FERTILIZATION AND OXIDATION 31 



were replaced in normal sea-water. Sperm was added to the 

 unfertilized eggs after their transference to ordinary sea-water. 

 The unfertilized eggs, which had been in the sea-water contain- 

 ing potassium cyanide for two days, developed in quite a normal 

 manner, whereas the eggs which had been fertilized before they 

 were put into the cyanide sea-water were no longer able to 

 develop beyond the blastula stage after an exposure of only 

 twenty-four hours to this solution. An exposure of five hours' 

 duration to the cyanide sea-water was already harmful to the 

 fertilized eggs; this was shown by the fact that while such 

 eggs did develop after transference to ordinary sea-water, 

 many larvae died during the first two days. 1 



These experiments leave no doubt that fertilization gives rise 

 to a class of chemical reactions in the egg which can proceed 

 independently of oxidations. It is very likely that other 

 reactions besides oxidations, e.g., hydrolyses, take place in the 

 egg. If such hydrolyses lead to the formation of harmful 

 oxidizable substances, e.g., lactic acid, it can be understood 

 why lack of oxygen must in time lead to the death of the 

 fertilized egg; without oxygen the harmful substances, which 

 are quickly rendered harmless by oxidation (or converted into 

 substances like C0 2 , which can be eliminated), can now accumu- 

 late in the cell. Assuming that such hydrolyses are set up in 

 the egg by fertilization, while they are lacking or are very slow 

 in the unfertilized egg, we could understand why the fertilized 

 egg suffers more quickly than the unfertilized egg from lack of 

 oxygen or from the prevention of oxidations by potassium 

 cyanide. 



5. Wasteneys and the writer raised the question whether the 

 oxidations are the independent variable in the development of 

 the egg. 2 From all we know, we should expect that hydrolyses 



1 Loeb, "Versuche ueber den chemischen Charakter des Befruchtungsvor- 

 gangs," Biochem. Zeitschr., I, 189, 1906. 



2 Loeb and Wasteneys, "Sind die Oxydationsvorgange die unabuangige 

 Variable in den Lebenserscheinungen ?" Biochem. Zeitschr., XXXVI, 345-56, 1911. 



