THE PINEAL BODY 171 



1) long and tubular, as in birds and reptiles; 2) short and 

 cup-shaped, resembling particularly that of carnivora. The 

 epiphysis is composed of a syncytial network, in the meshes of 

 which are scattered more or less highly differentiated or modified 

 ependymal cells and delicate bundles of nerve fibers. In the 

 opossum it appears to be in a state of instability. Its long, 

 tubular form connects it phylogenetically with the birds and 

 reptiles, while its short, cup-shaped form affiliates it with the 

 carnivora. Regarding the function of the pineal body in the 

 opossum, Jordan believes that his observations show it to be 

 unimportant in the body metabolism of mammals. This does 

 not necessarily mean that there is no specific secretion from 

 the organ, but rather that it has no direct or indirect influence 

 upon vegetative functions. 



Nerve fibers in the mammalian epiphysis have been observed 

 by Kolliker 210 in 1850, who appears to be the first to demonstrate 

 these elements. Krause 219 in 1868 recognized the fact that the 

 fibers have a double contour, and Darkschewitsch 79 in 1886 

 showed that they were myelinated nerve fibers. Connections 

 have been demonstrated to exist between the pineal body by 

 means of these fibers with the following parts: 1) internal capsule; 



2) striae medullares; 3) Meynert's bundle; 4) optic tract by 

 Darkschewitsch, ('86) 79 and 5) posterior commissure by Meynert 

 (77), 271 Pawlowsky (74), 305 Cionini ('88), 68 Favaro, ('04) 118 

 and Cutore ('10) ; 76 6) commissura habenularis by Kolliker ('50) 21 

 Hagemann (72), 164 Favaro ('04) 118 and Cutore ('10), 76 7) sym- 

 pathetic system, Henle (79), 172 Cionini ('86), 67 and Cajal 

 ('04). 54 Ganglion or nerve cells in the epiphysis have been 

 described by Kolliker 210 in 1850 and Hagemann 164 in 1872. 

 Cajal 53 in 1895 also found ganglion cells in the pineal body and 

 described two types. Dimitrova 92 in 1901 was able to find 

 ganglionic cells in young cats only. 



Pigment has been found in the epiphysis of mammals by 

 Flesch 123 ('88). Galeotti ('96) 14 observed pigment particles in 

 the cytoplasm and nuclei. Dimitrova ('01) 92 found a golden- 

 brown pigment in the parenchymal cells. Cutore ('10) 76 ob- 

 served pigment in the pineal cells. Brain sand has been described 



