BRAIN OF ONE OF THE SALAMANDERS I07 



just back of the supracommissure. Its fibers at first take a course 

 backward and a little downward as a loose bundle. Then turning 

 more directly ventralward they form a small but compact bundle. Near 

 the ventral surface of the brain, the bundle again turns backward and 

 ends in the gray matter on either side of the median line, just in front 

 of the origin of the third nerve (Figs. 12-15). 



Posterior commissure. — The fibers of this commissure cross deeply 

 intrenched in the gray matter of the mesencephalon some little distance 

 back of Meynert's bundle (Figs. 11-14). They take a course downward 

 and backward as a quite definite tract of medullated fibers, but the tract 

 soon becomes less compact, so that its relations could not be determined. 



Cerebellum. — As before stated, two bundles of fibers can be dis- 

 tinguished, a ventral one and a dorsal one. The ventral bundle is the 

 smaller of the two and its fibers curve forward into the mesencephalon. 

 The fibers of the dorsal bundle pass backward into the medulla. A 

 fold of the pia separates this bundle from the mesencephalon. 



Mauthner's fibers. — These are not very distinct, but fibers probably 

 representing them, can be distinguished in the ventral part of the cord 

 and medulla. They were not traced to their termination in the medulla. 

 In my sections one of these fibers is much larger than the other one. 



Literature Referred to in this Paper 



'02, Coghill, G. E. "The cranial nerves of Amblystoma tigrinum." Jr. Comp. 



Neur., 12:205. 

 '99, Edinger, Ludwig. The Anatomy of the Central Nervous System of Man and 



of the Vertebrates in General. Translation from the fifth German edition by 



Winfield S. Hall. 

 '95, Fish, Pierre A. "The central nervous system of Desmognathus fusca. " 



Jour. Mar ph., 10:231. 

 '03, Gage, Mrs. Susanna Phelps. "The brain of Diemyctylus viiidescens from 



larval to adult life and comparisons with the brain of Amia and Petromyzon." 



Wilder Quarter Century Book, 259. 

 '02, Hardesty, Irving. Neurological Technique. 

 '95, Kingsbury, B. F. "On the brain of Necturus maculatus. " Jr. Comp. Neiir., 



'02, Kingsley, J. S. "The head of an embryo Amphiuma. " Am. Nat., 26:671. 



'92, Minot, Charles Sedgwick. Human Embryology. 



■95, Strong Oliver S. "The cranial nerves of Amphibia." Jour. Morph., 10: loi. 



