152 



THE PHYSIOLOGY OF NERVE 



traction (C.C.C.) already obtained with the weak current, is, of course, 

 retained, but no effect is as yet in evidence on the break with the 

 cathode presenting. This cathodic opening contraction (C.O.C.) ap- 

 pears only after the strength of the current has been materially in- 

 creased by the addition of several cells. Attention should also be 

 called at this time to the fact that strong currents frequently give rise 

 to contracture-like reactions, which are designated as galvanotonus. 

 As far as human nerve and muscle are concerned, it will be seen, there- 



JV*fll.w!nari*| 



M. flexor carpi nlnaris 



M. flex, digitor. siib- 

 Itm, (digit! II et III) 



M. flex, digit, subl. 

 (digit! indicis et 

 minimi) 



Ntrvt ttlnaris 



I. flexor digits rain 



M. opponens digit 



min. 



M, lumbricales- 



M. flex. poll, brev, 



M. adductor polllc. brer- 



FiG. 90. — Motor Points in Upper Extremity. {Howell.) 



fore, that the gradual increase of the constant current brings forth 

 these contractions in the order indicated in the succeeding table : 



Galvanic current 



