[Morphogenesis of the frontal bone in the chick embryo. Study of induction phenomena].
Comparison of results obtained by SCHOWING (1968) with those of BALLIF (1985) shows that frontal bones of chick embryo, which are completely missing after removal of the anterior encephalic territories, are still partially existent after a localized microinjection of Actinomycin D into the embryonic encephalon. The remaining part of frontal bones corresponds to territories mainly derived from the neural crests (NODEN, 1982). These latters don't need any encephalic induction to develop into ossification centres.