1, 2, 3. Three Views of the Human Brain. 



Fig. 1. View of the upper surface of the brain. a, a, a, a, the cerebrum, divided by the fissure, 6, ft, into two hemi- 

 spheres; each hemisphere consisting 1 of three lobes, as seen on the basal view, fig. 2. 



Fig-. 2. Basal view of the brain a, a, anterior lobes of the cerebrum ; 6, b, middle lobes of ditto; c, c, posterior lobes 

 of ditto; d, d, cerebellum;*, pons Varolii ;f, medulla oblongata ; ^, peduncle of the infundibulum ; A, the pituitary 

 gland ; t, i, olfactory nerves; fc, optic nerves. The other nerves, the origin of which is seen in this view of the brain, can- 

 not, in so small a figure, be individually marked. 



Fig. 3. Vertical section of the brain. o, a, a, convolutions of the cerebrum; S, cut surface of the cerebellum, shewing 

 the arbor vitae ; c, c, the great commissure, or corpus callosum ; d, the septum lucidum ; e, the fornix ;-/, the anterior 

 commissure ; #, the posterior commissure ; h, the soft commissure ; i, the pineal gland; fc, corpora quadrigemma, or 

 uptic lobes, divided into four parts;/, pons Varolii, or tuber annulare, cut; m, cut surface of the medulla oblongata; n , 

 fourth ventricle ; o, infimdibulum. 



According to Cuvier, the characters which distinguish the brain of 

 Mammalia from that of the other red-blooded vertebrata, consist in the 

 existence of the corpus callosum, the fornix, the cornu Ammonis, and the 

 tuber annulare ; in the position of the tubercula quadrigemina upon the 

 aquaeductus Sylvii ; in the absence of ventricles, or cavities, in the optic 

 thalami ; in the position of these thalami within the hemispheres, and in 

 the alternate white and grey lines within the corpora striata. The cha- 



