Post-operative thrombosis was formerly fairly common after hysterectomy for fibroids and in the later stages of malignant disease of the uterus. Its frequency after operations for fibroids was attributed to the profound anæmia in patients who had severe and exhausting metrorrhagia. I am convinced that it is due to sepsis. In several instances I have caused the clot found in thrombosed veins to be examined bacteriologically, and pathogenic microscopic organisms have been isolated. I am also satisfied that in some cases of thrombosis of the veins of the thigh, especially those limited to the saphenous veins, the clotting spreads from the superficial veins of the hypogastrium which are infected from the abdominal incision. =Pulmonary embolism.= In perusing the clinical histories of a series of cases of ovariotomy, hysterectomy, myomectomy, and, indeed, after almost any surgical operation, here and there a record may be read to this effect: ‘The patient appeared to be doing well after the operation, when she sat up, laughed and chatted with the nurse, then suddenly fell back and died in a few minutes.’ Anything more tragic than this it is difficult to conceive, and, as a rule, after such a sad occurrence, the relatives are so distressed that they rarely permit an examination of the body. Death in such circumstances is usually attributed to embolism of the pulmonary artery. In some instances this is an assumption, but there are many in which an embolus has been demonstrated, and a few in which the source has been detected. Post-operative embolism of the pulmonary artery is an important matter for surgeons interested in the operative treatment of uterine fibroids, for it follows such operations more frequently than any other. In order to afford some notion of the relative liability of patients to this accident after subtotal and total hysterectomy for fibroids, I have gathered the following statistics, which are interesting as showing an extraordinary variation in the practice of different operators:-- Baldy ascertained that among 366 operations for fibroids in the Gynecean Hospital, Philadelphia, there were thirteen sudden deaths attributed to pulmonary embolism. In the Middlesex Hospital between the years 1896 and 1906 (both years inclusive) there were 212 abdominal hysterectomies performed for fibroids. Three of the patients died from pulmonary embolism. Spencer, in eighty-five total hysterectomies, had two deaths from pulmonary embolism. R. Lyle, in eight cases of subtotal hysterectomy, had one sudden death. Mallet collected the records of 1,800 cœliotomies: there were six deaths attributed to embolism, and of these, three followed operations for uterine fibroids. Chas. P. Noble, in forty-two vaginal myomectomies, lost two patients, one from septic endocarditis, the other from embolism; in the latter case the fibroid was gangrenous.