in ELECTRICAL EXCITATION OF MUSCLE '299 



THE ELECTRICAL EXCITATION OF UNFIBRILLATED PROTOPLASM 



The action of the electrical current upon muscle has long 

 since attracted the attention of physiologists ; the consequences 

 of the passage of current through unfibrillated protoplasm (which 

 are of the greatest interest in a theoretical connection) have until 

 lately been almost entirely disregarded, and only a few isolated 

 observations indicate that we are here concerned with facts of 

 wide-reaching significance. 



In connection with certain theoretical views as to the causa- 

 tion of plasmatic movements of the streaming movements in 

 vegetable cells in particular Bequerel examined the effect of a 

 strong current flowing through a spiral wire round a decorticated 

 cell of Chara. ISTo effect was produced, whether the axis of the 

 wire-coil was parallel, or at right angles, to the axis of the cell. 

 Later experiments were equally negative ; no action at a distance 

 of the current upon any sort of excitable protoplasm could be 

 detected, so that it may be taken as certain that such an action, 

 generally speaking, does not exist. 



In consequence of the direct action of weak induction 

 currents, Klihne and Engelmann observed the movement of 

 Amoebas to be at first arrested and then resumed after a short 

 time. With stronger induction shocks the Amoeba? assumed a 

 globular shape by the withdrawal of all their pseudopodia, which 

 at once arrested all molecular movement. Finally, with very 

 strong excitation the sphere of protoplasm may collapse and 

 extrude its endoplasm, which is equivalent to the total destruction 

 of the animal (45). 



Ehizopods with numerous long and slender pseudopodia with- 

 draw these when electrically excited, and in this case it is especi- 

 ally remarkable that those i^scudopodia which lie at right angles to the 

 lines of current show no change, or at any rate change only with far 

 stronger currents than those which lie parallel to it, a fact which 

 calls to mind the similar behaviour of muscle under similar con- 

 ditions. Klihne (46), when tetanising Actinosphaerrum with the 

 alternating currents of an induction coil, observed that the 

 pseudopodia lying along the line between the tivo electrodes soon became 

 varicose ; the granular protoplasm along the axial ray gathered 

 itself into little spheres and spindles, which flowed towards the 



