222 



COMPARATIVE ANATOMY 



individual sections it is more or less comparable to that of certain 

 of the latter (e.g. Chelonia). The basal ganglia (corpora striata) of 



NU 



\ 



M\K 



X 



,W- F i 



n Hyp vr w 

 s*S ^ 



FIG. 169. BRAIN OF PIGEON. A, dorsal; B, ventral ; and C, lateral view. 



HH, cerebellum ; Hyp, hypophysis; Inf, infundibulum ; L.ol, olfactory lobes; 

 Med, spinal cord ; MH, optic lobes ; NH, medulla oblongata ; Tr.opt, optic 

 tract; VH, cerebral hemispheres; I-XII, cerebral nerves; 1, 2, first and 

 second spinal nerves. 



the hemispheres reach a relatively larger size in Birds than in 

 any other Vertebrates. An advance on Reptiles is seen in the 



