FUNCTIONS OF THE SPINAL CORD. 639 



followed its natural course of diffusion, being rendered manifest in this case 

 by the convulsions which were excited, in consequence of increased activity 

 of the motor function of the Cord. It is further interesting to remark, that, 

 in the foregoing case, the reflex actions were very feeble during the first seven 

 day.-, in comparison with their subsequent energy ; being limited to slight 

 movements of the feet, which could not always be excited by tickling the 

 soles. (In another case of very similar character, it was three days after 

 the accident before any reflex actions could be produced.) It is evident, 

 then, that the Spinal Cord must have been in a state of concussion, which 

 prevented the manifestation of its peculiar functions, so long as this effect 

 lasted ; and it is easy, therefore, to perceive, that a still more severe shock 

 might permanently destroy its power, so as to prevent the exhibition of any 

 of the phenomena of reflex action. 



505. So many cases of this kind have now occurred, that it may be con- 

 sidered as a demonstrated fact, that the Spinal Cord, or insulated portions 

 of it, may serve in Man, no less than in the lower animals, as the centre of 

 very energetic reflex actions, when the Encephalic power which ordinarily 

 operates through it is suspended or destroyed, or when it is prevented from 

 influencing the Spinal nerves by such an injury to the Cord above their 

 points of connection with it, as prevents the transmission of nervous polar- 

 ity : and it is further evident that these movements are not more dependent 

 upon Sensation than they are upon the Will, since they may be excited 

 without the consciousness of the individual, even when this is fully directed 

 to the part. 1 And we thus have adequate ground for the assertion, that the 

 movements which may be called forth by stimulation in the states of pro- 

 found Sleep or Coma, are not to be held to indicate that conscious sensation 

 is even momentarily excited ; since we know that the reflex power of the 

 Spinal Cord may be called into action by impressions which do not travel 

 onwards to the sensorium, or which are powerless to affect the consciousness 

 even when they arrive there. These abnormal reflex actions of the Spinal 

 Cord of Man, though often powerful, have much less regularity and ap- 

 parent purposiveness, than have the movements executed by the lower Verte- 

 brata (as the Frog, 501) after decapitation or section of the cord; the 

 latter approaching, in respect to these qualities, to the reflex movements of 

 Articulated Animals as is well seen in the following experiment, which is 

 much relied on by those who hold that the Spinal Cord is the seat of sen- 

 sorial functions. 2 If a frog be decapitated and acetic acid be applied over 

 the internal coudyle of the femur, the animal will wipe away the acid with 

 the foot of the same side ; but if this be cut off, after some ineffectual efforts, 

 and a short period of hesitation, it will perform the same action with the 

 foot of the opposite side. The explanation seems to be that (in accordance 

 with the laws laid down by Pflu'ger) when the skin of one side of the body 

 is irritated the motor nerves of that side respond to the impression, but this 



1 The Author is informed by his friend Mr. Paget, that among the notes left by 

 John Hunter (which furnished some of the materials for the admirable Catalogue of 

 the Pathological portion of the Hunterian Museum drawn up hy Mr. Paget), there 

 was the record of a case of paraplegia, in which it appeared that Hunter had wit- 

 nessed reflex movements of the legs in which sensation did not participate. When 

 the patient was asked whether he ~felt the irritation by which the motions were ex- 

 cited, he significantly replied glancing at his limbs, "No, sir; but you see my 

 legs do." 



2 See Pfliiger, Die sensorischen Functionen des Ruckcnmarks, Berlin, 18-53; see 

 also an able review in the Med -Chir. Review for Jan. 1804, in which the above ex- 

 periment is quoted. The doctrine of the independent volitional as well as sensorial 

 power of the Spinal Cord is ingeniously sustained in Mr. G-. H. Lewes's Physiology 

 of Common Life, vol. ii ; whilst the opposite side is taken in a review upon that work 

 contained in the Med. -Chir. Review, vol. xxvi, 1860, p. 423. 



