Johnston, The Radix Mesencephalica Trigemini. 623 



section is unmistakable, since both lie in the plane of the transverse 

 section and the mesencephalic fibers run directly among the sensory 

 bundles. The motor bundles are crossing the mesencephalic bundle 

 obliquely. In the sections caudal to this one, other fasciculi of the 



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Fig. 20. Section next anterior to that sliown in Fig. 19. An interlacing of 

 the mesencephalic fibers with the crossed motor fibers. The two form with the 

 sensory root a Y-shaped figure. The mesencephalic fibers descend among the 

 sensory fibers in the stem of the Y, while the motor fibers in their oblique 

 course forward leave the section at the point where the two bundles interlace. 



mesencephalic bundle are cut lengthwise and show exactly the same 

 relations as are seen in this section. In the section next cephalad 

 there is an interlacing of the fibers of the crossed motor root with 

 the most cephalic fibers of the mesencephalic bundle. As this is the 



