The part of the ovum at which the separation of it from the uterus has taken place, not only determines which of the above symptoms will appear first, but also the probability of expulsion. "When a considerable separation takes place, as must be the case when it commences at the upper parts of the uterus, pain will more likely occur than when it happens near the neck; hence we sometimes have pain before the blood issues externally. The uterus in this instance suffers irritation from partial distension from the blood insinuating itself behind the ovum; contraction ensues; the blood is thus forced downwards, and is made to separate the attachment between the ovum and the uterus in its course, until it finally gains an outlet at the os tincæ. In consequence of the uterus being excited to contraction, the friendly coagula which may have formed from time to time are driven away, and the bleeding each time is renewed and accompanied most probably with increased separation of the ovum, until at last from its extent the ovum becomes almost an extraneous body, and is finally cast off. Hence a separation at or near the os uteri will not be so dangerous, and in all probability there will be hæmorrhage without pain, which is the contrary when it takes place near the fundus." (Dewees, _Compend. System of Midwifery_, § 981, 982.) The pain during the abortion is sometimes exceedingly severe, and not unlike that of dysmenorrhoea: this is probably owing to the violent contractions of the uterus, which are required to dilate the os and cervix before the ovum can pass: they are frequently attended with nausea, vomiting, and fainting, and sometimes with more or less general fever and local inflammatory action; the pain is generally attended with much irritability of the bladder, and frequent desire to pass water; the pulse is mostly quick and small, and where there is arterial excitement, it is sharp and resists the finger. _Treatment._ The treatment of premature expulsion consists in, 1, that which is intended to guard the patient against its occurrence, or _prophylactic_; and 2, in that which is required _during an attack_.