THE SENSES 



127 



end in synapses with neurons in the corpora quadrigemina, 

 and the fibres of these neurons pass downwards and control 

 the oculo-inotor mechanism already described (Fig. 65, 

 p. 126). 



The fibres of the anterior division make synapses with 

 other neurons in the posterior part of the thalamus, and 



Occ. L. 



FlG. 66. The Connections of the Retinae with the Central Nervous System. 

 R, retinae; Ch., chiasma leading to optic tract; Op. Th., optic thalamus ; 

 A.C.Q., anterior corpora quadrigemina; Oc. M., oculo-motor mechanism 

 (Fig. 65) ; Occ. L., occipital lobe of the cerebrum ; Teg.) tegmentum. 



these neurons send their fibres backwards to the occipital 

 lobe of the brain where they connect with the cortical 

 neurons (Fig. 66, Occ.) (see p. 181). ^ 



When the right occipital lobe or the strand of fibres leading 

 to it is destroyed, blindness on the outer part of the right 

 retina and on the inner and middle part of the left retina 

 results the individual is blind for all objects in the left half 

 of the field of vision. 



