THE NERVOUS SYSTEM. 



197 



of the septum of one hemisphere to those of the septum 

 in the other hemisphere is sometimes called the fifth 

 ventricle. Between each anterior pillar of the fornix and 



FIG. 93. DORSAL ASPECT OF THE BRAIN WITH THE CEREBELLUM AND 

 THE DORSAL THIRD OF THE CEREBRUM REMOVED AND MOST OF THE 

 CORPUS CALLOSUM CUT AWAY FROM THE RIGHT HALF. 



ac, Right anterior corpus quadrigeminum ; c, commissure of the quadri- 

 gemina; ca, the united superior and inferior peduncles of the cere- 

 bellum ; cr, the middle peduncle or crus cerebelli ad pontem ; cs, corpus 

 striatum; ct, edge of corpus callosum cut slightly to the left of the 

 median line; cal, dorsal surface of the callosum into which a hole 

 has been cut; lip, hippocampus major, or cornu ammonis, in the 

 median cornu of the lateral ventricle; h, hippocampus major near 

 where it is joined by the fibers of the crus of the fornix; i, uncut 

 portion of the callosum ; md, medulla oblongata ; n, anterior columns 

 or pillars of the fornix ; o, gray cortex of the cerebrum ; p, posterior 

 crus of the fornix; pn, pineal gland, cephalad to which is the heavy 

 white line, the commissure of the habenae or taeniae thalami; pp, 

 funiculus gracilis; re, funiculus of Rolando; 1, funiculus cuneatus; 

 ts, one of the testes or posterior corpora quadrigemina ; x, body of 

 the fornix. 



the optic thalamus is a cleft, the foramen of Monro, 

 leading from the third ventricle, laterad of the septum 

 lucidum, into the lateral ventricle. 



