in ELECTRICAL EXCITATION OF MUSCLE 305 



living. " If the current is broken when the process of destruction 

 has involved only a small portion of the entire mass, the disinte- 

 gration ceases to progress, whilst a swelling of granular disinte- 

 grated protoplasm suddenly breaks out at the kathode, similar to 

 that which appeared at the anode at the closure of the circuit. 

 But this process at the kathode makes no further progress after- 

 the opening of the circuit." The smallest undestroyed portion of 

 protoplasm is sufficient to form a new individual on a smaller 

 scale. With weaker currents the anodic effects may be preceded 

 by a long, latent period (1 minute or more). On Pelomyxa, 

 according to Verworn, the action of induced currents, and of con- 



Fio. 98. Pelomyxa palustris. Polar excitation effects with passage of a constant current. 



(Verworn.) 



stant currents of brief duration, is particularly striking ; at a 

 given current strength only a kathodic break excitation is obtained, 

 whereas with currents of longer duration an anodic make excita- 

 tion makes its appearance. The effects are thus contrary to 

 those obtained on muscle, not only as regards the law of polar 

 excitation, but also as regards the manner in which make and 

 break excitation depend upon the duration of the exciting current. 

 Various forms of Amoeba, investigated by Yerworn (A. Umax, 

 verrucosa, and diffluens), exhibited some apparently considerable 

 divergences from the phenomena observed on Pelomyxa : at any 

 rate with the strength of current made use of, instead of the 

 destruction of the anodic pole of the body, a protrusion (forma- 

 tion of pseudopodia) was produced at the kathodic pole. At make 



X 



