THE NERVOUS SYSTEM. 179 
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Fic. 93. VENTRAL ASPECT OF THE BRAIN. 
2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 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; 
Ila eleventh cranial nerve with roots from the spinal cord; c, 
mandibular branch of the trigeminal nerve; ca, corpus albicans; cb, 
cerebellum; cc, canalis centralis; cn, cornea; ct, cut surface of spinal 
cord; ex, external rectus muscle; cr, peduncle of the cerebrum; g, 
Gasserian ganglion of the trigeminal nerve; hl, 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; #1 and m2, first and second spinal nerves; ol, 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; ¢z, corpus trapezoideum; +, external arciform fibers. 
