[Development of the fetal mandible of rats in transplants onto the chorioallantoic membrane of chick embryos].

The evolution of mandibles of 15 to 17 days old fetal rats has been studied after transplantation on the chorio-allantoïc membrane of chicken embryos. The histological study of the samples grafts showed a remarkable adaptation of Meckel cartilage to the transplantation medium as well as the continuation of the ossification processes of membranous and endochondral origin. An important thickening of the oral epithelium, accompanied by an increased keratinization appeared in the grafts collected at 17 days "in utero". Only one tooth germ could be found in a graft collected at 17 days "in utero".