122 



Fibres of the Brain. 



\ 



Commiss. ant. 



Corp. mammill. 



Gyrus Jornicat. 2j o b U S * 6 



400. The Fibres of the PaSMtt Cerebri.* 



~L natural size. 



From the Corpus callosum the fibres pass outwards on both sides 

 into the cerebral hemispheres ; the fibres which curve backwards into 

 the posterior lobes are called the Forceps posterior, those which curve 

 forwards and inwards to the anterior lobe, Forceps anterior, finally those 

 which help to form the covering of the posterior and inferior horn of 

 the lateral ventricles, the Tapeturn. 



The upper surface of the pallium contains the convolutions enume- 

 rated above, and is covered by a layer of grey matter up to 2 lines 

 in thickness. On the anterior and median portions of the hemispheres 

 is a deep notch, the Inci.sura pallii, whose floor is formed by the 

 Corpus callosum, and its lateral Avails by the inner surfaces of the anterior 

 and upper lobes. Another deep notch is the Sylvian fissure, which 

 divides the inferior lobe from the anterior and upper lobes ; in it most 

 of the arterial branches are found. 



Fig. 464, 465 and 466 are drawn from alcohol specimens and 

 with the aid of Fr. Arnold's figures. 



* By some German anatomists, the brain is divided into two parts: ,,Hir ns t a mm", 

 Tmncufi ccrtJiri, and !!! r nmantel", Pallium cen-Jn-i, i. e. the cerebral hemispheres. The former 

 comprises the peduncles of the cerebrum and cerebellum and the tegmentum, the latter, the 

 C_'nn,na rruUata. commissures and convolutions. 



