The book contemplate the complex regulatory mechanism of cortisol secretion from adrenal gland.The book validate the new concept of non-classical regulatory mechanism of cortisol secretion. It incorporates the investigation of the impact of some adrenocorticotropic substances on the cortisol secretion, the pivotal corticosteroid, in birds where there is intermingling of interrenal cell and chromaffin cell.The book contains the results of Adrenaline, Dopamine, Melatonin and oxytocin uncovering their involvement in the regulation of Cortisol secretion by directly acting on adrenocortical cells and not by means of HPA (Hypothalamo-pituitary axis) and Renin angiotensin system as these classical regulatory mechanism have been obstructed by inhibitors like Dexamethasone and Captopril.The book is an esteemed addition in the field of Cortisol research as it contains an updated bibliography of the subject for research workers.