Primary malignant neoplasms of bone have been produced experimentally by irradiation. Schürch1 induced an osteosarcoma in the mandible of a rabbit by the application of a radium needle directly to the cortical surface. Lüdin2 produced a chondrosarcoma in the tibia of a rabbit by repeated exposures to the roentgen rays (total dose, 8,000 roentgens). Schürch and Uehlinger1 produced three ossifying sarcomas of the femur in rabbits by intra-osseous injections of minute quantities of radium salts. Widespread ossifying metastases in the lungs, spleen, liver and lymph nodes were observed. In two other animals nonossifying fibrosarcomas of bone developed. Daels3 and Sabin, Doan and Forkner4 also produced fibrosarcoma of bone in animals by means of radioactive substances.
In Martland's5 series of patients who were poisoned by the prolonged ingestion of radioactive material, which accumulated in the skeleton, nonossifying fibrosarcomas of bone developed. These instances constitute experiments