The pineal gland.

THE purpose of this review is to summarize the known functions of the pineal gland. Then, utilizing recent evidence linking the visual and limbic systems, a hypothesis will be advanced concerning interrelations that the limbic system may have with the pineal gland. Pineal Gland It has long been known that in fishes, amphibians and lacertilian reptiles, the pineal gland is primarily a photoreceptor organ,1 in which distinct sensory cells resembling retinal cone cells are found. In the frog the gland appears to be a wavelength discriminator that converts light energy of certain wavelengths into nervous impulses. However, in mammals there . . .