2 Scientific Proceedings (40). 
Since the egg changes in volume on change in concentration of 
the electrolytes, as well as some non-electrolytes, in the surrounding 
medium, it must be less permeable to electrolytes than to water, 
so by electrolysis one should be able to determine whether it is 
equally permeable to anions and kations. If an electric current 
be passed through the egg it begins to disintegrate first at the anode. 
Loeb and Budgett 1 found that the anodal disintegration of in- 
fusoria resembled the dissolution that occurs in alkali more than 
the coagulation in acid, and concluded that it was caused by the 
accumulation of kations, forming alkalis, on the outside of the 
animal. I found that coagulation is not the first effect of all 
acids. When acetic acid is passed under the cover glass of an 
infusorian preparation, those individuals first affected die so 
quickly that the process cannot be analyzed, but those specimens 
receiving the acid very gradually first undergo dissolution of their 
membranes and the protoplasm flows out, coagulating only after 
it reaches acid of greater concentration. 
The sea urchin egg undergoes cytolysis in sea water containing 
acetic acid (as well as in alkalis). On passing a current through 
sea water in which eggs are placed the cytoplasm disintegrating 
at the anode is not alkaline to neutral red or to the egg pigment 
as it should be if the disintegration were due to alkalis massed 
on the outside of the egg. Furthermore, much less current is 
required for anodal disintegration of eggs in isotonic sugar solution 
than in sea water, although in the latter case more kations would 
be thrown against the anode end of the egg. Therefore it is 
concluded that the anodal disintegration of the egg is due to con- 
fined anions, and indicates relative impermeability to these anions. 
Probably the anions affect the protoplasm without dissociating 
water, and some of them may be hydroxyl ions. The anions may 
change the permeability of the plasma membrane and the swelling 
of the protoplasm occurs as an effect of the resulting diffusion of 
undetermined substances. 
That the anodal disintegration is due to confined anions is an 
a priori conclusion if the plasma membrane be less permeable 
than the cytoplasm in general, to ions, since the anions migrating 
in the interior would be stopped by the membrane but the kations 
l Arch. f. d. ges. Physiol, lxv, 518 : but see ibid., cxvi, 193. 
