PROCEEDINGS 



OF 



THE ROYAL SOCIETY. 



"An Experimental Research, upon Cerebro-cortical Afferent 

 and Efferent Tracts." By David Ferrier, M.D., F.R.S., 

 Professor of Neuropathology, and William Aldren 

 Turner, M.D., F.R.C.P., Demonstrator of Neuropathology, 

 King's College, London. Received May 25. — Read June 17, 

 1897. 



(From the Neuropatkological Laboratory, King's College, London.) 

 (Abstract.) 



The primary object of the research has been to elucidate by the aid 

 of destructive lesions, and the study of the consecutive degenerations, 

 the tracts by which impressions of general and special sensibility are 

 conveyed to the cortex of the brain. For this purpose, the cortical 

 area, supposed to be the sensory centre under consideration, was 

 extirpated ; and, secondly, the nerve, tract or primary ganglionic 

 structure connected therewith was divided or destroyed. 



In this way strands of degeneration were induced, in due course, of 

 cortical afferent or efferent nature, revealed by the osmium-bichro- 

 mate method of Marchi. 



The systems upon which experiments have been performed 

 were : — 



(ft) The cerebral portion of the visual system, consisting of removal 

 of the occipital lobe, extirpation of the angular gyrus, destruc- 

 tion of the pulvinar thalami, and division of the splenium 

 corporis callosi. 



The degenerations showed that this portion of the visual system 

 was composed of a corticifugal tract, passing from the occipital lobe, 

 by way of the optic radiations, to the pulvinar thalami of the same 

 side, and to the anterior quadrigeminal bodies of the same and partly 

 of the other side. The angular gyrus has no descending or efferent 

 tract to the basal ganglia, but is connected by means of association 



VOL. LXII. b 



