THE MODIFICATION OF THE BRAIN. 



6] 



LOc. 



ri3. 21.— Lateral views of the 'brams of a Eabbit, a Pig, and a Chimpanzee, drawn of nearly 

 the same absolute size. The Eabbif s brain is at the top ; the Pig's, in the middle, the 

 Chimpanzee's, lowest.— 0^, the olfactory lobe; ^., the frontal lobe; B.^ the occipital 

 lobe; C, the temporal lobe; *??/., the Sylvian fissure; /«., the insula; S.Or., sui.ra- 

 orbital ; 8.F.^ M.F.^ I.F., superior, middle, and inferior frontal gyri ; A.P., antero-pari- 

 etal; P.P., postero-parietal gyri; R, sulcus of Rolando; P.Pl, postero-parietal lobule ; 

 (?.P/., external perpendicular or occipito-temporal sulcus; ^7i, angular gyrus ; 2,3,4, 

 annectent gyri; A.T., M.T., P.T., the three temporal, and S.Oc, M.Og., LOc., the threa 

 ot'^ipitiil gyri. 



