When the aneurism has reached a quiescent stage the question of further treatment arises, and whether this should consist in local interference or proximal ligature. The answer to this mainly depends on the size and situation of the vessels concerned. To take of the cases above described the five instances in which the cervical vessels were the seat of the aneurism. In No. 13 the symptoms appeared fairly conclusive of the injury being to the innominate artery and vein, or possibly innominate artery and jugular vein. Fortunately the aneurismal sac in this case was small and showed a tendency to decrease, but in any case no interference would have been justifiable. I think a similar opinion was unavoidable in No. 14, probably affecting the root of the right carotid. Here under any circumstances interference would have been most hazardous. The position of large aneurism made the route of approach to the wounded spot necessarily through the sac, exposing the patient to the double danger of immediate haemorrhage and of entrance of air into the great veins. Nos. 10, 11, and 12 fall into the same category, except that in No. 11 the immediate indication for interference was extension. In each, ligature of the artery above and below the point of communication would have necessitated so near an approach to the sac which must remain in communication with the vein as to have entailed injury to the latter, when both artery and vein must have been ligatured, probably risking serious cerebral trouble. In No. 11 I believe both the external and internal carotids were implicated; in No. 10 I believe the internal alone, close to its origin. The operation of proximal ligature ensured primary consolidation of the sac in both cases 10 and 11, but left the thrill unaltered, except in so far as it was temporarily weakened. It, in fact, converted these cases from arterio-venous aneurisms into pure aneurismal varices. In No. 10 a sac subsequently redeveloped. No. 12 stood on a different basis. No operation was done for him in South Africa, but the first portion of the carotid might have been ligatured in the episternal notch, or by aid of removal of a part of the sternum, and a second ligature placed above the sac. Here a ligature above and below the communication would have been comparatively easy. As a general rule proximal ligature is to be reserved for those cases alone in which double ligature is either impracticable or inadvisable, and it can only be expected to convert a varicose aneurism into the less dangerous condition of aneurismal varix. In the case of arterio-venous aneurisms in the limbs the possibilities of treatment are enlarged, and here the alternatives of (_a_) local interference with the sac and direct ligature of the wounded point, (_b_) simple ligature above and below the sac, (_c_) proximal ligature (Hunterian operation), come into consideration.