284 



Scientific Proceedings (129) 



Abstracts of Communications. 

 Minnesota Branch 



Tenth meeting. 



Minneapolis, Minnesota, February 14, 1923. 



136 (2096) 



Effects of electricity on noctilucca. 

 By E. P. LYON 



[From the University of Minnesota, Minneapolis, Minnesota."] 



I. A brief direct current or a single break induction shock 

 causes the protoplasm to pull away from the cell wall. The 

 effect is usually cathodal; sometimes anodal, particularly when 

 the aboral part of the cell is toward the anode. Sometimes 

 the effect is seen simultaneously at both poles. 



The phenomenon gives the impression of contraction and 

 breaking of the strands of protoplasm attached to the cell wall 

 or pellicle. A clear area looking like a blister filled with liquid 

 is formed, the shape being dependent on the extent of proto- 

 plasm pulled away from the wall and the resulting disturbance 

 of protoplasmic stresses. If the bleb is small, it may be pinched 

 off later without further deformation of the organism. If the 

 bleb is large, gradually the protoplasm pulls loose all the way 

 around, the strands being seen to give way one or a few at a 

 time. Finally the whole protoplasm shrinks into a shapeless 

 mass around the oral end. Recovery is sometimes possible, but 

 probably involves the formation of a smaller cell with new cell 

 wall. 



It appeared certain that the strands are solid structures along 

 which a considerable tension is exerted. 



A short tetanizing current gives blisters at both poles. 



II. If such a dye as phenolsulphonpthalein was placed in 

 the sea water between the cells of a dense culture, the color could 

 be observed for fifteen minutes or more. But if a break shock or 

 short tetanizing current was passed, the color disappeared at 

 once. The cell juice of Noctilucca is strongly acid (Ethel Brown 

 Harvey, Carnegie Reports, Marine Biology, 1917). Stimula- 



