1. Details of clinical, radiological, biochemical and histological investigations of a case of metaphysial dysostosis are presented.

2. The patient was a boy of seven years, and showed widespread lesions (involving long bones of limbs, small bones of hands and feet, pelvis, clavicles, and ribs) characterised by retardation of growth and ossification with masses of partly calcified tissue in the metaphyses.

3. No radiological, clinical or histological evidence of renal osteodystrophy was found in the case described.

4. Metaphysial dysostosis is discussed in relation to other chondrodystrophies.

A case is described of malignant osteoclastoma of the lower end of the femur in which death occurred from pulmonary metastases. The history was short and there was no interference with the primary growth, treatment being confined to disarticulation at the hip. Reasons are given for considering this neoplasm a malignant osteoclastoma rather than an osteogenic sarcoma, and the question of nomenclature is discussed.