Abstract
Study of postembryonic development of neurosecretory cells in the cerebral ganglia of Achatina fulica showed that they first appear in two month-old snails. The cells are located at the periphery of the procerebrum of cerebral ganglion. The number and size of the neurosecretory cells increase with increasing age of snails, reaching a maximum in eight-month-old snails and thereafter remaining constant in nine-to twelve-month-old snails.
Study of the ultrastructure of the cells showed that they each contain a round shaped nucleus with patches of heterochromatin and a conspicuous single large vacuole in the cytoplasm. In addition, electron-dense elementary granules with a mean diameter of 1600 A° are found to be associated with an extensive Golgi complex and rough endoplasmic reticulum.
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