2 



Prof. D. Ferrier and Dr. W. A. Turner. 



fibres with tlie superior temporal gyrus, the superior parietal lobule, 

 and the occipital lobe. A system of corticipetal fibres was traced 

 from the optic thalamus to the angular gyrus and the occipital lobe, 

 in which lobe their distribution was as well marked in the external 

 convolutions as in the cuneus and lips of the calcarine fissure. 



The angular gyri and occipital lobes are commissurally connected 

 through the splenium and forceps corporis callosi ; the callosal fibres 

 having the same cortical distribution as the thalamic fibres. 



In this respect our observations are in harmony wifch those of von 

 Monakow and Vialet. 



(b) The experiments upon tbe auditory system consisted of section 

 of the eighth nerve distal, as well as proximal, to the accessory 

 auditory ganglion ; destruction of the posterior quadrigeminal 

 body and the internal geniculate ganglion, and extirpation of 

 the superior temporal gyrus. 



Inasmuch as the experiments necessitated division of the pedun- 

 culus flocculi, the degenerations consequent thereon were first elimi- 

 nated. These were traced into Deiters' nucleus, the vermis cerebelli, 

 and tegmentum pontis, corresponding with the observations of Bruce 

 and Stscherbach by tbe myelination method. 



The direct connexions of the vestibular division, as shown by 

 section of the eighth nerve trunk distal to the auditory ganglion, 

 are with Deiters' nucleus and the tegmentum ; while there is also a 

 probable direct connexion with the nucleus of the sixth nerve. 



The connexions of the cochlear division, forming the central 

 auditory tract, were found to pass from the accessory auditory 

 ganglion by way of the corpus trapezoides, in association with the 

 lateral fillet, to the internal geniculate body of the opposite side. 

 Thence a tract was found to ascend to the superior temporal gyrus. 

 This forms the corticipetal or cerebral auditory tract. Degenera- 

 tion was also traced after destruction of the auditory ganglion into 

 both superior olives, and posterior quadrigeminal tubercles, chiefly 

 of the opposite side. These results are compared with those of 

 Flechsig, Kolliker, &c, obtained by other methods of investigation. 



After destruction of the superior temporal gyrus a tract of 

 degeneration was found to descend, to the upper part of the pons 

 Varolii, through the outer fifth of the pes cruris. This constitutes 

 the temporo-pontine tract of Bechterew and Dejerine. 



The superior temporal gyri are commissurally connected through 

 the forceps of the corpus callosum, and by means of association 

 fibres with the angular gyrus and occipital lobe. 



(c) The cutaneous sensory and other corticipetal systems were 

 studied by the aid of destructive lesions of the tegment of 

 the pons Yarolii, cms cerebri, optic thalamus, the posterior 



