History. —Lillian T., aged 13, was admitted to Lebanon Hospital, in the service of Dr. Henry Roth, April 25, 1922, complaining of abdominal pain and vomiting. Her past history was uneventful. She had never menstruated, and had been well up to the onset of her illness, four days prior to admission to the hospital. At that time she was seized suddenly with sharp pain in the right lower quadrant of the abdomen. This pain soon became generalized, but on the second day the pain localized in the right lower quadrant and became very severe. The patient vomited several times after onset of the pain. On the third day of her illness, her temperature was 103 F. She complained of frequent and painful micturition, and had a feeling of soreness in the epigastrium. Before entering the hospital, the child had received numerous cathartics, which resulted in frequent fluid stools. Examination. —On