94 THE CEREBELLUM. 



the stride medullares, and along with the anterior roots of the spinal nerves. These 

 degenerated fibres are numerous on the same side as the lesion, but a few occur in 

 the opposite nerves. Those which pass to the cranial nerves run along the posterior 



Fig. 71. OUTLINE OF SECTIONS SHOWING THE DEGENERATIONS FOLLOWING EXTIRPATION OF THE LEFT 



HALF OF THE CEREBELLUM IN THE DOG. (March!.) 



A, lumbar cord ; B, cervical cord ; C, medulla oblongata ; D, pons Varolii ; E, mid-brain at nucleus 

 of third nerve. 



In A and B, the degeneration is in the antero-lateral column of the same side as the lesion, except in 

 B, where there is a little degeneration on the opposite side. 



In C, a indicates the restiform body ; 6, the ascending root of the fifth ; c, the posterior longitudinal 

 bundle ; d, the antero-lateral tract ; e, the pyramids ; /, the olivary nucleus ; g, the fillet ; h, the 

 hypoglossal nucleus. 



In D, a is the superior cerebellar peduncle ; b, the middle peduncle ; c, the posterior longitudinal 

 bundle ; d, the fillet ; e, the antero-lateral tract ; /, the raphe. 



In E, a is the nucleus tegmenti (most degeneration in the crossed superior cerebellar peduncle) ; 

 b. the issuing fibres of the third nerve ; d, the posterior longitudinal bundle ; e, the crusta ; /, part of 

 the fillet. 



longitudinal bundle, those which pass to the spinal nerves down the descending 

 antero-lateral tract of the cord. 



Extirpation of worm. After hemi-extirpation of the middle lobe only 

 of the cerebellum the degeneration in the superior peduncle is comparatively 

 slight, and entirely crosses at the decussation to pass to the tegmental nucleus of 

 the opposite side. The degeneration of the middle peduncle is most marked 

 in the upper third of the pons ; but little occurring in the lower two-thirds. 



