121' M. Flourens o]i the Navoiis System. 



culty of flying; then, that of walking; and, lastly, that of 

 holding itself in the upright posture — and this, also, is only 

 gradually lost. The animal begins to be incapable of remain- 

 ing erect upon its legs ; then its feet become unable to sustain 

 it. At last every fixed position becomes impossible : it makes 

 incredible efforts to attain some particular posture, without 

 being able to accomplish it; and yet, when exhausted by 

 fatigue it seems desirous of obtaining some repose, its senses 

 are so clear, that the least gesture of the operator produces a 

 recommencement of its contortions, without the slightest con- 

 vulsive motion, so long as the tubercula or the medulla oblongata 

 remain uninj ured." 



We are not aware that any physiologist has hitherto pro- 

 duced any experiments which exhibited the slightest resem-^ 

 blance to these singular phasnomena. Experiments on the ce- 

 rebellum of quadrupeds, especially if adult, are extremely diffi- 

 cult, on account of the thick bony parietes which it is necessary 

 to remove, and the large vessels which are unavoidably opened. 

 Besides, most experimenters have conducted their operations 

 according to some established system, and have been too apt 

 to find that which they wished to discover ; and, assuredly, 

 none have hitherto surmised that the organ which balances 

 and regulates the motions of progression, was the cerebellum. 

 This discovery, if its universality be established by carefully 

 repeated experiments, cannot but confer the greatest honour 

 on the yoimg observer whose work we have just analysed. 



As to what remains, the Academy is as capable of judging 

 as we are, that, with the exception of the superfluous altera- 

 tions of terms, and of certain well-known facts which the au- 

 thor was compelled to adduce in order to give his work an air 

 of uniformity, this Memoir ofi^ers more precise details of old 

 observations than we have hitherto possessed ; and contains 

 others whose novelty and importance are equally worthy our 

 attention. 



The integrity of the cerebral lobes is indispensable for the 

 exercise of sight and hearing: when they are destroyed, the 

 will is no longer manifested by acts of spontaneous volition. 

 Nevertheless, if the animal be excited from without, it executes 

 regular acts of locomotion, as if endeavouring to avoid the 

 immediate pain and inconvenience. But these motions are 

 inadequate to the end; very probably because the memory, 

 which disappeared with the removal of the lobes which seem 

 to be its seat, no longer supplies the basis or elements of 

 judgement. For the same reason, these motions are followed 

 by no decisive result; because the impression which produced 

 them lca>e.s no trace on the memoiy, nor excites any durable 



volition. 



