Remodeling of the metaphysis was studied by roentgenographic and histologic examination of bones of newborn infants and by roentgenographic examination of lead-labeled bones of children. In contrast to the classical view, i.e., that longitudinal trabeculae are resorbed in the "cutting zone" by osteoclasts, it is shown that there is a symmetric conversion of trabeculae in the metaphysis and that the main or exclusive mechanism of bone resorption in this segment is osteolysis.