THE VISCERAL AFFERENT DIVISION. 



163 



to view in the cervical cord. The greater part of the fibers turn 

 forward and form in the myelencephalon a diffuse bundle which 

 runs parallel with and ventro-mesial to the spinal V tract. The 

 bundle continues to receive fibers from all parts of the visceral 

 column, runs on forward past the roots of the trigeminus and 

 enters a large nucleus lying in the lateral wall of the metencephalon 



Cerebellar crest 

 Tuberc. acusticum 



L. visceralis, pars vagalis 



/ 



Tr. spinal, trigein. 

 Sec. gustatory tract 



:rr" 



X, motor root 



-- ^1 



I 



i — IX 



Fig. 84. — Transverse sections through the medulla oblongata of the sturgeon; A, 

 at the level of the X nerve; B, at the level of the IX nerve. A is at a higher mag- 

 nification than B. 



(Figs. 89, 92). This bundle has been called the secondary vagus 

 tract in those fishes in which the vagal part of the visceral lobe 

 is especially developed, but it is evidently a secondary visceral 

 tract and the nucleus in which it ends, a secondary visceral nucleus. 

 There is reason to beheve that this tract and nucleus correspond 



