570 FRANK R, LILLIE 



July 18: Sperm suspensions in two lots of blood, (a) from males, 

 (b) from females, (a) Fertilized 40 per cent in 5 minutes and 25 per 

 cent in 18 minutes, (b) fertilized 30 per cent in 5 minutes and 20 per cent 

 in 18 minutes. Control sperm fertilized 70 per cent each time. (Sperm 

 = 0.0026 per cent) 



July 19: Sperm suspensions in two lots of blood, (a) from males, 

 (b) from females, (a) Fertilized 1-1. per cent in 10 minutes and 18 per 

 cent in 30 minutes; (b) fertilized 23 per cent in 10 minutes and 20 per 

 cent in 30 minutes. Control sperm fertilized 86 per cent in 10 minutes 

 and 76 per cent in 30 minutes. (Sperm = 0.012 per cent). 



July 21: Sperm suspensions in. blood of males. In this case the 

 sperm fertilized perfectly in two fertilizations. Sperm = 0.007 per cent 

 in first and 0.0068 per cent in second. The blood contained a large 

 amount of inhibitor as only 0.5 per cent segmented in it with 0.6 per cent 

 sperm suspension. 



August 1: A verj^ detailed experiment showed that a specimen of 

 blood very powerful in inhibitor had but little effect on the fertilizing 

 power either of eggs or of sperm after washing. 



On the whole we must conclude that though exposure to blood 

 containing inhibitor may decrease the fertilizing power of sperm 

 or of eggs, its effect is secondary and can probably be entirely 

 removed by sufficient washing or overcome by sufficient concen- 

 tration of sperm. 



2. MODE OF ACTION OF THE INHIBITOR 



It was natural to suppose that the inhibitor acted by occupy- 

 ing the side-chain of the fertilizin with which the sperm unites 

 normally. If this were the case it must be possible to neutralize 

 the agglutinating action of the fertilizin by a sufficient quantity 

 of blood containing the inhibitor. Therefore, if we took two 

 equal amounts of an agglutinating solution and diluted the one 

 with sea-water and the other with blood containing the inhibitor, 

 the agglutinating action ought to disappear more rapidly in the 

 latter than in the former. This, however, is not the case, as the 

 following experiment will show. 



July 11, 1913: A given agglutinating solution was tested in the usual 

 way b}^ diluting with sea-water and found to be of 400 agglutinating 

 power. Part of it was then diluted to 1/100 with blood; on test with 

 sea-water sperm suspension it gave two tests of 22 seconds each. Di- 

 luted to 1/400 with blood, it gave a 10 second reaction with a sea- 

 water sperm suspension, and an 11 second reaction with a blood sperm 

 suspension. 



