378 SEA-SIDE STUDIES. 



animals. No one even slightly acquainted with the present 

 state of science will fail to see the importance of such a result. 



In the first place, it does away with many of the difficul- 

 ties which have puzzled anatomists when unable to trace 

 fibres to their termination in cells. In the second place, it 

 may throw light on the startling discovery of M. Brown- 

 Sdquard, that the transmission of impressions along the 

 spinal chord is not due to the fibres of the posterior columns, 

 nor indeed to the fibres of either of the columns, but entirely 

 to the grey matter of the chord. The astonishment excited 

 by this discovery, which utterly destroys the doctrine pro- 

 mulgated by Sir Charles Bell, and accepted by all Europe, 

 seems so to have absorbed attention that its effect upon the 

 general theory of nervous transmission has escaped remark. 

 A few sentences may put the reader in possession of the capi- 

 tal points in this discovery. 



The spinal chord is composed of six columns of fibres, and 

 a central mass of vesicular matter ; two of the columns are 

 called the anterior, two posterior, and two lateral. Imagine 

 a bundle of six sticks enclosing a mass of pith, and a rude 

 conception of tlie arrangement of these colmnns will be 

 formed. When Sir Charles Bell came forward with his views, 

 the almost universal opinion was that the spinal chord was a 

 large nerve-trunk, presiding, like other nerve-trunks, over 

 both sensibility and motion. Every one knew that there 

 were nerves of sensation and nerves of motion ; but no one, 

 till Lamarck, seems to have conceived that this diversity of 

 function must be owing to the diversity of their central 

 origin ; and Lamarck only conceived the idea as an a priori 



