THE CEREBROSP1NAL NERVOUS SYSTEM. 493 



which are seen in the groove between the anterior pyramids. Thus 

 composed, the anterior pyramidal fibres proceeding onwards to the brain 

 are distributed in the following manner: 



1. The greater part pass on through the Pons to the Cerebrum. A 

 portion of the fibres, however, running apart from the others, joins some 

 fibres from the olivary body, and unites with them to form what is called 

 the olivary fasciculus or fillet. 2. A small tract of fibres proceeds to the 

 cerebellum. 



b. The lateral column of the cord on each side of the medulla, in 

 proceeding upwards, divides into three parts, outer, inner, and middle, 

 which are thus disposed of: 1. The outer fibres (direct cerebellar tract) 

 go with the restiform tract to the cerebellum. 2. The middle (crossed 



FIG. 337. Posterior view of the medulla, fourth ventricle, and mesencephalon (natural size). 

 p.n., line of the posterior roots of the spinal nerves; p.m./., posterior median fissure; f.g., funiculus 

 gracilis; cZ.,itsclava; /.c., funiculus cuneatus; f.R., funiculus of Rolando; r.6., restiform body; 

 c.s., calamus scriptorius; I, section of ligula or taenia; part of choroid plexus is seen beneath it ; 

 l.r., lateral recess of the ventricle; str., striae acusticae; i.f., inferior fossa; s./., posterior fossa; be- 

 tween it and the median sulcus is the fasciculus teres; cbL, cut surface or the cerebellar hemi- 



, ___, ^ 



seen on the surface of the tegmentumf c., crusti; l.g ., lateral groove; c g.i", corpus geniculum in- 

 ternus; th., posterior part of thalamus; p., pineal body. Theroman numbers indicate the corre- 

 sponding cranial nerves. (E. A. Schafer.) 



pyramidal tract) decussate across the middle line with their fellows, and 

 form a part of the anterior pyramid of the opposite side. 3. The inner 

 pass on to the cerebrum, at first superficially but afterwards beneath 

 the olivary body and the arcuate fibres, and then proceed along the floor 

 of the fourth ventricle, o'n each side, under the name of the fasciculus 

 teres. 



c. The posterior column of the cord is represented in the medulla by 



