676 FUNCTIONS OF THE CEREBRO-SPINAL NERVOUS SYSTEM. 



seem the most clear and decisive in their results ; and of these we shall ac- 

 cordingly take a general survey. He found that, when the Cerebellum was 

 mechanically injured, the animals gave no signs of sensibility, nor were they 

 affected with convulsions. When the Cerebellum was being removed by 

 successive slices, the animals became restless, and their movements were 

 irregular; and by the time the last portion of the organ was cut away, the 

 animals had entirely lost the power of springing, flying, walking, standing, 

 and preserving their equilibrium, in short, of performing any combined 

 muscular movements, which are not of a simply reflex character. When an 

 animal in this state was laid upon the back, it could not recover its former 

 posture ; but it fluttered its wings and did not lie in a state of stupor. When 

 placed in the erect position, it staggered and fell like a drunken man, not, 

 however, without making efforts to maintain its balance. When threatened 

 with a blow, it evidently saw it, and endeavored to avoid it. It did not seem 

 that the animal had in any degree lost voluntary power over its several mus- 

 cles ; nor did sensation appear to be impaired. The faculty of combining the 

 actions of the muscles in groups, however, was completely destroyed ; except 

 so far as those actions (like that of Respiration) were dependent only upon 

 the reflex function of the Spinal Cord. The experiments afforded the same 

 results, when made upon each class of Vertebrated animals ; and they have 

 been since repeated, with nearly corresponding effects, by Bouillard, Hertwig, 

 and by many other experimenters. 1 Wagner found that the chief symptoms 

 produced in Pigeons from which he had removed the whole or the greater 

 part of the Cerebellum were 1. A remarkable tendency on the part of the 

 animal to throw itself on one side, and to keep the legs completely extended, 

 with an indisposition to move them, though it was still evidently capable of 

 flexing them by an effort of the will. 2. Torsion of the head on the neck. 

 3. Persistent trembling of the muscles of the body generally, resembling 

 paralysis agitans. 4. Vomiting frequently accompanied by liquid alvine 

 evacuations ; and 5. The animals became thinner, the feathers fell off, and 

 the temperature was much depressed. No symptoms were observed having 

 reference to the generative organs. The perception of sensations and the 

 performance of psychical operations appeared to be perfect; and though the 

 voluntary control over the muscles was somewhat impaired, it was manifestly 

 not altogether lost. Hertwig, and especially Dal ton, 2 have moreover shown 

 that in pigeons a very considerable portion (two-third?) of the Cerebellum 

 may be removed with so little disturbance of the voluntary movements, that 

 after a few days the effects were scarcely, if at all perceptible. Lu.ssana ob- 

 serves that the results of irritation of the Cerebellum are usually vomiting, 

 cephalalgia, convulsions, and affections of the pupil, strabismus, amblyopia, 

 etc. ; and he believes that in every case of extensive disease of the (Yivbt'llum 

 there are concurrent symptoms of disorder of the muscular movements, in- 

 dicative of defect or absence of the "muscular sense." 



")(!). It was further affirmed by Magendie, that the removal of the Cere- 

 bellum, or the infliction of a deep wound in its substance on both sides, occa- 

 sions the animal to move backwards as if by an irresistible impulse; and this 

 he attributed to the retrograde power of the Corpora Striata, which now acts 

 wit lion) its due balance. That such a movement does xoiiii'tiitii'* present 

 itself after such injuries as have been described, cannot be questioned, the 



1 See Wanner, in Bro\vn-Si'c|iiard's Journal de la Physiol., 18G1, pp. 2'25 and 404; 

 Luss-ma in idem, lxi;-j, ,,. -Us, ISC,:;, p. 17() ; MM. Lcve'n and Ollivier, Arcliiv. Gen. 

 <! Mi'-d., NTov. and Ore. ISii-J; Dal ton, American Journal of Med. Science-, 1801, vol. 

 xli, p. s:; ; Brown-Sequard, Central Nervous System, isr.o. 



2 Amer. Journ. oi .Mrd. Sciences, 1861, vol. 'xli, p. 83. 



