THE NERVOUS SYSTEM. 



179 



rl- 



FIG. 93. VENTRAL ASPECT OF THE BRAIN. 



2 , 3, 4, 5, 6, 7, 8, 9, 10, n, 12, The cranial nerves; a, ophthalmic branch 

 of the trigeminal nerve ; an, anterior pyramids ; at, anterior horn of 

 gray matter ; b, superior maxillary branch of the trigeminal nerve ; 

 na eleventh cranial nerve with roots from the spinal _ cord; c, 

 mandibular branch of the trigeminal nerve ; ca, corpus albicans ; cb, 

 cerebellum ; cc, canalis centralis ; en, cornea ; ct, cut surface of spinal 

 cord; ex, external rectus muscle; cr, peduncle of the cerebrum; g, 

 Gasserian ganglion of the trigeminal nerve; hi, pyriform lobe; in, 

 opening into the tuber cinereum revealed by removal of the infundi- 

 bulum and pituitary body; i, internal rectus; io, inferior oblique; ir, 

 inferior rectus ; MI and n 2 , first and second spinal nerves ; pi, olfactory 

 lobe; op, optic commissure; ot, optic tract; p, posterior horn of 

 gray matter ; pt, anterior perforated space ; pv, pons Varolii ; r, 

 medial or inner root of olfactory nerve; rt, lateral root of olfactory 

 nerve; pr, postrhinal fissure; sy, Sylvian fissure; s, superior rectus 

 muscle ; tz, corpus trapezoideum ; x, external arciform fibers. 



