[The development of the clavicle in man].

The development of the human clavicle was studied in 50 to 60 d old human embryos. Our findings are summarized as follows: The whole clavicle develops from a cartilaginous anlage. In the middle part of the clavicle, an osseus cuff develops very early by the ossification in the perichondrium. In the lumen of this cuff, a cartilaginous cork persists which is resorbed and replaced by bone and marrow later than in other bones. It is possible that cartilaginous nests may persist in the middle part of the clavicle. In both extremities of the clavicle, the normal enchondral ossification exists as it is described in other anlages. It is difficult to explicate the syndrome of the cleido-facial and cleido-cranial dysostoses only as disturbances of the endesmal ossification.