Abstract
Lesions in the pituitary stalk and median eminence of the rat which block the compensatory adrenal hypertrophy, normally following unilateral adrenalectomy, have also an effect on the zonation of the remaining adrenals. The zonation of these adrenals differs markedly from that of the remaining adrenals of controls with an intact pituitary stalk and median eminence and also from that of the remaining adrenals of hypophysectomized animals. Moreover, there is a difference in zonation between the remaining adrenals of animals with stalk lesions and animals with lesions in the median eminence.