76 



CONVOLUTIONS OF THE BRAIN 



very marked feature, moreover, of the mammal's brain is the 

 development of regular fissures iipon its surface, which fissures 

 are only absent from Ornithorhynclivs, various small Eodents, 



_r77 



^ .'^//^^H 



^1 i 



A 



Tir 



^- "^^ V/c 



EH 



3 



7v V '^ 



%;; ^ i'*? YLYM 



Fig. 4i).^Brain of Dog. A, ventral ; B, dor.sal : C, lateral aspect. iJ.o/, Olfactory lobe ; 

 CV.ce, crura cereliri ; FLi), great longitiuiiiial fissure ; ////, IIH^, lateral lobes of 

 cerebellum ; Hijp, liypophysis ; Med, .spinal cord ; NH, medulla oltlongata ; Po, 

 l)ous Varolii ; I'i/, cerebral hemispheres ; Wu, middle lobe (vermis) of cerebellum ; 

 I-XII, cerebral nerves. (From Wiedersheim's Omiparafire Anolomy.) 



Bats, and Insectivores, among living mammals. It is some- 

 times, but erroneously, said that the more complicated the 

 fissures of the lirain are, the higher in intelligence and " zoological 

 position " is the possessor of that brain. Instances can un- 

 doubtedly be quoted to support such a view ; but they are 



