MEDULLA OBLONGATA OF AMBLYSTOMA 



417 



40 



Fig. 38 Transverse section at the level of the vagus roots, illustrating a neurone 

 whose dendrites are related both to the fasciculus solitarius and to the spinal V 

 root. The axon is directed into the secondary visceral tract. Other sections in 

 this region show similar neurones whose axones divide, one branch entering the 

 secondary visceral tract of the same side and the other entering the ventral com- 

 missure ; cf . also figure 40. This preparation also shows dendrites of two neurones 

 of the motor tegmentum. Golgi method. X 100. 



Fig. 39 Transverse section at the level of the vagus roots, illustrating (on the 

 right) the mode of termination of the visceral sensory vagus roots {r.X.v.s.) in tlie 

 fasciculus solitarius and various types of neurones of the tegmentum. Golgi 

 method. X 100. 



Figures 39, 40 and 41 are consecutive sections from the same specimen. 



Fig. 40 Transverse section at the level of the vagus roots, illustrating dorsally 

 a typical neurone related to the fasciculus solitarius and immediately ventrally of 

 this fasciculus several neurones of the substantia gelatinosa Rolandi (s.g.R.) 

 whose dendrites reach the VIII root, the spinal V root, the secondary visceral tract 

 and the underlying tegmentum. The axones of the latter neurones enter the 

 ventral commissure; those from the nucleus of the fasciculus solitarius enter the 

 secondary visceral tract (tr.v.a.) and probably also send branches into the ventral 

 commissure. Golgi method. X 100. 



