THE SPINAL COED. 675 



adequate ground for the assertion, that the movements which may be called 

 forth by stimulation in the states of profound Sleep or Coma, are not to be held 

 to indicate that 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 sensoriuni, or which are powerless to affect the con- 

 sciousness even when they arrive there. [That the source of the reflex faculty 

 is to be looked for in the spinal cord itself, may be shown by the simple experi- 

 ment of rapidly exciting reflex action in a decapitated animal. It will be found 

 that, after exhausting it entirely, it will reappear and become as energetic as 

 before, provided the circulation is kept up in the cord. Moreover, if the action 

 of the spinal cord be rapidly excited, it is capable of producing an amount of 

 muscular contraction in a frog's leg sufficient to raise, in divided portions, a 

 weight of twelve pounds to a height of two lines. In a pigeon it can produce 

 an amount of contraction sufficient to raise, also in divided portions, fifty pounds 

 to the height of two inches in the course of an hour. That the reflex power is 

 not derived from the medulla oblongata, as was supposed by Arnold and 

 Flourens, is shown by the fact that it (the reflex power) is very weak in frogs 

 immediately after the separation of the cord from the medulla oblongata, and 

 that it increases afterwards to such a degree as to elevate by muscular contrac- 

 tion more than double the weight which the influence of the will could ac- 

 complish before the division. 



The injection of blood into the carotid of an animal recently dead by hemor- 

 rhage, and in whom reflex action had ceased, is speedily followed by a return 

 of that faculty of the cord, even after its separation. 1 ED.] These reflex actions 

 of the Spinal Cord have much more regularity and apparent purposiveness in the 

 lower Vertebrata, approaching in this respect to the reflex actions of the gan- 

 glionic column of Articulata, than they have in Man. For we see that when a 

 portion of his Spinal Cord is withdrawn from the influence of the Cerebrum, the 

 reflex actions that may be excited in the limbs with which it has nervous connec- 

 tion, are disorderly and purposeless in their character, notwithstanding that they 

 may be powerful; whilst, on the other hand, if a Frog be decapitated, its body is 

 still supported on its limbs in the usual position, and will recover this if it be 

 disturbed ; irritation of the feet will cause it to leap ; tickling the cloaca with 

 a probe will excite efforts to push away the instrument ; in fact, the movements 

 altogether show almost as much adaptiveness and regularity, as if the mind of 

 the animal were engaged in directing them. It would seem absurd, however, to 

 attribute any psychical agency to the Spinal Cord ; since, to remove these move- 

 ments from the category of automatic actions, we must attribute to that organ 

 a power, not merely of feeling, but also of choosing and directing movements 

 with a conscious design ; and all our knowledge of the functions of the Nervous 

 System tends to the belief that such attributes belong only to the Brain. 

 Hence, the adaptiveness of the reflex actions performed by many of the lower 

 tribes of animals can only be held to indicate that a larger share of such 

 adaptation is effected in them by what may be termed the mechanism of their 

 nervous centres, and that less is left to voluntary choice and direction, which 

 can only be safely trusted where a considerable amount of Intelligence exists to 

 guide it. That the existence of even the most perfectly adapted combination of 

 different muscular actions, all obviously bearing upon a definite object, does not 

 in itself justify the attributing this combination to a design or voluntary choice 



thological portion of the Hunterian Museum drawn up by Mr. Paget), there was the re- 

 cord of a case of paraplegia, in which it appeared that Hunter had witnessed reflex move- 

 ments of the legs in which sensation did not participate. When the patient was asked 

 whether he felt the irritation by which the motions were excited, he significantly replied 

 glancing at his limbs " No, Sir, but you see my legs do." 

 1 [Phil. Med. Examiner, N. S. vol. viii. No. xcii. p. 482.] 



