The prenatal development of the rat dorsal metencephalic anlage was studied. A general embryological study was done one to describe the morphology of this part of the rhombencepraion The main migration waves were the Purfcinje cell migration wave and nuclear migration wave The dynamics of these migrations involved the translocat ion ; of the nuclear migration wave from a dorsal superficial position to a deep one. The primitive cerebellar cortex started to organics on the seventeenth embryonic day, it consisted of external gemina layer, primitive molecular layer and purkinje cell layer. The formation of this cortex was sequential following a genral to medial then caudo-rostral gradients over the develeloping cerebellum. Comparative hronological studies of the development of the main precerebellar systems and histogenetic events in the dorsal metencephalic anlage denoted that trophic effects of these systems are either absent or nonspecific. The Purkinje cells migrated to their settlement in the primitive cerebellar cortex: by nuclear translocat ion - EM studies revealed growth cones pioneering such migration and desnoid type junctions subserved as a mechanical anchorage device for the leading neurites. Mannosyl residues were important in the development of neuritis and their pirectional cues- Cell surface glycoconjugat.es of migrating cell somata expressed galactosyl residues,whi le such residues were penultimate in glycoconjugates of leading neurites.The terminal position was occupied by sialic acid. These glycoconjugates were involved in the navigation of the neurites in the developing cerebellum. A polysialylated zone on the dorsum of the developing cerebellum was recoenized. This zone was related to the cellular dynamic events occurring in the dorsdal part of the developing cerebellum. The finding of acetylcholinesterase activity in the developing Purkinje cells was considered as marker of differentiation rather than in neurotransmitter context.The outcomes of this study were integrated into a model that can be used for getting better understanding and prediction of the prenatal development of the dorsal metencephalic anlage.