Pbevention of Death by Fertilization 165 



We therefore believe that we may conclude that the rapid 

 death of the unfertilized egg of certain species is caused by the 

 oxidations which take place in these eggs; and that the life- 

 saving action of the spermatozoon consists in the fact that the 

 latter, ia addition to the membrane-formiag substance, carries 

 a second substance, or group of substances, into the egg which 

 renders it immune against the harmful effect or consequences 

 of oxidations. 



