_Operation._--Various incisions are recommended. The one which gives freest access and exposes the sac best, is shaped like a T, the horizontal limb of which is oblique, the direction of the obliquity varying on the two sides. The horizontal incision should be made just over Poupart's ligament, and parallel to it, the centre of the incision corresponding to the neck of the sac, and its length varying according to the size of the tumour and the depth of the parts; the other should extend downwards from the centre of the former, as far as is necessary to display the whole sac. The first should be made by pinching up and transfixing the skin, the second by ordinary incision, to the same depth as the first. The small flaps thus made must now be thrown back; any vessels that have been divided are to be tied. Now, with great care and caution the surgeon is to pinch up and divide any layers of condensed cellular tissue which may still cover the sac, till it is thoroughly exposed to its full extent, and remove any glands which may intervene. The neck of the sac being exposed, it may be possible in some very exceptional cases to give the patient the benefit of the minor operation, which consists in leaving the sac unopened. In such a case (to be described immediately), the surgeon passes his finger along the neck of the sac as far as possible into the ring, and then with a probe-pointed bistoury very cautiously nicks the upper edge of Gimbernat's ligament, in one or more places, being careful to feel for any pulsation before dividing a single fibre. He may then be able to empty the sac of its contents, and return the bowel and omentum, still retaining the sac outside.