The ovum, owing to some delay in passage to the uterus, is fertilized either in the ovary or in the tube, and by reason of a chronic inflammation of the tube or pelvis, or of overgrowth does not succeed in reaching the uterus at all. As the ovum develops, the tube expands, but it does not possess the power of growing into a large organ like the uterus, hence a sudden jar, a strain, or a blow may cause it to rupture and discharge the egg into the abdomen (ruptured tubal pregnancy) or force it out through the end of the tube (tubal abortion). This phenomenon may be accompanied by a severe or even fatal hæmorrhage; or the prostration may pass off in a few days or weeks, and leave the patient well. In the early stages the ovum is absorbed, but after the pregnancy becomes more advanced, it may remain as a tumor, or require an operation for its removal. Infection may occur and the mass ulcerate its way into neighboring organs (rectum, vagina, or bladder) and discharge itself in a long, suppurative process. Most cases of ectopic (extrauterine)gestation present definite and even dangerous symptoms between the second and fourth month. The _symptoms_ are those of pregnancy, together with irregular hæmorrhages from the uterus, which may result in the expulsion of pieces of tissue or of membrane. Besides this, there is a vomiting and acute irregular pain on one side, associated with a sense of fullness. Such symptoms should be brought to the attention of the physician, who will learn the true condition of the pelvis by internal examination, conducted as gently as possible so as not to produce rupture. If rupture occurs, it will be ushered in by a sharp lancinating pain on one side, followed by faintness, nausea, vomiting, prostration, rapid pulse, sighing respiration, and collapse. The temperature is subnormal and death may occur in a few hours, unless an operation is done. [Illustration: Fig. 30.—Diagram representing the sites for the various forms of tubal pregnancy. 1, interstitial pregnancy; 2, isthmial pregnancy; 3, ampullar pregnancy; 4, infundibular pregnancy; 5, tubo-ovarian pregnancy. (Gilliam.)] In cases of tubal abortion (where the ovum escapes through the end of the tube) the symptoms are very similar, but the patient soon rallies and gradual recovery takes place. If the diagnosis is made before rupture or abortion the _treatment_ is laparotomy. If rupture occurs, the laparotomy must be done immediately to check the hæmorrhage, which threatens the life of the patient. In tubal abortion, if the diagnosis is certain, some delay may be permitted under extreme watchfulness of the nurse and physician. In such case, the nurse will keep the patient absolutely quiet and forbid exertion of any kind.