a small, cone-shaped gland adhered by a stalk to the posterior wall of the brain's third ventricle. With regard to reptiles and amphibians, the gland seems to serve as a part of the visual system. Within mammals it excretes melatonin. Since it is an unpaired organ found in the middle of the brain, French philosopher Rene Descartes considered it to be the seat of the rational soul and the link between body and mind. Commonly referred to as epiphysis cerebri- pineal body.
PINEAL GLAND: "The pineal gland is somewhat eroded."