158 



PROFESSOK W. IT. THOMPSON. 



mentioned those of Dejerine,^ and of Ferrier and Turner^ whose 

 publications have appeared since the present research was 

 undertaken. 



It is interesting to note, at this stage, the existence of degener- 

 ated fibres in the posterior commissure (see d. 5, fig. 8). These 

 turned immediately downwards towards the dorsal grey nuclei 

 of the mesencephalon. They were no doubt continued from the 

 capsular set of fibres, and would thus supply the cross link for 



a 4 



d.5. 



d8 



d.6. 



d2 



d.3 



Fig. 8. — Vertical section through same brain as figs. 5, 6, and 7, but 

 posterior to fig, 7, showing degenerations in— 



d. 1, posterior part of internal capsule (subthalamic region). 



d. 2, inferior longitudinal fasciculus. 



d. 3, extending from tapetum into occipital lobe. 



d. 4, tapetum of opposite side. 



d. 5, posterior commissure. 



d. 6 and 7, scattered through middle parts of internal capsules. 



d. 8, traversing optic thalamus to reach corpora quadrigemina. 



a bilateral termination of the sets of fibres with which we are 

 now dealing. That such bilateral method is the general plan 

 of connection between a given portion of the cortex and other 

 masses of grey matter I have little doubt. 



Lastly, a very definite fasciculus continued downwards in the 

 internal capsule, traversing the subthalamic segment of this 



1 Dejerine, J., " Sur I'origiue cort. et trajet intra-cureb. des fibres de I'etage 

 inf. ou pied du pedoncle cerebrale," Mtm. dela Soc. do Biol., t. 5, pp. 193-206. 



- Ferrier and Turner, W. A., " An Experim. Research upon Cerebro-cortical 

 afferent and efferent Tracts," Proc. Roy. Sue, Ixxii. p. 1. 



