585 



spinal Vth. I have therefore called the enlargement of the dorsal 

 horn in the posterior part of the medulla, the nucleus of the funiculus 

 and of the spinal Vth. There is no separate nucleus corresponding 

 to the nuclei of Goll and of Burdach in the mammalian brain. 

 (Figs. 1 — 3.) Mesial to this nucleus, and imperfectly separated from 

 it, is a second collection of cells which is the terminal nucleus for a 

 part of the fibres of a large bundle which runs backward parallel 

 with the spinal Vth. from the tuberculum acusticum. The large size 

 of the bundle suggests that it is made up mostly of lateral line fibres. 

 As indicated in Figs. 1 — 3, the greater part of the fibres of this 

 bundle end in the same nucleus with those of the spinal Vth., but I 

 have not found spinal Vth. fibres entering the smaller median nucleus. 

 This bundle and nucleus are apparently homologous with the spinal 

 Vlllth. and its nucleus of human anatomy. 



Following these bundles forward, they are found to lie immedi- 

 ately ventral to the vagus roots, the ventral roots sometimes piercing 

 them (Fig. 4). In the region of the vagus roots there appears dorsal 

 to them the tuberculum acusticum (dorso-lateral tract of Gorono- 

 witsch) which, a little farther forward is capped by the cerebellar 

 crest, as described by Goronowitsch. In this region, some of the 

 cells of the acusticum send both dendrites and neurites ventrad 

 between successive vagus roots. Here the neurites form a fine-fibred 

 bundle intimately associated with the dorsal surface of the spinal Vth. 

 bundle. Whether these fibres from the acusticum end with those of 

 the spinal Vth. in the Nucleus funicuU, I do not know. It may be 

 these fibres which leave the spinal Vth. to end in the olive as 

 described above. Immediately in front of the roots of the IXth. nerve, 

 the spinal Vlllth. bundle joins the tuberculum acusticum and becomes 

 indistinguishable. The spinal Vth. can be traced forward as a compact 

 bundle, in the position shown in Figs. 4—8, to its point of entrance 

 with the trigeminus nerve. The spinal Vth. tract receives a con- 

 siderable number of fibres from both the IXth. and Xth. nerves, as 

 described by Strong ('95) and (Xth. only) by Kingsbury ('97). A 

 short distance in front of the IXth. nerve the lateral line Xth. enters 

 the dorsal part of the acusticum (Fig. 6), and a little farther forward 

 the Vlllth. and one root of the lateral line Vllth. enter. The Vlllth. 

 enters the ventral part of the acusticum, and the lateral line root 

 enters antero-dorsal to it. Between and anterior to these two, the 

 dorsal root of the Facialis proper pierces the acusticum to reach the 

 Lobus vagi (Figs. 7 and 7a). Still farther forward the Trigeminus 

 enters by several small roots (Fig. 8). A considerable part of the 



