let-wounds.

From the records of cases in which the vertebrae were injured by modern
rifle bullets, even although the bony walls of the spinal canal had
not been fractured and no haemorrhage had occurred within the spinal
canal, the cord in the vicinity was degenerated into a "custard-like
material" incapable of any conducting power (Makins). According to
Stevenson, "this must have been due to the vibratory concussion
communicated to it by the passage of the bullet at a high rate of
velocity." The importance of this observation lies in the fact that in
such cases no benefit can follow operative interference.

The _clinical features_ vary with the level at which the cord is
injured, and the diagnosis as to the nature and site of the lesion is
to be made by a careful analysis of the symptoms. By gently passing
the fingers under the patient's back as he lies recumbent, any
irregularity in the spinous processes or laminae may be detected, but
movement of the patient to admit of a more direct examination of the
spine is attended with considerable risk, and should be avoided.
Skiagrams are indispensable, as they show the exact site and nature of
the lesion.

_Immediate Symptoms._--At whatever level the cord is damaged there is
immediate and complete paralysis of motion and sensation (paraplegia)
below the seat of injury, and the paralysed limbs at once become
flaccid. On careful examination, a narrow zone of hyperaesthesia may be
mapped out above the anaesthetic area, and the patient may complain of
radiating pain in the lines of the nerves derived from the segments of
the cord directly implicated. In complete transverse lesions the
paralytic symptoms are symmetrical; any marked difference on the two
sides indicates an incomplete lesion.

Retention of urine and retention or incontinence of faeces are constant
symptoms. In young men priapism is common--the corpus cavernosum penis
is filled with blood without actual erection. There is other evidence
of vaso-motor paralysis in the form of dilatation of the subcutaneous
vessels, and local elevation of temperature in the paralysed parts.
The deep reflexes, including the tendon reflexes, are permanently
lost.

Unless regularly emptied by the catheter, the bladder becomes
distended, and there is dribbling of urine--the overflow from the full
bladder. As the bladder is unable to empty itself, and its trophic
nerve supply is interfered with, the use of the catheter involves
con