180 STUDIES IN ELECTRO-PHYSIOLOGY: 



muscle by an impulse originating in a constant or direct 

 current of normal potential. In both cases the motor 

 nerves convey the impulse or impulses to muscular fibres, 

 but the muscular response cannot, in my judgment, be 

 identical. 



" When the motor nerve is degenerated, and will not 

 respond to any form of electrical stimulation, the muscle 

 loses all its power of response to induction shocks. The 

 nerve-degeneration is accompanied by their rapid wasting, 

 and any power of response to f aradism they possessed in the 

 normal state is lost." 



That naturally follows. 



" But the response of the muscle to the constant 

 current remains, and is, indeed, more ready than in health." 



The meaning here is somewhat obscure. If it is sought 

 to convey the constant current to the muscle by means of 

 the degenerated motor nerve, and there is a complete break 

 of continuity, no current could pass and no response be 

 given. If, however, the sarcomeres are stimulated directly 

 the normal resistance of the motor nerve would be elimi- 

 nated and the muscle should certainly give a readier 

 response. This may be what is meant, because we have 

 been told that " when the motor nerve is degenerated and 

 will not respond to any form of electrical stimulus the muscle 

 loses all its power of response to induction shocks." But 

 the phenomenon may be due to the end-organs, as well as 

 the motor nerve-fibres, transforming or modifying in 

 normal health an induction shock a momentary impulse 

 so that the muscle could respond to it, and that after 

 degeneration no such modification could occur. 



" Suppose a patient comes before one with muscular 

 paralysis. This may be due to disease of the nerves, of the 

 cells of the spinal cord, or of the brain. If the paralysis is 

 due to brain disease, the muscles will be slightly wasted 

 owing to disuse, but the electrical irritability of the 



