312 



ANATOMY OF THE CENTEAL NERVOUS SYSTEM. 



diverted to the cerebellum; the tegmentum, however, passes through the 

 pontal region only slightly changed. 



In the last cross-section through the region of the corpora quadrigemina 

 (Fig. 199) we had the following essential constituents of the tegmentum: — 



1. The gray substance about the aqueduct, together with the nuclei of 

 its nerves. 



2. Below it the post. long, fasciculus. 



3. Outside the latter are the fibers of the commissura posterior. 



Cm pus quadr. pjBt 



Aquaiductua Sjiv. 



Nuc. N. troclil. 



Nucleus liiqu. 



F.'isc. long, post. 



Sutst. rot, Tr, tliiil. bull). 

 Cerebellar peduncle 



Lat. (inf.) fillet 



Median (sup.) fillet 



Fasc. from pes to tegmentum 



Raphe. Decussation) 



of peduncles J """ 

 Corj.iu3 interpedunculare 



Tr. mamillo-peduncular. 



Fig. 201. — a and 6, Two sections through the most anterior portion of the 

 pons. Fig. 201 « shows the corp. quadr. post., ventral to which are the nucleus 

 of the trochlearis and the decussation of the anterior cerebellar peduncles. Ven- 

 trally one sees on the left diagrammatically outlined the pes pedunculi which, on 

 the right, is shown to be traversed by pontal fibers. 



4. The fibers from the striae medullares thalami. 



5. The red nuclei in the center of the tegmentum, and the cerebellar 

 peduncles arising from them. 



6. The fillet. 



7. The Pedunculus corporis mamillaris. 



8. Fibers from the deep medullary stratum near the median line. 



