STRUCTURE OF THE SPINAL CORD. 



389 



things in structural anatomy to determine the course of indi- 

 vidual nerve-fibres, or even of fasciculi of fibres, through even 

 a short distance of the spinal cord ; and it is only by the exam- 



Different views of a portion of the spinal cord from the cervical region, with the 

 roots of the nerves slightly enlarged (from Quain). In A, the anterior surface of the 

 specimen is shown, the anterior nerve-root of its right side being divided; in B, a 

 view of the right side is given ; in c the upper surface is shown ; in D, the nerve-roots 

 and ganglion are shown from below. 1, the anterior median fissure ; 2, posterior 

 median fissure ; 3, anterior lateral depression, over which the anterior nerve-roots 

 are seen to spread ; 4, posterior lateral groove, into which the posterior roots are seen 

 to sink; 5, anterior roots passing the ganglion : 5', in A, the anterior root divided ; 6, 

 the posterior roots, the fibres of which pass into the ganglion 6' ; 7, the united or 

 compound nerve; 7', the posterior primary branch, seen in A and D to be derived in 

 part from the anterior and in part from the posterior root. 



iuation of transverse and longitudinal sections through the 

 substance of the cord, such as those so successfully made by 

 Mr. Lockhart Clarke, that we can obtain anything like a cor- 

 rect idea of the direction taken by the fibres of the roots of the 

 spinal nerves within the cord. From the information afforded 

 by such sections it would appear, that of the root-fibres of the 

 nerve which enter the cord, some assume a transverse, others 

 a longitudinal direction : the fibres of the former pa^s hori- 

 zontally or obliquely into the substance of the cord, in which 



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