THE PINEAL BODY 13 



rest of the nervous system and has an appearance strikingly 

 ike the pituitary gland. He, apparently, was first to recognize 

 that the cells of the epiphysis contained granules in their cyto- 

 plasm. These he called parenchymal cells. He also observed 

 that these cells were smaller in childhood than in adult life and 

 concluded that the parenchyma of the pineal body is composed 

 of a large number of globules. The globules are generally 

 elliptical and irregular in shape. Faivre believed the globules 

 to be the nuclei of the cells, and to him must be accredited the 

 first observation of these cellular characteristics of the pineal 

 body. 



Marshall ('61) 261 made some observations concerning size, 

 \veight, and sand-content in a chimpanzee. Schmidt ('62) 347B 

 showed the continuity of the epiphysis with the brain in the 

 human fetus and its relation as an evagination of the encephalic 

 roof. Stieda ('69) 376 studied the pineal body of birds and mam- 

 mals and described anastomoses of the cytoplasm of the cells 

 in the form of a reticulum. Luys ('65) 253 advances an ingenious 

 conception concerning the nature and connections of the pineal 

 body. In his opinion, this organ is a mass of gray substance 

 pertaining to the central gray matter surrounding the third 

 ventricle and having the same histological characters. He 

 claims that originally in the human embryo the structure is 

 bilobed like the mammillary bodies and that, therefore, it should 

 be considered as a transitory bilobed structure, a true posterior 

 mammillary body which has fused across the median line. Luys 

 concludes that the gray substance of the conarium, the hippo- 

 campal convolution, and the mammillary tubercles form with 

 the anterior pillars of the f ornix a complete system. The mammil- 

 lary bodies and the conarium are centers of reception for fibers 

 convergent from the hippocampal convolution. Efferently these 

 centers are connected with the optic thalami. Luschka ('67) 255 

 noted the presence of fibers in the pineal body of man. Frey 

 ('67) m believed that the pineal body was made up exclusively 

 of nerve tissue. He found in the adult the following elements: 

 1) multipolar ganglionic cells; 2) round cells with prolongations, 

 and 3) isolated nerve tubes. Leydig ('68) 232 states that the 



