[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.

[Apropos of the "Lesson in anatomy"].

Some striking features from the famous lesson of Prof. Tulp are presented: the implication of the spectator in the scene, the unity of the action exalted by the "chiaroscuro", the expression of the movement and of Tulp's personality. In addition, the probable scientific and philosophical underlying thoughts of Rembrandt are discussed having respect to historical data concerning Descartes and Constantin Huygens.

[The concept of branchial apparatus and cervico-facial embryology].

The so-called "branchial" embryonic organization corresponds to a segmental disposition, for which a determining role of the aortic arch, vascular component of the constitutive unit of this organization, has never been disputed. This attitude is only justified by virtue of the conception of this organization as preparatory to a branchial primordium, although this initial conception, which raises major objections, has now been discarded. Moreover, direct objections against this theory of a vascular preeminence are presented.

[The origins of embryology. Epistemologic and cultural viewpoints].

Embryology is exemplar from an epistemologic point of view, due to its close relation with philosophy as studying an immediately accessible link in the process of generation. It has evolved to its present form following the development of the microscopical techniques at the end of the 18th century, but remains close to the ancient approaches of generation. The roots of modern Embryology are still to be found in the presocratic philosophers, and the works of Aristotle represent a major step in its foundation.