[Appearance of the branchial system in cervicofacial embryology]

The aortic arch, vascular component of the branchial segment, is considered as its determining element. This is only justified in the conception of a branchial primordium, although this has now been discarded. The direct objections against this theory of a vascular preeminence are presented. Therefore, a revision of cervicofacial morphogenesis (formations cranial to the mandibular arch) is mandatory, based on somitomeres, neural systematization, evidence obtained from heterograft experiments and genetics, allowing to recognize in the "branchial" organization its proper somatic participation. The repartition of elements deriving from the para-axial in the "branchial" segmentation suggests that both types of segmentation represent two coordinate expressions of a single process.