Of these explanations that of the 'wobble' needs some passing notice. In its simplest form it depends merely on loss of velocity of flight on the part of the bullet, the centre of gravity of which lies behind its middle; hence a tendency to turn over and over is acquired. As a result of this, either the side of the tip, the side of the bullet, the side of the base, or the base itself may form the portion of the projectile which comes into contact with the body. The tendency to wobble is naturally greatly increased in ricochet bullets, since the contact, if lateral, serves to check the spin on which the bullet depends for its flight on an axis parallel to its long diameter. The first effect of wobbling is to increase the size and interfere with the regularity of outline of the wound of entry; but it also acts in a more serious manner, since the increase of the area of impact augments the resistance offered by the body; therefore the degree of damage to the tissues is accentuated and becomes greater than it would be from a bullet travelling at the same rate on its normal axis. Hence the wounds are both large and severe, or if the velocity is very low, the projectile is especially likely to be retained. Actual reversal of the bullet usually only slightly enlarges the aperture of entry, but injuries to cancellous bone are apt to be more severe when the bullet enters in this manner, or again it is often retained. I saw several such cases during the campaign. Another form of wobble is suggested by Nimier and Laval,[9] of which I can offer no experience. They suggest that, as rotation slows, the bullet may on impact wobble like a top before it ceases to spin. Probably the power of penetration possessed by a bullet wobbling in this manner would not be very great, but its effect would mainly be altered in the direction of an abnormal increase in the size of the aperture of entry, or possibly in the degree of comminution in fractures. It is probable that some of the more serious wounds observed were merely the result of unusual forms of impact with normal flight on the part of the bullet. The majority, however, depended, in the case of the wound of exit, on deformation of the bullet within the body, or the propulsion of bone fragments with it, and, when both apertures were affected, to previous ricochet on the part of the projectile.