GENERAL PROPERTIES OF THE SPINAL CORD. 273 



tions, and in this wise they are in communication with the 

 nerve-cells." 



General Properties of ike Spinal Cord. 



In treating of the functions of the spinal cord, we shall 

 consider, first, its general properties, as shown by direct 

 stimulation of its substance in different situations ; next, its 

 functions as a conductor ; and, finally, its action as a nerve- 

 centre. 



The first indication that the different columns of the 

 cord are possessed of different properties is to be found in 

 the experiments of Magendie. This observer, however, was 

 somewhat indefinite in his conclusions, particularly with re- 

 gard to the anterior columns ; but he stated distinctly that 

 the posterior columns are sensitive : " If we lay bare the 

 cord in any portion of its extent, and if we touch, or prick 

 slightly posteriorly, the two fasciculi situated between the 

 posterior roots, the animal gives signs of exquisite sensibil- 

 ity ; if, on the other hand, we make the same trials upon 

 the anterior portion, the evidences of sensibility are scarcely 

 apparent." a Since this time, numerous observers have ex- 

 perimented upon the different columns, both at the surface 

 and in the deep portions of the cord, with varying results. 

 These observations we do not propose to discuss fully in 

 detail, but will refer simply to certain of them, made within 

 a few years, with the advantage of a knowledge of the 

 reflex phenomena following irritation of the cord, which 

 must always be taken into consideration in such experiments. 



In 1861, Chauveau, as the result of numerous experi- 

 ments performed upon horses, cows, sheep, goats, rabbits, 

 pigs, dogs, and cats, stated that the antero-lateral columns 

 of the cord were inexcitable, both at the surface and in the 



1 GERLACH, in STRICKER, Handbuch der Lehre von den Geweben, Leipzig, 1868, 

 S. 691, et seq. 



MAGEXDIE, Note sur le siege du mouvement et du sentimerd dans la moelle 

 epinere. Journal de physiologic, Paris, 1823, tome iiL, p. 163. 



