The coronal suture with the adnexa was excised in 1-week-old rats and replanted onto the exposed dura mater of the same rat. After replantation, the original internal part of the suture (= pars interna) was located on the external surface of the cranial vault, while the original external part (= pars externa) was located on the dura mater. The animals were sacrificed 1, 2, 3, 4, 5, 6 and 7 weeks after operation. The microscopic observations, done 3, 4, 5, 6 and 7 weeks after replantations, reveal that gradually such alterations occur in the replanted suture that the pars interna transforms into a pars externa and vice versa. These modifications are discussed in the light of the general articulations of the cranial bones. In the observed alterations of the replanted coronal suture we see a confirmation of the hinge hypothesis proposed by Oudhof.