296 



ANATOMY OF THE CENTKAL NEEYOUS SYSTEM. 



the fibers which, compose the medullary substance of the brain-mantle is not 

 to be seen in the posterior sections of the interbrain. They have either, as 

 association-tracts, disappeared in the cortex itself or as coronal fibers of 

 the thalamus disappeared in the ganglia of the thalamus. A portion of the 

 corona radiata, passing beneath the interbrain, arrives at the base of the 

 brain as the pes pedunculi cerebri. Even the fiber-system of the striatum has 

 almost completely disappeared, only a bundle to the substantia nigra Som- 

 meringi being still demonstrable (see Fig. 191). 



V ' \ ^ '^ > I .^' ■■-■ ■■ i'Cr:ue!.um 



f-^-U? ^;/(m^. ]■/,,,-.;_ 





|t;^rtat.\\ 



Fig. 190. — Median sagittal section through tlie interbrain and the structures 

 j50sterior to it. The course of a number of coronal fibers is indicated by lines: 

 Zvr Briiclic, To the pons. Pyramidrii Fnsern, Pyramidal fibers. Haubeiistrahlung, 

 Tegmental radiation. Zii den Opticiixceiitrcn, To the opticus centers. Haube, 

 Tegmentum. Fyraiiinhiil;mi~iniii. Pyramidal decussation. 



In the plane of the last section a part of the lamina; medullar es thalami 

 and especially a lateral bundle, the superior lemniscus from the thalamus, 

 may be traced. Furthermore a few small bundles which arise from the 

 corpus mamillare and the Ggl. habenulte may be seen. 



Having now made ourselves somewhat familiar with the structures in 



