WHEN Kleinschmidt1 reported, in 1919, that he had observed large shadows in the lungs of tuberculous children and that these shadows disappeared without trace, and when Eliasberg and Neuland,2 in 1920, stated that these shadows were regressive and harmless—they named them "epituberculous infiltrations"—interest in the "epituberculous infiltration" was stirred up in all parts of the world. It is known that Simon and Redeker3 found, mostly by roentgen examinations, that these shadows partly around the primary focus and partly around the neighboring lymph nodes represented stored infiltrations. Interest increased when, in 1926, Assrnann and Redeker4 established that the pulmonary tuberculosis of adults also usually begins with infiltrations. These infiltrations are much smaller than the "epituberculous infiltrations"; they are round in shape and mostly located under the clavicle. They were called "early infiltrations" (Frühinfiltrat). The whole literature on tuberculosis, especially tuberculosis of children, from 1920 to 1930