When the bullet impinges at a right angle the wound is circular, with more or less depressed margins, and of a diameter, corresponding to the size of the bullet occasioning it, from a quarter to a third of an inch. The description 'punched out' has been sometimes applied to it, but it would be more correct to reverse the term to 'punched in,' since the appearance is really most nearly simulated by a hole resulting from the driving of a solid punch into a soft structure enveloped in a denser covering. The loss of substance, moreover, in the primary stage is not actually so great as appears to be the case, fragments of contused tissue from the margin being turned into the opening of the wound track. The true margin therefore is not sharp cut, and the nature of the line differs somewhat according to the structure of the skin in the locality impinged upon. Thus the granular scalp and the comparatively homogeneous skin of the anterior abdominal wall will furnish good examples of the nature of the slight difference in appearance. From the first the margin is also often somewhat discoloured by a metallic stain, similar to that seen when a bullet is fired through a paper book. This ring is, however, narrow, and not likely to be noticeable when the bullet has passed through the clothing. In any case it is subsequently obscured by the development of a narrow ring of discoloration due to the contusion. This latter varies in width, and still later a halo of ecchymosis half an inch or more in diameter surrounds the original wound. [Illustration: FIG. 18.--Oblique Exit Gutter. Diagram enlarged to actual size from case shown in fig. 24, p. 64.] With increasing degrees of obliquity of impact more and more pronounced oval openings of entry result, culminating in an actual gutter such as is seen in fig. 17. In all oval openings the loss of substance is more pronounced at the proximal margin, while the wound is liable to undergo secondary enlargement at the distal margin, since in the former the epidermis is mainly affected, while in the latter the epidermis is spared as an ill-nourished bridge, the deeper layers of the skin suffering the more severely. When the wound occurs in regions, such as the chest-wall or over the sacrum, where the skin is firmly supported, the oval openings are often very considerable in size, reaching a diameter at least double that of the circular ones. In the case of the oval openings the depression of the margins is not such a well-marked feature as in wounds resulting from rectangular impact of the bullet, since the distal margin is really lifted. [Illustration: FIG. 19.--Oval Entry Wound over third sacral vertebra. Exit wound, anterior abdominal wall. Slightly starred variety. Diagram made on second day]