XIII 



PHYLUM CHORDATA 



439 



with certain differences, of which the following are the most 

 important. 



The surface of the cerebral hemispheres (Fig. 1031, /. I., 

 Fig. 1032, c. h.), which are relatively long and narrow, presents 



/.&. 



f 



6.0 



Ill IV 



p.v. vi vii ix xii 



FIG. 1031. Lepus cuniculus. Brain. A, dorsal view ; B, ventral ; C. lateral, b. o. olfactory 

 lobe; cb', median lobe of cerebellum (vermis); cb". lateral lobe of cerebellum; cr. ca*uro 

 cerebri ; ep. epiphysis ; f,b, pareiicephala ; /, p, longitudinal fissure ; h.b. hind-brain ; lip. hype - 

 physis ; m.b. mid-brain (corpora quadrigemina) ; md. medulla oblongata ; p. v. pons Varolii ; 

 / XII, cranial nerves. (From Wiedersheim.) 



certain depressions or sulci, which, though few and indistinct, 

 jet mark out the surface into lobes or convolutions not distin- 

 guishable in the case of the Pigeon or the Lizard. A slight 

 depression the Sylvian fissure at the side of the hemisphere 

 separates off a lateral portion, or temporal lobe (Fig. 1033, c. A 2 .), 



