Here are collected a group of papers by members of the St. Thomas staff. Some papers, such as these on oxygen therapy, cerebral abscess, empyema and orbital inflammation, are instructional and deal with technics and clinical observations and indications. A review of the male sex hormone is followed by a case report of macrogenitosomia in one of twin boys. The surgical treatment of gastroduodenal hemorrhage is discussed. The anatomic changes associated with closure of the ductus arteriosus are outlined in pathologic changes in the wall of the ductus arteriosus. Other titles include acetylcholine and potassium in relation to cardiac function, thorium-x irradiation in cutaneous therapy and estimation of the water soluble vitamins in the body fluid. The typography is excellent.