1895.] folloioing Unilateral Lesions of the Cortex Cerebri. 209 



be traced from the corpus callosum into the right internal capsule. 

 The coarse degeneration, mixed with more or less fine, is found in 

 the middle third of the crus. In each case some fine degeneration 

 reaches the crus, where it invariably takes its position external to 

 the coarse fibres. In the entire group a large proportion of the 

 degeneration passes to the substantia nigra. This varies from a half 

 to nearly the whole of the degeneration reaching the crus. The fine 

 degeneration referred to external to the coarse disappears from the 

 crus, but could not be traced to its destination. The coarse degenera- 

 tion observed in one case in the right internal capsule reached the 

 crus, where all but a few fibres disappeared. In one case the last 

 remaining degenerate fibres disappeared in the upper levels of the 

 pons. In another about half those remaining disappeared in the 

 lower pons and upper medulla, but could not be traced after leaving 

 the pyramidal tract. In one case only was there a division of the 

 degenerated tract at the decussation of the pyramids, such as was 

 observed in lesions of the hallux centre, and the amount of degenera- 

 tion passing to the left lateral column was less than in either of the 

 hallux cases. This was also the only case in which a few degenerate 

 fibres remained in the left anterior column after the completion of 

 the decussation. lu one of the remaining cases the few degenerate 

 fibres remaining in the left anterior column cross to the right lateral 

 column, and in the other the degeneration in each pyramid apparently 

 goes to the crossed tract of the opposite side. In each of the three 

 cases in which the degeneration reaches the cervical cord, its amount 

 and relations remain unchanged in the upper and middle cervical 

 regions. From the level of the seventh cervical root downward the 

 degenerate fibres steadily and gradually disappear, and at the level 

 of the third dorsal root there are none left, thus confirming the 

 results obtained by excitation of the nerve roots (Ferrier and Yeo, 

 Forgue, &c.). 



Degeneration following Lesions of the Facial Area. 



Seven successful experiments were performed to determine if 

 possible the degeneration resulting from minute lesions within the 

 facial area. In four of these the lesion was practically the same, 

 the portion of cortex removed being just above the fissure of 

 Sylvius and just anterior to the plane of the fissure of Rolando, 

 representing the movement of opening the mouth straight ; in one 

 the lesion was in the same level, and just posterior to the fissure of 

 Rolando, and the movement elicited on stimulation was pursing the 

 mouth towards the opposite side ; in one the lesion was just above 

 the fissure of Sylvius and anterior to the plane of the sulcus trans- 

 versalis frontalis inferior, and the movement represented was the 



Q 2 



