672 OF THE FUNCTIONS OF THE NERVOUS SYSTEM. 



throughout organized nature, which, the more it is studied, the more invariably 

 is found to guide to truth, could not be disproved. Whatever experiments on 

 decapitated animals were appealed to, in support of the doctrine that the Brain 

 contains the only seat of sensibility, could be met by a simple denial that the 

 Spinal Cord is everywhere as destitute of that endowment as it appears to be in 

 Man. The cases of profound sleep and apoplexy might be cited as examples of 

 reflex action without consciousness; but these have been met by the assertion 

 that in such conditions sensations are felt, though they are not remembered. It 

 is difficult, however, to apply such an explanation to the case of anencephalous 

 human infants (in which all the ordinary reflex actions have been exhibited, 

 with an entire absence of brain), without supposing that the Medulla Oblongata 

 is the seat of a sensibility which we know that the lower part of the Spinal 

 Cord does not possess; and of this there is no evidence whatever. Experiments 

 on the lower animals, then, and observation of the phenomena manifested by 

 apoplectic patients and anencephalous infants, might lead to the conclusion 

 that the Spinal Cord does not itself possess sensibility, and that its reflex actions 

 are independent of sensation. At this conclusion, Unzer, Prochaska, Sir Gr. 

 Blane, Flourens, and other physiologists, had arrived; but it was not until 

 special attention was directed to the subject by Dr. M. Hall, that facts were 

 obtained by which a positive statement of it could be supported. For the 

 question might have been continually asked If the Spinal Cord in Man be 

 precisely analogous in function to that of the lower Vertebrata, why are not its 

 reflex phenomena manifested, when a portion of it is severed from the rest by 

 disease or injury ? The answer to this question is twofold. In the first place, 

 simple division of the cord with a sharp instrument leaves the separated por- 

 tion in a state of much more complete integrity, and therefore in a state much 

 more fit for the performance of its peculiar functions, than it ordinarily is after 

 disease or violent injury ; and as the former method of division is one with which 

 the Physiologist is not likely to meet in Man as a result of accident, and which 

 he cannot experimentally put in practice, the cases in which reflex actions would 

 be manifested are likely to be comparatively few. But, secondly, a sufficient 

 number of such instances have now been accumulated, to prove that the occur- 

 rence is by no means so rare as might have been supposed; and that nothing is 

 required but patient observation, to throw a great light on this interesting 

 question, from the phenomena of disease. A most valuable collection of such 

 cases, occurring within his own experience, has been published by Dr. W. 

 Budd; 1 and the leading facts observed by him will be now enumerated. 



707. In the first case, paraplegia was the result of angular distortion of the 

 spine in the dorsal region. The sensibility of the lower extremities was ex- 

 tremely feeble, and the power of voluntary motion was almost entirely lost. 

 u When, however, any part of skin is pinched or pricked, the limb that is thus 

 acted on jumps with great vivacity ; the toes are retracted towards the instep, 

 the foot is raised on the heel, and the knee so flexed as to raise it off the bed ; 

 the limb is maintained in this state of tension for several seconds after the 

 withdrawal of the stimulus, and then becomes suddenly relaxed." " In gen- 

 eral, while one leg was convulsed, its fellow remained quiet, unless stimulus 

 was applied to both at once." " In these instances, the pricking and pinching 

 were perceived by the patient ; but 'much more violent contractions are excited 

 by a stimulus, of whose presence he is unconscious. When a feather is passed 

 lightly over the skin, in the hollow of the instep, as if to tickle, convulsions 

 occur in the corresponding limb, much more vigorous than those induced by 

 pinching or pricking ; they succeed one another in a rapid series of jerks, which 

 are repeated as long as the stimulus is maintained." " When any part of 



1 " Medico-Chirurgical Transactions," vol. xxii. 



