In some cases of puerperal pyæmia a careful examination of the patient’s abdomen has enabled the surgeon to feel the thrombosed ovarian vein, and in others the vein has been exposed by an incision running from the tip of the eleventh rib to the spine of the pubes, parallel with Poupart’s ligament. The muscles are divided and the peritoneum reached; this is reflected until the thrombosed ovarian vein is exposed and separated from the ureter. About half an inch below its junction with the renal vein or the vena cava, as the case may be, it is securely ligatured and divided; the vein is then slit up and the clot turned out. The operation, when carried out in this way, is extraperitoneal. In some instances successful ligature of the thrombosed ovarian vein has been effected by the usual median incision into the peritoneal cavity. The object of ligaturing the thrombosed ovarian vein is to prevent the pathogenic micro-organisms in the clot from entering the circulation. Bumm reported five cases in which he ligatured these veins. Three of the patients recovered. It is more than probable that if operative interference be carried out on thrombosed ovarian veins before the condition of the patients become desperate, more of them might be rescued. Success has been attained even in desperate conditions; for example, Friedemann ligatured these veins in a woman whose general condition was not only bad, but who also had extensive bed-sores. She recovered. T. G. Stevens reported the details concerning a woman who died, of acute septicæmia, eleven days after a subtotal hysterectomy (by Galabin) for fibroids. The right ovarian vein was thrombosed from the ligature in the pelvis to its entrance into the vena cava, and he isolated from the clot and produced in cultures the _bacillus pyocyaneus_. He also stated that ‘the vein could have been easily dissected out, and possibly the fatal result might have been averted’. This operation rests on sound principles, for the ligature of the ovarian veins prevents the septic blood entering the circulation, thereby setting up, among other things, endocarditis and pulmonary embolism.