CHAP. XXIII.] OF THE HUMAN BRAIN. 



455 



to the convolutions forming the tip and inner or under sur- 

 face of the Temporal Lobe. It is, as Broadbent says, and 

 as other anato- 

 mists had pre- 

 viously recog- 

 nized, a sort of 

 accessory Cor- 

 pus Callosum 

 connecting 

 those parts of 

 the two Tem- 

 poral Lobes 

 which could not 

 otherwise be 

 easily brought 

 into relation 

 with one an- 

 other. 



In some 01 

 the lower ani- 



FJG. 164. Horizontal Section through the Cerebrum at a 

 deeper level, showing the Tlvlrd Ventricle and its Commis- 

 sures and the relations of each Corpus Striatum to the 

 Island of ReU. (Sappey.) 1, Fornix, together with Velum 

 Interpositum turned backwards in order to reveal the Third 

 Ventricle ; 2, Veins of Galen ; 3, anterior extremity of the 

 Pineal body ; 4, its superior peduncles ; 5, Posterior Cere- 

 are directly COn- bral Commissure; 6, Anterior Commissure; 7, section of 

 . * anterior pillars of Fornix ; 8, Third or Middle Ventricle ; 



With One 9, Grey or Middle Commissure ; 10, Corpus Striatum, the 

 u PP er an(i external strata of which have been sliced off ; 

 11, Thalamus ; 12, Tsenia Semicircularis ; 13, 14, 15, section of 

 means Of fibres Convolutions of the Island of Reil ; 16, section of the intra- 

 , . , ventricular nucleus of the Corpus Striatum ; 17, section of 



Wnicn lorm part the White Substance of the Hemisphere, at the part which 

 Of this Anterior intervenes between the Island of Reil and the upper part of 

 the Corpus Striatum. 



Commissure. 



The Middle Commissure is a soft bridge of grey 

 matter that passes across the ' third ventricle ' from one 

 Thalamus to the other (figs. 164,9; 157, Th), and may 



that have 

 large Olfactory 

 Lobes and 

 ' tracts/ these 



