CHAP. XXIII.] 



OF THE HUMAN BRAIN. 



435 



to, pass on each side in compact columns through the 

 Medulla, and through that continuation of it which is 

 crossed by the 

 'middle peduncles' 

 of the Cerebellum 

 (viz., the pons 

 Varolii). Beyond 

 this point, both 

 sets of fibres of 

 the one side di- 

 verge from those 

 of the other (fig. 

 154) so as to 

 form what are 

 known as the 

 'Cerebral Pe- 

 duncles.' These 

 parts are seen on 

 the under surface 

 of the brain, es- 

 pecially when the FIG. 155. On right side shows plane of fibres under- 

 Of the Tem- lying 8u P erficial convolutions on inferior aspect of Tem- 

 poral Lobe, and forming the floor of Descending Cornu. 

 LobeS are The Cornu has been opened anteriorly, and fibres (s x) 

 , n from the apex of the lobe to the extra- ventricular Cor- 



s pus Striatum are been. On the left side of figure, the 



01* removed (fi2f. dissection has been carried further, and the Optic Tract 

 j-, has been removed, rr, Crura Cerebri. re, Crusta. rt, 



HiaCll Fibres of Tegmentum (and from Thalamus) turning 

 SOOn round anterior edge of Crusta. th, Tail of Thalamus, 

 ... . . turning round posterior edge of Crusta, forming ' Collar 



disappears Within of Crus,' and distributing fibres to Sylvian margin of 

 Temporal Lobe, th' and sx', Fibres from Thalamus and 

 extra-ventricular Corpus Striatum respectively to Oc- 

 Hemi- cipital extremity of Hemisphere. The longitudinal 

 , i -t j-i fibres not indicated by letters belong chiefly to the sys- 



Spnere, and. then tern of the Gyms Uncinatus. (Broadbent.) 



its future course, 



or that of its constituent fibres, can only be made out by 



the most careful dissections. It spreads out rapidly into 



F F 2 



Sx 



tV 



ENS 



drawn 



155, re). 

 Peduncle 



