Abstract
1. A clinical, radiological and pathological study of sixty-nine cases of epiphysial chondroblastoma has been made.
2. The nature of the tumour is discussed and its clinical and radiographic features are described. A special type is described, for which the name "cystic chondroblastoma" is suggested.
3. The results of treatment are described and the generally benign behaviourof the lesion is noted.
4. The occurrence of malignant change is noted and discussed.