditions and the fractures were examined in a scanning electron microscope. Many fractures occur adjacent to the reversal zone and not through it, indicating that the reversal itself is strong, but, because of its existence in the fiber, it is a source of weakness in that it is the cause of fracture in a region adjacent to the reversal. The appearance of the fractures varies between cross-linked and scoured cotton and between fractures at a reversal and between reversals.