Thompson — Degeiierations from Lesions of Temporal Lo 



internal capsules were also described by Shaio and myself, loc. cit.' after 

 lesions of tbe cortex of the occipital lobe. 



On tracing these fibres downwards they were found to diminish in 

 number, and no doubt, as Ramilton} as well as Ferrier and Turner'^ 

 state, by the contribution of some to the optic thalami. 



Others were continued on into both peduncles where they occupied 

 the middle regions of the crustae (see d. 6. and d. y. fig. 8). From here 

 many were seen to enter the substantia nigra and terminate there. Such 

 a mode of ending of pedal fibres has been observed by many investiga- 

 tors, and has recently been confirmed by Bejerine and Long? It was 

 also described by Shaio and myself,^ in connection with similar fibres, 

 degenerating after lesions of the occipital cortex. Muratoff,^ Rothmann,^ 

 and Boyce' have also observed fibres leaving the pyramidal system in the 

 mesencephalon and passing towards the tegmentum. The remainder 

 of these fibres were followed in gradually reducing numbers as low as 

 the pons, beyond which they could not with certainty be traced. 

 These latter, no doubt, ended at different levels in ventral grey 

 matter on their way downwards. It will be noticed that this system 

 also fui'nishes bilateral connexions between a given cortical area, and 

 the grey matter of the basal ganglia, on the one hand, as well as that 

 ventral aspect of the mesencephalon on the other. (See Plate XV.) 



The view that the corpus callosum contains other than direct 

 commissural fibres, which was first set forth by Hamilton,^ received 

 much opposition. It has, however, been confirmed by the experi- 

 ments of BiancM and $ Abundo^^ in connexion with cortical localisa- 

 tion ; by those of 81iaio and myself on the occipital lobe ; and also by 

 those of Ferrier and Turner f^ on cortical afferent and efferent tracts. 



^ Samilton, B.J., "On the Corpus Callosum in the Embryo." — Brain, 1885, 

 p. 145 ; also " The Corpus Callosum in the adult Human Brain," Journ. of Anat. 

 and Physiol., vol. xix., p. 385-414. 



"^Ferrier and Turner, W. A., op. cit. 



^Bejerine, J. E., and Lonff, E., " Sur quelq. degener second du tronc enceph. 

 de I'homme, &c.," Compt. Rend, de la Soc. de Biol. 30 Juillet. 1898. 



^ Shaw, C, and Thompson, W. H., op. cit. 



^Muratoff, Arch. f. Anat. in Physiol., 1893. 



^ Rothmann, Neurolog. Centralbl., June, 1896. 



''Boyce, op. cit. ^Hamilton, B. J., op. cit. 



' Bianchi, L. e d^Abundo G. "La degeneraz speriment. nel cervello e nel midollo 

 spinale, &c.,"La Psychiatria, 1886 ; also, "Die in das Gehirn u. Eiickenmarkherab- 

 steig. Experim. Degener. als Beitrag z. Lehre v. cereb. Lokalisation." Neur.d. 

 Centr. bl. v. 17, 1886. 



'^^ Ferrier and Turner, op. cit. 



