Abstract
1. Changes in muscles and tendons in sm/sm are confined to hands and feet. They are closely correlated with the changes in the osseous skeleton.2. In Os/+, muscular changes are much more complex and not confined to hands and feet, but include the muscles of the forearms and of the lower legs. Some of the muscular changes, especially on the postaxial side, are not correlated with the changes in the osseous skeleton.