610 RALPH S. LILLIE 



10, 20 and 50 cc. 0.35 m MgCla, similar mixtures of 0.35 m CaCl. 

 and sea-water, and mixtures' containing both salts; 2 cc. x^ 

 butyric acid was added to 50 cc. of each solution, and the action 

 on unfertilized eggs was tested as above. The results again 

 were entirely negative as regards protective action: in all cases 

 two minutes' exposure to these solutions was followed by cytoly- 

 sis. After-treatment with hypertonic sea-water proved ineffec- 

 tive in all cases, none of the eggs so treated forming blastulae 

 (with the exception of a few from 100 volumes sea-water plus 10 

 volumes 0.35 m MgCl2). The presence of an excess of calcium or 

 magnesium in the sea-water thus prevents the eggs from devel- 

 oping favorably later, although it does not hinder the cytolytic 

 action of the fatty acid.^'^ 



1^ Experiments, with unfertilized eggs conducted in the summer of 1911 on the 

 antitoxic action of CaCU on isotonic NaCl solutions containing acetic acid gave 

 entirely negative results. The following series will illustrate. Eggs were left for 

 two hours in the solutions, then returned to normal sea-water and fertilized. The 

 results were as follows (condition of the eggs next day) : 



^Solution ' Retiult 



(1) Pure 0.55 m NaC) ca. 40-50 % form blast ukc 



^2) 95 vols. 0.55 m NaCl+5 vols. -^ CaCl> all form blastulae 



(.•« 0.55 m NaCl+^Q CH3COOH all eggs dead 



(4) 0.55 m NaCl+^ CH3COOH+ -^ CaCk all dead 



(5) 0.55 m NaCI+^ CH3COOH all dead 



(6) 0.55 m NaCl+^QQ CH3COOH+ -^ CaCh all dead 



(7) 0.55 m NaCl+-^ CH3COOH all dead 



<8) 0.55 m NaCH-g^ CH3COOH+ —^ CaCh all dead 



(9) 0.55 m NaCl+-g^ CH3COOH all dead 



<10) 0.55 m NaCl+-g^ CH3COOH+ -^ CaCh all dead 



Thus CaClo in concentrations which completely prevent the toxic action 

 of the NaCl solution has no effect on the toxic action of acetic acid. CaCl2 also 

 showed no antitoxic action in 0.55m NaCl containing NH4OH in concentrations 

 from |"„ to 27^0- It also failed to antagonize HCl in concentrations from ^^y to 

 3^^; but with weaker solutions (^-J^s to agfoi) HCl) some antitoxiq effect was 

 seen. Arbacia eggs thus differ from Fundulus eggs, which are protected by 

 salts to a considerable degree against injury by acetic acid in -gj^ concentration 

 (cf. J. Loeb, Biochemische Zeitschrift, 1912, vol. 47, p. 151). Fundulus eggs are, 

 however, surrounded bv a resistant chorionic membrane. 



