Morphologic development of the adrenal cortex in squirrel monkeys (Saimiri sciureus)

This study describes the morphology of the squirrel monkey (Saimiri sciureus) adrenal gland in the perinatal period. Adrenals of fetal monkeys had a broad central zone of large eosinophilic cells (fetal zone) surrounded by a subcapsular band of small dark cells (definitive zone). Adrenals of stillborn and neonatal monkeys had a reduced fetal zone and an expanded definitive zone that was differentiated into distinct zona fasciculata and zona glomerulosa. By day 18 postpartum, no remnant of the fetal zone remained.