The function of the pineal body in the human organism is still a subject of controversy. By some it is considered to be a gland of internal secretion; by others, a vestige of the median eye of certain reptilian forms. No one believes now in the suggestion of Descartes that it might be the seat of the soul, but numerous phylogenetic, embryologic, histologic and clinicopathologic studies, as well as experiments in feeding and extirpation, have not succeeded in establishing definitely its function.
Tilney and Warren1 believe that they have demonstrated a glandular structure in the pineal body of the human embryo, and von Volkmann2 thinks that he has found secretory granules in the pineal cells. On the other hand, Hortega3 cannot find evidence of secretory activity in either the neuroglia or pineal parenchyma, and he believes that the granules found by von Volkmann are blepharoplasten akin to
GILBERT HORRAX, PERCIVAL BAILEY. PINEAL PATHOLOGYFURTHER STUDIES. Arch NeurPsych. 1928;19(3):394–414. doi:10.1001/archneurpsyc.1928.02210090020002