In cases where the wounds were in the frontal or fronto-parietal regions, and hemiplegia existed, the rapid improvement in the paralytic symptoms, after operation, was very marked, showing that the signs were mainly, or entirely, due to 'radiation' injury. I am inclined to think that temporary injury of this kind from vibratory disturbance and small parenchymatous haemorrhages, were far more often the cause of the paralysis than surface haemorrhage, since the latter was rarely found in large quantity. Large clots, however, no doubt growing in both size and firmness, occasionally occupied the area of destroyed brain, and these sometimes manifestly exercised pressure that was at once relieved by their evacuation. In cases where inflammatory hernia cerebri developed, a secondary exploration was often indicated for the removal of fragments of bone or the evacuation of pus, otherwise the condition was best treated by dry dressings and gentle support. Abscess of the brain was treated by simple evacuation and drainage by metal or rubber tubes: the operations were always of extreme simplicity, since the abscess in every case I saw was in the direct line of the wound track, and was readily opened by the insertion of a director or blunt knife. The only trouble in the after treatment was that already referred to, of preventing premature closure of the drainage opening. I have made no special reference to the method of dressing, since it was of the ordinary routine kind. The most important factor in success was the efficient primary disinfection of the scalp; a piece of antiseptic gauze and some absorbent wool, efficiently secured, was all that was needed later. As usual the consideration of the treatment of cases in which the bullet was retained may be considered last. Such accidents were distinctly rare. I operated in only one (No. 54, p. 260) in whom the indications both for localisation and interference were obvious, since the bullet had palpably fractured the bone, although it had not retained sufficient force to enable it to leave the skull. In two other cases that I saw, in one the bullet was lodged in the zygomatic fossa, in the second just below the mastoid process. The former patient died; the latter exhibited symptoms indicative of injury to the occipital lobe (No. 68), and was successfully treated by Mr. J. E. Ker. I never happened to see a case in which a retained bullet in the skull was localised by the X rays, but such might have been possible in case No. 64, p. 275. In no case is primary interference indicated, unless a fracture exists where the bullet has tried to escape, or secondary symptoms develop pointing to irritation.