DEGENERATIONS FEOM LESIONS OF TEMPORAL CORTEX. 155 



the external capsule did not enter the anterior commissure. 

 Many descended to the anterior and lower part of the temporal 

 cortex on the side of the lesion. Through the external capsule 

 and anterior commissure another bilateral connection is thus 

 established between the cortex of the temporal lobe and both 

 hemispheres, comparable to that formed in a posterior direction 

 by the fibres of the tapetum. 



(c) Fornix. — In a small number of the brains examined, 



Fig. 5. — Vertical section through anterior part of brain of marmoset 7, 

 showing sites of degeneration. 



(I. 1, internal capsule. 



d. 2, parieto-temporal fasciculus. 



d. 3, anterior commissure. 



degenerated fibres wero detected in the body of the fornix (see 

 d. 6, fig. 4). They probably belonged to the set of fibres described 

 by authors under the name of fasciculus pericavitarius medialis. 

 They were traced forwards to the anterior end of the fornix, 

 but neither their exact source of origin nor termination could 

 be definitely determined. 



(d) Posterior Commissure. — Some degenerated fibres were found 

 in nearly all cases in the posterior commissure. Reference to 

 these will again be made. 



