HOMER W. SMITH AND G. H. A. CLOWES. 



enough to be significant, though the results do show very definitely 

 that chemical equilibrium between either eggs or sperm and the 

 pH solutions is reached in less time than is required for sperm to 

 reach the eggs and fertilize them. 



TABLE II. 



A. EFFECT OF EXPOSING Asterias SPERM TO pH SOLUTIONS FOR 5 MINUTES 

 BEFORE ADDING Asterias EGGS IN SEA WATER. 8-31-23. 



Per Cent. Eggs Fertilized. 



B. EFFECT OF EXPOSING Asterias EGGS TO pH SOLUTIONS FOR 5 MINUTES 

 BEFORE ADDING Asterias SPERM IN SEA WATER. 8-31-23. 



Per Cent. Eggs Fertilized. 



One of several experiments testing the influence of varying 

 quantities of sperm in shifting the limits of fertilization is given 

 in Table III. The eggs were placed in the pH solutions and 5 

 minutes later the sperm, diluted with the pH solutions, were added. 



TABLE III. 



INFLUENCE OF QUANTITY OF SPERM ON ACID BLOCK IN Asterias. 

 Per Cent. Eggs Fertilized. 



pH 



Quantity of sperm 



The smallest quantity of sperm was insufficient to fertilize all 

 the eggs even in sea water, and the largest quantity gave a dis- 



