The forefinger of the left hand is now to be deeply inserted into the wound, and any remaining fibres of the levator ani in front are to be divided, the edge of the knife being directed from above downwards. The left forefinger being still used to push its way through the cellular tissue, the groove in the staff is now felt in the membranous portion of the urethra covered by the deep fascia of the perineum. Now comes the deeper part of the incision. Guided by the finger-nail of the left hand, the surgeon introduces the point of the knife into the groove of the staff. He then takes hold of the staff for a moment to feel that it is held up properly against the pubis, and in the middle line, and also that the knife is fairly in the groove. Giving the staff back again to the assistant, and keeping the rectum well out of the way by the left hand, he now steadily directs the knife along the groove of the staff till the bladder is fairly entered, and the ring at the base of the prostate completely divided. When this is the case a gush of urine takes place, following the withdrawal of the knife. When making the deep incision, and in the groove of the staff, the blade of the knife should lie neither vertical nor horizontal, but midway between the two, so as to make the section of the left lobe of the prostate in its longest diameter, that is, in a direction downwards and backwards (Fig. XXXIV. L). The knife is now withdrawn, and the left forefinger inserted. In most cases it will be long enough to reach the bladder and touch the stone, and may then be freely used by gradual pressure to dilate the wound; this may be done very freely when necessary for a large stone, if only the ring of fibrous tissue surrounding the urethra be first cut and the bladder fairly entered. Whenever the stone is felt by the finger, the assistant may withdraw the staff. When the operator has thus felt the stone and sufficiently dilated the wound, the next step is to introduce the forceps; this should be done under the guidance of the finger, and with the blades closed. When the stone is felt the blades should be opened very widely, slightly withdrawn, and then pushed in again, the lower one, if possible, being insinuated under the stone. The blades must be made fairly to grasp and contain the stone in their hollow, for if they only nibble at the end of an oval stone, extraction is impossible. Extraction should then be performed slowly, with alternate wrigglings of the forceps from side to side, so as gradually to dilate, not to tear, the prostate, and the operator must remember to pull in the axis of the pelvis, not against the os pubis or the promontory of the sacrum.