The patient was kept quiet in the supine position for a month, and during this time the condition in many ways improved. The voice improved in strength, the pulse steadied, falling to 80, the prominence of the left eye disappeared, and all the blood effusion in the posterior triangle became absorbed. Meanwhile the aneurism contracted at first, until it became oval in outline, with a long axis of 2 inches by 1-1/2 broad extending in the line of the wound track, but mainly situated in the exit half. During the last fortnight, however, it remained quite stationary in size, and as it showed no further signs of diminution in spite of the favourable conditions under which the patient had been placed, it was considered best to try to ensure its consolidation by a proximal ligature. Thrill had become slightly less pronounced, and was less evident to the patient himself, but was otherwise unchanged. The probabilities in this case seemed rather in favour of wound of the internal carotid artery, and it was decided to bare the upper part of the common carotid, follow up the main trunk, and if possible apply the ligature to the internal branch. On April 12, 61 days after the injury, the classical incision for securing the common carotid was made, and the sterno-mastoid slightly retracted. It was found that the sac of the aneurism extended over the bifurcation of the artery, reaching to the wall of the larynx. The omo-hyoid muscle was therefore divided, and the artery ligatured beneath, in order to ensure against any interference with the sac. Some difficulty was met with, for on opening the vascular cleft the vein was exposed and found to completely overlie the artery: although it was on the left side of the neck, the position of the vein was so completely superficial that there seemed no doubt that it had been displaced by the development of the aneurismal sac. A striking appearance was noted on exposure of the vein, the coats of which vibrated visibly, quivering in exact consonance with the palpable thrill. On tightening the silk ligature all pulsation ceased in the aneurism, and the vibratory thrill in the vein became much lessened. The patient made a good recovery, only disturbed by a slight attack of vomiting, and at the end of a week the wound had healed, and pulsation in the aneurism had completely ceased. The thrill persisted as before.