530 FRANK R. LILLIE 



gave the following sperm-agglutination tests: diluted to 1/12800, 

 5-second reaction; 1/6400, 10 to 12-second reaction. 



Enough has been said to indicate the large amounts of this 

 substance produced by the eggs in sea-water. No attempt has 

 been made to produce the highest attainable concentration. The 

 standardization of solutions for experiments was a daily pro- 

 cedure and in the experiments themselves hundreds of tests were 

 made. 



Hitherto, I think, the unfertilized egg has been generally 

 regarded as a very inert cell, almost in a state of suspended ani- 

 mation. But it is necessary to modify such a point of view very 

 greatly. The egg of Arbacia, at least, is a very actively secreting 

 cell. Although the method which I have used enables us to cal- 

 culate only the relative concentration of the agglutinating sub- 

 stance produced, yet the quantity must be very considerable 

 when we consider that in tube 1, of the preceding experiment 

 the egg suspension was only 0.5 per cent and that the supernat- 

 ant fluid was charged with 50 units of the agglutinating substance 

 in 35 minutes. 



b. Comparison of ripe and unripe eggs 



The tests already given are from fresh, ripe eggs. Ovaries 

 containing a high proportion of ovocytes produce less fertilizin 

 proportionately; but such ovaries could be obtained only at the 

 beginning of the season so that only a few tests were made. On 

 June 16 I compared equal amounts of ripe ovaries with practically 

 all eggs mature, and umipe ovaries with only 50 per cent of the 

 eggs mature. One part finely cut up ovary was added in each 

 case to 3 parts sea-water. The first tested to 1/612, the second 

 to 1/64. In a second determination the same day, in which a 

 had only 5 per cent unripe eggs (ovocytes with germinal vesicle) 

 and b had 50 per cent, one part ovary to 2 parts sea-water in each 

 case, the tests were a 1/1000, b 1/600. In the latter case the 

 strength of the solutions was about proportional to the percent- 

 age of mature eggs. In the former case the unripe ovary did 

 not give as large a production of the fertilizin as would be expected 



