602 EALPH S. LILLIE 



treatment with hypertonic sea-water and remain intact the 

 next morning; but the majority either undergo cytolysis or 

 develop to a blastula stage. The proportion of eggs forming 

 blastulae is in general smaller the greater the protective action, 

 indicating that when the membrane-forming action of the salt is 

 prevented the eggs respond less readily to the hypertonic sea- 

 water; some entirely fail to respond. 



It wiy be noted also that the presence of the anesthetic in the 

 hypertonic sea-water greatly diminishes or entirely annuls the 

 effectiveness of the after-treatment. Such hypertonic sea- 

 water is not, however, entirely indifferent in its action, as is 

 shown by the fact that relatively few eggs so treated remain 

 intact; most undergo cytolysis and a few may develop. The 

 same result appeared in six other series of experiments with 

 hypertonic sea-water containing anesthetics. The favorable 

 effect of the treatment is, however, almost entirely prevented 

 by the presence of anesthetics in the protective or anesthetizing 

 concentrations. ' ' 



Removal of oxygen from hypertonic sea-water or the addition 

 of cyanide also prevents its characteristic action, as Loeb found 

 for Strongylocentrotus.^- Cyanide has the same effect with 

 Arbacia eggs (cf. table 3). Loeb has interpreted these facts as 

 indicating that some chemical process involving oxidations 

 underlies the favorable action of the hypertonic sea- water. 

 That this agent acts by modifying chemical processes in the egg 

 is also indicated by the high temperature-coefficient of the times 

 of exposure. ^^ The fact that anesthetics have the same effect 

 on the action of hypertonic sea-water as suppression of oxidations 

 seems highly significant. Evidently the hypertonic sea-water 

 induces some process of an oxidative nature; this process is 

 checked or prevented by anesthetics. Now the anesthetics 

 appear to act by altering the state of the lipoid components of 

 the plasma-membrane, thus rendering this structure more resist- 

 ant to change than normally: it thus appears probable that the 



12 J. Loeb, Biochemische Zeitschrift, 1906, Bd. 1, p. 183. 



1' J. Loeb, loc. cit.; also University of California Publitations, Physiology, 

 1906, vol. 3, p. 39. 



