SUR LES PROPRIÉTÉS DES RACINES DES NERFS RACHlblENS. 531 



Ce passage résume toutes les expériences rapportées par Bell 

 dans son premier essai. A en juger par la relation que M. Vuîpian 

 donne de ces expériences, il semblerait qu'il n'ait pas consulté 

 l'œuvre originale. Il parle de la première expérience sur la moelle 

 épinière, comme ayant été faite sur un lapin récemment tué, 

 chose dont il n'est fait aucune mention dans l'original. Il dit éga- 

 lement que la première expérience sur les racines des nerfs rachi- 

 diens fut pratiquée sur un animal vivant (1), ce qui n'est point 

 mentionné dans l'original. Bell parle, au contraire, de couper les 



put the matter to proof by experiment. But how is this to be accomplished, since any 

 direct experiment upon the brain itself must be diffieult if not impossible. I took this 

 Mew of the subject. 



» The medulla spinalis has a central division, and also a distinction into anterior 

 and posterior fasciculi, corresponding with the anterior and posterior portions ofthe 

 brain. Further we can trace down the crura of the cerebrum into the anterior fasci- 

 culus of the spinal marrow, and the crura of the cerebellum into the posterior 

 fasciculus. I hought that here I might have an opportunity of touching the cere- 

 bellum, as it were, through the posterior portion of the spinal marrow, and the 

 cerebrum by the anterior portion. To this end I made experiments which, though 

 they were not conclusive, encouraged me in the view I had taken. 



» I found that injury done to the anterior portion of the spinal marrow, convulsed 

 the animal more certainly than injury done to the posterior portion ; but I found it 

 diffieult to make the experiment without injuring both portions. 



» Next, considering that the spinal nerves have a double root, and being of 

 opinion that the properties of the nerves are derived from their connections 

 with !he parts of the brain, I thought I had an opportunity of putting my opinion to 

 the test of experiment, and of proving at the same time lhat nerves of différent 

 endowments were in the same cord, and held together by the same sheath. 



» On laying bare the roots of the spinal nerves, I found that I could eut across 

 the posterior fasciculus of nerves, which took ils origin from the posterior portion 

 ofthe spinal marrow without convulsing the muscles ofthe back; but that on tou- 

 ching the anterior fasciculus with the point of a knife, the muscles of the back were 

 immediately convulsed. Such were my reasons for concluding that the cerebrum and 

 the cerebellum were parts distinct in function, and that every nerve possessing a 

 double function obtained that by having a double root, i now saw the meaning ofthe 

 double connection of the nerves with the spinal marrow; and also the cause of that 

 seeming intricacy in the connections of the nerves throughout their course, which 

 were not double in their origins. 



» The spinal nerves being double and having their roots in îhe spinal marrow, of 

 which a portion cornes from the cerebrum and a portion from the cerebellum, they 

 convey the attributes of both grand divisions of the brain to every part ; and therefore 

 the distribution of such nerves is simple, one nerve supplying its distinct part » 

 (p. 50-52). 



(1) Vulpian, op. cit., p. 111. 



