398 ANATOMY OP THE CENTRAL NBETOXTS SYSTEM. 



again the picture of the quadrigeminal region, already considered, and it 

 remains so on upward. 



The median fillet extends at first in the lemniscal layer upward, and 

 finally arrives, as has been described, frontal to the corpora quadrigemina in 

 the area ventral to the thalamus, where it ends in the ventral nucleus of the 

 thalamus. 



The lateral fillet — which contains besides the acusticus-fibers, all the 

 fibers from the deep bulbar nuclei of the sensory nerves to the roof of the 



Fig. 253. — Section througli tlie upper region of the pons, in a nine-months' 

 fetus. Bitidearm, Anterior peduncle of cereljelluni. Hint. LhnyshundeJ , Post, 

 longitudinal fasciculus. Schleife, Fillet. Briicke, Pons. 



mesencephalon — in the levels above the exit of the trigeminal turns out of 

 the lemniscus layer dorsally, and extends on the external side of the pontile 

 tegmentum, diagonally upward to the corpora quadrigemina, under which 

 it disappears. Its well-marked band is easily recognizable laterally in the 

 uninjured cerebral axis. Where the fillet turns dorsally are found its gan- 

 glion-cells imbedded (lateral lemniscal nucleus, Obersteiner). This group 

 may be traced anteriorly as far as the superior nucleus of the lemniscus, 

 situated oli the outer edge of the substantia nigra. 



