The Pineal Organ

Abstract

Probably no organ in the body was less understood two decades ago than the pineal. Textbooks of physiology and endocrinology published during that "Dark Age" characteristically dismissed the pineal as Descartes' "Seat of the Soul," as the rudimentary "third eye" of lower vertebrates (but not mammals) or, most commonly, as a calcified vestige, which provided a useful landmark for neuroradiologists. They might have added that, at one time, the pineal has mistakenly been thought to secrete a gonad-inhibiting hormone, because its tumors were sometimes associated with precocious puberty in boys.Between 1959 and 1964, research on the pineal attained what . . .