528 FRANK R. LILLIE 



laid aboral side down in a Syracuse watch crystal and the sperm 

 allowed to collect in the crystal. In this way, as much as 2 cc. 

 of thick perfectly clean sperm may be obtained from a large ripe 

 male. If a few drops of sea- water have dripped off with the sperm 

 it may be removed with a pipette, but if the sperm is abundant 

 it is so dense that the fluid lies on it without intermingling. Such 

 a mass of sperm will keep perfectly fresh for several hours, and 

 suspensions may be made from it as needed for the tests. But 

 the suspension used in testing must be freshly prepared if deli- 

 cate reactions are desired. 



The fertilizin is actively secreted by the eggs in sea-water as 

 noted beyond; the concentration in the fluid of a given suspension 

 of eggs in sea-water is a function of the quantity of eggs in the 

 suspension. It will be convenient, therefore, in referring to any 

 given agglutination solution, to have a method of expressing the 

 relative quantity of eggs in proportion to the sea-water. The 

 most convenient way of expressing this relation is to express the 

 bulk of eggs as a percentage of the entire suspension. Thus 

 1 cc. of eggs added to 9 cc. of sea- water will be denominated a 

 10 per cent egg suspension, etc. This form of expression was 

 not adopted until after the experiments were done; the figures 

 are, therefore, not always even numbers, and are not intended 

 in any case to be absolutely exact, but this is a matter of little 

 importance as the density of a given egg suspension is only one 

 factor in the concentration of the fertilizin in it; the condition 

 of the eggs, whether entirely ripe or immature, fresh or stale, with 

 or without jelly, is more important. 



2. THE QUANTITY OF FERTILIZIN PRODrCED BY OVA OF ARBACIA 



a. By a single washing 



July 6, 1913: For this experiment I used the eggs of a single female 

 shed in a watch crystal in the same manner as described above for the 

 collection of clean sperm. The eggs were thus free from blood or frag- 

 ments of the ovaries, and contained only a trace of the sea-water. Graded 

 quantities of eggs were put in a series of six test-tubes containing 5 cc. 

 of sea-water each. The eggs were placed in the tubes at 9:45 a.m.; 

 each tube was turned upside down six times and the eggs then allowed to 



