A female, twenty-two years of age, was suddenly seized with severe pain in the left side of the abdomen, which was increased by inspiration. The bowels were obstinately confined. After a week in bed the pain was relieved but never quite disappeared, and vomiting occurred occasionally. Soon afterwards the patient noticed a small tumour in the left hypochondrium, which gradually increased in size and gave rise to excruciating pain. As the tumour appeared to be cystic, it was punctured, and a quantity of clear albuminous fluid was withdrawn, after which the pain disappeared and the tumour could hardly be detected. About a fortnight later, however, the pain returned, and the tumour was found to have regained its former dimensions. A second puncture resulted in the evacuation of a similar quantity of fluid, but the cyst filled up again in a couple of weeks. At this period it was noted that the abdomen was enlarged and the tumour occupied the left hypochondriac, umbilical, and left lumbar regions, extending from the margin of the ribs to the level of the iliac crest and to the right of the median line of the belly. The surface was smooth, the percussion-note was dull, and stomach resonance could be detected between the tumour and the diaphragm. Distinct fluctuation was perceptible. Two months later the patient was readmitted into hospital with the symptoms and signs of acute phthisis, but she still complained of pain in the tumour, which, however, did not appear to have increased in size. Death occurred from acute peritonitis about fourteen months after the first symptoms of the abdominal complaint had appeared. At the necropsy a cyst the size of the foetal head at term was found connected with the posterior wall of the stomach. Rupture of its wall had set up fatal peritonitis.- Gallois, Honlang, and Leflaive.