WHEN speaking of inflammation of the vagina, reference is had to its mucous lining alone. It undoubtedly happens that structures or tissues beneath the mucous covering become involved in the inflammatory action, but this occurs so seldom that it is not of sufficient moment to make it the subject of an inquiry in a practical work. The mucous membrane of the vagina, like all other mucous surfaces, has its natural secretion for the purpose of lubricating and keeping its surface moist. In a perfectly healthy state, the color of the vaginal mucous membrane is a pale red, this becomes scarlet red upon irritation. In girls who are not irritated or women who have not been abused by sexual excesses nor infected by disease, the normal secretion is just sufficient to preserve the moisture of its surfaces, but not in such an excess as to be noticed as a secretion or discharge outside of the vaginal canal. There is a physiological exception to this normal rule, a few days before and after the menstrual period, when the mucous membrane of the vagina sympathizes with the general congestion of the pelvic organs. The mucous secretion becomes then greatly increased, amounting to a catarrh or flow, this, however, is only transient and subsides with the cessation of the menses. This might with propriety be termed a natural or physiological catarrh. For convenience of description and corresponding with the anatomical changes and the sources of their origin, inflammation of the mucous membrane of the vagina may be _acute_ or _chronic_, simple or specific. Acute inflammation in this instance is no different in its characteristic symptoms from inflammations elsewhere; it develops suddenly, and there is congestive swelling and pain. There is considerable heat in the parts, increased redness, and the canal is very sensitive. In the beginning the mucous membrane is dry and contracted, but after a few hours or a day, relaxation and moisture supersede. The secretion is very scant at first, but becomes more abundant as the disease progresses, its character also changes from a white, glairy mucus to a creamy, muco-purulent or yellowish discharge. The urethra may also become involved, and then the symptoms that were detailed in connection with urethritis are also present.