16 FREDERICK TILNEY AND LUTHER F. WARREN 



and some nerve fibers. Debierre ('94) 84 believes the pineal 

 body to be a blood vascular gland with many degenerated 

 elements. Lotheissen ('94) 25 studying a large number of mam- 

 mals, recognized in marsupials (Macropus giganteus) some 

 fibers of the fasciculus retroflexus which penetrate the pineal 

 body, also some fibers which leave the summit of the epiphysis 

 which he believes represent the remains or rudiment of the 

 parietal nerve in reptiles. Cajal ('95) 53 thinks that the nerve 

 fibers in the pineal body are sympathetic and the body itself 

 is a blood vascular gland. Condorelli-Francaviglia ('95) 70 in 

 studying the brain of a marsupial (Halmaturus dorsalis), noted 

 in consequence of poor development of the corpus callosum that 

 the pineal body was only 2 mm. long and 1.5 mm. wide. Heitz- 

 mann ('96) 169B described the epiphysis as composed of gray 

 substance. Staderini ('97) 372 investigated the development in 

 many mammals. Soury ('99) 365 described connective tissue 

 septa dividing the pineal body into compartments which are 

 occupied by a second tissue resembling adenoid tissue in which 

 are round cells and cells with long prolongations. Bechterew 

 ('00) 20 found evidence of nerve fibers passing from the posterior 

 commissure to the peduncle of the pineal body. Zancla ('06) 432 

 studied the histology of the epiphysis in man. He observed 

 cells in the parenchyma which consist of a scant protoplasm and 

 large nuclei. These cells have a stellate form and prolongations 

 which often bifurcate at acute angles and then ramify still 

 further. The cells lie in a mesh of fibrils apparently nervous 

 in character. By the methods of Cajal, Weigert, and Biondi, 

 he was unable to interpret these cells either as nerve elements 

 or as glandular cells. He believed they are of a neuroglial 

 character and advances the hypothesis that they have an internal 

 secretory function. Around the calcareous concretions he found 

 necrobiotic areas. Romiti ('82) 336 studied the development of 

 the epiphysis in the rabbit. Anglade and Ducos ('08) 5 found 

 the organ made up mostly of neuroglia in man. 



