THE BRAIN. 



317 



Internal lateral face of the brain. 



13, its internal face; 14, commis- 

 suramollis; 15, infundibulum; 16, 

 portion of pituitary gland ; 17, por- 

 tion of tuber cinereum ; 18, pisiform 

 tubercle; 19, locus perforatus; 20, 

 oculo-inotor nerve ; 21, portion of 

 optic nerve ; 22, anterior cerebral 

 commissure ; 23, foramen of Mon- 

 roe ; 24, fornix ; 25, septum luci- 

 dum ; 26, corpus callosum ; 27, 

 splenium ; 28, genu ; 29, sinus of 

 the corpus callosum ; 30, gyrus 

 fornicatus ; 31, internal convolu- 

 tion of the anterior lobe ; 32, deep anfractuosity ; 33, convolution of pos- 

 terior lobe ; 34, anfractuosity. 



Fig. 157, base of the brain, photo- 

 graphed from a wax cast : 1, 1, anteri- 

 or lobes ; 2, 2, middle lobes ; 3, 3, pos- 

 terior lobes; 4, anterior portion of great 

 median fissure; 5, its posterior portion; 

 6, 6, fissures of Sylvius ; 7, 7, antero- 

 posterior portions of the great fissure 

 of Bichat ; 8, tuber cinereum ; 9, 9, 

 corpora albicantia; 10, locus perforatus 

 medius ; 11, 11, crura cerebri; 12, pons 

 varolii; 13, medulla oblongata; 14, 

 14, anterior pyramids; 15, 15, olivary 

 bodies; 16, 16, restiform bodies; 17, 

 17, lateral lobes of the cerebellum ; 18, 

 Base of the brain. portion of its middle lobe ; 19, 19, 



two small antero-posterior convolutions of the frontal lobe, separated by 

 the groove of the olfactory nerve ; 20, oblique convolution, limiting the 

 fissure of Sylvius ; 21, convolution of the great cerebral fissure ; 22, ol- 

 factory nerve ; 23, its bulb ; 24, 24, optic nerves and their chiasm ; 25, 

 25, oculo-motor nerves ; 26, 26, pathetici ; 27, 27, great and small roots 

 of the trifacial; 28, 28, external oculo-motor nerves; 29, 29, facial nerves ; 

 30, 30, auditory; 31, 31, glosso-pharyngeal ; 32, 32, pneumogastric 

 nerves ; 33, 33, spinal accessory ; 34, 34, great hypoglossal. In this 

 engraving several of the symmetrical numbers are not repeated, for the 

 sake of clearness. 



Fig. 158 is an analytical diagram of the brain in a vertical section 

 (from Mayo). It serves to impress on the mind the foregoing structure of 

 structural descriptions, s, Spinal cord preparing for bifurca- t ? e brain - 



