116 FREDERICK TILNEY AND LUTHER F. WARREN 



ing strand between the attached and detached parts of the 

 pineal organ, thus representing a degenerative process. Braem 39 

 in 1898 also found this fasciculus and made the further observa- 

 tion that it contained heavily myelinized nerve fibers. He 

 likewise was of the opinion that there was evidence of degenera- 

 tion in this nerve fasciculus, in this way confirming the view of 

 deGraaf and Leydig. Haller 166 in 1898 stated that the fibers of 

 the tractus pinealis spring from two branches of roots connected 

 with the thalamus ventromedial to the commissura posterior. 

 Gaupp 147 in 1898, who first applied the term of tractus pinealis 

 to these fibers, observed fine nerve bundles passing in the ventral 

 portion of the epiphyseal stalk. Most observers believe that 

 these fibers come into relation with the posterior commissure. 

 The proximal portion of the pineal organ. This, as already 

 stated, was known as the epiphysis or corpus pineale. It was 

 also called by Gaupp 147 in 1898 the pediculus corporis pinealis. 

 Osborn 288 in 1884 described it as a cylindrical, hollow, anteriorly 

 flexed sac whose lumen was in communication with the third 

 ventricle. Rabl-Ruckhard 317 in 1880 states that the proximal 

 portion is solid. Osborn, on cross section, described it as 

 round. Gaupp 147 and Braem 39 state that the organ has an 

 elliptical form with many short diverticula which give it a 

 glandular appearance. In this feature it is like some teleosts, 

 reptiles, and birds. Galeotti 140 in 1896 found evidence of secre- 

 tory activity in Rufo and Rana, for example, granules in the 

 cytoplasm staining with acid fuchsin. Studnicka 386 in 1896 saw 

 the same appearances in adult animals which he thought were 

 sensory cells and which he likened to the sense cells in the pineal 

 organ in Petromyzon. Ostroumoff 291 in 1887 found fine fibers 

 between these cells. 



Differences observed in the epiphyseal complex of the various 

 species of amphibia 



URODELA 



1. Amblysloma mexicanum. Stieda (75). 379 In this form the 

 chorioid plexus was first mistaken for the epiphysis. Orr 286 in 



