THE BRAIN 



175 



>SD thab an anterior, a posterior, and an inferior cornu can be dis- 

 iipguished in each ; the inferior cornu extends into what corresponds 

 •io the hippocampal lobe of Reptiles (p. 168), and an eminence on 

 its floor, known as the hip2Mcampus 7najor, is much more marked 

 than in lower forms. The olfactory lobes, in which an olfactory 



Fig. 144. 



-Bkain of Dog (Pointeb). (A, dorsal ; B, ventral ; and C, 

 lateral view.) 



VB, cerebral hemispheres ; Mil, optic lobes ; JIH, cerebellum , Wu, superior 

 vermis ; JIH'^, lateral lobe of cerebellum ; JS/'JI, medulla oblongata ; i/erf, 

 spinal cord; ffyp, hypophysis; Po, pons Varolii: Cr.ce, crura cerebri; 

 Fi.p, pallial fissure ; B. ol, olfactory bulb ; I-XII, cranial nerves. 



tract and bulb can be distinguished, usually extend forwards freely 

 from the base of the prosencephalon and each may {e.g., Horse) 

 contain a prolongation of the lateral ventricle ; but in some cases 

 (e.g., numerous aquatic forms and Primates) they are completely 

 covered by the frontal lobes. 



