In the early days of ovariotomy it was the custom to tap the cyst, or, in the case of multilocular tumours, to force the hand into the mass and break down the septa of contiguous loculi and allow the viscid material to escape. These devices were recommended because it was regarded as a method making for safety to extract the cyst through a small abdominal incision. Occasionally it is possible to extract the wall of a large single-chambered parovarian cyst, after tapping, through an incision 7 centimetres in length. When the tumour is multilocular, or malignant, or full of grease or pus, it is difficult and extremely dangerous to tap it, as the material may infect the peritoneum either with septic matter or with malignant particles, and end disastrously. Cases have been reported in which, after traumatic rupture, or tapping, of a dermoid, the epithelial contents escaped into the belly. Subsequently the peritoneum was found dotted over with minute nodules furnished with tufts of hair growing among the visceral adhesions. When a woman with an ovarian cyst contracts typhoid fever, the cyst may become filled with pus which contains the _bacillus typhosus_. Such a case occurred in my practice in 1907. For many years I have abandoned the use of clumsy trocars of all kinds and remove the tumour entire, although it may require an incision from the ensiform cartilage to the pubes. These large incisions heal quickly, and are no more prone to hernia than the short incisions. This is the only way of ensuring the safety of the peritoneum from being contaminated by the harmful, dirty, and often malignant contents of the cysts. In dealing with burst cysts a free incision enables the surgeon to thoroughly and gently clean the peritoneal cavity. The abdominal cavity is opened by a median subumbilical incision (see p. 7). Occasionally a difficulty may be encountered on reaching the peritoneum, for, if the cyst has been infected, the peritoneum and cyst wall may be so intimately adherent that they cannot be separated. In these circumstances it is a wise plan to extend the incision upwards and enter the abdominal cavity above the tumour. It is also to be borne in mind that when the tumour adheres to the abdominal wall it is extremely probable that a coil of intestine may be adherent also. When a tumour is impacted in the pelvis it may push the bladder high in the abdomen; in such an event this viscus is apt to be opened in making the incision. If the surgeon has any doubt concerning the position of the bladder, he should instruct an assistant to introduce a sound into it through the urethra.