The present paper reviews current data on the structural development of the human nervous
system. Focus is on the timing of ontogenetic events in the telencephalon. Neuronal
proliferation and migration especially occur during the first half of gestation; the second half
of gestation is the period of the existence of the functionally important transient structure
'subplate'and the major period of glial cell proliferation and programmed cell death. Axon
and dendrite sprouting and synapse formation bloom during the last trimester of gestation …