1915] 



MERRILL — ELECTROLYTIC DETERMINATION OF EXOSMOSIS 517 



penetrated cells of Spirogyra more slowly in the presence of 

 one per cent chloroform than when the anesthetic was not used. 

 If the cells were killed by the narcotic the rate was the same 

 as for normal cells. He also used Tradescantia discolor and 

 by the plasmolytic method found that the permeability to 

 KNO3 decreased during narcosis. This he explained on the 

 assumption that the anesthetics (chloroform and ether) ac- 

 cumulated in the disperse phase of the plasma membrane 

 which thereby leads to a hindrance of the solubility of KNO3 

 and aniline dyes in the same. He considered that his results 

 therefore showed that Nathansohn's hypothesis regarding the 

 mosaic structure of the plasma membrane is not correct. 



Another important piece of work dealing with the phenom- 

 enon of exosmosis from living tissue is that accomplished by 

 Lillie ( '09, '10, 11, '12, '12% '13, 13% 13 b ) and discussed at 

 length in his various papers. Among other things he worked on 

 the larvae of Arenicola and the eggs of Arbacia, each of which 

 contains a pigment, and found that on placing them in NaCl 

 or KC1 solution (.55m) isotonic with sea-water, there was a 

 rapid exosmosis of the contained pigment into the surround- 



& 



medium. When, however, the organisms were placed 



the salt solutions to which had previously been added in a cer- 

 tain concentration any one of several anesthetics belonging to 

 various classes (alcohols, esters, hydrocarbons, and miscel- 

 laneous compounds) a checking or possibly a complete preven- 

 tion of exosmosis resulted. In general, all the anesthetics tried 

 gave cytolysis in strong concentrations and therefore a rapid 

 exosmosis of the pigment, while in weaker concentrations they 

 showed a definite protective or anticytolytic action against the 

 salt solution when used in conjunction with it. Lillie finds the 

 explanation of the observed phenomenon in the relations of the 

 plasma membrane, the salt solutions used having a permea- 

 bility-increasing action which is offset or prevented by the tem- 

 porary alteration of the membrane as the result of the action 

 of the anesthetic. The alteration, he believes, is accompanied 

 by an increase in the volume of the lipoid particles of the 



membrane. 



In connection with the general subject of exosmosis it might 



