PROLONGATION OF THE LIFE OF THE EGG 89 



eggs in the second solution when transferred at the same time 

 to sea-water all developed into larvae. The fact that the NaCN 

 inhibited the development of the eggs in the hypotonic solution 

 saved their lives. An experiment with 27.5c.c. sea-water + 

 22.5 c.c. 6/8 m ethylalcohol with and without 5 drops of 1/10 

 of 1 per cent NaCN gave a similar result. In the same way it 

 could be shown that excessive amounts of chloroform, chloral 

 hydrate, phenylurethane, when applied in a definite concen- 

 tration, injured the fertilized eggs much more rapidly if oxygen 

 was present and oxidations were going on in the egg, than if 

 the oxygen was removed from the solution or the oxidations 

 were suppressed through the addition of KCN. 1 



4. The most striking experiments of this kind are perhaps 

 those published by the writer on the inhibition of the toxic 

 effects of hypertonic solutions on the eggs of purpuratus by 

 lack of oxygen or the addition of KCN, or of chloral hydrate. 

 A few examples may be given: 



Eggs were fertilized with sperm and put eleven minutes 

 later into three flasks, each of which contained 100 c.c. of sea- 

 water +16 c.c. 2| m CaCl 2 . One flask was in contact with air, 

 while the other two flasks were connected with a hydrogen 

 generator. The air was driven out from these two flasks before 

 the beginning of the experiment. The eggs were transferred 

 from one of these flasks after four hours and fourteen minutes, 

 from the second flask after five hours and twenty-nine minutes, 

 into normal (aerated) sea-water. The eggs that had been in 

 the hypertonic sea-water exposed to air were transferred simul- 

 taneously with the others into separate dishes with aerated 

 normal sea-water. The result was most striking. Those eggs 

 that had been in the hypertonic sea-water with air were all 

 completely disintegrated in a way which I will, for the sake of 

 briefness, designate as " black cytolysis" (Figs. 36, 37, 38). 



1 Loeb, "Die Hemmung verschiedener Giftwirkungen auf das befruchtete 

 Seeigelei durch Hemmung der Oxydationen in demselben," Biochem. Zeitschr., 

 XXIX, 80, 1910. It might be well to indicate that these experiments also contra- 

 dict the idea that narcosis is due to asphyxiation. 



