THE BRAIN. 539 
Corpora Quadrigemina.—The function of these parts in vision, 
as in the co-ordination of the movements of the ocular muscles, 
hw, 
Fig. 390.—Diagrammatic representation of brain on transverse section to illustrate course 
of fibers (after Landois). C,C, cortex cerebri; C.s, corpus striatum; NW. J, lenticular 
nucleus; 7.0, optic thalamus; P, peduncle; H, tegmentum; p, crusta; V, corpora 
quadrigemina ; 1,1, corona radiata of corpus striatum ; 2, 2, of lenticular nucleus ; 3, 3, of 
optic thalamus ; 4, 4, of corpora quadrigemina ; 5, direct fibers to cortex cerebri (Flech- 
rig); 6, 6, fibers from corpora quadrigemina to tegmentum ; m, further course of these 
fibers ; 8, 8. fibers from corpus striatum and lenticular nucleus to crusta of peduncle of 
cerebrum ; M, further course of these: S, S, course of sensory fibers; R, transverse sec- 
tion of spinal cord ; v. W, anterior, and h. W, posterior roots ; a, a, system of association 
fibers ; c, c, commissural fibers. 
and their relations to the movements of the pupil, will be 
considered later. However, the actual centers for these func- 
tions seem to lie in the anterior portion of the floor of the 
aqueduct of Sylvius, and are indirectly affected by stimulation 
of the corpora quadrigemina, Extirpation of these parts on 
