9 oo THE CEREBELLUM. 



further found that after removal of the cerebrum and optic lobes, 

 ablation of the cerebellum rendered the movements of progression, 

 which previously were quite possible, unsteady and well-nigh im- 

 possible. 



In fish, all observers l seem agreed no obvious disorder of locomotion 

 ensues on destruction of the cerebellum, unless deep and perhaps 

 extraneous connections are injured. Loeb and Steiner have recently 

 confirmed this in Squalius and in the shark, in both of which the 

 cerebellum is large. 



Phenomena caused by section of the cerebellar peduncles. — 

 Section of the anterior (superior) peduncle.— Section of the anterior 

 peduncle, after it has crossed the median line and is in the tegmentum, 

 causes rolling round the long axis from the side of the lesion toward the 

 sound side (Longet, Lafargue, Lussana, Lemoigne, 2 etc.), as does injury 

 to the posterior part of the optic thalamus (Flourens, Schiff, Lussana, 

 etc.). 3 The homonymous limbs are abducted, the crossed adducted 

 (Lussana). 4 The direction of progression swerves toward the crossed 

 side. 



Its section before the decussation, near its exit from the cere- 

 bellum, causes disturbances similar to the foregoing, but in the opposite 

 direction (Lussana, etc.). 5 Ferrier and Turner 6 noted also tilting of the 

 chin to the crossed side, the occiput being drawn to the homonymous 

 side, and (in monkeys) flexion and adduction of the homonymous limbs, 

 with tremor in them, increased on exertion, and reluctance to use them. 

 Intense perturbation and swaying of the body on the slightest attempt 

 at movement was present at first, but soon passed off. The knee-jerk 

 was brisker on the homonymous side. 



Section of the middle peduncle.— Rolling round the long axis of 

 the body 7 and deviation of the eyeballs 8 have long been known and 

 studied in connection with this peduncle. Much controversy has taken 

 place as to the direction of the rotation. Magendie described the 

 rotation as occurring from the sound side toward the injured, the devia- 

 tion as toward the sound side, the homonymous eye turning forward 

 and downward, the crossed backward and upward. The same result was 

 obtained by Schiff, Budge, Lussana, 9 etc., when following Magendie's 

 mode of operation, also by Ferrier and Turner, 10 following a different and 

 more exact method of section. Magendie's result is similar to that 

 obtained by lateral ablation of the cerebellum itself. Longet's method, 11 

 in other hands as well as in his own (Schiff, Lussana, Lemoigne), 12 causes 

 rotation from the side of the lesion. Rotation in a similar sense to 

 Longet's is produced by Bernard's glycosuric piqiire, 13 by evulsion of the 

 facial nerve, 14 scratching the pons in neurectomy of the trigeminus. It is 

 also seen sometimes as a first and quite transitory effect of Magendie's 

 section, 15 and is then soon replaced by the reverse and comparatively 

 permanent rotation. 



1 Desmoulins, Vulpian, Philipeau (with Vulpian), Ferrier, Bandelot, Steiner, loc. cit. 

 But Dickinson reported " loss of balance." 



2 Lafargue, " Inaug. These," Paris, 1838 ; the others, loc. cit. 3 Loc. cit. 

 4 Loc. cit. 5 Loc. cit. 6 Loc. cit. 



7 Pourfour du Petit, " Lettres, etc.," Nanrar, 1710. 



8 Magendie, loc. cit. 9 Loc. cit. 10 Loc. cit. 

 11 Longet, op. cit. 12 Loc. cit. 



13 "Leijons sur la physiol. du systeme nerveux," Paris, 1858. 



14 Brown-Sequard. 



15 Schiff, loc. cit. ; Budge, "Physiol, des Menschen," Leipzig, 1862, S. 755. 



