Dismissing at once all so-called palliatives, drugs, unguents, pressure, and injections, as mere waste of time, and holding that the only method of cure consists in laying the fistula fairly open, the question narrows itself into this: What is the best method of laying it open? Prior to the discovery by Ribes of the great principle that the internal orifice of the sinus is always within an inch or an inch and a half of the orifice of the anus, the operations for fistula were most unnecessarily severe; the gut used to be divided as far up as the sinuses extended; and large portions of the anus used to be excised bodily along with the sinuses. It is now a much simpler and more satisfactory operation. _Operation._--A common silver probe bent to the required shape is passed into the external opening, or, if there are more than one, into the largest and oldest one. The forefinger of the left hand being introduced into the rectum, the probe is passed through the internal orifice, and its point brought out by the anus. The portion of tissue raised by the probe can then be easily divided with the certainty that the fistula is laid fully open. Anal fistulæ have been divided by the elastic ligature, but it seems slower in action and more painful, with no counterbalancing advantages. The author has for last few years operated almost exclusively by a long knife which is continued into a steel probe. The probe is passed up the fistula, then into the bowel, and is hooked out at the anus, and in being simply pushed on the knife cuts the fistula--tuto, cito, et jucunde, the patient rarely knowing that more has been done than an exploration. In cases where, from the hardness and density of the parts it is impossible to pass the probe and bring it out at the anus, a strong probe-pointed bistoury may be passed in by the external orifice till its probe-point can be felt by the finger in the bowel at the internal opening. Supported by the finger it can then be made to cut outwards till the whole septum is divided. FISSURE OF THE ANUS, ULCER OF THE ANUS, resemble each other alike in the exceeding annoyance which they give to the sufferer, and in the simplicity of the treatment needed. _Operation._--Once the presence of either is determined by the finger in the anus, a sharp-pointed curved bistoury should be introduced, transfixing the base of the fissure or ulcer, and then guided on the finger, completely dividing it, so as to change the ragged ulceration into a simple wound which will rapidly heal. PROLAPSUS ANI, _Operation for_.--Complete prolapsus in which the whole gut is involved, as seen in the very young and the very aged, is suited for palliative rather than radical treatment. Cases of prolapsus of the mucous membrane only, as is not uncommon in connection with or as a result of hæmorrhoids in adults, give opportunity for operative interference.