424 



MARIE A. HINRICHS. 





experiment of 8/13 (Table VI.), are represented in Fig. 2. The 

 agglutinating units for each dilution, before and after adsorption 

 by charcoal, are indicated. 



TABLE VI. 



ADSORPTION OF FERTILIZIN BY CHARCOAL. 

 (Per cent, agglutinating units adsorbed.) 



* A. U. number of agglutinating units at the start. (No dilution.) 



A. U. .1 number of agglutinating units at a dilution of I part egg -water 

 to nine parts sea-water. 



f Figures represent per cent, agglutinating units adsorbed. 



Further evidence for the high adsorption constant of fertilizin 

 is obtained as follows : when a suspension of fresh sperm is added 

 to charcoal, the sperm swim actively about, often coming into con- 

 tact with the bits of charcoal, but not remaining attached to them. 

 If a few drops of egg- water are now added to this mixture, no 

 agglutinated masses are formed in the spaces between the pieces 

 of charcoal, but the fertilizin seems to be immediately adsorbed 

 by the charcoal, and the sperm are attracted by it, and become ag- 

 glutinated to each other in an irregular film around the bits of 

 charcoal, and remain there. The masses are irreversible and 

 permanent, due probably to the high concentration of still active 

 fertilizin about the charcoal, and the lack of sufficient activating 



