358 RALPH S. LILLIE. 



of permeability-increasing action and prevention of stimulation 

 was thus shown. Anaesthetics were also found to prevent other 

 effects depending on increase of permeability, such as the toxic 

 effects of pure solutions of Na and K salts on sea urchin and 

 starfish eggs, as well as on Arenicola larvae, 1 and also the activa- 

 tion of unfertilized sea-urchin eggs by pure salt solutions (KCNS, 

 Nal). 2 In general the anaesthetics appear to exert a stabilizing 

 influence on the plasma-membrane, rendering it more resistant 

 than normally to influences that tend to increase its permeability. 

 To this stabilizing action both the inhibitory or anti-stimulating 

 (anaesthetic) and the protective (anti-toxic) actions of both salts 

 and lipoid-solvent anaesthetics are due. 



Recently a large body of evidence has accumulated from 

 various sides indicating that anaesthetics either decrease the 

 permeability normal to the resting cell, or render the plasma- 

 membrane more resistant than normally to increase of permea- 

 bility. Thus, according to Lepeschkin, 3 the entrance of dyes 

 into plant cells (Spirogyra) is checked in the presence of low 

 concentrations of ether and chloroform, and according to Szucs, 4 

 also by neutral salts. I have made similar observations on 

 Arenicola larvae. 5 These effects indicate a decrease in the 

 general permeability of the plasma-membrane to diffusing sub- 

 stances; this change is apparently associated with a character- 

 istic alteration in the density or physical consistency of the 

 membrane, rendering it more than normally resistant to dis- 

 integrative or toxic agencies in general. Hence anaesthetics as 

 well as neutral salts protect the cilia, pigment-cells and muscula- 

 ture of Arenicola larvae against the injurious action of pure Na- 

 salt solutions; the same is true of sea-urchin and starfish eggs. 

 Similar observations are described by other authors. Arrhenius 

 and Bubanovic 6 find that blood-corpuscles may be protected by 

 anaesthetics against cytolysis in hypo tonic solutions; and Traube 



1 Ibid., 1912, Vol. 30, p. i. 



-Journal of Experimental Zoology, 1914, Vol. 16, p. 591. Cf. also Journ. Biol. 

 Chem., 1914, Vol. 17, p. 121. 



3 Lepeschkin, Ber. d. deutsch. Bot. Gesellsch., 1911, Vol. 29, p. 349. 

 Szucs, Jahrbuchf. wissenschaftliche Botanik, 1912, Vol. 52, p. 85. 

 Ainer. Journ. Physiol., 1909, Vol. 24, p. 26. 



6 Publications of Nobel Institute, 1913, No. 32 (quoted from Hober's "Physik. 

 Chem. d. Zelle," p. 466). 



