170 



COMPARATIVE ANATOMY 



ZH- 



HHi 



FIG. 140. BRAIN OF ALLIGATOR. (A, dorsal ; B, ventral ; and C, lateral view.) 



VH, cerebral hemispheres, each of which gives rise postero-laterally to a hippo- 

 campal lobe partially overlying the corresponding optic tract, Tr.opt ; ZH, 

 thalamencephalon ; MH, optic lobes ; HH, cerebellum ; NH, medulla 

 oblongata ; I-XII, cranial nerves ; 1, 2, first and second spinal nerves ; B.ol, 

 olfactory bulb ; Tro, olfactory tract ; G.p, pineal body ; Jnf, infundibulum ; 

 Hyp, hypophysis ; Med, spinal cord. 



