278 O. LARSELL 



Within the commissure the bundle is distinguishable for a short 

 distance toward the median plane by reason of the smaller diam- 

 eter of its myelin sheaths, but it soon becomes lost among the 

 numerous fibers of various size which compose the commissure. 

 Caudad this bundle runs mesial to the VIII tract, but before 

 reaching the superficial root of the V nerve, it turns ventrally 

 to pass beneath the latter. Cephalad of this point, however, it 

 becomes so intermingled with other fibers as to be very difficult 

 to follow. It takes its further course ventrally of the spinal V 

 tract for a short distance, but before reaching the level of the 

 VIII root it becomes lost among other fiber bundles. 



Some of the fibers of the mixed bundle cephalad of the V root 

 pass as far caudally as the superficial origin of the trigeminus. 

 At this point many of them pass ventrally just anterior to the V 

 root fibers, others find their way ventrally through the V root 

 bundle, and the two groups reunite below the spinal V tract. 

 These constitute the ascending gustatory tract (figs. 17 to 21, 

 tr.v.a.). Cephalad this tract passes through the auricular lobe, 

 and appears to come into relation with a group of cells just 

 rostrad of the lobe, but which are evidently a part of the mid- 

 brain. In adult Amblystoma this group of cells is more obscure 

 than in the larval form, in which they stand out very clearly. 

 The ascending gustatory tract does not appear to have any direct 

 connection with the cerebellum. 



A small bundle of myelinated fibers of reduced diameter from 

 the trigeminus shows bifurcation of the fibers just before the 

 nerve enters the medulla oblongata, or just within the latter. 

 One branch of these bifurcated fibers may be observed in Golgi 

 and Weigert sections to take its course ventrally of the VIII 

 tract to the auricular lobe, but some of these fibers appear to 

 into the cerebellar commissure in company with the dorsal 

 spinocerebellar tract. The other branch of the bifurcated fiber 

 passes posteriorly into the medulla and possibly into the cord. 

 This is the only indication of trigeminal fibers which appears to 

 terminate within the cerebellum. 



In Golgi sections cut sagittally a few fibers were observed to 

 pass between the pars dorsalis hypothalami and the lateral por- 



