This study was undertaken for the purpose of ascertaining just what pathologic changes were present in the lungs of children to account for shadows in the roentgenograms of the chest. A careful history of every patient was taken, with repeated physical examinations and the necessary laboratory work. Roentgenograms of the chest were made at intervals during life. If the patient died, films were taken of the chest post mortem, and finally films were made of the excised lungs in many cases.
In a previous paper,1 general roentgenographic interpretation, the normal chest, and the hilar and linear markings were discussed. Here, only the observations on tuberculosis in children will be considered. No children with open tuberculosis are admitted to the hospital. This study covered a period of more than one year.
Because of the fact that tuberculosis in children is an aerogenous infection in at least 90 per cent2