i68 



PROBLEMS OF FERTILIZATION 



hypothesis and has therefore confirmed the writer's 

 opinion that this is the activable substance of the egg. 



The same author (Moore, 1917) has also examined 

 Loeb's statement concerning the fertilizability of eggs 

 treated by hypertonic sea-water with results concordant 



8 3 S> 



FIG. 19. Curve of fertilization superimposed upon butyric acid 

 treatment in Arbacia. Curve b continues curve a. The ordinates 

 represent percentages of fertilization as measured by cleavage and the 

 abscissae length of previous exposure to butyric acid in seconds (after 

 C. R. Moore). 



