PHILOSOPHICAL TRANSACTIONS. 



XIII. Continuation of the Paper on the Relations between the Nerves of Motion and of 

 Sensation^ and the Brain ; more particularly on the Structure of the Medulla oblon- 

 gata and the Spinal Marrow. By Sir Charles Bell, F.R.S. Sgc. §c. 8sc. 



Received March 25, — Read April 30, 1835. 



In this paper it will be necessary to enter on minute details of the anatomy ; but 

 they regard a subject hitherto untouched, although essential to the comprehension of 

 the nervous system, without which, indeed, it could not be said that we had a know- 

 ledge of the nerves as a system. 



The author has advanced, by slow and laborious researches, from observing the 

 general arrangement of the nerves as they lie in the body, to the investigation of par- 

 ticular nerves and their endowments ; and, finally, to the examination of these parts 

 in the centre of the system, the brain and spinal marrow, which enables him to assign 

 the reason of that perfect symmetry which reigns through the whole. 



The subjects of his last paper have been examined again and again by dissection, 

 and reviewed in every aspect. They have been found correct in every particular. 

 But they necessarily lead to further investigation : they point more especially to a 

 minute inquiry into the structure of the spinal marrow, and its relations to the en- 

 cephalon on the one hand, and to the origin of the nerves on the other. 



It might be imagined that the author of this paper had, in these inquiries, fol- 

 lowed his preconceived notions ; but it has not been so. On the contrary, when 

 in search of the explanation of certain phenomena, he discovered a fact in the 

 structure which diverted him from his design, and carried him in a new course of 

 inquiry ^, 



In an anatomical investigation of so much delicacy, it is necessary, in order to un- 

 derstand the descriptions, that he who follows it by dissection should have the parts 

 presented exactly in the same aspect, and trace them in a prescribed manner. When 



* The paper on the Voice was undertaken as a preface to the investigation of the accessory respiratory nerves. 

 In following that subject, the author found it indispensable to deviate into this inquiry, which proves to be the 

 more important of the two. 



MDCCCXXXV. 2 L 



