212 Dr. E. L. Mellus. Experimental Degenerations [June 13, 



half as much as on the left, in another it was nearly equal on the two 

 sides, and in the lesion of the mastication centre there was quite as 

 much on the right as on the left side. In the other four lesions of 

 the facial area there was no degeneration observed in the right 

 internal capsule. In the lesion of the centre for the angle of the 

 mouth degenerate fibres were observed in the striations of the right 

 thalamus, some of them being pretty coarse. In two cases fine 

 degeneration was observed crossing in the posterior commissure. In 

 the three cases in which fine degeneration only resulted from t~he 

 lesion, most of this disappears before reaching the crus. In the 

 lesion of the mastication centre it could not be traced, but in the 

 other two it passed to the thalamus from both left and right capsule. 

 In all three a small amount of fine degeneration was 'found in the 

 middle third of both crura. In one case this passed to the sub- 

 stantia nigra, but in the other two it could not be traced. In the 

 other four lesions of the facial area the coarse degeneration from the 

 left internal capsule was scattered very evenly over the middle third 

 of the crus encroaching a little upon the lateral third. Some of the 

 fibres passed into the substantia nigra or the sub-thalamic region, and 

 in one case a considerable number to the anterior corpus quadri- 

 geminum. The remaining degenerate fibres begin to leave the left 

 pyramid at the junction of the pons and medulla, passing as single 

 degenerate fibres to the facial nucleus of one or the other side. 

 Below the level of the facial nuclei these fibres pass to the motor 

 nuclei of the glosso-pharyngeus and the vagus on both sides, the 

 majority crossing the raphe to reach the nucleus on the opposite side. 

 Occasional- fibres were observed, which apparently passed to some 

 termination dorsal to these nuclei. This movement of degenerate 

 fibres continued as far as the sensory decussation. A few degenerate 

 fibres (probably thumb or finger fibres) remained in the pyramid, 

 and crossed in the decussation to the right lateral column, and dis- 

 appeared in the lower cervical or upper dorsal region. No degenerate 

 fibres remained in the left anterior column after the decussation, and 

 there was no apparent division of the tract, as in hallux and thumb 

 lesions. 



Under the head of "other appearances resembling degeneration" 

 are recorded appearances which are of doubtful significance, but yet 

 so closely resemble degeneration that they are well calculated to 

 deceive and lead one into grave error. Among these may be men- 

 tioned apparent degeneration in the left lateral geniculate body and 

 optic radiation, in the posterior longitudinal fasciculi, the roots of all 

 the motor cranial nerves of both sides and the corpus trapezoides 

 (Marchi), and in one case extensive degeneration in the optic tract. 

 The degenerations in the roots of the motor cranial nerves and in the 

 corpus trapezoides could hardly have been due to the lesions, as 



