CAUSES OF NECROSIS 315 



extremely high rate of autolysis, one may ascribe the effects 

 either to a stimulating effect of oj-rays upon autolytic enzymes, 

 or, as Neuberg l does, to an inhibitive action of arrays and 

 radium rays upon the other intracellular enzymes without a 

 corresponding deleterious effect upon the autolytic enzymes. 

 This hypothesis agrees with the facts at hand, but more details 

 concerning the effects of these rays upon various enzymes are 

 needed. The long latent period before the appearance of ne- 

 crosis after exposure to x-rays is difficult to explain, and agrees 

 rather with the hypothesis of slow proliferative and obstructive 

 changes in the blood-vessels. 



Electricity. The effects of the electric current upon cells 

 are described by Davenport as follows : A weak constant cur- 

 rent causes a centripetal flowing of the protoplasm (in Aetino- 

 sphcerium) ; if the current is increased or long continued, the 

 cytoplasm of the pseudopodia becomes varicose, and droplets 

 are formed which soon burst, causing a collapse of the proto- 

 plasmic framework. Finally, the protoplasm on the anode side 

 begins to disintegrate, and the loose particles move toward the 

 positive electrode ; eventually the cell structure may be entirely 

 destroyed. If an alternating current is used, both anode and 

 cathode side of the cell are affected. In moving organisms 

 electric currents determine direction of motion, even certain 

 vertebrates (tadpoles, fish) being made to orient themselves 

 according to the current. The nucleus seems to be more sus- 

 ceptible to harm by electric currents than the cytoplasm 

 (Pfeffer 2 ), and there seems to be no oxidation-process involved 

 in cell destruction by electricity (as is the case with light rays), 

 for the effects are much the same in the absence of oxygen 

 (Klemm). Schmaus and Albrecht state that the effect of elec- 

 tricity upon protoplasm depends upon a loosening of the cohe- 

 sion and a solution of the constituents of the cell (vacuoliza- 

 tion), which last is, perhaps, due to direct chemical alterations. 

 It may be suggested that the electric current causes a migration 

 of ions toward one or the other pole of the cell, in this way 

 separating the movable inorganic ions of the ion-proteid com- 

 pounds of the cell from the immobile colloidal proteid ions, with 

 consequent serious alterations in the chemistry of the cell. 

 Zeit 3 found that continuous currents kill bacteria through the 

 production of antiseptic substances in the culture-medium, but 

 do not harm them directly. 



1 Zeit. f. Krebsforschung, 1904 (2), 171. 



2 Literature given by Davenport, " Experimental Morphology." 



3 Jour. Amer. Med/Assoc., 1901 (37), 1432, literature. 



