CHAP. XXIII.] 



OF THE HUMAN BRAIN. 



471 



The other two sensory nerves of the Medulla, the 

 Glosso-pharyngeal and the Pneumogastric, will be referred 

 to in the next section. The situation of the ' motor ' 



a, c7. 



FIG. 168. Enlarged View of part of the Base of the Brain to which the Cranial 

 Nerves are attached. (Ferrier, after Allen Thomson.) 



On the right side the Convolutions of the Central lohe (C), or Island of Reil, have 

 been left, on the left the incision has been carried between the Thalamus (TH] and 

 the Hemisphere. I', Olfactory Nerve cut short ; II, Optic Nerve in front of Com- 

 missure ; II', Right Optic tract, e. The external, and i, the internal 'corpus genicu- 

 lacuna'; h, Pituitary body; tc, Tuber cinereum and infundibulum ; a, one of cor- 

 pora mammillaria ; P, Cerebral peduncle. Ill, Third nerve (oculo-motor) ; IV, Fourth 

 nerve (patheticus) ; P V, Pons ; V, the greater root of Fifth nerve (trigeminus). +, 

 The lesser or motor root ; on the right side this is placed on the Gasserian ganglion. 

 1, 2, 3, The three divisions of the Fifth nerve ; 6, Sixth nerve ; Vila, the Facial ; 

 VII6, the Auditory ; VIII, the Vagus or Pneumogastric ; Villa, the Glosso-pharyn- 

 geal; VIII6, the Spinal-accessory; IX, the Hypo-glossal; fl, the 'flocculus' of Cere- 

 bellum ; p a, anterior Pyramid ; o, Olivary body ; r, Restiform body ; d, anterior 

 median fissure of the Spinal Cord, above which is the ' decussation ' of the Pyramids ; 

 c a, the anterior, and c I, the lateral column of the Spinal Cord. 



nerves will he seen hy an examination of fig. 168, though 

 no further reference to them is here needed. 



