Abstract
Extract
Liggins (Citation1969) and Van Rensburg (Citation1967) have shown that, if a sheep foetus is denied the use of its adrenal cortex prior to parturition, the gestation will be prolonged indefinitely. Bassett and Thorburn (Citation1969) have demonstrated that plasma Cortisol levels rise in the sheep foetus just before birth, and Liggins (Citation1968) and Halliday and Butler (Citation1968) have caused premature birth by Cortisol infusion into the sheep foetus. Comline and Silver (Citation1961) have weighed adrenal glands from sheep foetuses and found a sharp increase before birth. It would seem reasonable, therefore, to look for an increase in size of the adrenal cortex prior to birth.