FERTILIZATION REACTION IN ECHINARACHNIUS PARMA. 23 



the same inseminated lot with jelly still gave a test of over seventy- 

 five seconds. When these latter came negative is not stated. 

 From this and duplicate experiments Lillie concluded that after 

 fertilization the egg no longer produces fertilizin; the positive 

 tests with jelly-covered eggs show merely that the jelly is satur- 

 ated with the secretion. I have repeated this experiment with 

 Echinarachnius eggs and have also made some others slightly 

 different. My findings agree with those of Lillie. 

 An experiment of August I is typical of a number: 



9:15 A.M. Two tubes (A and B) each with 0.5 c.c. of eggs from the same female 

 plus 9.5 c.c. of sea-water; 9:16 A.M. inseminated; 9:18 A.M. all eggs have mem- 

 branes; 9:20 A.M. tube B gently shaken to remove jelly; 9:23 A.M. jelly off every 

 single egg, membranes intact. By means of a capillary pipette attached to a 

 rubber tube supernatant sea-water carefully removed from each tube as follows: 

 9:35, 9:45, 10:00, 10:16, 10:31, 11:00 and 11:13 A.M.; in each case 8 c.c. being 

 removed and 8 c.c. of fresh sea water added. At 11:05 A.M. at i/i dilution B is 

 slightly positive (?); at 11:15 A.M. and thereafter B is negative at i/i dilution. 

 A at 1/8 dilution gave an 8-second reaction. 99 + per cent, of the eggs in both lots 

 developed normally. 



Thus in two hours after insemination (seven washings) the 

 tests on jelly-free eggs came absolutely negative. (Vide supra, 

 Lillie's results.) 



The data on some of these experiments seemed to indicate 

 that the fertilizin is not lost in any given time but rather after a 

 certain amount of washing. If this be true, a certain amount of 

 water ought to remove from a given lot of eggs the free fertilizin 

 practically at once. The following experiments show this: 



Aug. 2, 9:40 A.M. Two cylinders (A and B) each with 0.5 c.c. of eggs from the 

 same female plus 9.5 c.c. of sea water. Both inseminated. 9:43 A.M. B shaken. 

 Eggs have 100 per cent, membranes in both A and B; none have jelly in B. 



9:50 A.M. Lots A and B each in 250 c.c. of sea-water. 



9:53 A.M. A is positive at 1/2 dilution; B is negative at i/i dilution, never 

 again positive. 



Aug. 3, 9:58 A.M. 2.5 c.c. of eggs from one female plus 7.5 c.c. of sea-water 

 inseminated and divided into two equal lots A and B. B shaken. A and B 

 each added to 250 c.c. of sea-water. 10:05 A.M. B positive at i/i dilution- 

 10:07 A.M. 190 c.c. of sea-water removed from A, 200 c.c. of sea-water removed 

 from B. 190 c.c. and 200 c.c. of sea-water added to A and B respectively. 10:25 

 A.M. A barely positive at 1/8 dilution; B is negative at I/I. 



These observations bear out findings of June: while making 

 experiments with shaken eggs I tested fertilized jelly-free and 

 membrane-free eggs and never obtained a positive test. Evi- 



