297 



April 14, 1853. 



COLONEL SABINE, R.A., Treas. & V.P., in the Chair. 



The Right Honourable Viscount Palmerston was admitted into 

 the Society. 



A paper was read, entitled " On certain Functions of the Spinal 

 Chord." By J. Lockhart Clark, Esq. Communicated by E. Solly, 

 Esq., F.R.S. Received March 15. 



These investigations were undertaken by the author partly with 

 the viev/ of settling the long- agitated question whether all the roots 

 of the spinal nerves terminate in the spinal chord, or whether any 

 part of them ascend within the white or grey columns to the brain. 

 The preparations employed for this purpose were made according to 

 the new method described in the author's former communication, 

 Phil. Trans. 1851, Part 2; and the animals selected were the Ox, 

 Calf, Cat, Rat, Mouse and Frog. Of the spinal chord of the Cat, 

 he has succeeded, after much trouble, in rendering transparent 

 longitudinal sections -^th of an inch in thickness, and more than 

 two inches in length, including the roots of four or five pairs of 

 nerves. 



The principal results at v/hich the author has arrived are as fol- 

 lows : — 



That the posterior roots of the spinal nerves consist of three kinds ; 

 two of these enter the posterior grey substance at right angles, and 

 the third kind with different degrees of obliquity upwards, a small 

 proportion of the latter taking a longitudinal course and becoming 

 lost in the posterior white columns. 



That in no instance were any of the fibres of the anterior roots 

 seen to ascend with the anterior white columns, before they entered 

 the grey substance. 



That besides the transverse bundles that form the anterior roots, 

 a continuous system of exceedingly fine transverse fibres issue from 

 the anterior grey substance and become lost as they proceed towards 

 the surface of the chord. 



That from the preceding facts, it may be inferred that nearly all, 

 if not the whole of the fibres composing the roots of the spinal nerves 

 proceed at once to the grey substance of the chord ; and that if any 

 of them ascend directly to the brain, it must be those only of the 

 posterior roots which run longitudinally in the posterior white 

 columns. 



That the communication between the sensorium and the spinal 

 nerves is not established by the posterior white columns, but by the 

 antero -lateral columns, especially the lateral. 



That many of the fibres which belong respectively to the anterior 

 and posterior roots in different regions of the chord, terminate there 

 by forming with each other a series of loops of various sizes and 

 lengths ; and that it is not improbable that some of them may reach 

 even as far as the brain, as it is well known that the formation of 

 loops is one mode in which nerve-fibres do terminate there. A por- 



