

CHAPTER 2 



HISTORICAL SKETCH 



The existence of the pineal organ was known by the ancient Greeks and 

 Romans. Galen (a.d. 131-201) spoke of it as " scolecoid," or worm- 

 like. His dissections were carried out on oxen, sheep, apes, and other 

 animals, and he mentioned that it had been named by other writers the 

 epiphysis. He also emphasized its intimate connection with the great 

 vein which to this day is known all the world over by his name. Other 

 classical writers who were impressed by its conical, pine-like form named 

 it the conarium. Various ideas were held as to its function, among which 

 was the notion that it acted as a valve or flood-gate, and regulated the 

 quantity of spirit (? cerebro-spinal fluid) necessary for the psychological 

 requirements of the individual. The theory that it functions as a gland 

 seems to have originated with the Romans, who described it as the 

 glandula pinealis. Little advance was made in the knowledge of the 

 pineal organ in the centuries which followed, and in 1637 Rene Descartes 

 taught that the human body was an earthly machine which was presided 

 over by the " rational soul," which was situated in the pineal gland, 

 " the little gland in the middle of the substance of the brain." This idea 

 was ridiculed by Voltaire, who suggested a coachman sitting on his seat 

 and holding the reins of the horses — which were supposed to be 

 represented by the peduncles of the gland. 



William Cowper (1666-1709), who considered the pineal to be a 

 lymphatic gland, wrote " the glandula pinealis which we take to be a 

 lymphatic gland, receiving lympha from the lymphe ducts which pass by 

 way of the third ventricle of the brain to the infundibulum and glandula 

 pituitaria." This idea of the lymphatic nature of the pineal body was 

 shared by some others, among whom we may mention that pioneer histo- 

 logist Jacob Henle (1809-85), who, being impressed by a general resem- 

 blance of its microscopic structure to that of a lymphatic gland, considered 

 that it might also function as a lymphatic node. With modern microscopes 

 and improvement in histological technique, however, the distinction 

 between lymphatic tissue and the peculiar structure of the normal adult 

 pineal organ has been rendered easy, and its developmental history coupled 

 with a more exact knowledge of its comparative anatomy have shown that 

 this conception of the nature and function of the organ is quite untenable. 



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