378 ANATOMY OF THE CENTEAL NEKVOUS SYSTEM. 



of the oblongata from the cord, especially the surface-changes, have been known 

 since Santorini, Reil, Burdach, and Eolando. The nuclei arciformes and their cov- 

 ering, fibrse arciformes anteriores, were first well described by Arnold, who regarded 

 them as "antepons." The strise acusticte were discovered by Pieolhomini. As to 

 their relationship to the auditory nerve, there arose even before the time of micro- 

 scopes a lively discussion. Real light on the construction of the medulla oblongata 

 was due to researches of Stilling, Kolliker, Meynert, Sehroeder, Van der Kolk, and 

 Deiter. In recent times attention has been given to the nerve- centers there found 

 (Gudden, Roller, Kreud, Duval, Koch, Darksehewiteh, v. Kolliker, S. EamOn y Cajal, 

 and others) . 



The existence of this "glosso-pharyngeal center" immediately in front 

 of the vagus center is disputed. It is, in fact, diiBcult to find by the usual 

 methods the small portion of the nerve dipping into it. The employment 

 of the Golgi method, however, teaches (Pleld) that the relations met are as 

 just described. When the glosso-pharyngeal nerve is found and has started 

 on its course, one sees that the small column of gray matter, in which it 

 terminated, extends still farther anteriorly. Wallenberg demonstrated in a 

 case of degeneration of the trigeminus, in which principally the sense of 

 taste suffered, that fibers coming from this anterior nucleus enter the trigem- 

 inus. It must therefore be conceded that this long, thin column of gray 

 matter near the fasciculus soKtarius is the taste-center, and that fibers enter 

 it which run partl}"^ in the trigeminus and partly in the glosso-pharyngeus. 

 The supply of the dorsum linguce with taste-fibers from the glosso- 

 pharyngeal and chorda iijinpani seems, accordingly, to depend upon a single 

 nucleus. The pneumogastric and glosso-pharyngeal very probably have an 

 additional descending root. It comes from the cerebellum, where we have 

 already recognized it as the direct cerebellar sensory tract. Exactly which of 

 its fibers reach the vagus is, in man, very difficult to demonstrate. Xaturally 

 the sensory fibers of the nerve just mentioned arise from the cells of the 

 root-ganglion, from which they (His) develop, the same here, near the cere- 

 brum, as do the sensory spinal nerves. The sensory cells just mentioned are 

 their end-stations. There the fibrils divide up around cells. On the ventral 

 side of the center one sees many fibers entering in by curves. By the aid of 

 the comparative-development method it has been demonstrated that they 

 arise from the lemniscus-layer of the opposite side. Therefore we have for 

 the sensory part of the vagus (and the same is true of the glosso-pharyngeus) 

 a decussation of its fibers soon after their entrance into the cerebro-spinal 

 axis. 



