[The modality of endoconnective ossification on cartilaginous substrate: observations on the long bones in the embryo].

The authors conducted a histologic study on the modalities of ossification of the "diaphyseal osseous ferrule" in embryos between the sixth and eighth week of intrauterine life: the ossification of this "diaphyseal osseous ferrule" presents some peculiarities compared to that of other areas: it occurs with the modalities of periosteal ossification, exploiting, however, a cartilagenous substrate. In addition, the authors compared the ossification of the diaphyseal ferrule to that of the "perichondrial ferrule of the layer of ossification", examining histologic sections of embryos in the 25th week of intrauterine life.