[Anatomy and development of the visual system of Pleurodeles poiretti]

After a deposit of HRP crystals in one eye of larval and adult Pleurodeles and the PAP immunocytochemical procedure, the organization of the visual system was described at stages 36, 45; 52 and postmetamorphic (according to Gallien and Durocher, 1975) and in the adult. At hatching stage, the retinopreoptic and the accessory pathways differentiate, soon after the retino-thalamico-pretectal pathway appears. The tectum differentiates later and a true retinotectal bundle can be seen only after the end of metamorphosis. In the whole, the pattern of the normal system is very simple in Pleurodeles especially as regard the ipsilateral fibres which never reach the tectum. This rudimentary organization lead us to conclude that the Pleurodeles and the Protopterus visual patterns are very similar.