348 JULIAN MAST WOLFSOHN. 



Table III. 



Solution. Treatment for I hr. 



50 c.c. sea water -f- 1.5 c.c. All mature and swimming. 



«/loNaHO. Little disintegration. 



50 c.c. sea water + 1.5 c.c. Not one mature egg, in whole culture. 



n/io NaHO + 1.2 c.c. ifiofo K.CN. No eggs disintegrated. 



The processes which were accelerated by the presence of the 

 alkali were completely inhibited by the potassium cyanide and it 

 is especially to be noted that while disintegrated eggs were found 

 in every case in the absence of potassium cyanide, no disinte- 

 grated eggs were found when potassium cyanide was present. 



If the eggs that had been prevented from becoming mature 

 through the presence of the potassium cyanide, were afterwards 

 treated with alkaline sea water, containing no potassium cyanide, 

 practically all became mature and formed larvae when sperm was 

 added. This shows further that no permanent injury is done to 

 the eggs by treating them with KCN or by depriving them of 

 oxygen for so short a period of time. 



I next tried the effect of fat solvents, such as benzol, chloro- 

 form, ether and ethyl acetate, upon the immature eggs to see if 

 by treatment with these substances maturation could be produced, 

 and I found that in every case I got positive results. The 

 method of procedure in general was as follows : 30 c.c. sea water 

 were heated to 45 ° C. and a known quantity of the solvent was 

 added and the mixture vigorously shaken to ensure complete 

 solution. If the solution is not complete the eggs that come in 

 contact with the droplets of the solute are immediately killed. 

 The solution was then cooled down to 26 C, and the eggs in- 

 troduced. At definite periods the eggs were removed to normal 

 sea water and sperm added. Eighteen hours after the results 

 obtained in Table IV were noted. 



The best results were obtained when the eggs were exposed 

 to the mixture for one minute ; 85 per cent, of the eggs develop- 

 ing into larvae upon the addition of sperm. If the eggs are ex- 

 posed longer to the solution they become mature, but a large 

 number segment irregularly. These irregularly segmenting eggs 

 finally disintegrate before they reach the larval stage, or in the 

 early larval stage. By this method of treatment the eggs become 



