THE NERVOUS SYSTEM. 185 
the anterior commissure. Here the two columns diverge 
slightly from the median line, but continue their descent, 
curving caudad to their termination in the corpora albi- 
cantia. The posterior columns, or crura, descend from the 
caudal border of the body, curving laterad into the median 
cornu of the lateral ventricle, and gradually unite with the 
cornu ammonis. The cornu ammonis, or hippocampus 
major, is a thickened projecting fold of the wall of the 
Fic. 96. DorsaL ASPECT OF THE BRAIN WITH THE CEREBELLUM AND 
THE DorsaL THIRD OF THE CEREBRUM ReMovepD AND Most oF THE 
Corpus CaLLosum Cut AWAY FROM THE RicHT Hatr. 
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 of the cerebellum; 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; ip, 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; 1, 
uncut portion of the callosum; md, medulla oblongata; , anterior 
columns or pillars of the fornix; 0, gray cortex of the cerebrum; 
p, posterior crus of the fornix; pn, pineal gland, craniad to which 
is the heavy white line, the commissure of the habene or teniz 
thalami; pp, funiculus gracilis; rc, funiculus of Rolando; J, funic- 
ulus cuneatus; ts, posterior corpora quadrigemina; x, body of 
the fornix. 
17 
