Chap. XXL] 



OF THE HUMAN BRAIN. 



397 



In the liigber forms of the Haman Brain — as in those of 

 Gauss and De Morgan, and also in the Journalist — the 

 Temporal and Occipital Lobes of each Hemisphere together 

 bear a mach smaller proportion to the mass of brain- 



\^l^ii!]^0llt^ 



Fig. 144.— Under Surface of the Human Brain. (Allen Thomson.) 

 1, 1, Great longitudinal fissure ; 2, 2', 2", convolutions of under surface of frontal 

 lobe ; 3, 3, 3, prolongation to base of the fissure of Sylvius ; 4, 4', 4", convolutions 

 of the temporal lobe ; 5, 5', occ'pital lobe ; 6, anterior pyramids of medulla ; +, pos- 

 terior extremity of median lobe of cerebellum ; 7, 8, 9, 10, lobules of the lateral lobe 

 of the cei ebelinm. I-IX. Cranial nerves, all but the first more fully Feen in next 

 figure. The ninth nerve of the right side has been removed. X. First cervical 

 nerve. 



substance comprised in the Frontal and Parietal Lobes 

 than is the case in brains of a lower type. In the lower 

 Quadrumana, also, the Tempore- Occipital segment of the 

 18 



