STUDIES OF FERTILIZATION 547 



luted fluiil would lead to the conclusion that A was 7^ times stronger 

 than B. The fact that the time of the reaction of the B extract is about 

 the same at all concentrations is in most pronoHUCSd-^ontrast to the 

 sea-water secretions in a very large number of tests, which had shown 

 that the duration of the reaction is about proportional to the concen- 

 tration of the agglutinating substance. The inference from the fact 

 would be that the extract {B) contained an inhibitor for the agglutinat- 

 ing reaction which is diluted equally with the agglutinating substance. 

 This might be a substance entering into combination with the aggluti- 

 nating substance, but slowly and loosely at first. 



4:07 P.M. Tube B was shaken vigorously to complete the plasmoly- 

 sis. Tube A was stirred up. Both were then left until the next morning. 



August 23, 1913: Tests of agglutinating power on fresh sperm: 



Tube A Tube B 



Dilution tests Dilution tests 



1/20— Gsec. Negative at all dilutions 1/1280, 



1/10— 12 sec. 1/640, 1/320, 1/160, 1/80, 1/40, 1/20, 



1/1 — 190 sec. 1/10, 1/1, but showing decided chem- 



otaxis. 



Thus the neutralization of the fertilizin had become complete in the 

 intervening time. 



The disappearance of the agglutinating substance is not due to any 

 destructive effect of distilled water on it, for control experiments showed 

 that this was not the case. 



A similar experiment on August 20 gave even more clear cut results. 

 In this case (1) the eggs were deprived of jelly by 6 shakes, and exami- 

 nation of the eggs in ink showed that jelly was almost completely re- 

 moved. (2) The eggs were allowed to settle and the supernatant fluid 

 poured off. (3) The eggs were then divided into two equal parts in 

 test-tubes A and B. (4) To A added 9 cc. fresh sea-water, to B added 

 9 cc. distilled water. (5) Each was stirred up twice and stood 30 

 minutes. 



Tested with fresh 1 per cent sperm suspension, A gave a 10 second 

 reaction at 1/40 dilution. B was negative at 1/2 and gave a faint re- 

 action only, undiluted. Thus as B must have contained as much ferti- 

 lizin as A, its disappearance must have been due to escape of anti- 

 fertilizin by plasmolysis, inasmuch as we know that distilled water does 

 not destroy it. 



It would follow from this experiment in which the jelly was practi- 

 cally entirely removed, that the eggs contained an amount of anti- 

 fertihzin sufficient to neutraUze all the fertihzin present in them. 



A third experiment yielded results similar to the first : 



August 23, 1913: Fine lot of fresh eggs; shaken 6 times, 2:15 p.m. 

 in test tube. Examination in ink showed about half have entirely lost 



