212 



COMPARATIVE ANATOMY 



The pallium is entirely epithelial in structure (Figs. 160 162) : 

 it presents no median involution dividing the anterior part of the 



A 



7 



L.ol. 



W 



M 



</jr 



. FIG. 160. BRAIN OF SALMON. A, dorsal ; B, ventral ; and C, lateral view. 



Ch, chiasma; G.p, pineal body; ffff, cerebellum; Hyp, hypophysis; Jnf, 

 infundibulum ; L.ol, olfactory lobe ; Med, spinal cord ; MH, rnid-brain ; NH, 

 medulla oblongata ; Pall, pallium (in part removed), and SGund Ba*G, basal 

 ganglia (corpora striata) of the telencephalon ; ,SV, saccus vascnlosus ; Tr.opt, 

 optic tract; UL, lobi inferiores; VH, telencephalon ; I-X, cerebral nerves ; 

 1 and 2, first and second spinal nerves (the first represents the hypoglossal, 



telencephalon into two lateral hemispheres, and is therefore further 

 reduced than in Ganoids: there is a median ventricle. The lower 



