156 



PROFESSOR W. H. THOMPSON. 



3. Projection Fibres : (a) Eetro-Lenticular Group. — The largest 

 group of degenerated fibres was in all cases traceable from the 

 seat of injury through the corona radiata towards the internal 

 capsule (see d. 1, fig. 3). On entering this system of fibres, the 

 majority were found to occupy the retro-lenticular segment of its 

 posterior limb, some extending slightly forwards, however, 

 between the posterior end of the lenticular nucleus and the optic 

 thalamus. Certain of these fibres were seen to reach the capsule 



— d.2 



d.f 



d3. 



d.4. 



Fig. 6. — Vertical section through brain of marmoset 7, posterior to fig. 5. 



d. 1 and d. 2, as in fig. 5. 



d, 3, external capsule. 



d. 4 and S, anterior commissure. 



d. 5, corpus callosum. 



d. 6, degenerations extending into opposite temporal lobe. 



d. 7, opposite internal capsule. 



by piercing the back part of the lenticular nucleus. These, no 

 doubt, correspond to the bundle which Fleclisuj'^ has recently de- 

 scribed in the brain of an eight months foetus, and which passes 

 from the internal geniculate body to the anterior transverse 

 temporal gyri perforating the putamen in its course. This 

 bundle was medullated before those of the fillet, which are con- 

 tributed to the posterior corpora quadrigemina. 



The above retro-lenticular group descended with the capsular 

 fibres, and was found to be distributed in the following ways. 



" Zur Anatomic des vord. Sehhugelstiels des Cingulum u. der 

 Acusticus-Bahn," Nmrol. Ce.nlrcdb., xvi. 7, p. 290. 



1 Flechsig, P. 



