396 MUSCULAR MOTION. 



Lastly, the motions of the tongue or of articulation are sometimes 

 alone affected in apoplexy. The seat of this variety^ of muscular 

 motion has been attempted to be deduced from pathological facts. M. 

 Foville places it in the cornu ammonis and temporal lobe ; and M. 

 Bouillaud 1 in the anterior lobe of the brain, in the medullary substance, 

 the cineritious being concerned, he conceives, in the intellectual part 

 of speech. 



It is sufficiently obvious, from the whole of the preceding detail, 

 that the mind must still remain in doubt, regarding the precise part of 

 the encephalon engaged in the functions of muscular motion. The 

 experiments of M. Magendie are, perhaps, more than any others, en- 

 titled to consideration. They appear to have been instituted without 

 any particular bias; to subserve no particular theory; and are supported 

 by pathological facts furnished by others. He is, withal, a practised 

 experimenter, and one to whom physiology has been largely indebted. 

 His vivisections have been more numerous, perhaps, than those of any 

 other individual. His investigations, however, on this subject clearly 

 show, that owing to the different morphology of animals, we cannot 

 draw as extensive analogical deductions from comparative anatomy and 

 physiology as might be anticipated. The greatest source of discre- 

 pancy, indeed, between his experiments and those of MM. Rolando and 

 Elourens, appears to have been the employment of different animals. 

 Where the same animals were the subjects of the vivisections, the 

 results were in accordance. The experiments demand careful repe- 

 tition, accompanied by watchful and assiduous observation of patho- 

 logical phenomena ; and, until this is effected, we can, perhaps, scarcely 

 feel justified in deducing, from all these experiments and investigations, 

 more than the general propositions regarding the influence of the 

 cerebro-spinal axis on muscular motion, which we have enunciated. .It 

 has been already shown, however, that strong evidence may be adduced 

 in favour of the view of M. Flourens, that the cerebellum is the regu- 

 lator or co-ordinator of the muscular movements, 2 and it is the one now 

 embraced by the generality of physiologists ; although it must be ad- 

 mitted, with M. Longet, 3 that " the precise determination of the uses 

 of the cerebellum is one of the most embarrassing problems in physi- 

 ology." 



The nerves, it has been shown, are the agents for conducting the 

 locomotive influence to the muscles. At one time, it was universally 

 believed, that the same nerve conveys both sensation and volition; but 

 the pathological cases, that not unfrequently occurred, in which either 

 sensation or voluntary motion was lost, without the other being neces- 

 sarily implicated; and, of late years, the beautiful additions to our 

 knowledge of the spinal nerves, for which we are mainly indebted to Sir 

 Charles Bell, 4 and M. Magendie, 5 have satisfied the most sceptical, that 



1 Magendie's Journal de Physiologic, torn, x.; also, Belhomme, Archiv. General, de Mede- 

 cine, Mai, 1845. 



2 Longet, Anatomie et Physiologie du Systeme Nerveux, i. 703, Paris, 1842. 



3 Traite de Physiologie, ii. 272, Paris, 1850. 



4 The Nervous System, &c., 3d edit., Lond., 1837, and Narrative of the Discoveries of Sir 

 Charles Bell in the Nervous System, by A. Shaw, London, 1839. 



5 Precis Elementaire, &c., 2de edit., i. 216. 



