f
the arm crossing the course of the brachial artery; in many of these the
radial pulse was diminished almost to imperceptibility. How far this
condition may prove permanent there has been little opportunity of
judging; nor as to the possible ultimate weakening of the vessel wall
and the development of a secondary aneurism has time allowed the
acquisition of experience. In the light of the observation of so many
cases in which large vessels were wounded without the occurrence of
severe haemorrhage, either primary or secondary, it is impossible to be
certain whether some of the cases of arterial obstruction were not
secondary to perforating lesions of the vessels.

Pressure on, or minor lesion of the vessel was sometimes evidenced by
the development of a murmur, as in the following case. A Mauser bullet
entered immediately within and below the left coracoid process, and
emerged at the back of the arm at its inner margin, 2-1/2 inches above
the junction of the right posterior axillary fold. During the first week
dysphagia and some pain and soreness in the episternal notch, with pain
and difficulty of respiration, were noticed. Eight weeks later no
trouble with the pharynx or oesophagus remained, but a short sharp
systolic murmur was audible over the first part of the left axillary
artery, which could be extinguished by pressure on the subclavian; the
radial pulse was normal.[14]

When primary union failed or was prevented by infection and
suppuration, lesions, although incomplete, of the vessel coat naturally
frequently gave rise to secondary haemorrhage.

2. _Perforation of the vessels._--(_a_) This may be oblique or
transverse to the long axis of a trunk; when the vessel is impinged upon
laterally, an oval or circular notch, as the case may be, is produced;
or (_b_) the bullet may strike more or less in the centre of the vessel,
perforating both in front and behind, while lateral continuity is
maintained; (_c_) beyond these degrees a vessel may, of course, be
completely divided. Cases of notching of the vessel will be referred to
under the heading of traumatic aneurism; those of perforation under that
of aneurismal varix and varicose aneurism, the perforations in these
cases affecting a parallel artery and vein.

RESULTS OF INJURY TO THE VESSELS

1. _Haemorrhage._--The fact that haemorrhage was not a prominent feature
in the wounds received during this campaign can scarcely be regarded as
an experience confined