ii8 THE SPINAL CORD AND CEREBELLUM 



appear to differ in function. Besides the fibres of this 

 column, derived from the posterior roots of the spinal 

 nerves, others are said to join it from the cells in the 

 posterior horn of the gray matter, some of them 

 proceeding from Clarke's column.* The fibres in 

 Burdach's column are for the most part thick.t 

 Although certain fibres of the posterior columns con- 

 stitute an uninterrupted path for sensory impulses 

 to the medulla oblongata, others, which are very 

 numerous, pass into the gray matter of the cord at 

 various levels, I the former being said to be chiefly 

 fine, the latter principally coarse fibres. § If we admit 

 Bechterew's view that the posterior column carries 

 only impulses of muscular sensibility, we have still 

 to account for the difference in calibre between the 

 two sets of fibres. Moreover, if the impulses of 

 muscular sensibility from the skeletal muscles pass 

 along the posterior column, what may be the path of 

 similar impulses proceeding from the muscular coats 

 of the intestines ? In the usual course of things, we 

 are not aware of the movements of these organs, but 

 the conclusion to which this fact leads is that the 

 sensory system is not in this case connected with the 

 cerebrum, the great seat of all sensation. The sensa- 

 tion is unconscious. There seems to be no sufficient 

 reason for denying the existence of muscular sensory 

 impulses depending on cells in the spinal cord. 

 Motion, indeed, is so entirely bound up with sensa- 



* Bechterew, loc. ait, p. 37. t Ibid., p. 57. 



I Ibid., p. 60. § Ibid., p. 58. 



