STUDIES OF FERTILIZATION 



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settle; there was no shaking or rough handling of the eggs, so that they 

 were absolutely uninjured. At 10:20 a.m., after the eggs had settled 

 to the bottoms of the tubes, samples of the sea-water in the tubes 1 to 

 5 were removed and tested by a series of dilutions ; at 1 1 :45 a.m. a sample 

 of 6 was taken and tested. The concentration of the sperm agglutinat- 

 ing substance in each is shown in table 1. 



TABLE 1 



It is interesting to note that the quantity of fertilizin produced 

 is so nearly proportional to the quantity of eggs. (No. 3 would 

 probably have tested to 1/200 with perfectly fresh sperm.) We 

 might expect in general that the quantity of fertilizin produced 

 would continue to be proportional to the quantity of eggs. This 

 however, may not be the case, as there are indications that in 

 the presence of a certain concentration in the sea-water more 

 is not secreted by the eggs. 



It would appear that after the eggs had settled in the tubes 

 into a dense layer on the bottom they ceased to produce more 

 agglutinating substance, because the concentration in tube 6 

 in which the sea-water had stood over the eggs much longer than 

 in tubes 1 to 5 was proportional to the quantity of eggs -and not 

 to the time. 



Higher concentrations of the fertilizin were often obtained: 

 August 9: A 25 per cent egg suspension stood for 12 minutes. 

 The supernatant fluid then gave the following sperm-aggluti- 

 nation tests: diluted to 1/6400, 7-second reaction; 1/3200, 15- 

 second reaction. August 18: egg suspension (density not given) 

 was shaken. After setthng of the eggs the supernatant fluid 



