_Ovariotomy signifies the removal through an abdominal incision of cystic and solid tumours of the ovary, and parovarian cysts._ The history of this operation is of great interest to surgeons because it was the forerunner, so to speak, of all abdominal gynæcological operations; they followed as a natural consequence on the establishment of ovariotomy, and operations on the abdominal viscera generally are to be regarded as an extension of pelvic surgery. It is usual to state that ovariotomy was first performed by Ephraim McDowell, of Kentucky, 1809: this is of historical interest only, for it had no effect whatever in drawing attention to the feasibility of removing ovarian cysts: it was in fact a still-born operation. The pioneers of this operation were undoubtedly Baker Brown and Spencer Wells in London, Thomas Keith in Edinburgh, and Clay in Manchester. These surgeons brought the operation out of a ‘slough of despond’ and placed it on firm ground. Spencer Wells and Keith were fortunate later in their work in receiving guidance from Lord Lister’s discovery of antisepsis: this, combined with the introduction of the short ligature, firmly established the operation. The improvement in securing the pedicle has played an important part in the development of ovariotomy. McDowell tied the pedicle, but left the ligature hanging out of the wound. Doran, who has written an excellent review of this matter, ascribes the intraperitoneal method of dealing with the pedicle to the systematic advocacy of Tyler Smith. The method has been followed by brilliant results. Baker Brown used to sear the pedicle with a cautery, and this method was adopted with great success by Thomas Keith. The method of ligature is so simple and safe that the cautery for this purpose has been long abandoned. =The operation.= The preliminary preparation of the patient and the necessary instruments are described on p. 5. The Trendelenburg position is not so necessary for the removal of large ovarian tumours as the smaller examples which are apt to be firmly adherent to the floor of the pelvis. In cases where the abdomen contains free fluid, ascitic or due to the bursting of a cyst, or pus, it is a wise precaution to conduct the early stages of the operation with the patient in the horizontal position, otherwise the tilting will cause the fluid to gravitate towards the diaphragm. As soon as the fluid has been removed the pelvis may be raised if it be likely to facilitate the operation.