The authors, using external fixators, have applied measured compression forces through the growth plate of the lower end of the femur in rabbits. They have calculated the degree of compression necessary to slow down or to stop growth. It was shown that growth may become normal following release of the compression provided that the compression was not excessive. An histological study was conducted with showed lesions varying from a simple diminution in the height of the cellular columns to the development of bony bridges depending on the intensity of the compression.