Prenatal development of the neurons in the brain of goats was studied using 52 foetuses ranging
from 1.4cm CRL (24 days of gestation) to 41.5cm CRL (full term). By 24 days, the middle mantle
layer of the neural tube showed two types of cells, viz., the larger neuroblasts and the smaller
spongioblasts. Primitive neurons could be clearly distinguished from spongioblasts at 40 days.
Aggregation of neuroblasts, the nuclei, first appeared in the seventh week in the thalamus,
mesencephalic tegmentum, pons and medulla oblongata. Neurofibrils appeared in the cytoplasm of
neurons towards the middle of gestation. But the Nissl granules appeared in the middle of fourth
month. Most of the neurons of the brain differentiated during fourth month. Nuclei of most of the
neurons were vesicular, centrally placed with dark staining nucleoli. In the granular layer of
cerebellum, the nuclei were chromatic and non-vesicular. Towards term, neurons in all parts of the
brain were well developed.