THE PONS FINAL REVIEW. 2'25 



cinereum, and, mainly, from the corpora quadrigemina. Fibres 

 from the optic radiation, which commences in the occipital lobe, 

 pass to all these sources. This radiation passes along the outer 

 side of the posterior horn of the lateral ventricle, and, therefore, 

 in its passage from the cortex to the primary optic centre?, it 

 runs under the lower parietal lobule. Hence, in diseases of the 

 latter, or when it has been experimentally destroyed in animals, 

 disturbances of vision arise which resemble those of cortical 



origin. 



The fibres of the optic tract run to the chiasm. There the 

 greater part of them cross to the opposite side. A small portion, 

 which, however, are not gathered into a distinct bundle, remain 

 on the same side. The conflict which was carried on for years 

 over the chiasm has lately been definitely settled by Singer and 

 Miinzer, with the results given above. The optic tract must 

 contain pupillary fibres coming from the oculo-motor nerve. 

 It is not yet known by what course they reach the former. 



