_Pari passu_ with the closure of the external openings, healing of the track takes place, but this is not always so rapid a process as is apparently the case. In many instances the closure, and even definite healing, of the external wounds is complete long before the track has actually healed, even though it be contracted up to complete closure as far as any cavity is concerned. This is well seen in many cases in which the exit opening is large as a result of deformation of the bullet, or the passage of bone splinters in conjunction with it; here, in spite of absence of all suppuration, the track may remain patent for many weeks. This may point to infection, but the tardiness in actual consolidation corresponds with what we are well acquainted with in the case of all aseptic wounds when a slough has to separate or become absorbed, and it is therefore only what might be reasonably expected when we remember that every such bullet track is lined by a thin layer of damaged tissue. [Illustration: FIG. 25 (_b_).--Great Omentum carried by the bullet into an exit track leading from the abdominal cavity. A. Outline of opening in the peritoneum] When fully healed, the points of entry and exit are so insignificant as to be less obvious than ordinary acne scars, and later are often hardly visible, but for a considerable period they are often more palpable than apparent. This depends upon the induration of the line of cicatrix corresponding to the course of the original track which is adherent to the two points. The induration is indeed so marked as to occasionally give rise to the suspicion that a foreign body such as a fragment of lead or of the mantle of the bullet has been enclosed during the healing of the wound. In the deeper portions of the tracks the extreme density of the cicatrix is a factor of great prognostic importance, since if it implicates muscles, tendons, vessels, or nerves, impairment of movement, circulatory disturbance, or signs of neuritis or nerve pressure are often witnessed. Thus, for instance, a track traversing the calf, will more or less tie the whole thickness of the structures perforated at one spot, and the apertures of entry and exit may be visibly retracted when the muscles are put in action with consequent pain and stiffness to the patient. Such pain and stiffness form some of the most troublesome after-consequences of many simple wounds. It is remarkable for how long a period after the healing of the wound and resumption of active duty the patients suffer from pain in and radiating from the locality of the wound, when fatigued or suffering from stiffness from the prolonged retention of one attitude or exposure to cold. The cords, however, eventually completely disappear, and the cicatrices become moveable. The effects of secondary pressure on the vessels and nerves are considered under the headings devoted to those structures.