70 THIRD REPORT — 1883. 



fully established, opposed as they are by those of so skilful an 

 experimenter as Magendie. Indeed, while Flourens conceives 

 the cei'ebellum to preside over motion, MM. Foville and Pinel 

 Grandchamps attribute to it the directly opposite function of 

 sensation : and this doctrine seems to derive some support from 

 anatomical disposition ; for it has been proved by Tiedemann 

 that the cerebellum is nothing more than an expansion or pro- 

 longation of the corpora restiformia, and posterior columns of 

 the spinal medulla, which columns have been shown by Sir 

 Charles Bell to have the office of conveying sensations. But 

 it is not the less true that all recent experiments, even those of 

 Fodera and Magendie, point to some connexion between the 

 cerebellum and the power of voluntary motion. In the present 

 state of our knowledge it would be unsafe to contend for more 

 than the probable existence of some such general relation. 



This, then, is all that seems deserving of confidence respect- 

 ing the functions of the cerebellum itself. But there are some 

 singular phenomena which, though residing in other structures 

 more or less near to the cerebellum, are so analogous to those 

 already described as to call for notice in this place. Magendie 

 has described * the results of injury to the crura cerebelli of a 

 rabbit. Complete division of the right crus was followed by 

 rapid and incessant rotation of the body upon its own axis, from 

 left to right. This singular motion having continued two hours, 

 Magendie placed the rabbit in a basket containing hay. On 

 visiting it the following day he was surprised to find the animal 

 still turning round as before, and completely enveloped in hay. 

 The eyes were rigidly fixed in different lines; that of the injured 

 side being directed forwards and downwards, that of the other 

 side backwards and upwards. If both crura were divided, no 

 motion followed. Magendie hence concluded that these ner- 

 vous cords are the conductors of impulsive forces which coun- 

 terbalance one another, and that from the equilibrium of these 

 two forces result the power of standing, and even of maintaining 

 a state of rest, and of executing the diflTerent voluntary motions. 

 The inquiry naturally presented itself, whether these forces 

 are inherent in the crura themselves, or emanate from the cere- 

 bellum or some other source. To determine this question, 

 portions of substance were removed from both sides of the 

 cerebellum, but unequally, so as to leave intact | on the left 

 side and ^ only on the right. The animal rolled towards the 

 right side, and its eyes were fixed in the manner already de- 

 scribed. But the left crus being divided, the animal rolled to 



* Journal tie Physiologie, torn. iv. 399. 



