In the management of gonococcus vulvovaginitis, one is frequently unable to determine whether or not a particular case is cured. The examination of smears is inconclusive; the gonococcus is often undemonstrable, especially in chronic discharges, and even if Gram-negative diplococci are seen within pus-cells, their identity is not always certain. To isolate the gonococcus from a culture medium on which all the other vaginal flora are growing is a task for which few hospital bacteriologists have time. The clinical history and physical condition may point to a complete disappearance of the disease, yet it has been alleged by many observers that, even where the absence of discharge is combined with negative smears, the discharge is prone to reappear. With the hope of securing another criterion of cure, the cases of gonococcus vulvovaginitis in the genito-urinary clinic of the Massachusetts General Hospital have, since January, 1912, been submitted to the complement