in ELECTRICAL EXCITATION OF MUSCLE 273 



muscle by the constant current, this ratio is reversed in 

 paralysed muscles at a certain degree of degeneration ("reaction 

 of degeneration "). Before giving a final judgment it would be 

 necessary here, as in fatigued muscle, to make further investiga- 

 tions with unassailable methods, for the conditions under 

 which alone the experiments in question can be tried in man, or 

 have been tried on other animals, by no means correspond 

 with the demands of an exact physiological method. On the other 

 side, there are so many results, derived from irreproachable ex- 

 periments upon different muscles and nerves, which are opposed 

 to the theory of a reversal of polar effects, that any supposed 

 exception must a priori encounter suspicion, and can only hope 

 for recognition if the conditions of experiment and all accessories 

 are perfectly simple and obvious. 



Among the visible manifestations of excitation which appear 

 in striated muscle, in consequence of the electrical current, must 

 be reckoned the so-called Porrct's effect or galvanic- muscle- wave. 

 Ku'hne (37), in 1860, first described this remarkable appearance. 

 A muscle with parallel fibres, traversed by a strong current, falls 

 into a characteristic wave-like, or flowing, movement, which 

 spreads in the direction of the positive current, and remains 

 localised to the intrapolar area. Kiihne only alludes tentatively 

 to a possible connection of this appearance with the Beuss-Porret 

 phenomenon of electric transfusion, but, on the other hand, he 

 expressly points out the " deep internal relation to what, with 

 electrical excitation, is termed a twitch." Du Bois-Reyrnond (38) 

 also recorded this wave as an excitation effect, the expression 

 of localised contraction proceeding from anode to kathode. The 

 whole appearance, indeed, recalls in a marked degree the fine 

 waves and ripples which sometimes appear in the frog's sartorius 

 with mechanical excitation also, and show directly that " the 

 wave is a form of muscular motion, which can arise without an if 

 excitation by current." Undoubtedly, waves of contraction of very 

 different heights may spread over the muscle ; " at one moment they 

 are enormously expanded, at the next so fine that to the naked 

 eye they only appear as a delicate ripple ; sometimes they run in 

 the single bundles quite independently of one another, so that 

 many swellings can be seen to spread simultaneously in different 

 directions ; sometimes a single swelling extends itself over a larger 

 area of the muscle surface" (Hermann, 3 9, p. 603). The velocity 



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